How your gut microbes might influence weight gain

At the European Congress on Obesity, researchers presented new evidence suggesting that the bacteria in the gut could be a significant contributor to obesity, especially in men and women. This study focused on understanding how changes in the types of bacteria in our gut can affect our metabolism and possibly lead to obesity.

Tiny organisms such as bacteria, viruses, and fungi, collectively known as the gut microbiota, reside in our gut. When there is a disturbance in this community, it can affect our health and increase the risk of diseases like obesity. However, we are still figuring out which bacteria are more likely to cause obesity and how they affect our health.

To learn more, scientists looked at data from a group of adults in Spain. They examined 361 volunteers' stool, looking at both the types of bacteria and the small molecules produced by these bacteria as they digest food. By entering our bloodstream, these molecules can influence our health.

They analysed the bacteria in their stool to see if there were any differences between people with low and high obesity levels.

They discovered that a bacterium known as Christensenella minuta, often associated with leanness and health, was present at lower levels in people with higher obesity levels. In men, higher levels of certain bacteria were associated with higher BMI, fat mass, and waist circumference. Different bacteria were associated with higher BMI and other measures of obesity in women.

Additionally, when they looked at the small molecules produced by these bacteria, they found that people with higher obesity levels had higher levels of certain molecules, particularly ones known to be involved in metabolic diseases like diabetes.

The lead researcher, Dr Paula Aranaz, explained that having more Christensenella minuta in the gut seemed to protect against obesity. However, the bacteria associated with obesity risk were different between men and women. This implies that we may need to tailor obesity prevention interventions differently for men and women.

Dr Aranaz emphasised the importance of using both genetics and metabolomics (the study of small molecules in the body) to understand how obesity develops. She hopes that by better understanding these mechanisms, we can develop more precise strategies to help people lose weight by targeting specific bacteria or molecules in the gut.

In summary, this research highlights the complex relationship between our gut bacteria, the molecules they produce, and obesity risk. By better understanding these relationships, we may be able to develop more effective strategies for weight loss and the prevention of metabolic diseases like obesity and diabetes.