A study of fecal microbiota in newly diagnosed Egyptian patients with type 1 diabetes mellitus

Abstract

Objectives: To evaluate the alteration of gut microbiota in patients with newly diagnosed T1DMand its relation to disease etiology. Methods: This case control study was carried out on 50 children and adolescents: 30 newly diagnosed TIDM patients (less than 6 months) recruited from Diabetes clinic, children hospital, Ain Shams University, their ages ranged from 1.5 to15 years with mean age of 6.6 ± 4.1 years, they were 18 males (60%) and 12 females (40%), their disease duration ranged from 2 to 180 days with mean duration 43 ± 54 days. In addition 20 age, gender, race, mode of delivery, and duration of breastfeeding matched controls. Data collected regarding; Age, sex, disease duration, weight, height and BMI, HbA1c% and fasting c peptide (for patients), anti-insulin antibody titer (Cutoff value: 10IU/ml), anti-islet cell antibody titer (≥ 0.9 ng/ml is positive) by ELISA. Detection of fecal microbiota by DNA extraction and polymerase chain reaction amplification. Results: The 4 dominant phyla of microbiota were Bacteriodetes (42%), fermicutis (35%), proteobacteria (10%) and actinobacteria (8%). Total number of microbiota was significantly less in patients (P = 0.023) especially those with antibody positive titer(P = 0.015). Dysgonomonas, Parabacteroides, Clostridium, Ruminococcus, Bilophila and Trabulsiella were significantly increased in controls (P < 0.05) , while; prevotella, Faecalibacterium, Veillonella and Dialister were significantly decreased in controls (P < 0.05). Prevotella significantly increased in patients (p = 0.03) especially those with Antibody positive titers (p = 0.025). Prevotella titer was positively correlated to antiinsulin, antiislet cell antibody titers, HbA1c% and negatively correlated to fasting C-peptide (<0.01). Conclusion: Patients with newly diagnosed T1DM have decreased gut microbiota and increase in Prevotella species that predominates with antibody positivity indicating a strong link between microbiota (Prevotella) and autoimmunity inT1DM.