Effect of bean structure on microbiota utilization of plant nutrients : An in-vitro study using the simulator of the human intestinal microbial ecosystem (SHIME®)

Colonic fermentation of resistant starch provides health benefits to the host. However, physical characteristics of the food matrix could limit the availability of starch and other dietary fibres for microbiota utilization. In this study, the influence of food structural aspects was studied by using cotyledon cells from red kidney beans with different levels of cellular integrity. In-vitro colonic fermentation was conducted in the simulator of the human intestinal microbial ecosystem (SHIME®) where the utilization of starch and other non-starch polysaccharides was investigated along the three colon regions. Results indicate that plant cell integrity modulates nutrient utilization by gut microbiota where higher amounts of starch were delivered to distal regions of the colon in intact samples. Other dietary fibre constituents, such as pectin, were also differentially fermented depending on the level of cellular integrity. Moreover, bean supplementation produced changes in microbiota population favouring the proliferation of Bifidobacterium species