Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the intestinal mucosa, with predominant localization in the colon in ulcerative colitis (UC) or affecting the entire length of the gastrointestinal tract in Crohn's disease (CD). Recent advances in the drug development space have been marked by a return to orally administered small molecules with novel mechanisms of action such as Janus kinase inhibitors. Additionally, the prevalence of certain chronic conditions is higher in IBD patients, many of which are treated with orally administered drugs. Given the pathophysiology and localization of IBD, altered drug absorption from the gastrointestinal tract can be expected. This review discusses several physiological differences between the small and large intestine with the potential to influence drug absorption including pathophysiology related alterations associated with IBD. The main physiological parameters which are identified include luminal fluid volume, luminal pH, transit time, bile salt concentration, microbiome, absorptive surface area, permeability and metabolizing enzymes and transporters. Literature regarding these factors in IBD patients is marked with high heterogeneity in reporting of disease severity and location leading to difficulties in interpreting data across different studies. While the influence of most of these factors has been directly assessed in healthy volunteers, this is rarely the case for IBD patients. Furthermore, studies which used PBPK modelling to describe the PK of an orally administered drug in an IBD population and were able to verify their findings using clinical data are critically examined. These models were able to incorporate the pathophysiological changes associated with IBD and partly succeeded in adequately predicting drug absorption in this population. Given the limited amount of PBPK studies performed on a limited number of drugs, the developed models are most likely not suitable to be used as a general PBPK model for the IBD population.

Enteric hyperoxaluria, a risk factor for kidney stone disease, often arises from malabsorptive bariatric surgeries or inflammatory bowel diseases. Current murine models for studying this condition are limited, necessitating new approaches. This study aims to establish two novel and distinct mouse models to investigate enteric hyperoxaluria: one simulating Roux-en-Y gastric bypass surgery and the other Crohn's ileitis. In the first model, diet-induced obese C57BL/6J male mice underwent either sham or bypass surgery, followed by 3 wk on a high-fat, oxalate-enriched diet. In the second model, SAMP1/YitFc and AKR mice were gradually introduced to high-fat diets, later supplemented with oxalate while reducing fat content. Samples of urine, blood, and feces were collected to assess oxalate, creatinine, and fecal lipid profiles. Results showed hyperoxaluria and increased stool fat content, indicating fat malabsorption, in both SAMP1 and bypass mice compared with controls. Kidney injury was also observed. These findings confirm the successful establishment of enteric hyperoxaluria in both models, highlighting the role of dietary oxalate, intestinal inflammation, and fat malabsorption in disease progression. These models provide valuable tools for exploring cellular and molecular mechanisms in enteric hyperoxaluria and may inform future therapeutic strategies.NEW & NOTEWORTHY This study is among the first to establish an enteric hyperoxaluria (EH) phenotype in two different and novel mouse models secondary to Roux-en-Y gastric bypass and ileitis. It also elucidates key factors affecting EH using the SAMP1 mice, revealing the significant roles of GI tract inflammation, fat malabsorption, and dietary fat in developing hyperoxaluria.

Inflammatory bowel disease (IBD) is an inflammatory disease of the intestine whose primary pathological presentation is the destruction of the intestinal epithelium. The intestinal epithelium, located between the lumen and lamina propria, transmits luminal microbial signals to the immune cells in the lamina propria, which also modulate the intestinal epithelium. In IBD patients, intestinal epithelial cells (IECs) die dysfunction and the mucosal barrier is disrupted, leading to the recruitment of immune cells and the release of cytokines. In this review, we describe the structure and functions of the intestinal epithelium and mucosal barrier in the physiological state and under IBD conditions, as well as the patterns of epithelial cell death and how immune cells modulate the intestinal epithelium providing a reference for clinical research and drug development of IBD. In addition, according to the targeting of epithelial apoptosis and necroptotic pathways and the regulation of immune cells, we summarized some new methods for the treatment of IBD, such as necroptosis inhibitors, microbiome regulation, which provide potential ideas for the treatment of IBD. This review also describes the potential for integrating AI-driven approaches into innovation in IBD treatments.

A chronic inflammatory condition of the colon called ulcerative colitis (UC) is characterized by mucosal surface irritation that extends from the rectum to the near proximal colon portions. The rationale of this work was to conclude if dulaglutide (Dula) could protect rats from developing colitis caused by exposure to acetic acid (AA). Rats were randomly divided into seven groups (each with eight rats): Normal control, Dula control, AA (received 2 milliliters of 3% v/v AA through the rectum), Sulfasalazine (SLZ); given SLZ (100 mg/kg) orally from day 11 to day 21 then AA intrarectally on day 22 and Dula groups ( pretreated with 50, 100 or 150 μg/kg subcutaneous injection of Dula - once weekly for three weeks and AA on day 22 to induce ulcerative colitis, colon tissues and blood samples were taken on day 23. By generating colonic histological deviations such as inflammatory processes, goblet cell death, glandular hyperplasia, and mucosa ulcers, Dula dropped AA-induced colitis. Additionally, these modifications diminished blood lactate dehydrogenase (LDH), C-reactive protein (CRP), colon weight, and the weight/length ratio of the colon. In addition, Dula decreased the oxidative stress biomarker malondialdehyde (MDA) and increased the antioxidant enzymes (total antioxidant capacity (TAC), reduced glutathione (GSH), and superoxide dismutase (SOD) concentrations). Dula also significantly reduced the expression of transforming growth factor-1 (TGF-β1), phosphatidylinositol-3-kinase (PI3K), protein kinase B (AKT) signaling pathway, and the inflammatory cytokines: nuclear factor kappa B (NF-κB), interleukin-6 (IL-6), and interferon-γ (IFN-γ) in colonic cellular structures. In addition, Dula enforced the levels of glucagon-like peptide-1 (GLP-1) and trefoil factor-3 (TFF-3) that were crucial to intestinal mucosa regeneration and healing of wounds. By modulating TGF-β1 in conjunction with other inflammatory pathways like PI3K/AKT and NF-κB, regulating the oxidant/antioxidant balance, and improving the integrity of the intestinal barrier, Dula prevented AA-induced colitis in rats.

