Pulses including common beans, chickpeas, lentils, and peas are rich sources of gut health promoting bioactives, including fermentable fibers and an array of phenolic compounds, and are globally recognized as foods with human health promoting potential. Consumption of pulses have the potential to beneficially modulate gut health, which includes direct effects on the gut barrier integrity and function, and modulation of the gut microbiota community structure and activity.
This project aimed to systematically determine the link between pulses and gut health, and the subsequent implications on human health and chronic disease. We placed a special emphasis on determining the mechanisms of action with regards to maintaining or enhancing the integrity of the colonic barrier and modulation of the gut microbiota structure and activity, as well as, determining implications with regards to the effects on relevant gut-associated chronic diseases, namely inflammatory bowel disease (IBD) and obesity.
We have also assessed the effects of different pulse processing/cooking procedures on the profile/content of relevant pulse bioactives before and after upper gut digestion and the resultant impacts on the structure and activity of the human fecal microbial community.
Our main findings and take home messages include:
1) The levels and profiles of pulse bioactives differ depending on the pulse preparation method: a) in general, canned pulses have lower phenolics and galacto-oligosaccharides (GOS) compared to cooked pulses; b) canned pulses have higher starch and insoluble fiber levels, compared to cooked pulses, c) in general, pulse crackers have lower resistant starch and insoluble dietary fiber compared to cooked pulses.
2) After in vitro upper gut digestion, the pulse digesta (pulse components remaining after upper gut digestion and absorption; the content available to the colon), contains increased concentrations of extractable phenolics compared to their concentrations extracted from the pulse food before upper gut digestion. This highlights an important finding that phenolic content analysis of pulse foods underestimates the level of bioaccessible/bioavailable pulse phenolics following consumption and digestion of pulse foods.
3) After in vitro lower gut fermentation (Robogut model), canned red lentil digesta altered human microbial community structure more so than cooked red lentil digesta, potentially due to the increased levels of starch and fiber in the canned red lentil digesta compared to the cooked red lentil digesta.
4) In vivo, following 3 weeks of dietary intervention in mice, navy bean, chickpea, and lentils beneficially enhance gut health through modulation of the colonic microenvironment including the microbiota community structure and its activity (increased SCFAs), as well as enhancing the integrity of the colonic mucosal barrier. Using a mouse model of human IBD, mice fed navy beans, chickpeas, or lentils demonstrate beneficial effects in reducing the severity of colonic inflammation (colitis).
Project lead: Dr. Krista Power (216) 217-8132 firstname.lastname@example.org