Research Article

A comparative study of the preventative effects exerted by two probiotics, Lactobacillus reuteri and Lactobacillus fermentum, in the trinitrobenzenesulfonic acid model of rat colitis

Laura Perana1, Saleta Sierraa2, Mònica Comaladaa1, Federico Lara-Villosladaa2, Elvira Bailóna1, Ana Nietoa3, Ángel Conchaa4, Mónica Olivaresa2, Antonio Zarzueloa1, Jordi Xausa2 and Julio Gálveza1 c1

a1 Department of Pharmacology, University of Granada, Campus Universitario ‘La Cartuja’ s/n, 18071 Granada, Spain

a2 Department of Immunology and Animal Sciences, Puleva Biotech SA, Granada, Spain

a3 Andalusian Stem Cell Bank, Health and Progress Foundation, Granada, Spain

a4 Department of Pathology, Hospital Universitario ‘Virgen de las Nieves’, Granada, Spain


The intestinal anti-inflammatory effects of two probiotics isolated from breast milk, Lactobacillus reuteri and L. fermentum, were evaluated and compared in the trinitrobenzenesulfonic acid (TNBS) model of rat colitis. Colitis was induced in rats by intracolonic administration of 10 mg TNBS dissolved in 50 % ethanol (0·25 ml). Either L. reuteri or L. fermentum was daily administered orally (5 × 108 colony-forming units suspended in 0·5 ml skimmed milk) to each group of rats (n 10) for 3 weeks, starting 2 weeks before colitis induction. Colonic damage was evaluated histologically and biochemically, and the colonic luminal contents were used for bacterial studies and for SCFA production. Both probiotics showed intestinal anti-inflammatory effects in this model of experimental colitis, as evidenced histologically and by a significant reduction of colonic myeloperoxidase activity (P < 0·05). L. fermentum significantly counteracted the colonic glutathione depletion induced by the inflammatory process. In addition, both probiotics lowered colonic TNFα levels (P < 0·01) and inducible NO synthase expression when compared with non-treated rats; however, the decrease in colonic cyclo-oxygenase-2 expression was only achieved with L. fermentum administration. Finally, the two probiotics induced the growth of Lactobacilli species in comparison with control colitic rats, but the production of SCFA in colonic contents was only increased when L. fermentum was given. In conclusion, L. fermentum can exert beneficial immunomodulatory properties in inflammatory bowel disease, being more effective than L. reuteri, a probiotic with reputed efficacy in promoting beneficial effects on human health.

(Received April 18 2006)

(Revised August 23 2006)

(Accepted September 19 2006)


c1 *Corresponding author: Dr Julio Galvez, fax +34 958248964, email


Abbreviations: COX-2, cyclo-oxygenase-2; IBD, inflammatory bowel disease; iNOS, inducible NO synthase; LTB4, leukotriene B4; MPO, myeloperoxidase; TNBS, trinitrobenzenesulfonic acid