Impact of Geographical Location on the Gut Microbiota Profile in Egyptian Children with Type 1 Diabetes Mellitus: A Pilot Study.

Purpose: To investigate the compositional and functional characteristics of T1DM-associated gut microbiota in two Egyptian cities and to study the geographical locality effects. Patients and Methods: This case-control study included 32 children with controlled T1DM and 16 controls, selected from two different regions of Egypt. The gut microbiota of both diabetic and control children was analyzed through 16S rRNA gene sequencing; this was done using the Illumina MiSeq platform. Results: Consistent findings among the diabetic children included significantly lower alpha diversity than the control children, as well as a lower mean Firmicutes/Bacteroidetes (F/B) ratio, and reduced proportions of Firmicutes and the genera Prevotella and Ruminococcus. In the diabetic children, there were also significantly enriched representations of Actinobacteria, Bacteroidetes, and Proteobacteria and the genera Lactobacilli, Bacteroides, and Faecalibacterium. When comparing the two diabetic groups, the Ismailia group (IsDM) was found to have a significantly higher F/B ratio and diversity indices, with resultant differences at the functional level. Conclusion: There are a number of consistent changes in the microbiota profile characterizing the diabetic groups irrespective of the geographical location including significantly lower alpha diversity, mean Firmicutes/ Bacteroidetes (F/B) ratio, and reduced proportions of Firmicutes and genera Prevotella and Ruminococcus. There are also significantly enriched representations of Actinobacteria, Bacteroidetes, and Proteobacteria and genera Lactobacilli, Bacteroides, and Faecalibacterium pointing to the greater driving power of the disease.