Abdominal fat located near the large intestine may play a distinct role in immune system communication, according to a recent study conducted by researchers from Karolinska Institutet, Steno Diabetes Center Copenhagen, and Helmholtz Munich. The findings were published in the journal Cell Metabolism.
The research team examined five different abdominal fat depots in individuals with severe obesity. They found notable differences among these fat tissues. In particular, epiploic fat tissue along the colon was found to have an unusually high number of inflammatory fat cells and immune cells.
Laboratory tests showed that bacterial signals can cause these fat cells to produce proteins that activate immune cells within the tissue. This suggests that fat tissue near the gut may be specially adapted to interact with the gut's immune environment, possibly as a response to substances produced by gut bacteria.
Researchers note that because the study focused on people with obesity, it is not yet clear if these results apply to individuals of normal weight or what direct clinical impact they might have.
"The next step is to understand the role of fat tissue around the colon in inflammatory bowel diseases such as Crohn's and ulcerative colitis. Now that we know it contains both fat cells and immune cells, we want to investigate how their interaction influences disease activity. Our goal is to find out whether this fat tissue contributes to amplifying or sustaining inflammation by sending signals that affect immune cells locally," says Jutta Jalkanen, researcher at the same department and co-first author of the study.
The project involved collaboration between institutions in Sweden, Denmark, and Germany and received funding from several organizations including the Swedish Research Council, Novo Nordisk Foundation, ERC, and Knut and Alice Wallenberg Foundation.
