Fermented dairy products are known for their efficiency in delivering and protecting probiotic microorganisms. However, there is a growing demand for diversification of the market with plant-based products. The aim of this study was to develop an oat beverage enriched with inulin and fermented with Lacticaseibacillus rhamnosus LR B and evaluate its synbiotic effects in vitro. For this purpose, the validated dynamic colon model (the TNO Intestinal Model TIM-2) was used with focus on the composition of the gut microbiota and its production of metabolites to evaluate the functionality. The fermentation kinetics, sugars, organic acids and inulin dosage in the fermented oat beverage were also evaluated. The acidification rate was 16.91 10-3 pH units.min-1, reaching the final pH of 4.5 in 2.38 ± 0.05 h. Dosages of sucrose, glucose and lactic acid were 23.35 ± 0.45 g.L-1, 21.37 ± 0.77 g.L-1, 0.94 ± 0.05 g.L-1, respectively. After simulated in vitro digestion, the inulin concentration was partially preserved with 20.11 ± 0.21 maltose equivalent (μg.mL-1). The fermented and pre-digested oat beverage (with 7.71 ± 0.44 log CFU.mL-1) was fed into TIM-2, which was previously inoculated with feces from healthy adults. The analysis identified nine bacterial taxa that were significantly modulated compared to the standard ileal effluent medium (SIEM) control. An increase in relative abundance of Lactobacillus and Catenibacterium, and reduction in Citrobacter, Escherichia-Shigella, and Klebsiella was observed. In addition, the cumulative means of short-chain fatty acids (SCFAs) increased, especially for acetate and butyrate. These findings suggest that the developed oat beverage can positively influence the gut microbiota and its activity, highlighting possible health benefits.

The development of plant polysaccharides for anti-inflammation and gut flora modulation has attracted extensive attention; however, it remains to be investigated whether the interaction between active polysaccharides and other macromolecules in the food matrix influences polysaccharide activity. In this study, a homogeneous heteropolysaccharide was purified from Moutan Cortex polysaccharide (PMCW1), the main glycosidic bonds of which were comprised of T-α-Araf-(1→, →5)-α-Araf-(1→, →3,5)-α-Araf-(1→, →3,4)-α-Glcp-(1→, and →4)-β-Galp-(1 → residues. PMCW1 reduced the Firmicutes/Bacteroidetesh ratio, promoted the growth of Prevotella, Bifidobacterium, and Lactobacillus, and increased SCFAs levels. Additionally, PMCW1 down-regulated the NO production and pro-inflammatory factor levels in lipopolysaccharide-induced RAW 264.7 macrophages. In the simulated plant protein beverage system, the PMCW1-soybean protein isolate complex formed in non-covalent interactions with better stability and solubility, which maintained their anti-inflammation effects after gastrointestinal digestion. These results provide a new perspective for the development of PMCW1 as a promising functional food ingredient for preventing and mitigating metabolic diseases.

Human sleep quality is intricately linked to gut health. Emerging research indicates that Bifidobacterium animalis subsp. lactis BLa80 has the potential to ameliorate gut microbiota dysbiosis. This randomized, placebo-controlled study evaluated the impact of BLa80 supplementation on sleep quality and gut microbiota in healthy individuals. One hundred and six participants were randomly assigned to receive either a placebo (maltodextrin) or BLa80 (maltodextrin + BLa80 at 10 billion CFU/day) for 8 weeks. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI), a validated tool consisting of 18 items assessing seven components of sleep quality over a one-month period, and the Insomnia Severity Index (ISI), a secondary measure of insomnia severity. Gut microbiota changes were assessed using 16S rRNA sequencing, while the in vitro gamma-aminobutyric acid (GABA) production capacity of BLa80 was analyzed by HPLC. After 8 weeks, the intervention group exhibited a significant reduction in the PSQI total score compared to the placebo group, suggesting improved sleep quality. While no significant changes in alpha diversity were noted, beta diversity differed markedly between groups. The gut microbiota predominantly consisted of Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria and Fusobacteria, collectively accounting for over 99.9% of the gut microbiota. Statistical analysis showed that BLa80 significantly decreased the relative abundance of Proteobacteria phylum and increased the abundance of Bacteroidetes, Fusicatenbacter, and Parabacteroides compared to placebo. PICRUSt2 analysis indicated noteworthy enhancements in the pathways of purine metabolism, glycolysis/gluconeogenesis, and arginine biosynthesis due to BLa80 intervention. Moreover, BLa80 demonstrated notable GABA production, potentially contributing to its effects on sleep quality modulation. These results demonstrate the ability of BLa80 to improve sleep quality through modulating gut microbiota and GABA synthesis, highlighting its potential as a beneficial probiotic strain.

