Impact of Nutritional Profile on Gut Microbiota Diversity in Patients with Celiac Disease

The pathogenesis of celiac disease (CD) is significantly influenced by gut microbiota. Daily nutritional profile influences the diversity of gut microbiota. This study was aimed to compare the abundance of gut microbiota in CD patients compared to normal control (NC), and to investigate the impact of nutritional factors on their fecal microbiota diversity. In this study, a selected panel of intestinal bacteria was assessed in 31 confirmed CD patients adhering to gluten-free diet (GFD) for more than 6 months and in 20 NC subjects. Stool samples were collected from each participant, DNA was extracted, and absolute quantitative real-time PCR (qPCR) was carried out. The gut microbiota including Bacteroidetes, Bifidobacterium, Clostridium, Staphylococcus, Enterobacteiaceae, Firmicutes, and Lactobacillus were assessed. The quantities of fruits, vegetables, meat, liquids, sugar and gluten-free candy/bread consumption were evaluated using a questionnaire. The proportion of Bifidobacterium, Firmicutes, and Lactobacillus in CD cases was significantly lower than NC (P < 0.005). Significant correlation coefficients between Bifidobacterium and Lactobacillus (P < 0.001), and also Firmicutes and Lactobacillus (P < 0.001) were recorded. Moreover, a significant association between medium amount of meat and bean consumptions and low abundance of Lactobacillus and Firmicutes (P = 0.024 and P = 0.027, respectively), and also high amount of bean consumptions and low abundance of Lactobacillus (P = 0.027) in CD were observed. The results showed that meat and bean consumptions could reduce the beneficial bacteria including Firmicutes and Lactobacillus in CD patients. Therefore, changes in the gut microbiota abundance may contribute to dietary changes and unimproved CD symptoms.