When we eat, the body focuses both on the distribution of the digested glucose and the bacteria that accompany this. This elicits an inflammatory response that activates the immune system. In healthy people, this short-lived postprandial inflammation plays an important role in glucose absorption in the cells and immune system activation.
Swiss researchers have recently proven that the number of macrophages (immune cells) in the intestines increases whilst eating. These cells produce IL-1β, an important signalling agent in the immune system. When blood glucose levels are high, insulin causes an increase in the production of IL-1β by the macrophages. In turn, this stimulates the production of insulin in the pancreas. Insulin and IL-1β therefore work together in regulating blood glucose, whilst the signalling agent ensures that the immune system receives glucose and therefore remains active for exactly long enough.
According to researchers, the postprandial inflammatory response depends on the bacteria and nutrients consumed during a meal. When there are sufficient nutrients, the immune system is able to defend itself against unknown bacteria. Unfortunately, the reverse is also true: when there is a deficiency of certain nutrients, the few remaining calories are reserved for the most important vital functions. This is at the expense of the immune system.
In people who are overweight, this inflammatory process fails and this can lead to diabetes. In patients with diabetes, the signal agent IL-1β sets in motion a chronic inflammation and prevents insulin-producing beta cells from doing their work.
Chronic activation of the immune system is caused by, for example, overeating, eating too often, sitting for protracted periods of time, sleep deprivation, a lack of exercise and non-resolved psycho-emotional problems. The risk factors as a whole lead to chronic activation of the stress axes and to bacterial waste entering the bloodstream. This causes a chronic low-grade inflammation.
It is becoming increasingly clear that chronic low-grade inflammations are the cause of the majority of, if not all, chronic non-communicable diseases. A healthy (organic) diet with plenty of nutrients (for example, paleo, Nordic or Mediterranean) ensures that the postprandial inflammation can work effectively and that this does not become a low-grade inflammation. Along with sufficient physical exercise, this is the most important way of preventing a wide range of Western diseases, including type 2 diabetes.
Erez Dror, Elise Dalmas, Daniel T Meier, Stephan Wueest, Julien Thévenet, Constanze Thienel, Katharina Timper, Thierry M Nordmann, Shuyang Traub, Friederike Schulze, Flurin Item, David Vallois, Francois Pattou, Julie Kerr-Conte, Vanessa Lavallard, Thierry Berney, Bernard Thorens, Daniel Konrad, Marianne Böni-Schnetzler & Marc Y Donath, Postprandial macrophage-derived IL-1β stimulates insulin, and both synergistically promote glucose disposal and inflammation, Nature Immunology (2017) 16 jan 2017.