Effects of Combined Inulin and VSL#3 on Susceptibility to Dextran Sodium Sulfate‐Induced Colitis

Abstract

Inflammatory bowel disease (IBD) is a chronic intestinal disease that includes Crohn's disease and ulcerative colitis. Previous studies have found alterations in the microbiome in IBD and in animal models of IBD, underscoring the role of the intestinal microbiota in IBD pathogenesis. Prebiotics are molecules in foods that support the growth or activity of beneficial microbes. Inulin, a soluble fiber molecule, is a commonly available prebiotic, and previous studies suggest that it can reduce symptoms in dextran sodium sulfate (DSS)-induced colitis in mice. VSL#3 is a commercially available mixture of 8 probiotic species that has shown beneficial effects in models of intestinal inflammation. This study aimed to determine whether pretreatment with 1% inulin for 1 week, followed by 7 days of 3% DSS administration with inulin plus VSL#3 treatment, altered the severity of disease in C57Bl/6 mice. Clinical signs of colitis, including weight loss, fecal occult blood, and fecal consistency, were monitored daily during the DSS treatment period. At the end of the experiment, samples were collected for histological scoring, and for RNA isolation and analysis of colonic pro-inflammatory cytokine expression by RT-PCR. At the end of DSS treatment, the disease activity index was not different between control colitic mice or those treated with inulin and VSL#3. In addition, colon length and colon wet weight were similar in the two groups. Treatment with inulin+VSL#3 did not significantly alter expression of mRNA for COX-2, TGF-beta, or KC in the colon of mice with DSS colitis. In conclusion, a combination of inulin + VSL#3 treatment did not significantly alter susceptibility to DSS-induced colitis.