Genetic analysis of seed traits in Sorghum bicolor that affect the human gut microbiome

Prebiotic fibers, polyphenols and other molecular components of food crops significantly affect the composition and function of the human gut microbiome and human health. The abundance of these, frequently uncharacterized, microbiome-active components vary within individual crop species. Here, we employ high throughput in vitro fermentations of pre-digested grain using a human microbiome to identify segregating genetic loci in a food crop, sorghum, that alter the composition and function of human gut microbes. Evaluating grain produced by 294 sorghum recombinant inbreds identifies 10 loci in the sorghum genome associated with variation in the abundance of microbial taxa and/or microbial metabolites. Two loci co-localize with sorghum genes regulating the biosynthesis of condensed tannins. We validate that condensed tannins stimulate the growth of microbes associated with these two loci. Our work illustrates the potential for genetic analysis to systematically discover and characterize molecular components of food crops that influence the human gut microbiome.

Automated summary

Prebiotic fibers, polyphenols, and other molecular components in food crops have significant effects on the composition and function of the human gut microbiome. Using in vitro fermentation techniques, researchers identified genetic loci in sorghum that influence the gut microbes. These loci were found to be associated with microbial taxa and metabolite abundance, some of which were regulated by sorghum genes involved in condensed tannin biosynthesis. The study highlights the potential of genetic analysis in discovering and characterizing molecular components in food crops that impact the human gut microbiome.