Distinctive Microbial Signatures and Gut-Brain Crosstalk in Pediatric Patients with Coeliac Disease and Type 1 Diabetes Mellitus.

Coeliac disease (CD) and Type 1 diabetes mellitus (T1DM) are immune-mediated diseases. Emerging evidence suggests that dysbiosis in the gut microbiome plays a role in the pathogenesis of both diseases and may also be associated with the development of neuropathy. The primary goal in this cross-sectional pilot study was to identify whether there are distinct gut microbiota alterations in children with CD (n = 19), T1DM (n = 18) and both CD and T1DM (n = 9) compared to healthy controls (n = 12). Our second goal was to explore the relationship between neuropathy (corneal nerve fiber damage) and the gut microbiome composition. Microbiota composition was determined by 16S rRNA gene sequencing. Corneal confocal microscopy was used to determine nerve fiber damage. There was a significant difference in the overall microbial diversity between the four groups with healthy controls having a greater microbial diversity as compared to the patients. The abundance of pathogenic proteobacteria Shigella and E. coli were significantly higher in CD patients. Differential abundance analysis showed that several bacterial amplicon sequence variants (ASVs) distinguished CD from T1DM. The tissue transglutaminase antibody correlated significantly with a decrease in gut microbial diversity. Furthermore, the Bacteroidetes phylum, specifically the genus Parabacteroides was significantly correlated with corneal nerve fiber loss in the subjects with neuropathic damage belonging to the diseased groups. We conclude that disease-specific gut microbial features traceable down to the ASV level distinguish children with CD from T1DM and specific gut microbial signatures may be associated with small fiber neuropathy. Further research on the mechanisms linking altered microbial diversity with neuropathy are warranted.

Outcome associated with EPCAM founder mutation c.499dup in Qatar.

Tufting enteropathy (TE) is a rare autosomal recessive congenital enteropathy that usually requires long-term parenteral nutrition (PN). In the Arabic Peninsula, four distinct EPCAM mutations have been identified to cause TE. As consanguineous marriages are socially favored, pre-marital and pre-conception testing has become a critical disease prevention strategy. This study aimed to identify the pathogenic EPCAM mutations causing TE in Qatari families and determine possible genotype-phenotype correlations. Twenty-two TE patients from seven multiplex families with TE were identified. Blood samples were collected from patients and first-degree relatives. Exons of the gene were amplified and sequenced. Retrospective chart review and/or family interviews were conducted to determine phenotypic characteristics of the disease. Sequence analysis revealed a single, previously described c.499dup mutation in exon 5 of all families tested, suggesting a founder effect. Of the 18 patients whose full clinical information was available, three patients (17%) were off PN with a good quality of life, without intestinal transplantation, and one (6%) was receiving partial PN. Our patients with TE were severely stunted compared to a similar group of patients receiving long-term PN for short bowel syndrome, suggesting that this could possibly be due to TE rather than secondary to inadequate nutrition. Our study identified the EPCAM mutation c.499dup as the genetic defect causing TE in all the participant Qatari families. This finding should facilitate early diagnosis of TE and genetic counseling. Furthermore, it should aid in the prevention of TE through pre-marital screening, antenatal diagnosis, and pre-implantation genetic diagnosis.