In this study, we developed a customized high-resolution mass spectrometry metabolomics workflow integrating the dual sugar test employing lactulose and mannitol as test probes for intestinal permeability assessment with untargeted screening of small molecules. Urine samples were collected from patients with major depression and healthy controls as part of a clinical study at the psychiatric department. Using a dual injection/dual chromatography setup, the test probes were quantified by hydrophilic interaction liquid chromatography (HILIC) in a targeted assay, while drugs and their metabolites were profiled in an untargeted manner by reversed-phase separation. Rigorous method development and validation allowed for selective separation of sugar isomers and consequently accurate quantification of lactulose and mannitol in urine. Internal standardization with compound specific stable isotope-labeled standards enabled excellent analytical figures of merit such as high recoveries, precision (< 5%), and working range (5 orders of magnitude). Within one analytical run, intestinal permeability was assessed together with drugs and their metabolites, allowing to screen for confounding drugs and patient compliance to the therapeutic scheme.

The gut microbiota plays crucial roles in the development and functions of the central nervous system (CNS) as well as in modulation of neurobehavior in heath and disease. The gut brush border enzyme intestinal alkaline phosphatase (IAP) is an important positive regulator of gut microbial homeostasis. In mice, IAP is encoded by Akp3 gene, which is specifically expressed in the duodenum of the small intestine. IAP deficiency alters gut bacterial composition and gut barrier function. Decreased IAP activity has been observed in aging, gut inflammatory diseases, and metabolic disorders. We hypothesized that this enzyme could also play an important role in modulating neurobehavior. We performed deep sequencing of gut bacterial 16S rRNA and found that IAP deficiency changed gut microbiota composition at various taxonomic levels. Using targeted metabolomic analysis, we also found that IAP deficiency resulted in changes of gut bacteria-derived metabolites in serum and brain metabolism. Neurobehavioral analyses revealed that Akp3-/- (IAP knockout) mice had decreased basal nociception thresholds, increased anxiety-like behavior, and reduced locomotor activity. Furthermore, Akp3-/- mice had more pronounced brain microglial phagocytic activity, together with an increase in the activated microglia population. Fecal microbiota transplantation from wildtype to Akp3-/- mice partially improved neurobehavior and reduced brain microglial phagocytic activity in Akp3-/- mice. This study demonstrates that deficiency of the endogenous gut-derived host factor IAP induces behavioral phenotype changes (nociception; motor activity, and anxiety) and affects brain microglia activity. Changes in the gut microbiota induced by knocking down Akp3 contribute to behavioral changes, which is probably mediated by microglia activity modulated by the gut bacteria-derived metabolites.

Crohn's disease (CD) is a chronic inflammatory disorder primarily affecting the gastrointestinal tract. Leukocyte recruitment, M1 macrophage polarization and associated metabolic reprogramming are hallmarks of its pathomechanism. Here, we tested TE-11, a potent MIF tautomerase inhibitor (IC50 = 5.63 μmol/dm3) in experimental Crohn's disease in male mice, in leukocyte recruitment and in inflammatory M1 macrophage activation.

2,4,6-trinitrobenzenesulfonic acid-(TNBS)-induced colitis was utilized as a CD-model in male mice. We performed macroscopic scoring and cytokine measurements. We also analyzed MIF-induced leukocyte migration and evaluated apoptosis. LPS+IFN-γ-induced RAW264.7 cells were applied as a M1 macrophage model. We performed qPCR, ROS and nitrite determinations, ELISA measurements, mitochondrial oxygen consumption rate and extracellular acidification rate determinations.

TE-11 improved mucosal damage, reduced inflammation score and concentration of IL-1β and IL-6 in the colon. It inhibited MIF-induced human blood eosinophil and neutrophil migration and counteracted the anti-apoptotic effect of MIF. In macrophages, MIF inhibition prevented M1 polarization by downregulating HIF-1α gene expression in LPS+IFN-γ-activated cells. Additionally, the molecule reduced mRNA transcription and protein expression of chemokine CCL-2 and cytokine IL-6 while further increasing SOD2 gene transcription and decreased ROS and nitrite production in macrophages. During inflammatory metabolic reprogramming, TE-11 prevented LPS+IFN-γ-induced metabolic shift from OXPHOS to glycolysis. Similarly to anti-inflammatory M2 cells, TE-11 improved mitochondrial energy production by increasing basal respiration, ATP production, coupling efficiency, maximal respiration and spare respiratory capacity.

Comprehensively, TE-11, a MIF tautomerase inhibitor ameliorates CD-like colitis, reduces MIF-induced eosinophil and neutrophil migration and prevents M1 polarization and associated metabolic reprogramming; therefore, it may prove beneficial as a potential drug candidate regarding CD therapy.

This study investigated the anti-inflammatory properties and sequence variations of soy peptides during simulated digestion and absorption. Results showed that 500 Da peptides with N-terminal Leu, Ile, and Tyr exhibited enhanced intestinal transport, while the absorbed peptides in the Bromelain + Flavourzyme group (SIA-BF) demonstrated the strongest anti-inflammatory activity by inhibiting IκB phosphorylation. Mass spectrometry revealed that SIA-BF peptides were rich in branched-chain amino acids at the N-terminus and basic amino acids at the C-terminus. Molecular docking and cellular experiments confirmed that peptides with key terminal amino acids, such as LLVK, exhibited lower binding energies with IκB, stabilizing it and reducing inflammatory cytokines and chemokines. LLVK showed the highest anti-inflammatory efficacy. This study highlights the significance of terminal amino acids in peptide function and provides insights into developing soy peptide-based functional foods for inflammation prevention.

Tissue injury induced by stroke is traditionally thought to be localised to the brain. However, there is an accumulating body of evidence to demonstrate that stroke promotes pathophysiological consequences in peripheral tissues including the gastrointestinal system. In this study, we investigated the mechanisms underlying gut permeability after stroke. We utilised the clinically relevant experimental model of stroke called permanent intraluminal middle cerebral artery occlusion (pMCAO) to examine the effect of cerebral ischaemia on the gut. We detected stroke-induced gut permeability at 5 h after pMCAO. At this timepoint, we observed significantly elevated intestinal epithelial cell death in post-stroke mice compared to their sham-operated counterparts. At 24 h after stroke onset when the gut barrier integrity is restored, our findings indicated that post-stroke intestinal epithelium had higher expression of genes associated with fructose metabolism, and hyperplasia of intestinal crypts and goblet cells, conceivably as a host compensatory mechanism to adapt to the impaired gut barrier. Furthermore, we discovered that stroke-induced gut permeability was mediated by the activation of the sympathetic nervous system as pharmacological denervation decreased the stroke-induced intestinal epithelial cell death, goblet cell and crypt hyperplasia, and gut permeability to baseline levels. Our study identifies a previously unknown mechanism in the brain-gut axis by which stroke triggers intestinal cell death and gut permeability.

