Lactobacillus paracasei TK1501 fermented soybeans alleviate dextran sulfate sodium-induced colitis by regulating intestinal cell function.

Abstract

Probiotic food provide health benefits by regulating intestinal floras via live bacteria, but the shelf life is short and the preservation condition is demanding due to the bacteria being fragile. Owing to these problems, we have tried to find a fermented food that is helpful for inflammatory bowel disease treatment but independent of live bacteria. In addition, the mechanisms of fermented food were investigated. Dextran sulfate sodium was used to model inflammatory bowel disease in mice, and Lactobacillus paracasei TK1501 fermented soybeans and their metabolites were used to treat inflammatory bowel disease. In this study, TK1501 fermented soybean alleviated colitis. However, the efficacy was associated with bacterial metabolites but not live or dead bacteria. Compositional analysis of soybean before and after fermentation shows that soy carbohydrates were used for bacteria growth and produced functional substances. Further, we display the main active ingredient was lipoteichoic acid and peptidoglycan, because lipoteichoic acid reduced the colonic macrophage and peptidoglycan may increase the mucin-2 expression. A cell experiment displayed that lipoteichoic acid could enhance the phagocytosis of macrophages. In general, TK1501 fermented soybean alleviating colitis is dependent on metabolites of TK1501, particularly lipoteichoic acid and peptidoglycan. The fermented food may have a long shelf life and lax storage condition. © 2023 Society of Chemical Industry.