In vitro digestion of the whole blackberry fruit: bioaccessibility, bioactive variation of active ingredients and impacts on human gut microbiota

In vitro digestion and fermentation of blackberry fruit was investigated, and results showed that the phenolics were mainly released in gastric phase while carbohydrates in small intestinal phase. The bioaccessibility for phenolics and carbohydrates were 42.80% and 69.30%, indicating most of phenolics still remain in colon and available for intestinal flora. The total phenolics released during the digestion account for the improvement of antioxidant and hypoglycemic activities. Especially, cyanidin-3-O-glucoside with higher released amount and bioaccessibility index (63.21%), exhibited the strongest alpha-glucosidase inhibitory activity. After fermentation, the non-digestible fractions of blackberry affected the ecosystem of the intestinal tract by decreasing the colonic pH (opH = 1.10), enhancing the production of SCFAs and modulating gut microbiota composition (the ratio of Firmicute/Bacteroidetes decreased from13.18 to 0.87). The results provided insights into the digestive properties and health benefits of blackberry fruit after consumption.

Automated summary

The study investigated the in vitro digestion and fermentation of blackberry fruit, revealing that phenolics were mainly released in the gastric phase while carbohydrates were mainly released in the small intestinal phase. The bioaccessibility of phenolics and carbohydrates were found to be 42.80% and 69.30% respectively, contributing to antioxidant and hypoglycemic activities. Additionally, the non-digestible fractions of blackberry affected the intestinal tract ecosystem by modulating gut microbiota composition and enhancing the production of short-chain fatty acids.