A new study published by the Scientists from the CNRS, INSERM, UPMC and Université Paris Descartes, working with research clinicians from Paris Public Hospitals has revealed inflammation of the small and intestine and enhanced immune response accompanies obesity.
The metabolic mechanism is based on the fact that inflammation has increased the insulin sensitivity of enterocytes and increases the absorption of nutrients, thus exacerbating the disease. Insulin resistance in fat, liver, pancreatic and muscle tissue has previously been observed in obese patients.
The study participants consisted of 185 severely obese patients compared to 33 lean individuals. The study consisted of collecting small intestine samples from patients during surgery to reduce their obesity and revealed a a state of chronic inflammation affecting the small intestine in the obese patients, and colonization of the jejunal epithelium by T lymphocytes whose density increased in proportion to the degree of obesity. Epithelial cells are cells that line the intestine. T lymphocytes release cytokines that inhibit the insulin sensitivity of absorbent intestinal epithelial cells.
Inflammation is linked to a chronically sensitized immune system shown by an increase in the intestinal density of T lymphocytes; previously linked to complications associated with obesity such as liver disease (NASH) and dyslipidemia. The study revealed that the microvilli (which consists of specific folds in the intestine) were longer than those found in lean subjects; increased by 250% and these patients absorbed more nutrients.
Milena Monteiro-Sepulveda, Sothea Touch, Carla Mendes-Sá, Sébastien André, Christine Poitou, Omran Allatif, Aurélie Cotillard, Hélène Fohrer-Ting, Edwige-Ludiwyne Hubert, Romain Remark, Laurent Genser, Joan Tordjman, Kevin Garbin, Céline Osinski, Catherine Sautès-Fridman, Armelle Leturque, Karine Clément, Edith Brot-Laroche. Jejunal T Cell Inflammation in Human Obesity Correlates with Decreased Enterocyte Insulin Signaling. Cell Metabolism, 2015; DOI: 10.1016/j.cmet.2015.05.020