Exopolysaccharides and Surface-Layer Proteins Expressed by Biofilm-State <i>Lactiplantibacillus plantarum</i> Y42 Play Crucial Role in Preventing Intestinal Barrier and Immunity Dysfunction of Balb/C Mice Infected by <i>Listeria monocytogenes</i> ATCC 19115
Jiayi Li, Jiang Yu, Yinglong Song, Sihan Wang, Guangqing Mu, Yanfeng Tuo
Abstract
Our previous study showed that Lactiplantibacillus plantarum Y42 in the biofilm state can produce more exopolysaccharides and surface-layer proteins and showed a stronger promoting effect on intestinal barrier function than that in the planktonic state. In this study, oral administration of the live/pasteurized planktonic or biofilm L. plantarum Y42 and its metabolites (exopolysaccharides and surface-layer proteins) increased the expression of Occludin, Claudin-1, ZO-1, and MUC2 in the gut of the Balb/C mice after exposure to Listeria monocytogenes ATCC 19115 and inhibited the activation of the NLRP3 inflammasome pathway, which in turn reduced the levels of inflammatory cytokines IL-1β and IL-18 in the serum of the mice. Furthermore, oral administration of the live/pasteurized planktonic or biofilm L. plantarum Y42 and its metabolites increased the abundance of beneficial bacteria (e.g., Lachnospiraceae _NK4A136_group and Prevotellaceae _UCG-001 ) while reducing the abundance of harmful bacteria (e.g., norank_f__ Muribaculaceae ) in the gut of the mice, in line with the increase of short-chain fatty acids and indole derivatives in the feces of the mice. Notably, biofilm L. plantarum Y42 exerted a better preventing effect on the intestinal barrier dysfunction of the Balb/C mice due to the fact that biofilm L. plantarum Y42 expressed more exopolysaccharides and surface-layer proteins than the planktonic state. These results provide data support for the use of exopolysaccharides and surface-layer proteins extracted from biofilm-state L. plantarum Y42 as functional food ingredients in preventing intestinal barrier dysfunction.