Overweight and Obesity in Children Are Associated with an Abundance of Firmicutes and Reduction of Bifidobacterium in Their Gastrointestinal Microbiota

Background: Obesity in children continues to be a global epidemic. Given the recent focus on the potential role gut microbiota play in the development of obesity and the continuous rise of obesity in childhood worldwide, it has become necessary that the association between gut microbes and weight is explored in previously unexplored regions such as the Caribbean island of Trinidad. As such, our objective was to characterize the composition of the gut microbiota in children with obesity/overweight and children of normal weight to determine if there are any gut microbes associated with overweight and obesity. Methods: Fifty-one children provided stool samples and their BMIs were calculated and classified. 16S amplicons from stool samples were individually barcoded and sequenced in multiplex in the NextSeq 500 platform in a 150 bp paired-end modality and a complete gut microbiome profile was generated. Results: The relative abundance and diversity of the microbiota of the lean and children with obesity/overweight were analyzed against each other and showed that children with obesity/overweight recorded significantly more (p = 0.001) Firmicutes and significantly less Bifidobacterium (p = 0.039) than the children of normal weight. Children with obesity/overweight also recorded significantly (p = 0.009) reduced alpha diversity compared with the lean children. Conclusion: This study has shown associations of Firmicutes to obesity/overweight and Bifidobacterium species with healthy weight in children.