Background/Objectives: Anthocyanins (ACNs) derived from mulberry (Morus alba L.) exhibit potent antioxidant and anti-inflammatory activities. However, their low stability and bioavailability in physiological environments limit their therapeutic potential. This study aimed to enhance the stability and controlled release ACNs using a hot-melt extrusion drug delivery system (HME-DDS) formulation, HME-MUL-F2, and evaluate its effects on gut barrier function and microbiota composition in a DSS-induced colitis model. Methods: The anthocyanin content of HME-MUL-F2 was quantified and compared with that of raw mulberry extract. The formulation's protective effects were assessed in Caco-2 and RAW 264.7 cells, confirming its biocompatibility and anti-inflammatory properties. The therapeutic efficacy was further evaluated in a dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD) model, focusing on gut barrier integrity, inflammatory cytokine modulation, and gut microbiota composition. Results: HME-MUL-F2 significantly improved gut barrier function by upregulating tight junction proteins and reducing inflammatory cytokine levels in the colitis model. Moreover, the formulation modulated gut microbiota composition, promoting beneficial bacteria while suppressing pathogenic strains. HME-MUL-F2 administration led to a significant increase in the Bacteroidetes-to-Firmicutes ratio, which is associated with improved gut health. These results indicate that HME-MUL-F2 significantly enhances anthocyanin bioavailability, leading to improved gut health and potential therapeutic applications for inflammatory conditions. Conclusions: This study highlights the potential of HME technology for improving the stability, bioavailability, and therapeutic efficacy of anthocyanins. HME-MUL-F2 is a sustained-release formulation that enhances gut barrier function and modulates intestinal microbial balance in a DSS-induced inflammatory bowel disease model. These findings strongly suggest that the observed therapeutic effects of HME-MUL-F2 are primarily due to enhanced anthocyanin bioavailability and targeted delivery to the colon, although further clinical studies will provide more definitive confirmation.

Mental disorders are associated with inflammatory bowel disease (IBD), but the genetic pathophysiology is not fully understood. We obtained data on mental disorder-related gene methylation, expression, protein levels, and summary statistics of IBD, and performed Summary data-based Mendelian randomization and colocalization analyses to explore the causal associations and shared causal genetic variants between multiple molecular traits and IBD. Integrating multi-omics data, we found QDPR, DBI and MAX are associated with ulcerative colitis (UC) risk, while HP is linked to IBD risk. Inverse associations between gene methylation (cg0880851 and cg26689483) and expression are observed in QDPR, consistent with their detrimental role in UC. Methylation of DBI (cg11066750) protects against UC by enhancing expression. Higher levels of DBI (OR = 0.79, 95%CI = 0.69-0.90) and MAX (OR = 0.74, 95%CI = 0.62-0.90) encoded proteins are inversely associated with UC risk, while higher QDPR (OR = 1.17, 95%CI = 1.07-1.28) and HP (OR = 1.09, 95%CI = 1.04-1.14) levels increase UC and IBD risk. Our findings advance the understanding of IBD's pathogenic mechanisms and gut-brain interaction.

This study compared the protective effects of both live Lacticaseibacillus paracasei 6235 (LLP 6235) and heat-killed Lacticaseibacillus paracasei 6235 (HK-LP 6235) on ulcerative colitis. Using a dextran sulfate sodium (DSS)-induced colitis mouse model, we evaluated physiological state, colon tissue integrity, inflammatory factors, tight junction (TJ) proteins, and intestinal microbiota variations. The findings demonstrated that both LLP 6235 and HK-LP 6235 have the capacity to mitigate colitis damage, enhance TJ protein levels, and restore colon morphology. In addition, these interventions modulated the intestinal inflammatory response by inhibiting pro-inflammatory factors and upregulating anti-inflammatory factors through the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways. Moreover, treatment with LLP 6235 and HK-LP 6235 significantly altered intestinal microbiota diversity, increased the relative abundance of beneficial bacteria, and regulated the short-chain fatty acid (SCFA) levels. Spearman correlation analysis revealed a strong association between TJ proteins, SCFAs, intestinal microbiota, and inflammatory response, suggesting that LLP 6235 and HK-LP 6235 may provide an effective approach to colitis prevention. In conclusion, LLP 6235 and HK-LP 6235 have similar abilities; furthermore, HK-LP 6235 modulated the intestinal microbiota through lipid metabolic pathways, resulting in a greater improvement. Moreover, considering the high stability and safety of prebiotics and their wide applicability, HK-LP 6235 is recommended for use as a modulator of intestinal inflammatory diseases.

Gastrointestinal (GI) barrier dysfunction is an early pathogenic event in many complex diseases. Despite the routine applications of invasive tests, saccharide molecules are used noninvasively for assessing GI tract mucosal barrier function. However, currently available methods for quantification of saccharides molecules are costly and laborious. Simplified, reliable, and high-throughput methods are desired so that GI permeability testing can become routine and widely used. Here, we have developed a one-component system comprising of a naphthyl-pyridine core coupled to a boronic acid receptor, which can be used for early detection of saccharide biomarkers (i.e., lactulose) for applications related to GI barrier dysfunction. For quantitation of lactulose as a model biomarker, we have designed gold nanoparticle decorated surfaces in a highly scalable 96-well format to enable sensitive testing of lactulose within a broad range of concentrations. To tackle current challenges in saccharide biomarker sensing, we developed a hybrid sensing principle integrating two optical modalities (plasmonics and fluorescence) with a synthetic smart-probe (naphthyl-pyridinium) for monitoring GI permeability. This technology can be further developed as an affordable and portable diagnostic tool for GI permeability screening for routine use, facilitating early detection of various diseases affecting the GI tract.

