Bifidobacterium CECT 7765 improves metabolic and immunological dysfunction associated with obesity in high-fat diet fed mice

GAUFFIN CANO, PAOLA; SANTACRUZ, ARLETTE; TREJO, FERNANDO; SANZ, YOLANDA

OBESITY

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2011

1930-7381

Objective: To evaluate the effects of oral administration of Bifidobacterium pseudocatenulatum CECT 7765 on metabolic and immune dysfunction in mice with high-fat diet (HFD) induced obesity. Design: Adult (age 6–8 week) male wild-type C57BL-6 mice were fed a standard diet (SD) or HFD, supplemented or not with B. pseudocatenulatum CECT 7765 for seven weeks  (n³ 6/group). The following parameters were assessed: animal weight, serum levels of cholesterol, triglyceride, glucose and leptin, liver steatosis, white adipose tissue weight and adipocyte size, lipid micelles per enterocyte, functions of immunocompetent cells (macrophages and dendritic cells [DCs]) and composition and pro-inflammatory properties of the faecal microbiota. Results: B. pseudocatenulatum CECT 7765 administration reduced serum cholesterol, triglyceride and glucose levels by 36, 25 and 35 %, respectively, in obese mice. This bacterial strain also induced an increase in serum leptin levels in SD-fed mice but a decrease in HFD-fed mice. The administration of B. pseudocatenulatum CECT7765 significantly reduced liver steatosis and the number of larger adipocytes (2000 to 4000 ìm2) in HFD-fed mice.  These effects were associated with reductions in the number of fat micelles in enterocytes, suggesting reductions in dietary fat absorption. The strain also increased the macrophage oxidative burst, the ability of macrophages and DCs to induce cytokines (TNF-a) in response to pathogenic bacteria (LPS), and the ability of DCs to present antigens and to boost T lymphocyte proliferation. The bacterial strain also restored the composition of the gut microbiota of HFD-fed mice, increasing Bifidobacterium numbers and reducing those of Enterobacteriaceae, which altogether led to reducing inflammatory signals coming from the gut.   Conclusion: B. pseudocatenulatum CECT7765 was shown to ameliorate alterations in both metabolic and immunological dysfunctions related to obesity, in mice with HFD-induced obesity.