Research discovers Gut Microbiota role in Childhood Obesity

In a recent study published in the journal Clinical Nutrition ESPEN, researchers explored causal associations between the gut microbiome and pediatric adiposity.

Childhood adiposity is a growing concern, associated with numerous health issues in both children and adults. Childhood obesity is significantly influenced by genetics, environment, lifestyle, and gut flora. While lifestyle factors like diet and exercise play a crucial role, the causal relationship between adiposity and gut microbes remains unclear.

Gut microbes affect obesity by altering host metabolism, with studies noting imbalances in bacteria such as Clostridium and Eubacterium among individuals prone to obesity. The proposed gut-brain axis suggests that treatments like fecal microbiota transplantation and prebiotic supplementation could be potential anti-obesity strategies.

In the study, researchers employed Mendelian randomizations (MR) to investigate the causal association between gut microbes and childhood obesity. The study involved 32 children, with 16 classified as obese and 16 without adiposity.

Researchers assessed their weight, body mass index (BMI), abdominal circumference (AC), serum lipid levels (triglycerides (TG), total cholesterol (TC), low-density lipoproteins (LDL), very low-density lipoproteins (VLDL), and high-density lipoproteins (HDL)), and gut microbiomes. Participants also provided faecal samples for genetic sequencing.

The children, aged nine to twelve years, had no history of thyroid or liver-related diseases, congenital disorders, or genetic defects, and had not yet reached puberty. Obese children underwent a three-month weight reduction intervention, which included calorie restrictions and increased physical activity. To validate the impact of obesity on gut flora, researchers examined the gut flora macro-genes before and after the weight reduction intervention in obese participants.

Using Mendelian randomization, researchers identified 16 causal associations between gut microbes and pediatric adiposity. The results revealed five significant differences in intestinal microbes between obese participants and those without adiposity. Notably, the team observed increased abundances of Romboutsia, Turicibacter, and Clostridium following weight reduction in obese children.

The findings highlighted that gut microbes produce various compounds during digestion, such as short-chain fatty acids (SCFAs), which influence adipogenesis and hormone synthesis. Reduced gut microbial diversity may increase insulin resistance and levels of pro-inflammatory markers. Obesity-related bacteria contribute to the development of obesity by affecting host energy balance and central hunger regulation through gut-brain interactions.

Reference: Lu M, Feng R, Li M, Liu L, Xiao Y, Liu Y, Yin C, Causal relationship between gut microbiota and childhood obesity: a Mendelian randomization study and case-control study, Clinical Nutrition ESPEN, DOI: 10.1016/j.clnesp.2024.05.012, https://www.sciencedirect.com/science/article/pii/S2405457724001311