Epimedium polysaccharide (EPS) is a bioactive compound derived from the traditional Chinese herb Epimedium brevicornum. The objective of this study was to investigate the protective effects of EPS on ulcerative colitis (UC) and to elucidate the underlying mechanisms involved.

The findings showed that EPS treatment mitigated UC symptoms, including weight loss, anal bleeding, elevated disease activity index (DAI), and colon shortening. Hematoxylin and eosin (H&E) and Alcian blue-periodic acid-Schiff (AB-PAS) staining demonstrated that EPS alleviated histopathological damage and improved the integrity of the colonic mucosa. Mechanistically, EPS was found to substantially decrease inflammation by inhibiting the Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling pathway and to alleviate oxidative stress through modulation of the Kelch-like ECH-associated protein 1/nuclear factor erythroid-derived 2-like 2 (Keap1/Nrf2) pathway. Notably, EPS failed to exert protective effects against dextran sulfate sodium (DSS)-induced UC in Nrf2-knockout (Nrf2-/-) mice. Additionally, Western blotting and immunohistochemical analysis demonstrated that EPS facilitated autophagy via the adenosine monophosphate-dependent protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathway. In vitro experiments revealed that EPS effectively suppressed lipopolysaccharide (LPS)-mediated cellular damage and oxidative stress by regulating Keap1/Nrf2 pathway. Transcriptomic analysis of LPS-treated Caco-2 cells following EPS treatment revealed a significant up-regulation of Nrf2 expression.

In conclusion, the findings of this study suggest that EPS exerts protective effects against DSS-induced UC through the inhibition of the TLR4/NF-κB signaling pathway, regulation of the Keap1/Nrf2 pathway, and promotion of autophagy via the AMPK/mTOR pathway. Consequently, EPS may represent a potential therapeutic target for the treatment of UC. © 2024 Society of Chemical Industry.

Periodontitis has been linked to systemic inflammation, however research on its role in causing systemic diseases remains limited. Recent studies explore probiotics for microbiome modulation and enhancing natural compound bioavailability. This study investigated periodontitis-related systemic disease mechanisms, and evaluated the mitigation effects of bioconversion product using Lactiplantibacillus plantarum SMFM2016-RK and Artemisia herba-alba extracts. Four types of bioconverted milk [BM1 (L. plantarum SMFM2016-RK), BM2 (BM1 + A. herba-alba ethanol extract), BM3 (BM1 + A. herba-alba hot-water extract), and BM4 (BM1+ both A. herba-alba extracts)] were studied in a periodontitis-induced rat model. Rats were divided into six groups: normal control, skim milk with ligature, and four BM groups with ligature.   Periodontitis induction elevated trabecular resorption (0.325 ± 0.057 mm³) and histopathological symptoms. Serum ALT (55.6 ± 6.6 U/L), glucose (261.7 ± 64.3 mg/dL), insulin (1.90 ± 0.87 ng/mL), inflammation in the liver and colon, and gluconeogenesis-related enzyme expression increased. Periodontitis-induced rats showed gut dysbiosis, with decreased Lactobacillaceae level and increased Oscillospiraceae level. BM3 administration significantly reduced the serum glucose (190.9 ± 27.8 mg/dL), ALT (40.5 ± 5.0 U/L), inflammation, and gluconeogenesis-related enzymes, while increasing tight junction proteins expression and phylum Actinobacteria levels in the gut microbiome. The findings highlight the systemic impact of periodontitis on inflammation, glycemic control, and gut microbiome balance. BM3 effectively alleviated these effects suggesting therapeutic potential.

Proper regulation of intestinal permeability is essential for maintaining the integrity of the intestinal mucosal barrier. An abnormal increase in permeability can significantly contribute to the onset and progression of various diseases, including autoimmune disorders, metabolic conditions, allergies, and inflammatory bowel diseases. The potential connection between intestinal permeability and maternal health during pregnancy is increasingly recognized, yet a comprehensive review remains lacking. Pregnancy triggers a series of physiological structural adaptations and significant hormonal fluctuations that collectively contribute to an increase in intestinal permeability. Although an increase in intestinal permeability is typically a normal physiological response during pregnancy, an abnormal rise is associated with immune dysregulation, metabolic disorders, and various pregnancy-related complications, such as recurrent pregnancy loss, gestational diabetes mellitus, overweight and obesity during pregnancy, intrahepatic cholestasis of pregnancy, and preeclampsia. This paper discusses the components of the intestinal mucosal barrier, the concept of intestinal permeability and its measurement methods, and the mechanisms and physiological significance of increased intestinal permeability during pregnancy. It thoroughly explores the association between abnormal intestinal permeability during pregnancy and maternal diseases, aiming to provide evidence for the pathophysiology of disease development in pregnant women. Additionally, the paper examines intervention methods, such as gut microbiota modulation and nutritional interventions, to regulate intestinal permeability during pregnancy, improve immune and metabolic states, and offer feasible strategies for the prevention and adjuvant treatment of clinical pregnancy complications.

6:2 fluorotelomer alcohol (6:2 FTOH) is considered an emerging contaminant as a substitute for perfluoroalkyl and polyfluoroalkyl substances. Autism spectrum disorder (ASD) is a highly heterogeneous childhood neurodevelopmental disorder, the prevalence of which has been significantly increasing globally, possibly due to rising exposure to environmental pollutants. Additionally, the microbe-gut-brain axis plays a crucial role in the development of ASD. The purpose of study was to investigate the impact of embryonic 6:2 FTOH exposure on neurological development in mice and explore the potential involvement of the microbe-gut-brain. Pregnant mice were orally administered 6:2 FTOH from gestation day 8.5 until delivery, and follow-up testing was performed on day 22 post-delivery. The findings revealed that embryonic exposure to 6:2 FTOH led to ASD-like symptoms, cortical neuron apoptosis, glial cell activation, and abnormal synapse formation in mice. Furthermore, impairment of colonic barrier function, inflammatory response, and dysbiosis in gut microbiota were observed. Interestingly, supplementation with Lactobacillus rhamnosus GG during embryonic development mitigated these adverse outcomes. This study enhances our understanding of how environmental pollutants can impact neurological development in children and provides valuable insights for clinical prevention, diagnosis, and treatment strategies for non-genetic ASD.