Antibiotic-induced disruption of the gut microbiome in the first 1000 days of life is linked to an increased risk of the development of immunological, metabolic, and neurobehavioral childhood-onset conditions. Supporting the recovery of the gut microbial community after it has been perturbed by antibiotics might be a promising strategy to reduce these risks. In this clinical study, the effect of a 6 weeks supplementation with synbiotics (Bifidobacterium breve M-16 V, short chain galacto-oligosaccharides and long chain fructo-oligosaccharides) after antibiotic treatment on the recovery speed of the gut microbiota of toddlers will be studied.

A cohort of 126 Dutch toddlers aged 12 to 36 months old, who receive an amoxicillin or amoxicillin/clavulanic acid treatment, will be followed for 12 weeks. Participants will be randomized into an intervention group, who will consume the study product over a 6 weeks period starting at the last day of the antibiotic treatment or into a control group that will continue their usual eating pattern. Stool samples and their characteristics will be collected weekly by both groups. Stool samples will be analyzed for total microbiota and Bifidobacterium spp.. The differences in the proportion of Bifidobacterium out of total gut microbiota, composition of species belonging to Bifidobacterium, and beta diversity overtime will be compared between the two groups to study the effect of the intervention on the gut microbiota after perturbation. Furthermore, the effect of the treatment will also be studied in terms of the gut microbiota metabolic activity and stool characteristics. Additionally, food intake will be recorded to investigate whether diet, especially dietary fibers, may influence the gut microbiota as well. The findings may highlight a potential intervention strategy to support the recovery of the gut community after it has been perturbed by antibiotics in early life.

The TOBBI trial was approved by the board of Medical Ethics Review Committee NedMec in June 2022 and registered at  https://www.onderzoekmetmensen.nl/en/trial/20358 under the code NL75975.081.20, and at the World Health Organization at https://trialsearch.who.int/Trial2.aspx?TrialID=NL-OMON20358 under NTR-new: NL8996.

Lactobacillus is widely recognized for its probiotic benefits and has been widely used in food production. While biofilms are typically associated with pathogenic bacteria, they also served as a self-protective mechanism formed by microorganisms in an adverse environments. In recent years, relevant studies have revealed the excellent characteristics of Lactobacillus biofilms, offering new insights into their potential applications in the food industry. The Lactobacillus biofilms is important in improving fermentation processes and enhancing the resilience of Lactobacillus in various conditions. This paper reviews how quorum sensing regulates the formation of Lactobacillus biofilms and explores their roles in stress resistance, bacteriostasis and food production. Additionally, it highlights the emerging concept of fourth-generation probiotics, developed through biofilm technology, as a novel approach to probiotic applications.

Bifidobacterium longum (B. longum) is a species of the core microbiome in the human gut, whose abundance is closely associated with host age and health status. B. longum has been shown to modulate host gut microecology and have the potential to alleviate various diseases. Comprehensive understanding on the colonization mechanism of B. longum and mechanism of the host-B. longum interactions, can provide us possibility to prevent and treat human diseases through B. longum-directed strategies. In this review, we summarized the gut colonization characteristics of B. longum, discussed the diet factors that have ability/potential to enrich indigenous and/or ingested B. longum strains, and reviewed the intervention mechanisms of B. longum in multiple diseases. The key findings are as follows: First, B. longum has specialized colonization mechanisms, like a wide carbohydrate utilization spectrum that allows it to adapt to the host's diet, species-level conserved genes encoding bile salt hydrolase (BSHs), and appropriate bacterial surface structures. Second, dietary intervention (e.g., anthocyanins) could effectively improve the gut colonization of B. longum, demonstrating the feasibility of diet-tuned strain colonization. Finally, we analyzed the skewed abundance of B. longum in different types of diseases and summarized the main mechanisms by which B. longum alleviates digestive (repairing the intestinal mucosal barrier by stimulating Paneth cell activity), immune (up-regulating the regulatory T cell (Treg) populations and maintaining the balance of Th1/Th2), and neurological diseases (regulating the kynurenine pathway and quinolinic acid levels in the brain through the gut-brain axis).

