Pinto Bean Supplementation Modulates Gut Microbiota and Improves Markers of Gut Integrity in a Mouse Model of...

Emerging research suggests that changes in gut microbiota play a key role in menopause-related diseases by modulating gut health.

This study investigated the effects of pinto bean (PB) supplementation on gut integrity in an estrogen-deficient mouse model.

Sixty 3-mo-old female C57BL/6J mice were injected with either sesame oil (vehicle) or vinylcyclohexene diepoxide (VCD, 160 mg/kg) for 30 d to induce estrogen deficiency. Mice were then randomly assigned to 2 dietary groups (n = 15/group): control (AIN-93M) or AIN-93M + 10% (wt/wt) PB for 16 wk. Ovarian failure was confirmed by uterine weight and serum follicle-stimulating hormone (FSH). Gut health was assessed by measuring tight junction proteins, β-glucuronidase activity, short-chain fatty acids (SCFAs), and 16S microbiota composition. PB was evaluated for its estrogenic effects by molecular docking analysis of the identified polyphenols against estrogen receptor (ER)-α and ER-β. Data were analyzed by 2-way analysis of variance, with estrogen status (VCD) and diet as factors followed by post hoc tests when significant (P < 0.05) interaction effect was observed.

VCD significantly (P_VCD < 0.05) reduced relative uterine weight (∼35%) and increased serum FSH (∼60%), confirming estrogen reduction. PB restored jejunal Cldn1 (P_{diet × VCD} < 0.05) in VCD-treated mice and significantly increased (P_diet=0.010) β-glucuronidase activity (∼25%). PB enriched some beneficial bacteria genera (i.e., Bifidobacterium, Bacteroides, Dubosiella, and Lactobacillus) and increased fecal acetic, propionic, n-butyric, and total SCFAs by 2-fold compared with those on the control diet. Molecular docking analysis identified sinapic and ferulic acid as phytoestrogens in PB with high binding affinity for ERs.

PB supplementation improves gut microbial diversity and integrity in estrogen deficiency, offering potential benefits for menopause-related gut health.