Metabolic syndrome (Mets) is an important contributor to morbidity and mortality in cardiovascular, liver, neurological, and reproductive diseases. Short-chain fatty acid (SCFA), an organismal energy donor, has recently been demonstrated in an increasing number of studies to be an important molecule in ameliorating immuno-inflammation, an important causative factor of Mets, and to improve lipid distribution, blood glucose, and body weight levels in animal models of Mets. This study reviews recent research advances on SCFA in Mets from an immune-inflammatory perspective, including complications dominated by chronic inflammation, as well as the fact that these findings also contribute to the understanding of the specific mechanisms by which gut flora metabolites contribute to metabolic processes in humans. This review proposes an emerging role for SCFA in the inflammatory Mets, followed by the identification of major ambiguities to further understand the anti-inflammatory potential of this substance in Mets. In addition, this study proposes novel strategies to modulate SCFA for the treatment of Mets that may help to mitigate the prognosis of Mets and its complications.

The ocular surface microbiota plays a critical role in maintaining corneal homeostasis, but its disruption and subsequent effects on corneal functions remain poorly understood. This study investigates how antibiotic-induced microbial depletion affects the corneal circadian transcriptome in C57BL/6J mice. Dysbiosis was induced using a topical antibiotic cocktail, and RNA sequencing was employed to analyze gene expression across eight time points over 24 h. Antibiotic treatment disrupted corneal circadian rhythms, eliminating rhythmicity in 1,812 genes and introducing rhythmicity in 1,928 previously arrhythmic genes. Furthermore, epithelial adhesion was impaired, inflammation was elevated, and neural sensitivity was reduced. More than 50 % of ocular microbial genera exhibited daily oscillations, with six genera showing significant correlations with corneal rhythmic transcripts. Additionally, the administration of TLR agonists restored circadian gene expression patterns, with partial recovery of corneal barrier function and immune homeostasis, further highlighting the potential of microbiota-targeted therapies in treating ocular surface disorders. These findings underscore the critical role of the ocular microbiota in regulating corneal health and suggest that restoring microbial balance via TLR activation may offer new therapeutic avenues for eye diseases.

Type 1 diabetes (T1D) is an autoimmune-mediated disorder caused by the destruction of pancreatic beta cells. Although there is an underlying genetic predisposition to developing T1D, the trigger is multifactorial and likely includes environmental factors. The intestinal microbiome has been identified as one such factor. Previous studies have illustrated differences in the microbiota of people with T1D compared with healthy controls. This study aims to describe the evolution of the microbiome and metabolome during the first year of clinical T1D, or stage 3 T1D diagnosis, and investigate whether there are differences in the microbiome and metabolome of children who present with and without diabetic ketoacidosis. The study will also explore possible associations between the microbiome, metabolome, glycaemic control and beta cell reserve.

This prospective cohort study will include children with newly diagnosed T1D and sibling controls (n=100, males and females) and their faecal microbiome will be characterised using shotgun metagenomic sequencing at multiple time points during the first year of diagnosis. We will develop a microbial culture biobank based on culturomic studies of stool samples from the healthy controls that will support future investigation. Metabolomic analysis will aim to identify additional biomarkers which may be involved in disease presentation and progression. Through this initial exploratory study, we aim to identify specific microbial biomarkers which may be used as future interventional targets throughout the various stages of T1D progression.

This study has been approved by the Clinical Research Ethics Committee of the Cork Teaching Hospitals. Study results will be available to patients with T1D and their families, carers, support networks and microbiome societies and other researchers.

The clinicaltrials.gov registration number for this trial is NCT06157736.

Inflammatory Bowel Diseases (IDB) are chronic disorders characterized by gut inflammation, mucosal damage, increased epithelial permeability and altered mucus layer. No accurate in vitro model exists to simulate these characteristics. In this context, drug development for IBD or intestinal inflammation requires in vivo evaluations to verify treatments efficacy. A new model with altered mucus layer composition; altered epithelial permeability and pro-inflammatory crosstalk between immune and epithelial cells will be developed to enhance in vitro models for studying IBD treatments. The effects of dextran sulfate sodium and/or lipopolysaccharides on intestinal permeability, cytokines synthesis (IL-6, IL-8, TNF-α and IL-1β), mucins (MUC2, MUC5AC) and tight junction proteins expression (Claudin-1, ZO-1 and Occludin) were investigated in a tri-coculture model combining differentiated Caco-2/HT29-MTX cells and THP-1 cells. Two anti-inflammatory agents were evaluated to assess the model's therapeutic strategy applicability (corticoids and pro-resolving factors). Two in vitro models have been developed. The first model, characterized by increased permeability of the epithelial layer and subsequent secretion of inflammatory cytokines, can reproduce the different phases of inflammation, and enables the evaluation of preventive treatments. The second model simulates the acute phase of inflammation and allows for the assessment of curative treatments. Both models demonstrated reversibility when treated with betamethasone and pro-resolving factors. These in vitro models are valuable for selecting therapeutic agents prior to their application in in vivo models. They enable the assessment of agents' anti-inflammatory effects and their ability to permeate the inflamed epithelial layer and interact with immune cells.

While Ca2+ signaling plays a vital role in maintaining normal endothelial function and vascular activity, aberrant Ca2+ signaling in endothelial dysfunction is involved in the pathogenesis of inflammation. As a safe anti-psychotic drug to mobilize Ca2+ signaling, we repurposed spiperone as a potential drug for two intestinal epithelial injury related diseases, colitis and sepsis.

Spiperone-induced vasorelaxation of human submucosal arterioles and mesenteric arterioles from wide-type and TRPV4 KO mice was determined by Mulvany-style wire myograph. The action of spiperone in HUVEC was tested by Ca2+ imaging and patch clamp, and its action on murine mesenteric arterioles was measured in vivo. LPS- and CLP-induced septic mice and DSS-induced colitic mice were used to examine the anti-inflammatory effects of spiperone.

