The study finds gut microbiota or gut flora is closely related to fat distribution in children and teenagers.
"Our findings show children and teenagers with obesity have a different composition of gut flora than lean youth," said Nicola Santoro, Researcher at the Yale University in Connecticut, US.
"This suggests that targeted modifications to the specific species composing the human microbiota could be developed and could help to prevent or treat early-onset obesity in the future," said Santoro.
The study examined gut microbiota and weight in 84 children and teenagers, who were between seven and 20 years old. The participants included 27 obese, 35 severely obese, seven overweight and 15 with normal weight.
The researchers analysed the participants' gut microbiota and performed an MRI to measure body fat partitioning. They also tested blood samples and reviewed their three-day food diary.
They found eight groups of gut microbiota that were linked to the amount of fat in the body. Four of the microbial communities were seen flourishing in children and teens with obesity as compared to their normal-weight counterparts.
Smaller amounts of the other four microbial groups were found in participants, who were obese compared to children and teenagers of normal weight.
The gut microbiota found in youth, who were obese, tended to be more efficient at digesting carbohydrates than those found in teenagers and children's gut from normal weight category.
In addition, the children with obesity had higher levels of short chain fatty acids in the blood than those of normal weight.
The study found short chain fatty acids -- produced by some gut bacteria -- to be associated with the production of fat in the liver.
"Our research suggests that short chain fatty acids can be converted to fat within the liver and then accumulate in the fat tissue," said Santoro.
The researchers said this association could signal that children with certain gut bacteria face a long-term risk of developing obesity.
The study was published in the journal Clinical Endocrinology and Metabolism.
