Immunomodulatory effects of Bifidobacterium bifidum 231 on trinitrobenzenesulfonic acid-induced ulcerative colitis in rats.

AIM: Ulcerative colitis and Crohn's disease are two important chronic Inflammatory bowel diseases (IBD) characterized by prominent intestinal inflammation. Probiotics are the bacteria that promote the host health by its immunomodulatory activity. The present study investigated the correlation between in vitro adhesion and immunomodulatory properties, and to assess the therapeutic potential of Bifidobacterium bifidum 231 (BIF 231), a new strain of probiotic in ulcerative colitis in rats.

METHODS: In vitro adhesion assays and immunomodulatory effect of BIF 231 on interleukins (IL-1β and IL-10) in IEC-6 cell lines were quantified by gram staining, scanning electron microscopy and q-PCR respectively. Colitis was induced by intra-rectal instillation of trinitrobenzenesulfonic acid. Colitis was evaluated by alterations in colon gross morphology, histologically and biochemically. Colonic interleukin-1β (IL-1β) and interleukin-10 (IL-10) mRNA and protein expression were assessed by q-PCR, ELISA and western blot.

RESULTS: BIF 231 showed better adhesion and immunomodulation by up-regulating IL-10 levels in IEC-6 cell lines. In vivo studies with treatment of BIF 231 (1.4×1011 CFU/rat/day) revealed anti-inflammatory effects both macroscopically and histologically. BIF 231 lowered TBARS, nitric oxide and augmented GSH levels. BIF 231 treatment to colitic rats down regulated IL-1β levels with concurrent increase in IL-10 levels.

CONCLUSIONS: BIF 231 exerted beneficial in vitro adhesion and immunomodulatory properties which facilitated the recovery of the damaged tissue in TNBS-induced colitis.