A Comparison Among the Effects of the Low FODMAP Diet, a Tritordeum Based Diet, and Dietary Advice on the Gastrointestinal Symptom Profile in Patients With Irritable Bowel Syndrome-Diarrhea Variant (IBS-D): a Randomized Controlled Trial

A structured dietary approach could represent a reliable alternative strategy to treat patients with functional gastrointestinal disorders such as irritable bowel syndrome (IBS), mainly in its diarrhea variant (IBS-D). It is now well established that many people with IBS often describe worsening symptoms eating certain foods, such as those containing fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). These short-chain carbohydrates are present in some foods, including wheat and beans. They may contribute to different digestive symptoms such as bloating, abdominal pain, and diarrhea due to poor absorption in the small intestine. In this way, FODMAPs are digested by colonic bacteria, releasing gas in the colon.

Furthermore, FODMAPs can act as osmotic agents, increasing the water volume in the stool. In the last years, our group has focused research on the properties of a low FODMAPs diet (LFD) in the clinical management of patients with IBS-D, demonstrating that these patients benefit from a 12 weeks-LFD in mitigating the symptoms, reducing the inflammatory status, increasing the vitamin D content, and affecting the lipidomic profile. Unfortunately, adherence to LFD can be somewhat problematic, needing continuous nutritional support.

Actually, alternative dietary approaches for these disorders may be hypothesized. It is now well established that, beyond non-celiac wheat sensitivity (NCWS), many individuals suffering from IBS-D or generical gluten-related disorders and mainly complainIng of abdominal bloating seem to benefit from removing wheat from the diet.

The multifaceted setting of nutrients in wheat-based foods, other than gluten, could account for the different IBS symptoms. It has already been postulated that some monococcal diploid grain lines, with minimal activation of the innate immunity and a reduced amount of toxic gluten peptides, could be helpful for IBS-D patients. Among them, alternative grains such as Tritordeum seem to achieve good results. Tritordeum is a cereal derived from durum wheat and wild barley hybridization. Originally cultivated with traditional techniques in Spain, it has more recently grown in Apulia, a southern Italy region. Tritordeum grows well with little care, even in adverse conditions. Noteworthy, this cereal has significantly lower levels of gliadins, fewer carbohydrates and fructans, and a higher content of dietary fibers, proteins, and antioxidants than classic wheat. However, the presence of gluten makes this cereal not suitable for celiac patients.

Thus, cereals such as Tritordeum, once further characterized in their proteomic profile and gluten composition, could offer opportunities for an innovative nutritional approach for patients suffering from IBS and, more in general, wheat-related disorders. Our group recently performed a pilot study to investigate the effects of a 12-week diet with Tritordeum-based foods (bread, bakery products, and pasta) in substitution of other cereals on the GI symptoms and the status of the GI barrier in IBS-D patients. This diet proved to reduce the patients' symptoms by affecting intestinal permeability significantly. The purpose of this study is to evaluate, in a randomized controlled trial, the beneficial effects of 12-weeks of TBD compared with LFD or specific advice for IBS of the same duration in improving the symptom profile of IBS-D patients.