Spiperone induced endothelium-dependent hyperpolarization (EDH)-mediated vasorelaxation of healthy arterioles with EC50 of ∼50 nM predominately via PLC/IP3/IP3R pathway to induce endoplasmic reticulum (ER) Ca2+ release and further to promote Ca2+ entry via TRPV4-constituted SOCE. In both LPS- and CLP-induced septic mice, spiperone effectively prevented and treated sepsis by reducing serum proinflammatory factors, alleviating multiple organ dysfunction, rescuing the impaired EDH-mediated vasorelaxation and improving murine survival rate. Similarly, spiperone could also protect against murine colitis.

We reveal new action mode and mechanism of spiperone to induce EDH-mediated vasorelaxation of both human and murine arterioles to protect against colitis and sepsis by innovatively inducing PLC/IP3R/Ca2+ signaling rather than canonically antagonizing GPCR. Spiperone could be repurposed as a potential new drug for the prevention/treatment of colitis and sepsis.

Portulaca oleracea L. (purslane) is a dietary plant and a botanical drug with antioxidant, antidiabetic, and anti-inflammatory activities. However, the effects of purslane against intestinal-inflammation-associated obesity are yet to be studied. In the present study, we hypothesized that purslane extract could reduce intestinal inflammation associated with metabolic disorder.

Male C57BL/6J mice were fed a high-fat diet (HFD, 60% kcal% of fat) for a total duration of 14 weeks to establish an obesity model; further, the treatment group was orally administered purslane extract (200 mg/kg/day) during the last 4 weeks. Then, intestinal tissues were detached from the mice for detecting protein expressions through Western blot and immunohistochemical analyses. Pro-inflammatory cytokines were determined using ELISA kits, whereas the components of purslane extract were detected by ultra performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry. Chronic oral administration of purslane extract ameliorated colon shortening syndrome and reduced bowel inflammation in HFD-induced obese mice through suppression of the toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway to downregulate TLR4, myeloid differentiation factor 88 (MyD88), Ser32 phosphorylation of NF-κB inhibitor alpha (IκBα), and Ser536 phosphorylation of NF-κB p65 expression levels, thereby inhibiting the pro-inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels.

The present study supports the anti-inflammatory potential of purslane extract for modulating bowel inflammation under obesity through inhibition of the TLR4/NF-κB signaling pathway.

Chronic gastrointestinal disorders such as inflammatory bowel diseases (IBDs) and irritable bowel syndrome (IBS) impose significant health burdens globally. IBDs, encompassing Crohn's disease and ulcerative colitis, are multifactorial disorders characterized by chronic inflammation of the gastrointestinal tract. On the other hand, IBS is one of the principal gastrointestinal tract functional disorders and is characterized by abdominal pain and altered bowel habits. Although the precise etiopathogenesis of these disorders remains unclear, mounting evidence suggests that non-coding RNA molecules play crucial roles in regulating gene expression associated with inflammation, apoptosis, oxidative stress, and tissue permeability, thus influencing disease progression. miRNAs have emerged as possible reliable biomarkers, as they can be analyzed in the biological fluids of patients at a low cost. This review explores the roles of miRNAs in IBDs and IBS, focusing on their involvement in the control of disease hallmarks. By an extensive literature review and employing bioinformatics tools, we identified the miRNAs frequently studied concerning these diseases. Ultimately, specific miRNAs could be proposed as diagnostic biomarkers for IBDs and IBS. Their ability to be secreted into biofluids makes them promising candidates for non-invasive diagnostic tools. Therefore, understanding molecular mechanisms through the ways in which they regulate gastrointestinal inflammation and immune responses could provide new insights into the pathogenesis of IBDs and IBS and open avenues for miRNA-based therapeutic interventions.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent chronic liver condition marked by excessive lipid accumulation in hepatic tissue. This disorder can lead to a range of pathological outcomes, including metabolic dysfunction-associated steatohepatitis (MASH) and cirrhosis. Despite extensive research, the molecular mechanisms driving MASLD initiation and progression remain incompletely understood. Oxidative stress and lipid peroxidation are pivotal in the "multiple parallel hit model", contributing to hepatic cell death and tissue damage. Gut microbiota plays a substantial role in modulating hepatic oxidative stress through multiple pathways: impairing the intestinal barrier, which results in bacterial translocation and chronic hepatic inflammation; modifying bile acid structure, which impacts signaling cascades involved in lipidic metabolism; influencing hepatocytes' ferroptosis, a form of programmed cell death; regulating trimethylamine N-oxide (TMAO) metabolism; and activating platelet function, both recently identified as pathogenetic factors in MASH progression. Moreover, various exogenous factors impact gut microbiota and its involvement in MASLD-related oxidative stress, such as air pollution, physical activity, cigarette smoke, alcohol, and dietary patterns. This manuscript aims to provide a state-of-the-art overview focused on the intricate interplay between gut microbiota, lipid peroxidation, and MASLD pathogenesis, offering insights into potential strategies to prevent disease progression and its associated complications.

Autoimmune diseases are complex conditions characterized by immune-mediated tissue damage and chronic inflammation. Protease-activated receptor 2 (Par2) has been implicated in these diseases, exhibiting dual roles that complicate its therapeutic potential. This review examines the perplexing functions of Par2, which promotes inflammation through immune cell activation while facilitating tissue healing in damaged organs. By analyzing findings across diverse autoimmune conditions, including rheumatoid arthritis, type 1 diabetes, and inflammatory bowel disease, we highlight how the context and location of Par2 activation determine its effects. Recent studies from our laboratory have resolved some of these contradictions by distinguishing Par2's immune-mediated inflammatory roles from its tissue-reparative functions. These insights pave the way for context-specific therapeutic strategies, such as selective Par2 modulators, that can mitigate inflammation while enhancing tissue repair. However, achieving such precision in modulation remains a significant challenge, necessitating further research into Par2's signaling pathways. This review underscores Par2's complexity and its transformative potential in autoimmune disease management, offering a nuanced perspective on its duality and therapeutic implications.

