Purple‐fleshed potatoes suppress colon‐systemic oxidative stress/inflammatory markers via alternations in the gut bacterial signature

Abstract

Purple‐fleshed potatoes (PP) are rich in putative anti‐oxidant/antiinflammatory anthocyanins. We hypothesized that PP, even after processing, suppress colon‐systemic oxidative stress/inflammatory markers by altering gut bacterial signature and metabolite profile. To test this hypothesis, 40 pigs on high‐fat diet (HFD) for 12 wk were provided with one of the five diets: HFD, white‐fleshed potato (WP) or PP chips at 10/20% for 5 wk. Serum, distal colon mucosa/digesta and fecal samples were utilized to analyze oxidative stress (MDA; colorimetric assay) and inflammatory (TNFα; ELISA and prostaglandins; LC‐MS/MS) markers, gut bacteria (pyrosequencing) and metabolites (LC‐MS). All diets, except WP (20%), suppressed (p = 0.04) systemic levels of TNFα compared to HFD. However, only PP suppressed MDA and colonic PGE2 levels (p ≤ 0.05). Potato diets increased members of Clostridia and Lachnospiraceae. Only PP increased distal colon bacteroidetes to firmicutes ratio (BFR) compared to HFD. This is particularly important as BFR is reduced during obesity. Indeed, MDA and TNFα elevated during obesity positively correlated with Firmicutes (0.518, p = 0.002; 0.380, p = 0.024, respectively) and MDA negatively correlated with BFR (−0.413, p = 0.036). Preliminary metabolomics data revealed 4350 metabolites in both distal colon and feces and the correlations with gut bacteria are being carried out.Grant Funding Source: National Research Initiative Grant 2009–55200‐05197 from the USDA National Institute for Food and Agriculture (2009–2012)