Gut microbiota and short chain fatty acid composition as affected by legume type and processing methods as assessed by simulated in vitro digestion assays

Authors: CHEN, Y.X - Jilin University; CHANG, S.K.C. - Mississippi State University; ZHANG, Y. - Mississippi State University; HSU, C.Y. - Mississippi State University; NANNAPANENI, R. - Mississippi State University

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2019
Publication Date: 5/15/2020
Citation: Chen, Y., Chang, S., Zhang, Y., Hsu, C., Nannapaneni, R. 2020. Gut microbiota and short chain fatty acid composition as affected by legume type and processing methods as assessed by simulated in vitro digestion assays. Food Chemistry. 312:126040. https://doi.org/10.1016/j.foodchem.2019.126040.
DOI: https://doi.org/10.1016/j.foodchem.2019.126040

Interpretive Summary: Recently, legumes have gained considerable interest globally due to the positive association between the consumption of legumes and the reduction in the risk of various chronic diseases. The health benefits are partially attributed to the dietary fiber. However, little is known about how cooking methods affect digestibility, gut microbiota and short chain fatty acids which are the fermentation products in the large intestine. Soybean and pinto bean were used for autoclaving and germination and then the soluble and insoluble fibers were analyzed after simulated in vitro digestion. The two types of fibers were subjected to fermentation. The results showed that legume variety, processing method, type of fiber had significant effect on the acidity, short chain fatty acid composition and the microbial profile of the fermented fiber. In general, bean fibers, especially soluble fiber promoted the growth and activities of beneficial gut microflora. This study offered new knowledge to help individuals or industry select optimal legume variety and processing method to promote gut health and disease prevention benefits.

Technical Abstract: This study’s objective was to investigate how legume type and processing method affected digestibility, and subsequent gut microbiota and short chain fatty acid (SCFA) formation. After autoclaving and germinating-cooking, pinto bean and soybean were subjected to in vitro digestion. The digestion residues were fractionated into soluble and insoluble fiber, and fermented by microbiota from pig feces. Results showed the in vitro digestibility was affected significantly by processing method and legume type. Autoclaving resulted in higher digestibility. The in-vitro digested bean residues caused a rapid pH decrease in the first 12 h during the fermentation with pig feces, and a significant increase in the formation of SCFAs. A positive modulation of the gut microbiota by the in-vitro digested bean residues was observed. Gut bacteria Prevotella copri and Bacteroides vulgatus exhibited the highest relative abundance in the treatments with germinated bean’s soluble residues. Phascolarctobacterium succinatutens was increased by the insoluble fiber residues.