Cheese consumption prevents fat accumulation in the liver and improves serum lipid parameters in rats fed a high-fat diet

International audienceAbstractCheese consumption has been reported to reduce the risk of metabolic syndrome; however, the mechanisms by which cheese prevents these disorders are not fully understood. The purpose of this study was to examine the effects of cheese consumption on lipid accumulation in the liver as well as to evaluate various serum lipid parameters. Two groups (n = 7) of male Fischer-344 rats were fed the following high-fat diets for 9 weeks: AIN76-modified 20% fat diet containing casein and butter oil (control diet) or the 20% fat diet containing a freeze-dried cheese powder (cheese diet). Blood samples, liver tissue, and fecal specimens were collected and analyzed. Cheese consumption for 9 weeks reduced the accumulation of triglyceride and cholesterol in the liver (P = 0.016 and P < 0.001, respectively), as well as the serum non-high-density lipoprotein (non-HDL) cholesterol concentration (P = 0.013). In contrast, cheese consumption increased the serum HDL concentration with statistical tendency (P = 0.086). We also observed an increase in the serum adiponectin concentration at week 9 in rats fed the cheese diet (P = 0.029). Furthermore, cheese consumption also increased fat excretion in the feces (P < 0.001). Taken together, our results suggest that cheese mediates various beneficial effects for preventing the development of metabolic syndrome by suppressing the accumulation of fat in the liver

Lactobacillus gasseri SBT2055 induces TGF-β expression in dendritic cells and activates TLR2 signal to produce IgA in the small intestine.

Probiotic bacteria provide benefits in enhancing host immune responses and protecting against infection. Induction of IgA production by oral administration of probiotic bacteria in the intestine has been considered to be one reason for this beneficial effect, but the mechanisms of the effect are poorly understood. Lactobacillus gasseri SBT2055 (LG2055) is a probiotic bacterium with properties such as bile tolerance, ability to improve the intestinal environment, and it has preventive effects related to abdominal adiposity. In this study, we have found that oral administration of LG2055 induced IgA production and increased the rate of IgA(+) cell population in Peyer's patch and in the lamina propria of the mouse small intestine. The LG2055 markedly increased the amount of IgA in a co-culture of B cells and bone marrow derived dendritic cells (BMDC), and TLR2 signal is critical for it. In addition, it is demonstrated that LG2055 stimulates BMDC to promote the production of TGF-β, BAFF, IL-6, and IL-10, all critical for IgA production from B cells. Combined stimulation of B cells with BAFF and LG2055 enhanced the induction of IgA production. Further, TGF-β signal was shown to be critical for LG2055-induced IgA production in the B cell and BMDC co-culture system, but TGF-β did not induce IgA production in a culture of only B cells stimulated with LG2055. Furthermore, TGF-β was critical for the production of BAFF, IL-6, IL-10, and TGF-β itself from LG2055-stimulated BMDC. These results demonstrate that TGF-β was produced by BMDC stimulated with LG2055 and it has an autocrine/paracrine function essential for BMDC to induce the production of BAFF, IL-6, and IL-10