(P15-033-24) Phaseolus vulgaris Extract Combined With a Low-Calorie Diet Positively Modulates Gut Microbial Ecosystem in Subjects With Severe Obesity: A Randomized Controlled Trial

Objectives: The present study aims to investigate the effects of an extract of Phaseolus Vulgaris (EPV) combined with a balanced low-calorie diet on the gut microbial ecosystem, biomarkers of inflammation and intestinal permeability in subjects with severe obesity eligible for a functional metabolic rehabilitation program.

Methods: A double-blind randomized controlled trial was conducted on 28 subjects enrolled at the Istituto Auxologico Italiano, with a BMI ≥ 35 kg/m2 and HOMA index >2.5. Volunteers were divided into two arms: one group received EPV (200 mg/day) for 4 weeks, while the control group was administered an identical placebo. Blood samples were collected at baseline and after 4 weeks. Fecal samples were also collected for gut microbiota and metabolite analysis. The composition of the gut microbiota was evaluated through metataxonomic profiling via sequencing of the 16S rRNA gene. Quantification of fecal short-chain fatty acids (SCFA) was conducted using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Serum levels of adiponectin and zonulin were measured using ELISA kits.

Results: Analysis of microbiota composition revealed a modulation in two alpha-diversity indices associated with richness measurement: "Faith's Phylogenetic Diversity" (p < 0.05) and the "observed features" index (with a trend towards significance, p=0.09). The augmentation in these indices was absent in the placebo group. Additionally, in the EPV group, an increase in fecal SCFA was observed (p < 0.05). Specifically, acetate, valerate, and butyrate were the three fatty acids modulated after the intervention. No significant differences were observed in serum adiponectin and zonulin between the two groups.

Conclusions: The use of EPV combined with a balanced low-calorie diet may positively influence the bacterial taxonomic diversity of the gut microbiota and SCFA production. These findings suggest a new potential approach for managing obesity through gut microbiota modulation.

Funding Sources: This research was funded within the project MIND FoodS Hub: Innovative concept for the eco-intensification of agricultural production and the promotion of dietary patterns for human health and longevity through the creation in MIND of a digital Food System Hub (P.O.R. 2014–2020_BANDO Call HUB Ricerca e Innovazione).