Chronic inflammation is a common trait in the pathogenesis of several diseases of the gut, including inflammatory bowel disease and celiac disease. Control of the inflammatory response is crucial in these pathologies to avoid tissue destruction and loss of intestinal function. Over the last 50 years, the identification of the mechanisms and mediators involved in the acute phase of the inflammatory response, which is characterized by massive leukocyte recruitment, has led to a number of therapeutic options. New drugs targeting inflammatory flares are still under development. However, interest on the other end of the spectrum-the resolution and repair phases-has emerged, as promoting tissue functional repair may maintain remission and counteract the chronicity of the disease. This review aims to discuss the current and future pharmacological approaches to the treatment of chronic intestinal inflammation and the restoration of functional tissues.

Atmospheric particulate matter (PM) is one of the most dangerous air pollutants of anthropogenic origin; it consists of a heterogeneous mixture of inorganic and organic components, including transition metals and polycyclic aromatic hydrocarbons. Although previous studies have focused on the effects of exposure to highly concentrated PM on the respiratory and cardiovascular systems, emerging evidence supports a significant impact of air pollution on the gastrointestinal (GI) tract by linking exposure to external stressors with conditions such as appendicitis, colorectal cancer, and inflammatory bowel disease. In general, it has been hypothesized that the main mechanism involved in PM toxicity consists of an inflammatory response and this has also been suggested for the GI tract. In the present study, we analyzed the effect of specific redox-active PM components, such as copper (Cu) and iron (Fe), in human intestinal cells focusing on ultrastructural integrity, redox homeostasis, and modulation of some mitochondrial-related markers. According to our results, exposure to Cu- and Fe-PM components and their combination induced ultrastructural alterations in the endoplasmic reticulum and in the mitochondria with an additive effect when combined. The increase in ROS and the loss of the mitochondrial mass in the cells exposed to PM indicates that mitochondria are a target of acute metal exposure. Furthermore, the gene expression and the protein levels of mitochondria dynamics markers were affected by the PM exposure. In particular, OPA1 increases at both gene and protein levels in all conditions while Mitofusin1 decreases significantly only in the presence of Fe. The increase in PINK expression is modulated by Fe, while Cu seems to affect mainly Parkin. Finally, a significant decrease in trans-epithelial resistance was also observed. In general, our study can confirm the correlation observed between pollution exposure areas and increased incidence of GI tract conditions.

Ulcerative colitis is a chronic inflammatory bowel disease of the colon mucosa associated with a higher risk of colorectal cancer.

This study classified hematoxylin and eosin (H&E) histological images of ulcerative colitis, normal colon, and colorectal cancer using artificial intelligence (deep learning).

A convolutional neural network (CNN) was designed and trained to classify the three types of diagnosis, including 35 cases of ulcerative colitis (n = 9281 patches), 21 colon control (n = 12,246), and 18 colorectal cancer (n = 63,725). The data were partitioned into training (70%) and validation sets (10%) for training the network, and a test set (20%) to test the performance on the new data. The CNNs included transfer learning from ResNet-18, and a comparison with other CNN models was performed. Explainable artificial intelligence for computer vision was used with the Grad-CAM technique, and additional LAIR1 and TOX2 immunohistochemistry was performed in ulcerative colitis to analyze the immune microenvironment.

Conventional clinicopathological analysis showed that steroid-requiring ulcerative colitis was characterized by higher endoscopic Baron and histologic Geboes scores and LAIR1 expression in the lamina propria, but lower TOX2 expression in isolated lymphoid follicles (all p values < 0.05) compared to mesalazine-responsive ulcerative colitis. The CNN classification accuracy was 99.1% for ulcerative colitis, 99.8% for colorectal cancer, and 99.1% for colon control. The Grad-CAM heatmap confirmed which regions of the images were the most important. The CNNs also differentiated between steroid-requiring and mesalazine-responsive ulcerative colitis based on H&E, LAIR1, and TOX2 staining. Additional classification of 10 new cases of colorectal cancer (adenocarcinoma) were correctly classified.

CNNs are especially suited for image classification in conditions such as ulcerative colitis and colorectal cancer; LAIR1 and TOX2 are relevant immuno-oncology markers in ulcerative colitis.

There has been growing evidence that perturbations in gut-microbiota-brain axis (GMBA) are involved in mechanisms of chronic sequelae of traumatic brain injury (TBI). This review discusses the connection between GMBA and post-traumatic epilepsy (PTE), the latter being a common outcome of TBI. The focus is on two aspects of post-TBI GMBA dysfunction that are relevant to epilepsy. First are impairments in intestinal permeability with subsequent translocation of gut bacteria into the bloodstream. Specifically, endotoxemia following TBI may have a serendipitous protective effect against PTE through lipopolysaccharide conditioning, which may be leveraged for the development of therapeutic interventions. Second are changes in microbial composition (i.e., dysbiosis). Here, the GMBA-PTE connection is explored from predictive biomarker perspective, whereby the risk of PTE can be stratified based on specific microbial profiles. Finally, microbiota transplantation is discussed both as a tool to examine the role of gut microbiota in PTE and as a prelude to novel approaches for PTE therapy and prevention.

Inflammatory bowel diseases (IBDs) are chronic immune driven intestinal disorders with marked metabolic alteration. Mass spectrometry imaging (MSI) enables the direct visualization of biomolecules within tissues and facilitates the study of metabolic changes. Integrating multiple spatial information sources is a promising approach for discovering new biomarkers and understanding biochemical alteration within the context of the disease.

This study evaluates the metabolomic changes in gut tissue samples from a preclinical model of spontaneous colitis, the HLA-B27/hβ2m transgenic rat, to uncover disease biomarkers.

We applied MSI to study the biochemical profile of bowel samples from HLA-B27/hβ2m transgenic and WT control rats in an unbiased manner. Statistical comparison was used to identify discriminative features. Some features were annotated using LC-MS/MS. The significance of these discriminative features was evaluated based on their distribution within histological layers and the presence of immune infiltration.

We identified spatially resolved changes in the metabolomic pattern of HLA-B27+ samples compared to WT controls. Out of the 275 discriminative features identified, 83 were annotated as metabolites. Two functional groups of discriminative metabolites were discussed as markers of gut barrier impairment and immune cell infiltration.

MS imaging's spatial dimension provides insights into disease mechanisms through the identification of spatially resolved biomarkers.

