Dr. Devin J. Rose
Date of this Version
Leow, S. (2021). Gut Community Response to Wheat Bran and Pinto Bean. (Master Thesis, University of Nebraska- Lincoln, Lincoln, NE, United States).
There is general consensus among the scientific community that dietary fibers reduce the risk of Western diseases through their fermentation by beneficial microbial communities in the human gut. However, dietary fibers in wheat bran (WB) and pinto bean (PB) are incompletely fermented by the gut microbiota. Therefore, there is a critical need to identify gut microbial communities that can increase fermentation of dietary fibers from these foods to maximize their disease-preventing properties. The goal of this study was to identify such communities with increased capacity to ferment the dietary fibers in WB and PB. To accomplish these goals, a stepwise in vitro fecal fermentation strategy with a modification to select for WB- and PB-associated microbes was employed. Over the course of 96 h of fermentation, fecal microbiomes treated with WB either maintained or improved their carbohydrate utilization capability, while the carbohydrate utilization capability of fecal microbiomes treated with PB varied by microbiome. At the end of 96 h of fermentation, WB-associated microbiomes had higher relative abundances of Bifidobacterium, Bacteroides, Prevotella 9, Enterococcus, Agathobacter, Roseburia, Ruminococcus 1, Dialister, Mitsuokella, and Veillonella, while PB-associated microbiomes had higher Bifidobacterium, Bacteroides, Prevotella 9, Enterococcus, [Ruminococcus] gnavus group, [Ruminococcus] torques group, Agathobacter, Lachnospiraceae NK4A136 group, Roseburia, Dialister, Veillonella, and uncl_Enterobacteriaceae compared with a control containing only media. There were also other genera that were associated with WB or PB substrates, but varied by microbiome. Both WB- and PB-associated communities were propiogenic in nature. These findings are important in developing effective intervention strategies to help increase dietary fiber fermentation and reduce the risk of disease.
Advisor: Devin J. Rose