Effect of Soymilk Fermented by Lactobacillus amylolyticus L6 on Intestinal Microorganisms and Short-chain Fatty Acids in Vitro

This study was conducted to investigate the effect of soymilk fermented by Lactobacillus amylolyticus L6 on intestinal microorganisms and short-chain fatty acids in vitro. After simulated gastrointestinal digestion of the fermented soymilk, the survival rate of L. amylolyticus L6 was determined. Then, the digested product was inoculated with human fecal microorganisms and cultured at 37 ℃ under anaerobic conditions for 48 h, and the changes of short chain fatty acids were determined during the fermentation process. The relative abundance of intestinal flora was analyzed by 16S rRNA sequencing. The results showed that L. amylolyticus L6 in the fermented soymilk maintained a high survival rate after simulated gastrointestinal transport. After 48 h in vitro fermentation with the fermented soymilk, the relative abundance of many harmful intestinal bacteria decreased, and the content of short-chain fatty acids (SCFAs) increased significantly (P < 0.05). These findings suggest that L. amylolyticus L6 fermented soymilk can increase the content of SCFAs after 48 h in vitro fermentation. This study provides a theoretical guidance for the development of fermented soybean products.