Objectives:Treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). Patients should be followed-up with dietary interviews and serology as CD markers to ensure adherence to the diet. However, none of these methods offer an accurate measure of dietary compliance. Our aim was to evaluate the measurement of gluten immunogenic peptides (GIP) in stools as a marker of GFD adherence in CD patients and compare it with traditional methods of GFD monitoring.Methods:We performed a prospective, nonrandomized, multicenter study including 188 CD patients on GFD and 84 healthy controls. Subjects were given a dietary questionnaire and fecal GIP quantified by enzyme-linked immunosorbent assay (ELISA). Serological anti-tissue transglutaminase (anti-tTG) IgA and anti-deamidated gliadin peptide (anti-DGP) IgA antibodies were measured simultaneously.Results:Of the 188 celiac patients, 56 (29.8%) had detectable GIP levels in stools. There was significant association between age and GIP in stools that revealed increasing dietary transgressions with advancing age (39.2% in subjects ≥13 years old) and with gender in certain age groups (60% in men ≥13 years old). No association was found between fecal GIP and dietary questionnaire or anti-tTG antibodies. However, association was detected between GIP and anti-DGP antibodies, although 46 of the 53 GIP stool-positive patients were negative for anti-DGP.Conclusions:Detection of gluten peptides in stools reveals limitations of traditional methods for monitoring GFD in celiac patients. The GIP ELISA enables direct and quantitative assessment of gluten exposure early after ingestion and could aid in the diagnosis and clinical management of nonresponsive CD and refractory CD. Trial registration number NCT02711397.

Gluten, a common component in the human diet, is capable of triggering coeliac disease pathogenesis in genetically predisposed individuals. Although the function of human digestive proteases in gluten proteins is quite well known, the role of intestinal microbiota in the metabolism of proteins is frequently underestimated. The aim of this study was the isolation and characterisation of the human gut bacteria involved in the metabolism of gluten proteins. Twenty-two human faecal samples were cultured with gluten as the principal nitrogen source, and 144 strains belonging to 35 bacterial species that may be involved in gluten metabolism in the human gut were isolated. Interestingly, 94 strains were able to metabolise gluten, 61 strains showed an extracellular proteolytic activity against gluten proteins, and several strains showed a peptidasic activity towards the 33-mer peptide, an immunogenic peptide in patients with coeliac disease. Most of the strains were classified within the phyla Firmicutes and Actinobacteria, mainly from the genera Lactobacillus, Streptococcus, Staphylococcus, Clostridium and Bifidobacterium. In conclusion, the human intestine exhibits a large variety of bacteria capable of utilising gluten proteins and peptides as nutrients. These bacteria could have an important role in gluten metabolism and could offer promising new treatment modalities for coeliac disease.

These results suggest that tritordeum may be an option of interest for general food processing, and especially for those who want to reduce their intake of gluten. However, it is not suitable for celiac disease sufferers as it contains gluten. © 2017 Society of Chemical Industry.

Celiac disease may appear both in early childhood and in elderly subjects. Current knowledge of the disease has revealed some differences associated to the age of presentation. Furthermore, monitoring and prognosis of celiac subjects can vary depending on the pediatric or adult stage. The main objective of this review is to provide guidance for the adult diagnostic and follow-up processes, which must be tailored specifically for adults and be different from pediatric patients.