Novel sorghum brans containing bioactive compounds alter the production of microbial secondary metabolites in response to a DSS‐induced chronic inflammatory state

Abstract

We have shown that black bran containing bioactives reduces colonic injury and NF‐κB activity with chronic inflammation, which may result from altered microbiota and short chain fatty acids (SCFA e.g., butyrate). Rats (n=80) were fed diets with 6% fiber from cellulose (C), or bran from black (B), sumac (S), or high tannin (HT) sorghum (anthocyanins, condensed tannins, or both, respectively). Ten rats in each diet received 3% dextran sulfate sodium (DSS) three times to stimulate inflammation. Feces were collected pre and post DSS to assess SCFA. On day 63, colon tissue was collected to determine injury and gene expression. After DSS, butyrate concentrations were higher (p<0.0001) with C and B (19.7 and 22.6) compared to S and HT (8.5 and 14.1). SCFA transporter (MCT1 and Slc5a8) expression was upregulated in C, S or HT DSS rats (avg 35, 48, and 12%) and downregulated in B DSS rats (avg 18%) compared to controls. In DSS rats, butyrate excretion, as a percent of total SCFA, was elevated with B (23%) compared to C, S or HT (19, 9, 15%). Thus, with chronic inflammation, there was an inverse relationship between the direction of transporter expression change and butyrate excretion. To determine the implications of the diet effects on butyrate and SCFA transporter levels in chronic inflammation, it will be necessary to evaluate proliferation and apoptosis. Funding: United Sorghum Checkoff Board Roo31A‐09.