Influence of Polysaccharides From Polygonatum kingianum on Short-Chain Fatty Acid Production and Quorum Sensing in Lactobacillus faecis

Abstract

Polysaccharide is one of the main active ingredients of <i>Polygonatum kingianum</i>, which has been proven to regulate the balance of gut microbiota. For the first time, this study focused on the regulation of polysaccharides from <i>Polygonatum kingianum</i> (PS) on <i>Lactobacillus faecis</i>, a specific probiotic in the intestinal tract. PS effectively promoted the biomass, biofilm and acetic acid production in <i>L. faecis</i> 2-84, and enhanced quorum sensing (QS) signaling. The characteristics of gene sequence were analyzed using genomics approaches, and <i>L. faecis</i> 2-84 was found to encode 18 genes that are closely related to QS and 10 genes related to short-chain fatty acids (SCFAs). Additionally, transcriptome and proteome analysis demonstrated that PS could promote the QS system of <i>L. faecis</i> by enhancing the transcription of <i>oppA</i> gene and expression of oppD protein. PS also regulated the production and metabolism of SCFAs of <i>L. faecis</i> by upregulating the expression of <i>ldh</i> and <i>metE</i> gene and adh2 protein, and downregulating the expression of <i>mvK</i> gene. In conclusion, it was speculated that PS could affect intestinal SCFAs production by affecting the QS system and SCFAs production in <i>L. faecis</i>. The present study implied that PS might have a role in promoting the growth of intestinal probiotics, where the QS system and SCFAs might be two of the important mechanisms for the probiotic activity of PS.