Prevention of TNBS-induced colitis by probiotic supplement in mice

Probiotics may protect against inflammatory bowel disease (IBD). The aim of this study was to investigate whether a commercial probiotic mixture prevented gut inflammatory disease. CD-1 mice received daily a probiotic mixture of Lactobacillus casei and Bifidobacterium lactis (Citogenex, Bromatech, Milano, Italy) for 1, 2 or 3 weeks by gavage. Colitis was induced by intrarectal administration of trinitrobenzene-sulfonic acid (TNBS) at the end of the treatment periods. Large bowelwasstained and assessed for histological alterations, according to a scoring system. Large bowel was also assessed for apoptosis by TUNEL assay. TNBS induced inflammation and severe damage in colon and rectum, including increased nuclearcytoplasmatic ratio, distortion of gland architecture, reduction of globet cells and apoptosis. Probiotic administration in advance protects from inflammation showing a significant reduction of histological alterations and exerting antiapoptotic effects in vivo. Therefore, the probiotic supplementation was able to prevent the TNBS-induced colitis, in particular when a treatment of 3 weeks was performed. The beneficial effects are probably due to the ability of probiotics of restoring intestinal immune system and microbiota balance. Further investigations are needed to confirm these results and to understand the mechanisms by which probioticsmayreduce the histological alterations in subjects with IBD.