Potential Prebiotic Properties and Proliferation Mechanism of Fermented Milk-Derived Polypeptides

Abstract

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 of1000-2000Da were identified by LC-MS.The results showed that the peptides could affect the arginine biosynthesis pathway as well as 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.

Keywords: prebiotics, fermented milk-derived peptides, intestinal flora, Proliferation, high-throughput sequencing technology, metabolomics