A new large-scale study by scientists from the Karolinska Institute (Sweden), the Steno Diabetes Center (Denmark), and the Helmholtz Institute in Munich has shown that abdominal fat near the intestines is not merely an energy reservoir, but an active tissue organ with unique properties that can influence inflammation in the body and the functioning of the immune system in people with obesity.

The results were published in the journal Cell Metabolism.

The authors analyzed different depots of adipose tissue in the abdominal cavity of people with severe obesity and found that fat tissue adjacent to the large intestine—epiploic adipose tissue—differs markedly from other fat deposits.

This tissue contains particularly high numbers of fat cells associated with inflammatory processes, as well as a wide variety of immune cells, distinguishing it from typical subcutaneous fat tissue.

Such an abundance of immune components and “inflammatory” fat cells suggests that this fat depot interacts especially actively with the intestinal immune system.

In laboratory experiments, the researchers also showed that signals from gut bacteria can stimulate fat cells to produce substances that activate immune cells directly within the tissue. This means that adipose tissue does not merely passively store energy, but is actively involved in immuno-metabolic processes—especially in areas closest to the intestine.

The interaction between the gut microbiota and adipose tissue may amplify inflammatory responses, making it more difficult to combat obesity and its associated metabolic disorders.

The authors emphasize that their findings expand the understanding of adipose tissue as a complex organ that participates in the regulation of immunity and metabolism, rather than serving solely as a fat storage site.

It is likely that epiploic adipose tissue is adapted to its proximity to the intestine and its microbiome, which itself influences inflammation and metabolic processes. It remains unclear how common these features are in people of normal weight and how exactly these processes could be harnessed for the treatment of obesity.

Future research will focus on studying the role of this tissue in inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis.