Improvement of Gut Barrier Function by Potato Anthocyanins Is Dependent on Gut Microbiota

Abstract

Abstract Objectives Ulcerative colitis (UC) is characterized by chronic colonic inflammation, impaired barrier function and gut bacterial dysbiosis. Anthocyanin-containing potatoes have been shown to maintain the intestinal barrier function in colitic mice. However, the role of gut microbiota in the anti-colitic effects of anthocyanin-containing potatoes is not clear. This study evaluated the gut barrier protective efficacy of purple- and red-fleshed potatoes using a DSS-induced murine model of colitis with the intact and antibiotic-depleted microbiota. Methods Four-week-old mice (C57BL6) were randomized into four groups, receiving a standard control diet, or a 20% purple-/red-fleshed potato (PP/RP) supplemented diet. A broad-spectrum antibiotic cocktail was used to deplete the gut bacteria. After eight weeks, mice were treated with 2% DSS in their drinking water for five days to induce colitis. The polyphenol composition of potatoes was analyzed by LC-MS/MS. Intestinal permeability was measured using FITC-dextran. Colonic myeloperoxidase (MPO) activities were determined using the o-dianisidine dihydrochloride method. The fecal short-chain fatty acids (SCFA) content of mice was measured by GC-FID. RT-PCR was used to analyze the relative gene expression levels of cytokines and bacterial abundance. Results The predominant anthocyanin detected in RP was pelargonidin (93.13%). Whereas petunidin (75.57%) and malvidin (21.05%) were the two major anthocyanins present in PP. Administration of antibiotics resulted in a reduction in fecal SCFA. Antibiotic-treated mice were more prone to the DSS-induced increase in gut permeability. Anthocyanin-containing potato diets alleviated DSS-induced colonic damage, elevation in histology score and gut permeability only in non-antibiotic mice. RP alone suppressed the elevated colonic MPO activity and the gene expression levels of MUC2 in mice with intact gut microbiota. Conclusions In summary, anthocyanin-containing potatoes alleviated colitis-associated colonic epithelial damage and increased gut permeability in intact microbiota mice but not in microbiota-ablated mice. This suggests that the gut microbiome is essential for the gut barrier protective activity of anthocyanin-containing potatoes. Funding Sources USDA-NIFA awards 2016–67,017-29,285 and 2019–67,017-29,258.