More Than a Gut Feeling?

Populations of bacteria, living in human large intestines, have many useful roles, such as producing some vitamins. It now appears likely that, in some folk, they can also drive obesity and increase the risk of developing associated conditions, like type 2 diabetes (https://www.theguardian.com/science/2023/may/21/toxins-from-gut-damage-fat-cells-and-drive-weight-gain-study-suggests). A group from Nottingham Trent University took blood and fat cell samples from 156 subjects. Sixty-three of these were classed as 'obese' and several others had had bariatric surgery, to address their weight problem. The study focused on endotoxins, produced when cell walls break down in gut bacteria. Healthy gut endotoxins are part of the normal lifecycle of these microbes. These endotoxins were more likely to leak into the bloodstreams of obese subjects. Obese folk had more fragile gut barriers. White fat cells from these same subjects were also less likely to transform into 'healthy' brown-fat versions. This would make it more likely that these folk would continue to gain weight. Bariatric surgery reduced both blood endotoxins and the deleterious effects on fat cells. The researchers suggest the endotoxins influence the function of fat cells. They think this, at least partially, accounts for weight gain, with its associated negative conditions.