Effects of Orally-Administered Bifidobacterium animalis subsp. lactis Strain BB12 on Dextran Sodium Sulfate-Induced Colitis in Mice

Inflammatory bowel disease, including Crohn's disease and ulcerative colitis (UC), is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Intestinal epithelial cells (IECs) constitute barrier surfaces and play a critical role in maintaining gut health. Dysregulated immune responses and destruction of IECs disrupt intestinal balance. Dextran sodium sulfate (DSS) is the most widely used chemical for inducing colitis in animals, and its treatment induces colonic inflammation, acute diarrhea, and shortening of the intestine, with clinical and histological similarity to human UC. Current treatments for this inflammatory disorder have poor tolerability and insufficient therapeutic efficacy, and thus, alternative therapeutic approaches are required. Recently, dietary supplements with probiotics have emerged as promising interventions by alleviating disturbances in the indigenous microflora in UC. Thus, we hypothesized that the probiotic subsp. strain BB12 could protect against the development of colitis in a DSS-induced mouse model of UC. In the present study, oral administration of BB12 markedly ameliorated DSS-induced colitis, accompanied by reduced tumor necrosis factor-α-mediated IEC apoptosis. These findings indicate that the probiotic strain BB12 can alleviate DSS-induced colitis and suggest a novel mechanism of communication between probiotic microorganisms and intestinal epithelia, which increases intestinal cell survival by modulating pro-apoptotic cytokine expression.