Go with your gut

Bacteria link to obesity

Imbalances in a toddler’s gut bacteria may play an important role in the development of obesity, say international researchers.

The new study has found the makeup of a toddler’s gut bacteria can predict whether they will be overweight at five years old.

The findings also suggest changes to the gut microbiota that predispose adults to obesity may begin in early childhood.

“The reason these gut bacteria affect weight is because they regulate how much fat we absorb,” lead researcher Gael Toubon said.

The make-up of the gut microbiota grows and changes in the first few years of life and disruption to its development is associated with conditions including inflammatory bowel disease, type 1 diabetes, and childhood obesity.

Mr Toubon and colleagues examined how the gut microbiota of children at 3.5 years from two French nationwide birth cohorts was associated with their BMI at five years old and changes in their BMI between two and five years old.

They included 143 preterm infants 369 full-term infants born in metropolitan France in 2011 in the study.

Stool samples were collected at 3.5 years. Genetic microbiota profiling revealed a positive association between BMI z-score (a measure of bodyweight based on height for each age group by sex) at five years and the ratio of the gut bacteria Firmicutes to Bacteroidetes that are directly involved with obesity.

The more Bacteroidetes compared to Firmicutes in the gut, the leaner individuals tend to be.

“Children with a higher ratio of Firmicutes to Bacteroidetes will absorb more calories and be more likely to gain weight,” Mr Toubon said.