Gut microbiome contributes differently to obesity onset in men and women, finds study

The gut microbiota consists of a complex community of microorganisms (bacteria, viruses, fungi and protozoa) that inhabit the gastrointestinal tract. Disruption in this community significantly affects metabolic health and influences the risk of certain diseases, including obesity. However, it is still unclear which species represent a greater or lesser likelihood of developing obesity, as well as the impact of these species on our metabolic health.

In the study, researchers analyzed metagenomic and metabolomic data from a Spanish population to understand how gut microorganisms contribute to obesity development. They examined fecal metabolites, produced by gut bacteria during food metabolism, impacting health. The study included 361 adults, classified based on obesity levels. Genetic microbiota profiling was done to identify the different types, composition, diversity, and relative abundance of bacteria present in stool samples of the participants.

The results revealed that individuals with a higher obesity index had lower levels of C. minuta, associated with health. In men, higher abundance of P. helcogenes and C. canadensis correlated with increased BMI, fat mass, and waist circumference. Conversely, in women, higher levels of P. micans, P. brevis and P. sacharolitica predicted higher BMI, fat mass, and waist circumference, but not in men.

“Gut microbiome composition, specifically higher levels of the Christensenella minuta bacterium, appeared to protect against obesity. Whereas the species that influence the risk of developing obesity appear to be different between the sexes and interventions to help prevent an obesity-favourable microbiome may need to be different in men and women. Further research is needed to better understand when the switch to an obesity favorable gut microbiota may take place, and therefore the right timing for possible interventions," said Dr Paula Aranaz, lead author from the Centre for Nutrition Research at the University of Navarra in Spain.

“Our findings reveal how an imbalance in distinct bacterial groups are likely to play an important role in the onset and development of obesity, with considerable differences between the sexes, which might affect the metabolism of different bioactive molecules present in the metabolome that influence the development of metabolic disease."

Reference: European Association for the Study of Obesity; European Congress on Obesity (ECO 2024)