An association between the MAGI2 (S-SCAM) intron variant rs521851 and depression symptoms, as measured by the depression subscale of the Hospital Anxiety and Depression Scale (HADS-D), has been recently reported. The role of MAGI2 in depression has been linked to disruptions in the gut-brain axis. In this study, we investigated the association between rs521851 and HADS-D scores in an independent cohort of 380 individuals, consisting of 238 patients with an ICD-10 diagnosis of depression and 142 healthy controls. The original association was replicated in the patient cohort but not in the control group. Further analysis revealed that the effect size of rs521851 on HADS-D scores was moderated by Eating Attitudes Test 26 (EAT-26) scores. In participants with an EAT-26 score of ≥20, the effect size of rs521851 on HADS-D was more than 20 times greater compared to those with an EAT-26 score of <20. These findings successfully replicate the original association signal for MAGI2 and HADS-D, and highlight the role of MAGI2 in gut-brain interactions.

Microorganisms that colonize the intestine communicate with the host in various ways and affect gut function and health. Extracellular vesicles (EVs), especially their encapsulated microRNAs (miRNAs), participate in the complex and precise regulation of microbiota-host interactions in the gut. These roles make miRNAs critically important for the prevention, diagnosis, and treatment of intestinal diseases. Here, we review the current knowledge on how different sources of EVs and miRNAs, including those from diets, gut microbes, and hosts, maintain gut microbial homeostasis and improve the intestinal barrier and immune function. We further highlight the roles of EVs and miRNAs in intestinal diseases, including diarrhea, inflammatory bowel disease, and colorectal cancer, thus providing a perspective for the application of EVs and miRNAs in these diseases.

The development of inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, involves various factors and is characterized by persistent inflammation of the mucosal lining. However, the role of neutrophils in this process remains controversial. Neutrophil extracellular traps (NETs), which consist of chromatin, antimicrobial proteins, and oxidative enzymes, are released by neutrophils to trap pathogens. They are also involved in various immune-mediated and vascular diseases. NETs act as a vital defense mechanisms at the gut-mucosal interface and are frequently exposed to bacterial, viral, and fungal threats. However, they can also contribute to inflammation and worsen imbalances in the gut bacteria. Recent studies have suggested that NETs have a significant impact on IBD development. Previous studies have shown increased levels of NETs in tissue and blood samples from patients with IBD, as well as in experimental colitis mouse models. Therefore, this review discusses how NETs are formed and their role in the pathophysiology of IBD. It discusses how NETs may lead to tissue damage and contribute to IBD-associated complications. Moreover, non-invasive biomarkers are needed to replace invasive procedures such as endoscopy to better evaluate the disease status. Given the crucial role of NETs in IBD progression, this review focuses on potential NET biomarkers that can help predict the evolution of IBD. Furthermore, this review identifies potential therapeutic targets for regulating NET production, which could expand the range of available treatment options for IBD.

The intestinal immune system is the largest immune organ in the human body. Excessive immune response to intestinal cavity induced by harmful stimuli including pathogens, foreign substances and food antigens is an important cause of inflammatory diseases such as celiac disease and inflammatory bowel disease (IBD). Although great progress has been made in the treatment of IBD by some immune-related biotherapeutic products, yet a considerable proportion of IBD patients remain unresponsive or immune tolerant to immunotherapeutic strategy. Therefore, it is necessary to further understand the mechanism of immune cell populations involved in enteritis, including dendritic cells, macrophages and natural lymphocytes, in the steady-state immune tolerance of IBD, in order to find effective IBD therapy. In this review, we discussed the important role of innate and adaptive immunity in the development of IBD. And the relationship between intestinal immune system disorders and microflora crosstalk were also presented. We also focus on the new findings in the field of T cell immunity, which might identify novel cytokines, chemokines or anti-cytokine antibodies as new approaches for the treatment of IBD.

The damnification of mitochondrion is often considered to be an important culprit of inflammatory bowel disease (IBD), however, there are fewer reports of mechanisms of mitochondria-mediated IBD treatment. Therefore, we first proposed to reboot mitochondrial energy metabolism to treat IBD by capturing the double-sided factor of ROS and creatine (Cr)-assisted energy adjustment. Herein, an oral Cr-modified selenium-based hyaluronic acid (HA) nanogel (HASe-Cr nanogel) was fabricated for treatment of IBD, through ROS elimination and energy metabolism upgradation. More concretely, due to IBD lesion-specific positive charge and the high expression of CD44, HASe-Cr nanogel exhibited dual targeted inflammatory bio-functions, and ROS-driven degradation properties in high-yield ROS levels in inflammation areas. As expected, multifunctional HASe-Cr nanogel could effectively ameliorate IBD-related symptoms, such as mitochondrial biological function restoration, inhibition of M1-like macrophage polarization, gut mucosal reconstruction, microbial ecological repair, etc., thus excellently treating IBD. Overall, the proposed strategy underlined that the great potentiality of HASe-Cr nanogel by restarting mitochondrial metabolic energy in colitis lesions, providing new a pavement of mitochondrion-mediated colitis treatment in clinical applications.

Urinary tract infections (UTIs) are one of the most common bacterial infections, affecting more than 150 million people each year in the world. UTIs have grown exponentially in the last few years. They represent a major load for both individuals and society. The highest incidence (about 55-60%) concerns women. Many pathogens are involved in UTIs, most of which are derived from the gut. Recent studies, together with recent diagnostic techniques (such as quantitative culture of urine or next-generation sequencing), have improved the knowledge of microbial communities in the urinary tract. It turned out that gut dysbiosis is strictly involved in the pathogenesis of UTIs. In particular, the human gut is the natural habitat for Escherichia coli (E. coli), the main bacterium responsible for UTIs. The overgrowth of E. coli pathogenic strains represents a risk factor for them. Furthermore, the human gut microbiota acts as a "global reservoir" for genes conferring resistance to clinically relevant antibiotics, thus influencing the treatment of UTIs. In addition, differently from the past, the idea of a sterile urinary environment has been replaced by the characterization of a urinary microbiome. The aim of our review is to explore recent studies on the association between gut microbiota and urinary microbiome and to summarize the current knowledge about the effects of interactions between gut and urinary microbial communities in the pathogenesis of UTIs, considering UTIs more as a "gut disease" and not only a urinary disease and providing new insight into the therapeutic options such as the use of probiotics.