Evaluation of intestinal microbiota and metabolic endotoxemia in a high-fat diet-induced obesity model in rats

The aim of this study was to evaluate both feaces and colonic microbiota and metabolic endotoxemia in a high-fat diet-induced obesity model in rats. The material of this study consisted of 14 wistar albino male 6-7 week old rats. During the experiment, rats whose feed and water were provided ad libitum were divided into two groups as experimental (7) and control (7). The control group was fed by a commercial rat diet (3% fat, 53% carbohydrate and 23% protein) while the experimental group was fed a high-fat diet (66.75% fat, 2.65% carbohydrate and 22.36% protein with the addition of animal tallow) fed along 12 week. Weekly Lee Index and BMI calculations and fasting and postprandial blood glucose levels were measured every two weeks. Blood samples were taken from the heart under anesthesia, and the rats were decapitated and fresh stool samples and distal colon tissue samples were taken rapidly. At the end of the study, there was no difference between the groups for body weight, naso-anal lengths, HOMA-IR, albumin, IP, T Bil, Ca, CHOL, Cre, iron, GGT, LDH, lipase and CK, and postprandial glucose levels. BMI and Lee Indexes increased in the experimental group in the last two weeks and were statistically significant (p <0.05). Fasting blood glucose levels were higher in the experimental group after the first week (p <0.05). Amylase, TG, ALP and AI were high (p <0.01) and BUN, T Pro and HDL were low (p <0.01) in the experimental group. There was no difference between groups for serum TNF-α and IL-6. In the experimental group, TLR4 (p <0.05), LPS and insulin levels were high, and total protein was low (p <0.01). In the colon tissue, TLR4, LPS and total protein were similar, although TNF-α and IL-6 were higher in the experimental group (p <0.01). In feces, LPS increased in the experimental group (p <0.01). In metagenomic analysis, the percentage of archaea in the stool at kingdom level was higher in the control group (p <0.01). Colonic microbiota was similar. According to other taxonomic classifications, Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria in feces; Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria in the colon microbiome the difference between the groups was determined. In addition, Marvinbryantia formatexigens mucosal inflammation and dysbiosis determined in both stool and colonic microbiome; Adlercreutzia equolifaciens, Streptococcus peroris and Roseburia faecis mucosal inflammation; Ruminococcus bromii and Allobaculum stercoricanis, on the other hand, show a healthy microbiome and represent the colonic microbiome by determining it from stool as an alternative to mucosal biopsy samples, which is an invasive method.