Denesyuk O. Evaluating patients general condition and quality of life in a clinical laboratory context with the background of clinical nutrition for patients who have major gluten-dependent disorders

This dissertation is dedicated to studying the clinical and laboratory parameters as well as the quality of life in patients with celiac disease (CD) and non-celiac gluten sensitivity (NCGS) against the background of a gluten-free diet (GFD). Celiac disease is a chronic, lifelong immune-inflammatory condition that affects genetically predisposed individuals (carriers of the HLA-DQ2/DQ8 histocompatibility complex genes) in response to exposure to gluten, the main protein in grains. It affects the mucous membrane of the small intestine and leads to its atrophy with corresponding clinical gastrointestinal and extraintestinal manifestations reflecting malabsorption syndrome [1]. Non-celiac gluten sensitivity (NCGS) is a condition characterized by intestinal and extraintestinal symptoms associated with gluten-containing food intake in individuals without celiac disease or wheat allergy [2]. The only method of treatment and control for celiac disease and NCGS is a gluten-free diet (GFD), which requires complete elimination of wheat (gluten), rye (secalin), and barley (hordein) from the diet [3]. It was believed that adherence to the GFD would completely reduce the manifestations of the disease in patients with gluten-related pathologies. Indeed, adherence to the GFD by patients with celiac disease and NCGS leads to restoration of the mucous membrane of the small intestine. However, according to the literature, 2042% of patients with celiac disease continue to experience symptoms during the glutenfree diet. Other estimates show that more than one-third of celiac disease patients have altered intestinal motility or "IBS-like" symptoms [4]. Similarly, approximately 2545% of people with NCGS continue to experience symptoms during the gluten-free diet [5]. Currently, there is insufficient information regarding the impact of the GFD on the quality of life of patients with celiac disease and NCGS, functional digestive disorders in this patient group, the possibility of correcting these conditions, as well as the impact of the GFD on the intestinal microbiome (IM). This dissertation studied the quality of life of patients with celiac disease and NCGS before and during the full-scale introduction of the GFD in Ukraine, examined the prevalence of IBS-like complaints in patients with celiac disease and NCGS in Ukraine regardless of adherence to the GFD, and also investigated the microbiome against the background of the GFD. Aim of the research: To investigate the clinical and laboratory parameters as well as the quality of life in patients with celiac disease (CD) and non-celiac gluten sensitivity (NCGS) on a gluten-free diet (GFD) before and after its widespread implementation in Ukraine. Objectives of the research: 1. Evaluate the quality of life in patients with CD and NCGS before and during the widespread implementation in Ukraine. 2. Assess the structure of complaints in patients with CD and NCGS who experience symptoms despite long-term adherence to GFD. 3. Assess the possibility of correcting IBS-like complaints in patients with CD and NCGS on a gluten-free diet using a multicomponent probiotic supplement. 4. Investigate the status of the intestinal microbiome in patients with CD and NCGS on a GFD.