The antioxidant activity of selenium-containing soybean peptides (SePPs) has been previously demonstrated, despite their limited absorption in the small intestine. This study investigates the antioxidant mechanism of a selenium-containing tetrapeptide, Ser-Phe-Gln-SeM (SFQSeM), identified from SePPs, with particular emphasis on its interaction with the intestinal microbiota and its role in modulating host antioxidant defenses. The effects of SFQSeM were evaluated in a D-galactose-induced oxidative stress model and an antibiotic-treated mouse model. SFQSeM supplementation significantly reduced the oxidative stress in D-galactose-treated mice. It also promoted the growth of beneficial bacteria and increased the levels of acetate, butyrate and lactate in the intestine (P GPx-1) expression (48. 77%) compared to normal mice supplemented with SFQSeM (P 2SeO3 and selenomethionine, SFQSeM effectively restored the diversity of the intestinal microbiota disrupted by antibiotics. Lactobacillus, LachnospiraceaeNK4A136group, and Muribaculaceae were identified as predominant bacteria in the SFQSeM group, and were strongly associated with increased hepatic GSH-Px activity and GPx-1 mRNA expression (P < 0. 05). In conclusion, intestinal microbiota enhances the antioxidant efficacy of SFQSeM by modulating microbial composition, producing active metabolites, and converting SFQSeM into a bioactive form of selenium.
Zhang et al. (Thu,) studied this question.