Antinutritional factors in feedstuffs may limit their utilization in livestock production, but fermentation process can be used to improve feed quality; however, studies on fermented soybeans for laying hens remain limited. We investigated the effect of fermented soybean meal (FSBM) at various inclusion levels as a partial replacement for soybean meal (SBM) on egg production, egg quality, amino acid digestibility, gut morphology and microbiota, antioxidant capacity and immune response of young laying hens. A total of 360 Hy-line Brown laying hens aged 18 weeks were selected and divided into 5 groups of 6 replicates each and 12 birds per replicate. The control group received a basal diet while the trial group received the basal diet with FSBM included at 2.5%, 5.0%, 7.5% and 10.0%, respectively, for 12 weeks. Our findings revealed that the nutritional value of FSBM was higher compared to that of SBM in terms of reduced content of trypsin inhibitors and increased contents of crude protein, amino acids and minerals. FSBM enhanced egg production (P < 0.05), feed-to-egg ratio (P < 0.05), and albumen quality (albumen height and Haugh unit) (P < 0.05). Furthermore, FSBM improved apparent fecal amino acid digestibility (P < 0.05), gut morphology (increased villus height, villus width, villus height-to-crypt depth ratio and decreased crypt depth) (P < 0.05), antioxidant capacity (reduced malondialdehyde and increased catalase, total superoxide dismutase, glutathione peroxidase and total antioxidant capacity) (P < 0.05) and immune function (increased concentrations of IgG, IgA, and IgM; increased levels of transforming growth factor beta and Toll-like receptor 2; and reduced levels of interleukin 1β and tumor necrosis factor alpha) (P < 0.05). Further analysis showed that FSBM altered the composition of the gut microbiota favoring beneficial microbes. These findings suggest that probiotic fermentation improved the nutritional value of SBM. The inclusion of FSBM in the diets of laying hens at 2.5% or 5.0% improved amino acid digestibility, gut health, immune function, egg production and egg quality.

Gastric ulceration is a prevalent worldwide clinical presentation due to altered gastric defense mechanisms. Nonsteroidal anti-inflammatory drugs are one of the common causes of gastric ulcers mediated by the release of inflammatory mediators. The study aimed to investigate the potential protective effect of soyasaponin I (soya) against diclofenac (DIC)-induced gastric ulcer in rats and to highlight the underlying mechanisms. The experiment was conducted on 40 male Wistar albino rats, equally distributed into five groups: control, DIC-induced ulcer (9 mg/kg/d, orally, twice daily for 3 days), ulcer/soya-, ulcer/ranitidine-, and ulcer/soya/selective nuclear factor kappa B inhibitor (JSH-23)-treated groups. The doses of soya, ranitidine, and JSH were 20, 25, and 5 mg/kg/d, respectively, given orally. Gastric specimens were prepared for gene and histological study and for biochemical analysis of gastric prostaglandin E2 (PGE2), oxidative markers, and inflammatory cytokines. The gastric samples were formalin-fixed, paraffin-embedded, and subjected to hematoxylin and eosin (H&E), PAS staining, and immunohistochemical assay for identification of nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), and proliferation marker (Ki67) expressions. The findings revealed decreased gastric PGE2 and altered inflammatory and oxidative markers in the ulcer model group. The H&E staining showed mucosal injury characterized by mucosal surface defects and inflammatory cell infiltrations. The polymerase chain reaction (PCR) and immunohistochemistry demonstrated an upregulation of NF-κB and COX-2 expression at gene/protein levels; meanwhile, Ki67 downregulation. The soya-treated group showed maintained biochemical, histological, and PCR findings comparable to the ranitidine-treated group. The JSH-23-treated group still showed partial gastric protection with biochemical and immunohistochemical changes. Soyasaponin I ameliorated DIC-induced gastric ulcers by targeting the COX-2 activity through modulation of NF-κB signaling.

Allergic contact dermatitis is one of the most common recorded occupational diseases. There are many different substances that the skin comes into contact with on a daily basis and that can cause ACD, e.g., preservatives, surfactants, and antimicrobial agents. The development of a mouse model of ACD has provided insight into the immune mechanisms involved. Drugs used in the treatment of skin diseases have many side effects. Therefore, alternative methods of suppressing the immune response to reduce the symptoms of skin diseases are being sought. In recent years, high hopes have been placed on dietary modulation and supplementation to affect the intestinal microbial composition and promote anti-inflammatory responses. In addition, other studies have shown the crucial role of intestinal microbiota in many immune-mediated diseases. Recognition and characterization of pro- and anti-inflammatory nutrients and supplements may be crucial to support the treatment of diseases such as atopic dermatitis, acne vulgaris, psoriasis, and allergic contact dermatitis.

Soya saponin (SS) is a natural active substance of leguminous plant, which could improve lipid metabolism and regulate immune function. Intestinal flora might play a key role in the biological functions of SS. The objective of this study was to measure the effects of dietary SS on immune function, lipid metabolism, and intestinal flora of laying hens with or without antibiotic treated. The experiment was designed as a factorial arrangement of 3 dietary SS treatments × 2 antibiotic treatments. Birds were fed a basal diet (CON) or a low-SS diet (50 SS) containing 50 mg/kg SS, or a high-SS diet (500 SS) containing 500 mg/kg SS. Birds were cofed with or without antibiotics. The growth experiment lasted for 10 wk. Results showed that birds fed the 50 mg/kg SS diet tended to have lower abdominal fat rate. The gene expression of liver X receptor-α (LxR-α) in liver and serum total cholesterol (TC) were dropped, and the gene expression of acyl-CoA thioesterase 8 (ACOT8) in liver were upregulated. Compared with CON group, the levels of lysozyme, IL-10, and transforming growth factor (TGF-β) in the serum were elevated as along with gene expression of IL-10, TGF-β, and LYZ in ileum of both 50 and 500 SS group. However, the level of secretory immunoglobulin A (sIgA) and Mucin-2 in the ileum were downregulated in the 500 SS group. Additionally, Lactobacillus and Lactobacillus gasseri were the dominant bacteria in the 50 SS group, whereas the relative abundance of Lactobacillus was dropped in the 500 SS group. With combined antibiotics treatment, the α-diversity of bacteria was reduced, and the biological effects of SS were eliminated. In conclusion, the lipid metabolism, immune function, and intestinal flora of the laying hens were improved with the dietary supplementation of 50 mg/kg SS. But dietary 500 mg/kg SS had negative effects on laying hens.

