Effect of daily intake of pomegranate juice on fecal microbiota and feces metabolites from healthy volunteers

Abstract

Scope: The purpose of the study was to evaluate the effect, regarding the metabolic and microbial profile of feces, of diet supplementation of healthy adults with pomegranate juice (PJ).

Methods and results: Twelve healthy adults were recruited to the study, which consisted of the intake of 200 mL/day of PJ during 4 weeks. Feces were collected before and after the supplementation with PJ. Metabolites (phenolic catabolites, short-chain fatty acids, and fecal steroids) and microbial profile were analyzed at baseline and at 4 weeks. Fecal phenolic metabolites, 3-phenylpropionic acid, catechol, hydroxytyrosol, and urolithin A, showed a significant increase in their concentration after supplementation with PJ. Among fecal steroids, parallel to the significant increase of cholesterol concentration, a significant decrease of coprostanol was observed. Although no significant changes in the microbiota profile were observed, different relationships between initial microbiota and the metabolites produced were found. Catechol showed positive and negative correlation with Oscillospora and Paraprevotella genera, respectively, and 3-phenylpropionic acid was positively correlated with Odoribacter genus.

Conclusion: Inclusion of PJ in the diet did not significantly alter the gut microbiota composition in healthy adults, but the individual bacterial composition could contribute to the generation of potential health-promoting phenolic metabolites.

Keywords: Fecal steroids; Microbiota; Phenolic compounds; Pomegranate; Short-chain fatty acids.