Obesity as a risk factor for diseases of the digestive system

Currently, the global prevalence of obesity among the world’s adult population is about 650 million people, which makes it possible to consider this chronic metabolic disease as a non-infectious pandemic of the 21st century. It has been proven that obesity is associated with several gastroenterological diseases, while the mechanisms of these associations are extremely heterogeneous and multifactorial. Hypertrophy and hyperplasia of adipocytes in obesity lead to a change in the profile of adipokine production (a decrease in adiponectin, an increase in leptin), an increase in the production of pro-inflammatory cytokines (interleukin-1, 6, 8, tumor necrosis factor a), C-reactive protein, free fatty acids, as well as active forms of oxygen (superoxide radicals, H 2 O 2 ). All the above induces the development of chronic slowly progressive inflammation, oxidative stress, and insulin resistance. In addition, peptides secreted by adipocytes (adiponectin, leptin, nesfatin-1 and apelin) can modulate gastrointestinal motility, acting both centrally and peripherally. The qualitative and quantitative changes in the intestinal microbiota observed in obese patients (increased Firmicutes and decreased Bacteroidetes ) lead to a decrease in the production of short-chain fatty acids and an increase in the intestinal permeability due to disruption of intercellular tight junctions, which leads to increased translocation of bacteria and endotoxins into the systemic circulation. Numerous studies have demonstrated the association of obesity with diseases of the esophagus (gastroesophageal reflux disease, Barrett’s esophagus, esophageal adenocarcinoma, esophageal motility disorders), stomach (functional dyspepsia, stomach cancer), gallbladder (cholelithiasis, gallbladder cancer), pancreas (acute pancreatitis, pancreatic cancer), liver (non-alcoholic fatty liver disease, hepatocellular carcinoma), intestine (diverticular disease, irritable bowel syndrome, colorectal cancer).