Figure 4. intestinal villus length

Background: Childhood obesity affects children's health and increases the risks of obesity-related disorders in adulthood. However, the exact relationship between these stages is not well understood. The composition of gut microbiota changes alongside childhood obesity, influencing how our bodies function.Methods: To understand the link between childhood obesity and the likelihood of obesity in adulthood, we examined the gut microbiota in children and mice with obesity. We aimed to uncover how different intervention ages could impact metabolism, gut barrier function, and immune cell differentiation. Additionally, we explored the role of gut microbiota in obesity by using faecal microbiota transplantation (FMT).Results: Gut microbiota signatures were significantly altered in childhood obesity rather than adulthood. The intervention at different growth phases reshaped the gut microbiota and caused relevant impacts, significantly affected if the intervention was given after post-puberty. The intervention on childhood obesity given before puberty did not increase the predisposition to adulthood obesity. The alpha diversity of jejunal microbiota significantly decreased along with the increase of intervention age, and it was significantly negatively correlated with the serum lipopolysaccharide (LPS). The relative abundance of propionate producer Muribaculaceae correlated negatively with the intervention delay. Obesity-related gut microbiota impacted the host significantly in combination with the obesity-related diet in the FMT assay.Conclusions: This study elucidates the connection between childhood obesity and the risk of obesity in adulthood through the lens of gut microbiota. It underscores the critical importance of early intervention for children with obesity to mitigate future health risks.