The effect of new probiotic strain Lactobacillus plantarum on counts of coliforms, lactobacilli and bacterial enzyme activities in rats exposed to N,N-dimethylhydrazine (chemical carcinogen)

Abstract

The aim of the present study was to evaluate the effect of the new probiotic strainLactobacillus plantarumon chemically induced carcinogenesis in rats.Sprague dowleyrats (n = 33) were divided into control and experimental groups and were fed a conventional laboratory diet. In the experimental group, rats were treated with the probiotic at the dose of 1 × 109CFU (colony-forming units)/ml. Two weeks after the beginning of the trial, N,N-dimethylhydrazine (chemical carcinogen) injections were applied s.c. at the dose of 21 mg/kg b.w., 5 × weekly. At the end of the 8-month experimental period, faeces samples were taken from the rats and used for laboratory analysis. The counts of lactobacilli and coliforms and bacterial enzyme activity were determined. The probiotic strainL. plantarumas single species or in combination with oil(Lini oleum virginale)decreased the count of total coliforms and increased lactobacilli in faeces of rats. Application of probiotic microorganisms significantly (P< 0.05) decreased the activities of bacterial enzymes (β-galactosidase and β-glucuronidase) compared to the control group rats. The results of this study indicate that probiotic microorganisms could exert a preventive effect on colon carcinogenesis induced by N,N-dimethylhydrazine.