Soya saponin (SS), an active compound in soybean meals, has been widely studied in the medical field. However, it was considered as an anti-nutritional factor in poultry diets. The objective of this experiment was to measure the effects of dietary SS using three dietary treatments on egg-laying performance and immune function of laying hens. Birds were fed a low soybean meal basal diet (CON), a low-SS diet (50 SS) containing 50 mg/kg SS, or a high-SS diet (500 SS) containing 500 mg/kg SS for 10 weeks. At the end of the 5th and 10th week of the trial, samples were collected for analysis.

Results showed that with 50 mg/kg SS supplementation, the egg production rate, feed conversion ratio (FCR), and eggshell quality tended to be improved. Serum follicle stimulating hormone (FSH) and Interleukin-4 (IL-4) levels were also elevated as well as the peripheral blood LPS stimulation index, the proportion of B lymphocytes, and antibody titer of bovine serum albumin (BSA). We also found that mRNA levels of follicle stimulating hormone receptor (FSHR) in ovarian, nuclear transcription factor kappa B (NF-κB), Transforming growth factor (TGF-β) and interferon γ (IFN-γ) in spleen were up-regulated at the end of the trial. Additionally, dietary 50 mg/kg SS improved the ileal flora via up-regulating the relative abundance of Lactobacillus, Romboutsia and Lactobacillus delbrueckii. Although the immune related indicators were improved with 500 mg/kg SS supplemented, it seemed to have a negative influence on the laying-performance. Specifically, serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), and the ratio of IFN-γ to IL-4 were increased in the 500 SS group at the end of the trial. The mRNA levels of gonadotropin releasing hormone 1 (GnRH1) in Hypothalamus, the estrogen related receptor (ERR) in ovaries were downregulated as well as the egg production rate during the trial with 500 mg/kg SS supplemented.

The egg production performance was improved by dietary supplemented with 50 mg/kg SS via increasing ovarian FSHR transcription level and serum estrogen level. A beneficial shift in intestinal microflora was recorded, and the immune function of laying hens was also improved with 50 mg/kg SS supplementation. Surprisingly, the long-term supplementation of 500 mg/kg SS exerted a negative impact on the laying performance and physiological functions of the liver of laying hens.

Saponins, prominent secondary plant metabolites, are recognized for their roles in plant defense and medicinal benefits. Soyasaponins, commonly derived from legumes, are a class of triterpenoid saponins that demonstrate significant potential for plant and human health applications. Previous research and reviews largely emphasize human health effects of soyasaponins. However, the biological effects of soyasaponins and their implications for plants in the context of human health have not been well-discussed. This review provides comprehensive discussions on the biological roles of soyasaponins in plant defense and rhizosphere microbial interactions; biosynthetic regulation and compound production; immunological effects and potential for therapeutics; and soyasaponin acquisition attributed to processing effects, bioavailability, and biotransformation processes based on recent soyasaponin research. Given the multifaceted biological effects elicited by soyasaponins, further research warrants an integrated approach to understand molecular mechanisms of regulations in their production as well as their applications in plant and human health.

Cellulose nanofiber (CN) consumption with exercise could be a potential strategy to control obesity. Here, we studied the effects of CN supplementation and voluntary exercise on obesity and gut microbiota in high-fat diet (HFD)-fed mice. Consumption of CN increased voluntary wheel running activity. CN intake and exercise together suppressed the increase in body weight and fat mass, and improved glucose tolerance. The fecal gut microbiota was analyzed by sequencing 16S ribosomal RNA genes. Principal component analysis revealed a shift in the microbiota composition resulting from exercise, but not from CN supplementation. Erysipelotrichaceae and Rikenellaceae decreased with exercise. Exercise also increased Ruminococcaceae, whereas exercise and CN intake together increased Eubacteriaceae. These two families are butyrate producers. Exercise increased the amount of acetate in the cecum. These results suggest that CN consumption improves exercise performance and exerts anti-obesity effects by modulating the balance of the gut microbiota.

Soymilk is rich in phytochemicals such as soy isoflavones (SIs) and soyasaponins (SSs). Dietary SIs and SSs display inhibitory effects on contact hypersensitivity (CHS), which was reported in a mouse model for allergic contact dermatitis (ACD); however, the beneficial effects of soymilk consumption on CHS remain unknown. Here, we studied the effects of drinking soymilk on CHS and gut microbiota. Soymilk consumption attenuated ear oedema and swelling, decreased the infiltration of Gr-1-positive cells into ear tissues, and reduced the production of chemokine (C-X-C motif) ligand 2 and triggering receptor expressed on myeloid cells-1 in ear tissues. The analysis of bacterial 16S ribosomal RNA gene sequences indicated that CHS caused changes in the gut microbiota structure and that consuming soymilk reduced these changes. These results suggest that soymilk consumption may be of therapeutic value for patients with ACD and may help control the balance of intestinal microbiota.