Alzheimer's disease (AD) is a complex multifactorial neurodegenerative disease. With the escalating aging of the global population, the societal burden of this disease is increasing. Although drugs are available for the treatment of AD, their efficacy is limited and there remains no effective cure. Therefore, the identification of safe and effective prevention and treatment strategies is urgently needed. Functional factors in foods encompass a variety of natural and safe bioactive substances that show potential in the prevention and treatment of AD. However, current research focused on the use of these functional factors for the prevention and treatment of AD is in its initial stages, and a complete theoretical and application system remains to be determined. An increasing number of recent studies have found that functional factors such as polyphenols, polysaccharides, unsaturated fatty acids, melatonin, and caffeine have positive effects in delaying the progression of AD and improving cognitive function. For example, polyphenols exhibit antioxidant, anti-inflammatory, and neuroprotective effects, and polysaccharides promote neuronal growth and inhibit inflammation and oxidative stress. Additionally, unsaturated fatty acids inhibit Aβ production and Tau protein phosphorylation and reduce neuroinflammation, and melatonin has been shown to protect nerve cells and improve cognitive function by regulating mitochondrial homeostasis and autophagy. Caffeine has also been shown to inhibit inflammation and reduce neuronal damage. Future research should further explore the mechanisms of action of these functional factors and develop relevant functional foods or nutritional supplements to provide new strategies and support for the prevention and treatment of AD.

Bifidobacterium animalis subsp. lactis BLa80 is a new probiotic strain with extensive applications in food products both domestically and internationally. Given the rising consumption of this probiotic, its safety assessment is increasingly crucial in the food industry. This study evaluates the safety of strain BLa80 using a combination of in vitro and in vivo assays along with genomic analysis. Methods included exposing the strain to artificial gastric and intestinal fluids, as well as a medium containing bile salts, to stimulate human digestive conditions. The strain showed high tolerance to gastric fluid at pH of 2.5 and to 0.3 % bile salts. It maintained a 99.92 % survival rate in intestinal fluid. Additional tests assessed hemolytic activity, antibiotic susceptibility (revealing sensitivity to 7 antibiotics), and biogenic amine production using HPLC-ELSD, confirming the absence of histamine, and other harmful amines. Bile salt hydrolase activity was demonstrated qualitatively, and metabolic byproducts were quantitatively analyzed using a D-/l-lactic acid assay kit, showing that BLa80 produces 1.48 mg/mL of l-lactic acid and no harmful d-lactic acid. Genomic analysis confirmed the absence of virulence or pathogenicity genes, and a 90-day oral toxicity study in rats confirmed no toxic effects at various doses. Overall, these findings support the safety classification of the strain BLa80.

Many health-promoting effects have been attributed to the intake of probiotic cells. However, it is important that probiotic cells arrive at the site of their activity in a viable state in order to exert their beneficial effects. Careful selection of the appropriate probiotic formulation is therefore required as mainly the type of probiotic species/strain and the administration strategy may affect survival of the probiotic cells during the upper gastrointestinal (GIT) passage. Therefore, the current study implemented Simulator of the Human Microbial Ecosystem (SHIME®) technology to investigate the efficacy of different commercially available probiotic formulations on the survival and culturability of probiotic bacteria during upper GIT passage. Moreover, Colon-on-a-Plate (CoaP™) technology was applied to assess the effect of the surviving probiotic bacteria on the gut microbial community (activity and composition) of three human donors. Significantly greater survival and culturability rates were reported for the delayed-release capsule formulation (>50%) as compared to the powder, liquid, and standard capsule formulations (<1%) (p < 0.05), indicating that the delayed-release capsule was most efficacious in delivering live bacteria cells. Indeed, administration of the delayed-release capsule probiotic digest resulted in enhanced production of SCFAs and shifted gut microbial community composition towards beneficial bacterial species. These results thus indicate that careful selection of the appropriate probiotic formulation and administration strategy is crucial to deliver probiotic cells in a viable state at the site of their activity (distal ileum and colon).

