| Gut microbiota have tight relationship with the obesity of its host, obesity is associated with low-grade chronic inflammation, which can lead to hypertension, hyperlipidemia, cardiovascular disease. Pseudo germ-free mice as a useful animal model is suitable for studying the connection among gut microbiota, obesity and other related diseases. 20 C57BL/6J male mice, which were administered with antibiotic cocktails in drinking water to remove some of the gut microbiota, were established as the pseudo germ-free mice model. These mice were randomly divided into two groups: pgf CK and pgf HF group; respectively fed with normal diet and a high fat diet for 8 weeks. 20 C57BL/6J male mice as a control group; respectively fed with normal diet and a high fat diet for 8 weeks. Body weight, blood glucose, serum lipid levels and insulin concentration of the mice were measured by standard methods. Hematoxylin-Eosin staining was applied to fat pad tissue section. Areas of fat cells, long diameters and short diameters were calculated by image processing software of Image Pro-Plus 6.0.The results revealed that body weight, fat pad and perirenal fat weight of high fat diet administered pseudo germ-free mice group were significantly lower than high fat diet administered SPF mice group(P<0.001), and insulin level, areas of fat cell were also significantly lower than those of SPF mice(P<0.01). Pseudo germ-free mice of the high fat diet group show up low-bodyweight and low-fat phenotype, which were extremely similar to germ-free mice. In this study, we used pseudo germ-free mice model to predict the result of germ-free mice, to research the difference between pseudo germ-free mice and SPF mice response to tea polyphenals for weight loss.Obese mice were fed with tea polyphenols and then body weight, blood glucose were measured by normal methods. Serum lipid levels and insulin concentration of the mice were measured by radio-immunoassay and enzyme-linked immunosorbent assay technique. Hematoxylin-Eosin staining was applied to fat pad tissue section. Areas of fat cells, long diameters and short diameters were calculated by image processing software of Image Pro-Plus 6.0.The results revealed that SPF mice and pseudo germ-free mice' body weight were respectively reduced by 7.7% and 7.6%, which treated by 0.8% tea polyphenols, 1.6% tea polyphenols can reduced SPF mice and pseudo germ-free mice' body weight respectively by 8.6% and 10.8%. After the mice were administrated with tea polyphenols, obese SPF and pseudo germ-free mice' fasting glucose were significantly reduced(P<0.01), total cholesterol and triglycerides in serum were reduced respectively by 7.7% and 26.51% of obese SPF mice, high-density lipoprotein cholesterol rose 10.08%. However, it had no significant effect on triglycerides and high-density lipoprotein cholesterol in pseudo germ-free mice serum. The areas of fat cells of SPF mice were significantly restrained by tea polyphenols diet(P<0.01) and its adipose tissue morphology extremely closed to the control group's. Fat cells' long diameter, short diameter and areas of pseudo germ-free mice were significantly greater than that of SPF mice's, its areas of fat cells was not reduction.High fat diet induced SPF and pseudo germ-free obese mice produce higher levers of pro-inflammation cytokines, including interleukin-1(IL-1), interleukin-6(IL-6) and tumor necrosis factor-alpha(TNF-?). However, production of the anti-inflammation cytokine IL-10 is reduced in obese mice. After 8 weeks of high fat diet feeding with tea polyphenals supplementation, levels of these cytokines was altered in a dose-dependent manner by tea polyphenals dose. Tea polyphenals reduced the levels of IL-1?IL-6?TNF-?, increased the level of IL-10. Moreover, tea polyphenals reduced pseudo germ-free mice' IL-1, IL-6 levels inferior to SPF mice and increased IL-10 level superior to SPF mice.The bacteria abundance of Firmicutes, Actinibacteria and Proteobacteria of spf HF group's mice were significantly higher than spf CK group's mice. After tea polyphenols treatment, the bacteria abundance of Actinibacteria and the ratio of Firmicutes/Bacteroides decreased. Pseudo germ-free mice' intestinal flora diversity was reduced by antibiotic treatment, but a large number of Verrucomicrobia bacteria colonized in pseudo germ-free mice' intestinal. High fat diet caused Enterobacteriaceae, Prevotella abundance increased, Lactobacillus abundance declined; the pseudo germ-free mice' intestinal flora diversity has been improved by tea polyphenols, the abundance of Akkermansia, Lactobacillus increased and the abundance of Enterobacteriaceae, Prevotella decreased or even disappeared.Therefore, the result illustrated that tea polyphenols can significantly control the weight gain, restrained the fasting plasma glucose, promoted the insulin sensitivity, inhibited the fat accumulation and regulated the inflammation of SPF mice, but it has significant difference between pseudo germ-free mice and SPF mice in response to tea polyphenols for weight loss. High fat diet induced the intestinal microbiota disorder, which was improved by tea polyphenols. Even if the weight loss of pseudo germ-free mice inferior to SPF mice, however, the body weight, inflammation lever of pseudo germ-free mice administrated by tea polyphenols superior to pgf HFgroup's mice. It shown the tea polyphenols exert reducing fat function should depend on gut microbiota. |
PDF Full Text Request