No association between the early-life gut microbiota and childhood body mass index and body composition.

Abstract

The gut microbiota has been implicated in adult obesity, but the causality is still unclear. It has been hypothesized that an obesity-prone gut microbiota can be established in infancy, but only few studies have examined the early-life gut microbiota in relation to obesity in childhood, and no consistent associations have been reported. Here, we examine the association between the early-life gut microbiota and body mass index (BMI) development and body composition throughout childhood. Gut microbiota from stool were collected from 700 children in the Copenhagen Prospective Studies on Asthma in Childhood2010 (COPSAC2010) cohort at ages of 1week, 1month, 1 year, 4 years, and 6 years and analyzed by 16S rRNA gene sequencing. Outcomes included BMI World Health Organization (WHO) Z scores (zBMI), overweight (zBMI>1.04) and obesity (zBMI>1.64) (0-10 years), and adiposity rebound and body composition from dual-energy X-ray absorptiometry at 6 years. The early-life gut microbiota diversity, overall composition, and individual taxon abundances in unsupervised and supervised models were not consistently associated with either current or later BMI Z scores, overweight, obesity, adiposity rebound, or body composition in childhood. In a deeply characterized longitudinal birth cohort, we did not observe any consistent associations between the early-life gut microbiota and BMI or risk of obesity in later childhood. While this does not conclusively rule out a relationship, it suggests that if such associations exist, they may be more complex and potentially influenced by factors emerging later in life, including lifestyle changes. COPSAC is funded by private and public research funds (all listed on www.copsac.com).