Impact of probiotics on gut microbiota composition and clinical symptoms of coeliac disease patients following gluten-free diet.

Coeliac disease (CD) is associated with alterations in gut microbiota composition. This study evaluated the effects of probiotics on gut microbiota composition and clinical symptoms of treated CD patients. In this double-blind, placebo-controlled trial study, 31 CD patients that were randomly classified as probiotics (n = 15) and placebo (n = 16) groups received 109 colony-forming units/capsule for 12 weeks. Fecal samples were collected before and after probiotics, or placebo administration and the changes in intestinal microbiota were assessed by quantitative real-time PCR. Probiotic administration improved the patients' clinical symptoms when compared to the placebo group. Fatigue score was significantly reduced by the intake of probiotic supplements (P = 0.02). Except for Staphylococcus spp., the relative abundances of Bacteroidetes, Lactobacillus spp., Bifidobacterium spp., Clostridium cluster I, Enterobacteriaceae, and Firmicutes were higher in probiotics group. Accordingly, a 12-week multi-strain probiotic treatment regimen may modify the composition of intestinal microbiota and improve GI symptoms in CD patients.

Evaluation of gut microbiota of iranian patients with celiac disease, non-celiac wheat sensitivity, and irritable bowel syndrome: are there any similarities?

BACKGROUND AND AIMS: Individuals with celiac disease (CD), non-celiac wheat sensitivity (NCWS), and irritable bowel syndrome (IBS), show overlapping clinical symptoms and experience gut dysbiosis. A limited number of studies so far compared the gut microbiota among these intestinal conditions. This study aimed to investigate the similarities in the gut microbiota among patients with CD, NCWS, and IBS in comparison to healthy controls (HC). MATERIALS AND METHODS: In this prospective study, in total 72 adult subjects, including CD (n = 15), NCWS (n = 12), IBS (n = 30), and HC (n = 15) were recruited. Fecal samples were collected from each individual. A quantitative real-time PCR (qPCR) test using 16S ribosomal RNA was conducted on stool samples to assess the relative abundance of Firmicutes, Bacteroidetes, Bifidobacterium spp., and Lactobacillus spp. RESULTS: In all groups, Firmicutes and Lactobacillus spp. had the highest and lowest relative abundance respectively. The phylum Firmicutes had a higher relative abundance in CD patients than other groups. On the other hand, the phylum Bacteroidetes had the highest relative abundance among healthy subjects but the lowest in patients with NCWS. The relative abundance of Bifidobacterium spp. was lower in subjects with CD (P = 0.035) and IBS (P = 0.001) compared to the HCs. Also, the alteration of Firmicutes to Bacteroidetes ratio (F/B ratio) was statistically significant in NCWS and CD patients compared to the HCs (P = 0.05). CONCLUSION: The principal coordinate analysis (PCoA), as a powerful multivariate analysis, suggested that the investigated gut microbial profile of patients with IBS and NCWS share more similarities to the HCs. In contrast, patients with CD had the most dissimilarity compared to the other groups in the context of the studied gut microbiota.

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.

Dietary patterns interact with APOA1/APOC3 polymorphisms to alter the risk of the metabolic syndrome: the Tehran Lipid and Glucose Study.

The interaction of genetic and dietary factors, as an area of CVD research, has been explored poorly. The aim of the present study was to examine the interaction of dietary patterns and three genetic variants of APOA1 and APOC3, both independently and in combination, relative to the risk of the metabolic syndrome (MetS) in Tehranian adults. In the present matched, nested case-control study, 414 subjects with the MetS and 414 controls were selected from the participants of the Tehran Lipid and Glucose Study. Dietary patterns were determined by factor analysis. APOC3 (rs5128 3238C>G) and APOA1 (rs670, -75G>A and rs5069,+83C>T) SNP were genotyped by the conventional PCR followed by the restriction fragment length polymorphism technique. Overall, three major dietary patterns were extracted: healthy dietary pattern (HDP); Western dietary pattern (WDP); fat-sweet dietary pattern (FSDP). The A and T allele carriers of the APOA1 SNP had a greater risk of developing the MetS in the highest quartile of WDP scores (OR 3·22, 95 % CI 1·21, 8·58, P(interaction)= 0·03). Compared with other genotype combinations, the combined effect of APOC3/APOA1 (CC/GA+AA/CT+TT) genotypes showed a further increase in the risk of the MetS in the highest quartile of WDP scores (OR 1, 2·49, 8·73, 6·32, P trend< 0·001, P(interaction)= 0·003). A significant interaction was found between the quartiles of FSDP scores and the APOA1 diplotype (GA+AA/CT+TT). OR for these genotype carriers were 1, 0·65, 0·57 and 0·22 (P(trend)= 0·006) in the lowest to the highest quartile of FSDP scores when compared with the other combined genotypes (P(interaction)= 0·03). Our findings suggest that the WDP and FSDP are associated with APOA1 and APOC3 SNP in relation to the risk of the MetS.