Legume Consumption and Gut Microbiome in Elderly Chinese Men and Women.

backgroundLegumes, important components of a healthy diet, may exert their health benefits through the influence of the gut microbiome. However, this hypothesis has not been well investigated.

objectiveThis study aimed to examine the associations between long-term legume consumption and the gut microbiome among elderly Chinese.

methodsThe gut microbiome was profiled by 16S ribosomal RNA sequencing in 2302 Chinese adults enrolled in 2 large cohort studies, the Shanghai Women's Health Study and Shanghai Men's Health Study. Legume consumption, including peanuts, soy foods, and other beans, was assessed by food-frequency questionnaires prior to the stool collection. The associations of legume consumption with microbiome diversity and taxa abundance were evaluated by linear or negative binomial hurdle models, adjusting for sociodemographics, lifestyle factors, and BMI. False discovery rate (FDR)-corrected P values (PFDR) < 0.1 were considered significant.

resultsRespectively, 52% and 48% of study participants were male and female. The mean age at stool collection was 68.03 y for females and 70.28 y for males. Total legume consumption was not associated with gut microbiome ɑ-diversity; however, male peanut consumers had a higher Chao1 index (β = 22.52, P = 0.01), whereas peanut consumption was associated with decreased Shannon (β = -0.03, P = 0.02) and Simpson (β = -0.002, P = 0.04) indexes among females. In female and male combined analyses, total legume consumption was associated with increased Enterobacteriales (β = 0.30, PFDR = 0.06). Within this order, an unclassified genus in the family Enterobacteriaceae was positively associated with total legume (β = 0.46, PFDR = 0.03) and peanut (β = 0.59, PFDR = 0.01) consumption. Stratified analyses showed significant associations were primarily confined to females and participants without metabolic conditions.

conclusionsLegume consumption was associated with gut microbiome diversity and abundance of some bacteria in elderly Chinese. Associations were significant only among 1 sex group. Further research, including large-scale prospective studies and feeding trials, is needed to fully understand the role of the gut microbiome in legume-health associations.