Spilling the beans on gut health

Lentils, chickpeas, beans and peas, collectively known as pulses, may improve overall gut health and help safeguard against gut-associated diseases when consumed regularly.

Inflammatory bowel disease (IBD), colon cancer and obesity are diseases associated with reduced gut health and increased inflammation, and "pulses are rich in components that might help reduce the development of those diseases," says Dr. Krista Power, research scientist at Agriculture and Agri-Food Canada's (AAFC) Guelph Research and Development Centre in Ontario. Consumption of beans can affect multiple aspects of gut health, including the integrity of the gut barrier (the mucus-covered lining of the large intestine), as well as the activity and community structure of the gut microbiota (bacteria). 

"If you strengthen the gut barrier and enhance the activity and diversity of the microbiota, it can impact the development of many gut-associated diseases," she notes.

"(Pulses) are rich in non-digestible carbohydrates that can reach the colon. Therefore, they can have direct effects on the colonic environment, which includes microbiota."

- Dr. Krista Power, Research Scientist, Agriculture and Agri-Food Canada (AAFC)

Dr. Power, in collaboration with AAFC scientists Dr. Susan Tosh and Dr. Rong Cao, and University of Guelph's Dr. Lindsay Robinson and Dr. Emma Allen-Vercoe are currently studying the link between different pulse foods and gut health in a project jointly funded by AAFC and Pulse Canada.

"Pulses are rich in non-digestible carbohydrates (fibre) that can reach the colon," she says. Most nutritional compounds in foods are absorbed in the upper gut, or small intestine, and therefore not available for utilization in the colon. The rich fibre content of pulses "can have direct effects on the colonic environment, which includes the gut barrier and the microbiota," notes Dr. Power. Gut microbiota are a community of bacteria that coexist in the digestive tract and play an important role in regulating gut health and disease.

The gut microbiota ferments the undigested fibre, producing short-chain fatty acids, including butyrate, which can enhance the integrity of the gut barrier (increase mucus production, reduce permeability) and reduce inflammation. Dr. Power's team has demonstrated that pulse consumption increases short-chain fatty acid levels, alters the structure of the microbiota community and can decrease the severity of colonic inflammation. Furthermore, they have demonstrated that this is in part due to a pulse-induced increase in gut-barrier integrity, including increased mucus production and reduced gut permeability. Impairments to the gut barrier, including permeability and insufficient mucus production, are associated with inflammatory bowel disease.

The team is using an in vitro "Roboguts" model of the human colon to determine how pulses impact the gut microbiota community, as well as "in vivo preclinical studies using mice fed pulse-supplemented diets to determine how pulses impact gut health and disease," she notes.

While the team determines the link between different pulse types (that is, white versus dark beans) and gut health, and their ability to reduce diseases associated with the gut barrier, Dr. Power notes that all pulses are relatively alike in terms of their beneficial effects on gut health. "We are not seeing significant differences, so far, between pulse types," she notes, therefore, "incorporating any pulse into your diet could improve gut health."

The Guelph Research and Development Centre is part of AAFC's network of 20 centres across the country. The Centre is committed to specialized research in the areas of food safety, quality and nutrition to ensure Canadian-produced food is the safest and highest quality in the world.

Key discoveries (benefits)

• Pulses, which include lentils, beans, chickpeas and peas, can improve gut health by strengthening the gut barrier and reducing risk of gut-associated diseases, such as inflammatory bowel disease (IBD).
• Pulses, which are rich in non-digestible fibre, alter the colonic microbiota community structure and activity, resulting in increased short-chain fatty acid production, which promotes gut mucus secretion and reduces gut permeability.
• Pulse food consumption can decrease the severity of colonic inflammation in animal models.

Photo gallery

Related information

• Dr. Krista Power
• Guelph Research and Development Centre
• Eat Your Pulses (video)
• Pulse Canada