Impact of wheat-free and ancient grain-based diets on symptoms, quality of life and inflammation in patients with Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) patients report symptoms, which affect their quality of life (QoL) and increase costs of national healthcare systems. Food intake causes symptom onset/worsening in IBS. Evidence indicates that gluten and fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) evoke IBS-related symptoms. Thus, wheat, containing gluten, FODMAPs, and other potentially harmful components, e.g. amylase/trypsin inhibitors (ATIs), are major symptom triggers. Furthermore, ATIs can cause inflammation via innate immunity response. In this scenario, an overlap between IBS and non- celiac wheat sensitivity can occur. Compared to modern grains, ancient ones, containing lower ATI concentrations, provide better tolerability and reduction of inflammatory markers in IBS patients. This research aims to test whether: 1) a wheat-free diet can reduce symptoms and improve QoL in IBS patients; 2) the use of ancient grains could represent a valid and tolerable dietary alternative; 3) a minimal inflammation occurs in the lamina propria of the gut mucosa increasing the intestinal mucosal permeability (i.e. `leaky gut¿). A number of surrogate markers will be assessed, namely zonulin assay, tight junction expression, as well as lactulose/mannitol ratio test along with serum cytokine profile before (TO) and after (T1) G/WFD and before and after DBWC with ancient vs. modern grains in IBS patients. Also, gut microbota changes and related metabolomic features will be analyzed in a subset of IBS patients.