Potential prebiotic properties and proliferation mechanism of fermented milk-derived polypeptides

The purpose of this paper is to investigate the potential prebiotic properties and proliferation mechanism of fermented milk-derived peptides. In this study, fermented milk-derived polypeptides were obtained by extraction, separation, and purification. The purified peptides were used to culture fecal flora in vitro, , and the relative abundance and composition of the flora were analyzed by high-throughput 16S rRNA sequencing technology. The results showed that peptides can promote the proliferation of beneficial bacteria Lactococcus in the intestine and inhibit the proliferation of harmful bacteria Escherichia coli-Shigella. . The amino acid sequence of polypeptide components was determined and synthesized in vitro to verify the proliferation of intestinal flora; the proliferation mechanism of peptides on Lactococcus lactis was studied using non-targeted LC-MS metabolomics technology. Five important peptides with molecular weights of 1000-2000 Da were identified by LC-MS: GRP1 (LTEEEK), GRP2 (ENDAPSPVM*K), GRP3 (ITVDDK), GRP4 (EAM*APK) and GRP5 (LPPPEK). The results showed that the peptides could affect the arginine biosynthesis pathway and the amino sugar and nucleotide sugar metabolism of Lactococcus lactis. . In addition, the peptides increased the expression of organic acids and their derivatives in Lactococcus lactis. . This study provides a research basis for expanding the potential sources of new prebiotics and also opens up a new idea for discovering new prebiotics in vitro. .