A systematic review of the effect of dietary pulses on microbial populations inhabiting the human gut

Abstract

Pulses are dry leguminous crops consisting of beans, lentils, chickpeas, and peas. They are a broad category of food that are often aggregated when their contribution to healthy dietary patterns are disseminated. However, the different genera and varieties of pulses vary in composition and are consumed in different amounts, largely dictated by geographic region and ethnicity. Given the number of pulse-derived components, including fibre, that have the capacity to alter the composition of the gut microbiome, the objective of this study was to systematically review dietary pulses and pulse-derived ingredients as a broader food group, to determine their effect on gut microbiota in humans. Major scientific databases were used to conduct the search, which spanned from 1990 until February 2019. The search strategy identified 2,444 articles and five studies were included in this analysis. Two studies used whole pulses (chickpeas and pinto beans), one study used cooked navy bean powder, and the two remaining studies used pulse-derived fibre (lupin or yellow pea hulls). Although inconsistent, some studies demonstrated that whole pulses (pinto beans and chickpeas), cooked navy bean powder, and pulse-derived fibre (lupin kernel fibre), did impose changes to the microbiota that inhabit the human large intestine. However, there was considerable variability concerning the methodologies and endpoints used to decipher the observed effects on the abundance, diversity, and/or richness of specific microbiota or the microbiome. More extensive human studies that directly link the effects of specific types of pulses on the gastrointestinal microbial environment to health outcomes in the host are required.

Prebiotic mechanisms of resistant starches from dietary beans and pulses on gut microbiome and metabolic health in a humanized murine model of aging

“…Then, mice were subjected to our previously validated gut depletion and cleansing procedure to eradicate the gut microbiota (12,19). Briefly, the gut-cleansing procedure included a 4-day microbial-depletion treatment with a broad-spectrum antibiotic cocktail [containing ampicillin (1 g), Metronidazole (7)(8)(9)(10)(11) (1 g), S2). We have previously shown that these four pulses, out of 18 different pulses, retain a considerable proportion of RS pre-and post-cooking and lead to the production of short-chain fatty acids (SCFAs) production by human gut microbiota in-vitro (11,22).…”

The role of pulses in improving human health: A review

“…These SCFAs are associated with abundant benefits, including reduced chronic disease risk, strengthened gut barrier function, and improved glucose homeostasis (Chambers et al, 2018;Myhrstad et al, 2020). Although clinical studies are still limited, pulses have been linked to promoting gut health in humans (Fernando et al, 2010;Marinangeli et al, 2020). • No association between overall breast cancer risk and bean/legume intake in postmenopausal women participating in the original Nurses' Health Study (Fung et al, 2005) • Bean intake can decrease breast cancer risk (Thompson et al, 2008;Thompson et al, 2009;Zhu et al, 2012) • Beans in the diet reduced cancer incidence from 95% to 67%, and the number of tumors per animal from 3.23 to 1.46, versus the control (Thompson et al, 2009) Colorectal • **However, there was no further effect of beans on recurrence of nonadvanced adenomas in the Polyp Prevention Trial (Lanza et al, 2006) • Compared to control-fed animals, the investigators reported lower incidence of colon lesions in mice fed whole bean, bean residue, and bean extract (Bobe et al, 2008) • The incidence of tumors in rats with chemically-induced colon cancer was reduced in animals fed bean-based diets compared to control animals (Bennink, 2002;Rondini & Bennink, 2012) Prostate • 10% reduction in risk of prostate cancer in men consuming the highest amount of legumes (excluding soybeans and soybean products) compared with the lowest consumers (Park et al, 2008) • High legume intake correlates with lower prostate cancer incidence, and the dose-response meta-analysis indicated that for each 20 g/day increase in legume intake there was a reduction in the risk of prostate cancer by 3.7% (Li & Mao, 2017).…”

“…These SCFAs are associated with abundant benefits, including reduced chronic disease risk, strengthened gut barrier function, and improved glucose homeostasis (Chambers et al, 2018; Myhrstad et al, 2020). Although clinical studies are still limited, pulses have been linked to promoting gut health in humans (Fernando et al, 2010; Marinangeli et al, 2020). For example, one study ( n = 82) investigated the intricate relationship between sex, BMI, and fiber on the gut microbiome composition (Dominianni et al, 2015).…”

Essential Factors for a Healthy Microbiome: A Scoping Review

“…The pulses are the edible seeds of the legume plant and include beans, lentils, and peas. A limited number of studies have looked at the effect of pulses on the microbiome, but those that do exist have found that whole pulses and pulse-derived flour have positive effects on diversity and richness [ 28 ]. Little is known about the components of each type of pulse and their prebiotics, fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) [ 126 ].…”