According to a recent study by a team of international researchers, toxic substances that escape from the intestine can interfere with the functioning of fat cells and lead to obesity. The findings could shed light on how we deal with excessive and dangerous weight gain in the future.
Substances, called endotoxins, are fragments of bacteria in our guts. Although an integral part of the ecosystem of the digestive tract, microbial debris can cause significant damage to the body if it finds its way into the bloodstream.
Here, the researchers wanted to specifically study the impact of endotoxins on fat cells (adipocytes) among people. They found that key processes that typically help control fat buildup are affected by the material.
“Fragments of gut microbes that enter the bloodstream reduce the normal function of fat cells and their metabolic activity, which is exacerbated by weight gain, contributing to increased diabetes risk,” said molecular biologist Mark Christian from Nottingham Trent University in the UK.
“It appears that as we gain weight, our fat stores are less able to limit the damage gut microbe fragments can cause to fat cells.”
The study involved 156 participants, 63 of whom were classified as obese and 26 had undergone bariatric surgery for obesity – a procedure where the size of the stomach is reduced to limit food intake.
Samples from these participants were processed in the lab as the team examined two different types of fat cells, described as white and brown.
White fat cells, which make up most of our fat storage tissues, store lipids in larger volumes. Brown fat cells take fat stores and break them down with the help of their numerous mitochondria, for example when the body is cold and needs warmth. In good conditions, the body can convert lipid-storing white fat cells that behave like lipid-burning brown fat cells.
The analysis showed that endotoxins reduced the body’s ability to turn white fat cells into brown fat cells and reduce the amount of stored fat.
This browning process is crucial for maintaining a healthy weight, and if scientists can learn more about how it works and how to control it, it will open up more potential treatments and therapies for obesity.
“Gut endotoxin reduces metabolic activity of fat cells and their ability to become brown fat cells which may be useful in aiding weight loss,” said Christian.
We know that the intestines of obese people are less resistant than normal, so endotoxins have a better chance of escaping. What this study also shows is that these leaky substances make it even more difficult for fat cells to function normally.
The study authors also point out that bariatric surgery reduces levels of endotoxins in the blood, which adds to its value as a weight control method. This should mean that the fat cells are more able to function normally.
All sorts of factors play into how our weight is biologically controlled, and now there is another important one to consider. With obesity and its associated health problems becoming more and more of a problem all over the world, we need all the information we can get.
“Our study highlights the importance of the gut and fat as critical interdependent organs that influence our metabolic health,” said Christian.
“As such, this work suggests that the need to limit endotoxin-induced fat cell damage is even more important when you are overweight because endotoxin helps reduce healthy cellular metabolism.”
The research has been published in BMC Medicine.