<i>Lactobacillus paracasei</i>influences the gut-microbiota-targeted metabolic modulation of the immune status of diarrheal mice

Abstract

Koumiss is a traditional fermented drink widely consumed by nomads owing to its rich nutritional value and therapeutic effects. <i>Lactobacillus paracasei</i> is a bacterial strain isolated from koumiss and has a positive effect on diarrhea; however, the relationship between gut microbial dysbiosis and <i>L. paracasei</i> gut microbial metabolism remains unclear. Therefore, this study aimed to explore the anti-diarrheal activity of <i>L. paracasei</i> in a murine <i>E. coli</i>-induced diarrhea model to provide novel insights into its probiotic properties by analyzing its intestinal metabolites and effects on the intestinal barrier. Oral administration of the probiotic, <i>L. paracasei</i>, enhanced tight junction protein expression, alleviated clinical manifestations consistent with <i>E. coli</i>-induced diarrhea, and positively affected overall intestinal microecological homeostasis. Moreover, it increased the goblet cell count and the secretory immunoglobulin A content and regulated intestinal metabolism <i>via</i> gut microbes, consequently preventing <i>E. coli</i>-mediated disruption of the intestinal epithelial cell barrier.