Bifidobacterium breve Protects the Intestinal Epithelium and Mitigates Inflammation in Colitis via Regulating the Gut Microbiota-Cholic Acid Pathway.

In this study, we aimed to explore the protective effects of Bifidobacterium in colitis mice and the potential mechanisms. Results showed that Bifidobacterium breve (B. breve) effectively colonized the intestinal tract and alleviated colitis symptoms by reducing the disease activity index. Moreover, B. breve mitigated intestinal epithelial cell damage, inhibited the pro-inflammatory factors, and upregulated tight junction (TJ)-proteins. Gut microbiota and metabolome analysis found that B. breve boosted bile acid-regulating genera (such as Bifidobacterium and Clostridium sensu stricto 1), which promoted bile acid deconjugation in the intestine. Notably, cholic acid (CA) was closely associated with the expression levels of inflammatory factors and TJ-proteins (p < 0.05). Our in vitro cell experiments further confirmed that CA (20.24 ± 4.53 pg/mL) contributed to the inhibition of lipopolysaccharide-induced tumor necrosis factor-α expression (49.32 ± 5.27 pg/mL) and enhanced the expression of TJ-proteins (Occludin and Claudin-1) and MUC2. This study suggested that B. breve could be a probiotic candidate for use in infant foods.

Musculus senhousei as a promising source of bioactive peptides protecting against alcohol-induced liver injury.

Alcohol-induced liver injury has become a leading risk for human health, however, effective strategies for the prevention or treatment are still lacking. Hence, the present study explored the potential of Musculus senhousei as a source of hepatoprotective peptides against alcoholic liver injury using in vitro, in vivo and in silico methods. Results indicated that Musculus senhousei peptides (MSP, extracted by simulated gastrointestinal digestion of cooked mussel) exhibited notable antioxidant (ABTS and DPPH assays) and alcohol dehydrogenase (ADH) stabilizing activity in vitro. The ingestion of MSP markedly alleviated alcohol-induced liver injury in mice, as indicated by the decrease of serum transaminases (AST and ALT). In line with in vitro assays, significantly increased hepatic ADH activity and activated antioxidative defense system (GSH, SOD, GSH-Px and CAT) were observed, whereas the oxidative stress (MDA) was decreased. Peptidomic analysis revealed over 6000 peptides with favorable amino acid compositions, and a total of 20 potentially novel peptides with bioactivity and bioavailability were excavated among 746 of the most influential peptides using an in silico strategy. Peptides (i.e. WLPMKL, WLWLPA, RLC and RCL) were further synthesized and validated in vitro to be bioactive. These findings suggest that Musculus senhousei can be an ideal source of bioactive peptides for the prevention of alcoholic liver injury.