Pomegranate peel polyphenols interaction with intestinal flora and its metabolic transformation

1. Pomegranate peel polyphenols (PPPs) have anti-oxidation, anti-atherosclerosis, anti-obesity effects, and so on. However, few studies have been conducted on the absorption and transformation of pomegranate polyphenols in the gut and the biologically active forms that ultimately work in the body.2. In this study, PPPs (300 mg/kg/day) was given to normal rats and relatively sterile rats by gavage respectively. The relatively sterile rats were obtained by neomycin sulphate (250 mg/kg/day) gavage to rats. The purpose of this study is to elaborate on the relationship between intestinal flora and polyphenol metabolism of pomegranate peel and to quantitatively analyse the transformation process of its metabolite urolithin in rats.3. The results showed that decreased bacterial diversity could significantly reduce the abundance of PPPs metabolites in faeces and urine in relatively sterile rats. PPPs can regulate intestinal flora structure, significantly enhance the content of Clostrida Firmicutes (P < 0.05), and effectively promote acetic acid, propionic acid, butyric acid, iso-butyric acid and valeric acid production in the rat (P < 0.05 or P < 0.01 or P < 0.001). PPPs can significantly elevate the relative proportion of Ruminococcaceae (P < 0.05). Ruminococcaceae_NK4A214_group, Ruminococcaceae_UCG-014 and Ruminococcaceae_UCG-005 can promote the metabolic transformation of PPPs and make the utilisation of Urolithin A more effective.