IgG levels to food antigens depend on nutrition and levels of general inflammation in healthy persons and individuals with metabolic syndrome

The intestinal mucosa selectively passes food antigens, which are foreign agents but do not provoke an immune response in the intestine. The increased permeability of the intestinal barrier is affected by chronic sluggish inflammation, deficiency of IgA, impaired paracellular transport and the frequency of food consumption. The aim of the study was to provide a comparative quantitative assessment of IgG class antibodies to food antigens in patients with metabolic syndrome and practically healthy people, depending on the type of diet and levels of general inflammation. In the prospective cohort study in 230 people, including 110 patients with metabolic syndrome (average age 33.9±1.1 years), clinical and biochemical parameters: total cholesterol, low and high density lipoproteins, triglycerides and glucose, cytokines: IL-1b, IFN-γ, IL-10, C-reactive protein, levels of apoptosis and necrosis of lymphocytes, catecholamines: adrenaline, noradrenaline, dopamine, serotonin, as well as levels of specific IgG to food antigens in blood serim have been compared. The analysis of personal data on the nutrition (frequency of food consumption) and hereditary predisposition to metabolic syndrome was carried out. It was found that the parents of the examined individuals with metabolic syndrome are twice as likely to hav e obesity and type 2 diabetes mellitus (correspondingly in 73.3 and 36.4% vs 36.7 and 23.3% in healthy persons, p<0.05). The diet of people with metabolic syndrome is characterized by more frequent consumption of foods containing refined carbohydrates, salt, saturated and trans-isomers of fatty acids, with low levels of plant products, dietary fiber, polyunsaturated fatty acids and complex carbohydrates. A 3-fold increase in IgG levels to food antigens in patients with metabolic syndrome was associated with a higher (p<0.05) blood serum level of pro-inflammatory cytokines (IL-1β - 8.99±1.05 vs 1.99±0.30 pg/ml in healthy persons, IFN-γ - 22.21±6.50 vs 7.59±0.96 pg/ml), IL-10 (13.90±1.96 vs 5.03±0.81 pg/ml), C-reactive protein (1.96±0.31 vs 4.47±0.61 mg/ml), noradrenaline (168.4±6.8 vs 131.3±2.8 ng/ml), which was not compensated by adrenaline (52.3±9.3 vs 54.3±2.4 ng/ml). Against the background of impaired glucose and lipid homeostasis in metabolic syndrome and higher levels of general inflammation, epithelial dysfunction is formed, resulting in increased permeability to antigens through the intestinal barrier. Changes in the level of antibodies to food antigens in metabolic syndrome are non-specific, which is reflected in an increase in IgG levels for all food groups independent from the frequency of their consumption.