Effects of Lactobacillus rhamnosus GG and Lactobacillus reuteri R2LC on acetic acid-induced colitis in rats

Background: Certain lactobacilli reduce the severity of experimental coliti s. The aim of this study was to compare the effects of a human strain Lacto bacillus rhamnosus GG and a rat strain Lactobacillus reuteri R2LC on acetic acid-induced colitis in rats. Methods: Lactobacillus rhamnosus GG, Lactoba cillus reuteri R2LC or sulphasalazine were given orally to the rats. Coliti s was assessed 72 h after induction with acetic acid. Results: Lactobacillu s reuteri R2LC significantly antagonized body weight loss caused by inflamm ation compared with Lactobacillus rhamnosus GG and sulphasalazine. and oede ma formation in the colon compared with sulphasalazine. Lactobacillus reute ri R2LC reduced the median value of macroscopic ulceration and the protein content of inducible nitric oxide synthase by 50% and the median of the pro tein content of inducible cyclooxygenase by 30% compared with that of the c olitis control group, and Lactobacillus rhamnosus GG reduced the median of inducible nitric oxide protein content by 40% and increased the median of i nducible cyclooxygenase protein content by 30% compared with the median val ue of the colitis control group, but these differences were nut statistical ly significant. Conclusions: The rat strain Lactobacillus reuteri R2LC, but not the human strain Lactobacillus rhamnosus GG, is of benefit in reducing the severity of acetic acid-induced colitis in rats. These results suggest that it is not the total amount of Lactobacillus but the particular specie s or strain of Lactobacillus that is important in attenuating experimental colitis.