Can we evaluate the risk of childhood obesity based on the intestinal flora?
The composition of the gut microbiota of a two-year old child could predict their subsequent risk of obesity, according to a Norwegian study that opens up new outlooks on the prevention of this disorder that keeps gaining ground all over the world.
Although poor diet and insufficient physical activity are unquestionable risk factors for excess weight and obesity, the gut microbiota could also play a major role: according to different studies, its composition during the first two years of life is related to the weight progression during that same time period. In a new study, researchers analyzed the gut microbiota of 165 Norwegian children as well as their mother’s BMI during pregnancy at 6 different timepoints between birth and the age of two. They then tried to correlate these results with the body mass index (BMI) of these same children ten years later.
An “obesogenic” microbiota despite a “normal” BMI
In children of normal weight, the BMI remains the same during their entire childhood; while in obese children, BMI constantly increases between 2 and 12 years old. However, the authors point out that only an extremely small minority of these children have a BMI at the age of 2 that heralds a future obesity. On the contrary, they observed a strong association between the composition of the microbiota at the age of 2 and the BMI at the age of 12. According to their calculations, the impact of the intestinal ecosystem on the BMI largely exceeds that of other known factors such as mode of delivery, duration of exclusive breastfeeding, exposure to antibiotics, or various maternal factors such as smoking, pre-pregnancy BMI, education level.
Early identification for a better prevention
According to the authors, having an “obesogenic” gut microbiota precedes weight gain by several years and seems to be mainly the result of direct mother-to-child transmission (mother excess weight or obesity, excessive weight gain during pregnancy…). They suggest that these findings are a step towards new and more targeted strategies to prevent childhood obesity that are based on the identification of high-risk children before the age of two, when their weight is still within the normal range.
Stanislawski MA, Dabelea D, Wagner BD, Iszatt N, Dahl C, Sontag MK, Knight R, Lozupone CA, Eggesbø M. Gut Microbiota in the First 2 Years of Life and the Association with Body Mass Index at Age 12 in a Norwegian Birth Cohort. MBio. 2018 Oct 23;9(5). pii: e01751-18