The Effect of Concord Grape Polyphenol-soy Protein Isolate Complex (GP-SPI) on Gut Microbiota

The proposed study will investigate how short-term supplementation with GP-SPI may modify the gut microbial community in healthy participants while monitoring liver and kidney function/health.

Significance:

Biochemical properties of the GP-SPI food ingredient are well-documented and GP-SPI and SPI supplements have been tested extensively in mice. The proposed study is a logical follow up to animal studies, which showed that compared to control mice fed a high-fat diet (HFD) supplemented with SPI alone, mice fed an isocaloric HFD supplemented with GP-SPI exhibited greater resistance to weight gain, adiposity, and glucose intolerance. These effects were accompanied by changes in murine gut microbiota composition, including increased abundance of the microbe Akkermansia muciniphila, associated with metabolic resilience. Similar gut microbiota changes were observed in lean mice fed low-fat diet (LFD) supplemented with GP-SPI.

The B-type proanthocyanidin (PAC) class of polyphenols contained in grape berries, especially skins and seeds, have been associated with health benefits; however, PACs are poorly absorbed and reach high concentration only in the colon raising questions about mechanism(s) of action. Prior studies showed that dietary PACs from grape and cranberry alter the gut microbiota in association with metabolic resilience. PACs are also biotransformed by gut bacteria to yield microbial metabolites (MMs) that may contribute to health benefits.

Research Design and Methods