This study aims to evaluate the efficacy of Lacticaseibacillus rhamnosus LRa05 supplementation in enhancing Helicobacter pylori (H. pylori) eradication rate and alleviating the gastrointestinal side effects associated with bismuth quadruple therapy.

H. pylori-positive patients were randomized to receive levofloxacin-based bismuth quadruple therapy combined either probiotic LRa05 or a placebo for two weeks, followed by LRa05 (1 × 1010 CFU) or maltodextrin for the next two weeks. H. pylori infection was detected by 13C breath test pre- and post-treatment. Blood and stool samples were collected at week 0 and week 4 for routine and biochemical analysis, and serum inflammatory markers. Gastrointestinal symptoms were evaluated using the gastrointestinal symptom rating scale (GSRS). Intestinal microbiota was analyzed using 16S rRNA sequencing. The research was listed under the Chinese Clinical Trial Registry (ChiCTR2300072220), and written informed consent was obtained from all participants.

The LRa05 group exhibited a trend toward higher H. pylori eradication rates (86.11%) compared to the placebo group (82.86%), though the difference was not statistically significant. Significant reductions in neutrophil count, alanine aminotransferase, aspartate aminotransferase, pepsinogen I, interleukin-6 (IL-6), tumor necrosis factor α (TNF-α) (p < 0.05) suggest that LRa05 supplementation may mitigate inflammation, enhance liver function, and potential aid in early cancer prevention. GSRS symptom scores showed that LRa05 alleviated abdominal pain, acid reflux, bloating, and diarrhea, enhancing patient compliance. Furthermore, 16S rRNA sequencing showed that LRa05 countered the antibiotic-induced disruption of gut microbiota diversity, primarily by increasing beneficial bacteria.

Although LRa05 did not significantly improve the success rate of H. pylori eradication therapy, it has the potential to improve liver function and reduced levels of inflammatory markers such as IL-6 and TNF-α in the body, regulating the inflammatory response. In addition, it played a positive role in alleviating the adverse symptoms and gut microbiota disturbances caused by eradication therapy, providing a possible way to improve the overall health of patients and demonstrating promising clinical potential.

http://www.chictr.org.cn, identifier ChiCTR2300072220.

The interplay between gut microbiota (GM) and the metabolization of dietary components leading to the production of short-chain fatty acids (SCFAs) is affected by a range of factors including colonic pH and carbohydrate source. However, there is still only limited knowledge on how the GM activity and metabolite production in the gastrointestinal tract could be influenced by pH and the pH gradient increases along the colon.

Here we investigate the effect of pH gradients corresponding to levels typically found in the colon on GM composition and metabolite production using substrates inulin, lactose, galactooligosaccharides (GOS), and fructooligosaccharide (FOS) in an in vitro colon setup. We investigated 3 different pH regimes (low, 5.2 increasing to 6.4; medium, 5.6 increasing to 6.8 and high, 6.0 increasing to 7.2) for each fecal inoculum and found that colonic pH gradients significantly influenced in vitro simulated GM structure, but the influence of fecal donor and substrate was more pronounced. Low pH regimes strongly influenced GM with the decreased relative abundance of Bacteroides spp. and increased Bifidobacterium spp. Higher in vitro simulated colonic pH promoted the production of SCFAs in a donor- and substrate-dependent manner. The butyrate producer Butyricimonas was enriched at higher pH conditions, where also butyrate production was increased for inulin. The relative abundance of Phascolarctobacterium, Bacteroides, and Rikenellaceae also increased at higher colonic pH, which was accompanied by increased production of propionate with GOS and FOS as substrates.

Together, our results show that colonic substrates such as dietary fibres influence GM composition and metabolite production, not only by being selectively utilized by specific microbes, but also because of their SCFA production, which in turn also influences colonic pH and overall GM composition and activity. Our work provides details about the effect of the gradients of rising pH from the proximal to distal colon on fermenting dietary substrates in vitro and highlights the importance of considering pH in GM research.