Investigation of the effect of Lactobacillus reuteri and Xylooligosaccharide (synbiotic) in the high-fat diet-induced obesity rat model

Regulation of gut microbiota has emerged as a significant target in obesity treatment in recent years. Probiotics and prebiotics are effective components in balancing gut microbiota. While probiotics promote the proliferation of beneficial bacteria in the gut, prebiotics serve as a nutrient source for these bacteria, contributing to the positive shaping of the microbiota. Synbiotics are a combination of probiotic and prebiotic components and are thought to have more potent effects in regulating gut microbiota. Lactobacillus reuteri is a probiotic species that can show significant effects in protecting intestinal microbiota and suppressing inflammatory processes. As a prebiotic component, Xylooligosaccharide supports maintaining a healthy microbial ecosystem by supporting the development of beneficial bacteria in gut microbiota. This study aims to investigate the inflammatory, metabolic, and neurotrophic effects of the combination of Lactobacillus reuteri and xylooligosaccharide (synbiotic) in a high-fat diet-induced obesity rat model. The research was conducted on 8-week-old Wistar albino rats. In the current study, Control, Obese, Synbiotic, and Obese+Synbiotic groups were formed. The study continued for 8 weeks. The control group was fed with standard rat chow, while the Obese and Obese+Synbiotic groups were fed a high-fat diet. Oral Lactobacillus reuteri and xylooligosaccharide combination were applied to the Synbiotic and Obese+Synbiotic groups for prophylaxis. At the end of the experiment, inflammation markers, metabolic parameters and neurotrophic factors were examined in serum, liver and brain tissues. Compared to the control group, the highest live weight gain occurred in the Obese group. TNF-α, insulin, and NGF increased in serum, and BDNF decreased in serum and brain. NT- 4 increased in liver. Live weight gain decreased in the Obese+Synbiotic group compared to the obese group. NGF and NT-3 decreased in the liver, and NT-4 decreased in the serum. Compared to the control group, insulin increased in the serum of the Synbiotic group, and HDL, NT-3, and NT-4 decreased. Our findings showed that high-fat diet feeding accelerates body weight gain and leads to obesity, triggers inflammation, increases the risk of type 2 diabetes, and reduces cognitive and intellectual capacity. The administration of Lactobacillus reuteri and xylooligosaccharide combination to subjects fed a high-fat diet slowed body weight gain, suppressed obesity development, and showed a tendency to increase cognitive capacity.