Modulation of the murine microbiome with a concomitant anti-obesity effect by Lactobacillus rhamnosus GG and Lactobacillus sakei NR28.

摘要

The microbiota of the gastrointestinal tract (GIT) constitutes the major part of the total human microbiome, and is considered to be an important regulator of human health and host metabolism. Numerous investigations in recent years have focused on the connection between the human microbiota and metabolic diseases, such as obesity, type II diabetes and atherosclerosis. Yet, little is known about the impact of probiotic consumption on the GIT microbial population and the potential effect on chronic diseases. In this study, modulation of the microbial community in the murine small intestine (C57BL/6J mice) as a result of probiotic feeding was investigated. Changes in the microbiota of the mouse faeces and small intestine were monitored using quantitative real-time PCR and by following the mRNA expression levels of various obesity-related biomarkers following probiotic feeding. Lactobacillus rhamnosus GG and L. sakei NR28 (a putative probiotic strain isolated from kimchi) were administered at a daily level of approx. 1 x 108 viable bacteria per mouse for up to 3 wk. Results showed probiotic feeding to be associated with an anti-obesity effect. Feeding these strains resulted in a significant reduction in epididymal fat mass, as well as obesity-related biomarkers, like acetyl-CoA carboxylase, fatty acid synthase and stearoyl-CoA desaturase-1, in the liver. The total number and ratio of the microbial groups, i.e. Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp., were modulated in the small intestine, and the Firmicutes:Bacteroidetes ratio was decreased. In contrast, no noticeable effect of probiotic feeding could be detected on the faecal microbiota, neither quantitatively nor with regard to the aforementioned bacterial groups.