ADMINISTRATION OF THREE PROBIOTIC STRAINS MODIFIES THE INTESTINAL MICROBIOTA IN AN OBESITY RAT MODEL

Background and objectives: Intestinal microbiota (IM) plays a central role in the host's health and, consequently, control of the IM is a priority to prevent a plethora of health issues. Probiotics are used in the treatment of diverse pathologies. However, evidences of their capacity to influence the IM is scarce. The aim of this work was to investigate the effects of Lactobacillus paracasei CNCM I-4034, Lactobacillus rhamnosus CNCM I-4036 and Bifidobacterium breve CNCM I-4035 on the IM of genetically obese rats. Methods: Forty-eight obese Zucker-Leprfa/fa rats and 16 Zucker-lean+/fa rats were used. Eight obese and 8 lean rats were sacrificed as baseline. The remaining 40 obese rats were randomly assigned to receive one of the 3 probiotic strains, a mixture of L. paracasei and B. breve, or a placebo by oral administration each day for 30 days. An additional group of 8 lean rats received placebo for 30 days. Fecal samples were taken to perform fluorescence in situ hybridization (FISH) and 16S rRNA gene pyrosequencing. Results: FISH analysis showed significant increases in the Bacteroides genus in the rats treated with the mixture of B. breve and L. rhamnosus, and the Atopobium cluster in the B. breve group. Pyrosequencing analysis showed: 1) an increase in the Marinilabiaceae and Streptococcaceae families in the rats fed the mixture; 2) a decrease in the Lactobacillales order in the B. breve group; 3) a decrease in the Anaerostipes genus in the L. paracasei group; 4) a decrease in the Parabacteroides genus in the L. rhamnosus group. An increase in the relative abundance of the Parabacteroides and Lactobacillus genera together with a decrease in the Prevotella and Lactococcus genera were found in the obese rats fed the placebo. Conclusions: These probiotic strains are capable of modifying the IM of genetically obese rats.