CONICET | Buscador de Institutos y Recursos Humanos

Obesity is a chronic disease, multifactorial, characterized by excessive accumulation of body fat, adipose tissue hypertrophy and alterations of the immune system. Dietary factors and intestinal bacteria play an important role in the increased incidence of obesity. The aim of this work was to evaluate the effect of a probiotic fermented milk (PFM) or the probiotic bacterium Lactobacillus casei CRL 431 in obese mice. Mice received conventional (G1) or high-fat (G2) diet and were given milk (A), PFM (B), the bacterial suspension (C) or water (D) during 3 months. The samples were taken each month. Body weight, clinical parameters (glucose, TG, LDL, HDL and total cholesterol) in serum, intestinal microbiota, the release of IFN-γ, IL-10 and IL-6 in intestinal fluid and the histological alterations in liver were evaluated. We observed decrease in body weights and in clinical parameters in G2B and G2C compared to G2A and G2D. IL-10 and IFN-γ were higher in G2D (1166±118) and (475±153) respectively than in G1D (824±54) and (363±23) respectively at the 1st month. After 3 months, IL-10 increased in G2B (1196±174) and G2C (1367±118) compared to G2D and IFN-γ increased in G2B (565±30) compared to the others groups. IL-6 increased in G2B after 2 months (575±0) and it was maintained similar to G2C in the 3rd month, being higher than the others groups (G2D:335±109 and G2A:231±188). These immune variations could be related with changes in the intestinal microbiota. Significant increases of Bifidobcterium and Bacteroides were observed in G2B compared to G2A, G2C and G2D after 3 months of obesity. G2B also decreased steatosis in the liver in relation the others groups. PFM administration avoided the clinical and immunological side effects induced by the high fat diet with increases of Bifidobacterium and Bacteroides. The histological recovery of the liver and stimulation the immune response at the intestinal levels was regulated by the increases of IL-10.