La Boucle du Diabète 2016

Summary on Estelle Grasset Rémy Burcelin team, INSERM U1048 -Toulouse. According to the World Health Organization, since 1980, the number of people with diabetes has increased by 4 and remains a leading cause of death worldwide. All types of diabetes is concerned. A cause "infectious" is sought. Recent years have seen appear the concept of intestinal microbiota representing all the bacteria that inhabit our intestines. It has been observed that in patients with type 1 and type 2, the composition of bacteria in the microbiota was different from that of non-diabetic subjects. In laboratory animals, the colonization of germ-free mice (bacteria-free) by diabetic mice bacteria gives the first hyperglycemia. This experience is proof of causation of the microbiota in the induction of diabetes especially type 2. In type 1 diabetes, recent studies show that the autoimmune component of the disease is under the control of bacteria gut which "educate" the immune intestinal system which affects the overall immune system. Indeed, the gut is the largest reservoir of immune cells. The composition of the intestinal microbiota is an extremely important agent in the maturation of the immune system and thus its potential role in autoimmunity. In the laboratory, we have obtained results that show that the intestinal microbiota is a regulating agent of insulin secretion. The mechanisms are not known but our preliminary work shows that the alteration of the intestinal microbiota by antibiotics, prebiotics or an unbalanced diet strongly affects the intestinal immune system. Other preliminary studies suggest that this effect affects the action of a hormone produced by the intestine in response to food and called GLP-1. This hormone sends a nutritional message to the brain. The latter transmits the information to the pancreas that secretes insulin. This hormone is therefore important for the control of blood glucose. Its secretion is stimulated by glucose that is ingested and actions are diverse and their main function is to lower blood sugar: it increases insulin secretion, it decreases glucagon secretion, it reduces the emptying of the stomach ensuring gradually arrival of ingested glucose in the blood and activates satiety. Thus, our working hypothesis is that a change of intestinal microbiota, which may happen very early in the life of the intestines, contributes to the reduction of the action of GLP-1 on the nervous axis brains and intestines pancreas. This mechanism would especially involve the intestinal immune system and ultimately control of some autoimmunity. We study the mechanisms at the interface between the microbiota and nervous tract and involving the immune system. We conduct animal studies and clinical trials is being installed for the treatment of intestinal microbiota in the context of the islet of Langerhans. Thus, we will combine the action of the microbiota on the secretion of GLP-1 secretion of insulin, the study of the role of the immune system and nervous system of the intestine in the regulatory framework of secretion insulin. To go further ... Inserm - February 2016: intestinal microbiota and health Science & Outlook - August 2015: Diabetes: the microbiota play a protective role