Features of Food Intolerance in Patients with Irritable Bowel Syndrome
Authors:   A.S. Loginov Moscow Clinical Scientific Center, Dbar S.R. , Bykova S.V. ,   National Medical and Surgical Center named after N.I. Pirogov, Moscow,   A.I. Yevdokimov Moscow State University of Medicine and Dentistry, Sabelnikova E.A. , Akhmadulina O.V. , Belostotsky N.I. , Parfenov A.I. 
Published: July 2023

The aim was to evaluate the activity of intestinal carbohydrases in patients with irritable bowel syndrome (IBS) with symptoms of food intolerance. Material and methods. 126 patients with IBS (83 women and 43 men, median age – 32.0 years (Q1–Q3: 27–38 years)) were examined. The diagnosis of IBS was established on the basis of Roman Criteria IV. A questionnaire was conducted for all patients to identify food intolerances, according to the results of which the patients were divided into three groups: the first – patients with isolated intolerance to foods with a high content of FODMAP; the second – patients with isolated intolerance to milk and dairy products; the third – patients with combined intolerance. To determine the activity of intestinal carbohydrates: lactase, sucrose, maltase and glucoamylase, all patients underwent esophagogastroduodenoscopy with biopsy samples from the duodenum. The activity of carbohydrases was determined by the Dahlquist method in the modification of N.I. Belostotsky. The control group consisted of 30 conditionally healthy people (10 men and 20 women, median age – 33.9 years (Q1–Q3: 24–35)), comparable in age and gender with patients with IBS. The activity of intestinal enzymes in this group was within the reference values. Statistical data processing was carried out using the computer program Statistica 8.0. Results. According to the results of the survey, it was found that out of 126 patients with IBS, 52 (41.3%) patients believed that they had food intolerance to certain foods. Isolated intolerance to foods with a high content of FODMAP was noted by 13 (10.3%) patients, 16 (12.7%) patients believed that they had isolated intolerance to milk and dairy products, and 23 (18.3%) patients indicated combined intolerance. In patients with IBS and isolated intolerance to foods high in FODMAP, the median activity of glucoamylase was 120.0 (68.5–209.2) ng/mg of glucose per 1 mg of tissue per minute (ng/mg × min), maltase – 630.5 (480.7–951.0) ng/mg × min, sucrose – 50.0 (32.8–68.8) ng/mg × min, lactase – 10.5 (5.5–40.5) ng/mg × min. Comparing the activity of carbohydrases with the control group revealed the statistically significant difference (p < 0.05) for each enzyme studied.In the group of patients with IBS and isolated intolerance to milk and dairy products, the median activity of all the intestinal enzymes studied was also lower than that in the control group: the activity of glucoamylase was 107.0 (64.0–174.0) ng/mg × min, maltase – 622.0 (481.5–887.0) ng/mg × min, sucrose – 48.0 (35.5-60.0) ng/mg × min, lactase – 8.0 (3.0–22.5) ng/mg × min. Among patients with IBS and the presence of combined intolerance to foods (with a high content of FODMAP and dairy products), the median activity of all enzymes significantly differed from the control group (p < 0.05). The activity of glucoamylase was 107.5 (57.5–194.2) ng/mg × min, maltase – 627.0 (480.7–911.7) ng/mg × min, sucrose - 47.5(34.8–61.5) ng/mg × min, lactase - 9.0 (4.0–28.8) ng/mg × min. Conclusion. Food intolerance was noted in 52 (41.3%) patients with IBS. Among the patients who noted the presence of all the studied food intolerances (isolated or combined intolerance to milk and dairy products, as well as products with a high content of FODMAP), a significant decrease in the activity of intestinal enzymes (glucoamylase, lactase, sucrose and maltase) was found compared with the control (p < 0.05), which may indicate the presence of they have disaccharidase deficiency