Near isogenic lines (NIL) of sorghum carrying wild type or waxy alleles of the granule-bound starch synthase (GBSS) gene have distinct effects on human gut microbiome phenotypes and host physiological characteristics

Abstract

Background:Waxy starches contain >90% amylopectin and are derived from grain crops carrying naturally-occurring mutations that block amylose biosynthesis. The absence of amylose in waxy starches produces unique physiochemical properties that are desirable for food processing, but the effects of increased amylopectin/amylose ratios in waxy starches on the gut microbiome and physiological characteristics of the host are not well characterized. Here, we used a whole-grain model with isogenic pairs of wild type sorghum lines and their waxy derivatives to test the hypothesis that major differences in amylose/amylopectin ratio produce significant effects on the human gut microbiome. Results:Fermentation of grain from waxy versus wild type derivatives produced substantial differences in overall microbiome composition, abundances of multiple taxa, and production of microbial metabolites (butyrate). Several of the taxonomic and metabolic signatures of fermentations from parental versus waxy lines were shared across fermentations with microbiomes from different human donors, including reduced levels of butyrate production and lower abundances of Roseburia and other amylolytic, butyrate-producing members of Lachnospiraceae in fermentations of waxy lines. Using a human microbiome-associated mouse model, we also detected significant differences in microbiome composition in animals fed low-fiber diets supplemented with 20% grain from isogenic pairs of parental versus waxy derivatives of sorghum. Remarkably, these microbiome changes were accompanied by significant differences in weight gain, with animals consuming waxy sorghum gaining significantly more weight. Conclusions:We conclude that the benefits of waxy starches on food functionality can have trade-off effects on the gut microbiome and host physiology that could be particularly relevant in human populations consuming large amounts of waxy grains.

The Unique Seed Protein Composition of Quality Protein Popcorn Promotes Growth of Beneficial Bacteria From the Human Gut Microbiome

“…To accurately measure the growth of Roseburia at a species level in response to lysine and FL, a previously reported qPCR protocol with primers for four species was employed ( Yang et al, 2022 ). In brief, species-specific primers were designed with the Rapid Identification of PCR Primers for Unique Core Sequences (RUCS) software ( Thomsen et al, 2017 ) and validated with Primer BLAST against the RefSeq representative genome database ( Ye et al, 2012 ).…”

Complex Trait Analysis of Human Gut Microbiome-Active Traits in Sorghum bicolor: a new category of human health traits in food crops

“…RILs were grouped by haplotype of markers linked to Tan1 and Tan2 and were randomly selected and pooled within each haplotype group (Tan1Tan2: 41 lines, Tan1tan2-c: 15 lines, tan1-bTan2: 15 lines, tan1-btan2-c: 15 lines) (supplementary Dataset S5). Selected RILS groups and NILs were digested and dialyzed following established procedures (73).…”