Prebiotic Effect of Polysaccharides and Flavonoids from Passiflora foetida Fruits on the Human Intestinal Microbiota Associated with Obesity.

Passiflora foetida fruit is rich in beneficial polysaccharides and flavonoids. Recent studies have found that these polysaccharides and flavonoids may influence health through interaction with the gut microbiota, for example by modification of the microbial composition or by conversion of the polysaccharides and flavonoids to further bioactive compounds. In the current study, a three-stage dynamic simulator of the human gut microbiota, namely BFBL gut model, inoculated with either normal-weight or obese fecal bacteria, was tested with two aqueous-extracted fractions from P. foetida fruit, containing complex dietary P. foetida polysaccharides (PFP) and P. foetida flavonoids (PFF) mixtures, respectively. Within the context of the gut model, the effects of these interventions on targeted microbial composition as well as metabolite levels were assessed. The results showed that the consumption of PFP and PFF could modulate the microbiota associated to obesity, through regulating the abundance of several microbial groups (Alistipes, Bacteroides, Faecalibacterium and sulphate-reducing bacteria) and enriching the short-chain fatty acids (SCFAs) production, to the levels closer to those in the normal-weight microbiota. Furthermore, this study demonstrated that these complex polysaccharides and flavonoids in the context of an in vitro dynamic gut model showed prebiotic effects on the human intestinal microbiota by modulating some anti-obesity-related bacteria such as Akkermansia and Faecalibacterium as well as an increase of propionic acid production by the obese microbiota. These microbiota members represent novel targets of P. foetida fruit polysaccharides and flavonoids degrading or resistant microbes to be validated under physiological conditions in vivo and further investigated for P. foetida fruit beneficial effects.