Compositional changes of the high-fat diet-induced gut microbiota upon consumption of common pulses

Authors: LUTSIV, TYMOFIY - Colorado State University; WEIR, TIFFANY - Colorado State University; MCGINLEY, JOHN - Colorado State University; NEIL, ELIZABETH - Colorado State University; WEI, YUREN - Colorado State University; THOMPSON, HENRY - Colorado State University

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2021
Publication Date: 11/9/2021
Citation: Lutsiv, T., Weir, T.L., Mcginley, J.N., Neil, E.S., Wei, Y., Thompson, H.J. 2021. Compositional changes of the high-fat diet-induced gut microbiota upon consumption of common pulses. Nutrients. 13. Article 3992. https://doi.org/10.3390/nu13113992.
DOI: https://doi.org/10.3390/nu13113992

Interpretive Summary: Our gut is populated by bacteria, known collectively as the gut microbiome, which includes health-beneficial bacteria that contribute to our body’s metabolism, our weight status, and that protect against disease organisms. Dietary fiber is a major contributor to the bacterial composition of our gut microbiome, but we don’t understand all the types of fiber that help promote beneficial bacteria in our gut. Because pulses are a source of dietary fiber, we conducted studies to determine how the consumption of different pulse grains modulated the gut microbiome, using a mouse model. Male mice were fed a high-fat diet formulation (to promote obesity), with or without one-third of the protein component comprised by one of four commonly consumed pulses: lentil, chickpea, dry bean, or dry pea. Mice consuming pulses had microbial communities that were quite different from animals on the pulse-free diet. Weight reduction also was seen in the pulse-fed mice, relative to those not consuming pulses. The bacterial changes in the gut microbiome of the pulse-fed mice were consistent with common bacteria that have been shown to protect against obesity. These studies help advance the concept that the positive health effects of pulse consumption may, in part, be mediated by the gut microbiota. These results will further facilitate the design of diet-based precision nutrition approaches to promote health and prevent disease in human populations.

Technical Abstract: The gut microbiome is involved in the host’s metabolism, development, and immunity, which translates to measurable impacts on disease risk and overall health. Emerging evidence supports pulses, i.e., grain legumes, as underutilized nutrient-dense, culinarily versatile, and sustainable staple foods that promote health benefits through modulating the gut microbiota. Herein, the effects of pulse consumption on microbial composition in the cecal content of mice were assessed. Male mice were fed an obesogenic diet formulation with or without 35% of the protein component comprised by each of four commonly consumed pulses—lentil (Lens culinaris L.), chickpea (Cicer arietinum L.), common bean (Phaseolus vulgaris L.), or dry pea (Pisum sativum L.). Mice consuming pulses had distinct microbial communities from animals on the pulse-free diet, as evidenced by ß-diversity ordinations. At the phylum level, animals consuming pulses showed an increase in Bacteroidetes and decreases in Proteobacteria and Firmicutes. Furthermore, a-diversity was significantly higher in pulse-fed animals. An ecosystem of the common bacteria that were enhanced, suppressed, or unaffected by most of the pulses was identified. These compositional changes are accompanied by shifts in predicted metagenome functions and are concurrent with previously reported anti-obesogenic physiologic outcomes, suggestive of microbiota-associated benefits of pulse consumption.