Contribution of clinical factors and gut microbiota composition to weight loss in a pre-post dietary intervention pilot study in male children with obesity.

Purpose: Childhood obesity is a global health problem that may be linked to changes in the gut microbiota. The aim of this pilot study was to link the clinical parameters of children with obesity, who underwent a dietary intervention, with their gut microbiota profiles to better understand the factors associated with weight loss.

Methods: The study focused on 36 male children with obesity (aged 12-15 years) who were referred for treatment of primary obesity. Personal medical history information was collected at enrollment. Body composition was assessed before and after a three-week balanced hypocaloric diet with preserved nutritional value. Bacterial taxa were analyzed by 16S rRNA gene amplicon sequencing. Linear regression models and machine learning algorithms were used to determine how subjects' clinical factors and gut microbiota contribute to weight loss efficacy.

Results: Results showed that higher abundance of Lachnospiraceae members (Blautia and Anaerostipes) prior to the diet intervention, and later introduction of non-dairy food were positively related to weight loss efficacy, while higher abundance of Erysipelotrichaceae UCG-003 and Faecalibacterium in the pre-diet samples was negatively correlated with BMI change. The change in the abundance of Enterobacteriaceae and Bacteroidetes members between the pre- and post-diet samples was negatively associated with delta BMI.

Conclusion: The efficacy of weight loss in male children with obesity under dietary treatment is related to the composition of the gut microbiota and the timing of the introduction of non-dairy food. Promoting beneficial gut bacteria could increase the success of dietary treatment for weight loss and improve long-term health outcomes in children with obesity.