Gut microbiota in children with type 1 diabetes differs from that in healthy children: a case-control study Original paper

What was studied?

This case-control study characterized gut microbiota signatures in pediatric type 1 diabetes by comparing fecal bacterial community profiles and targeted bacterial quantification in children with established type 1 diabetes versus matched healthy controls. Using PCR–denaturing gradient gel electrophoresis (PCR-DGGE) to assess dominant community structure plus quantitative real-time PCR (qPCR) for specific taxa, the investigators tested whether type 1 diabetes is linked to a distinct gut microbiota pattern and whether those microbial differences relate to glycemic measures (plasma glucose and HbA1c).

Who was studied

Thirty-two Caucasian children were enrolled: 16 with type 1 diabetes (mean age ~7.2 years; mean diabetes duration ~4.8 years) and 16 healthy children (mean age ~7.5 years). Controls were matched for age, sex, race, delivery mode (vaginal vs Cesarean), and breastfeeding duration, and all participants avoided antibiotics, probiotics, or other microbiota-altering treatments for the prior 3 months. Children with other inflammatory or infectious conditions were excluded; stool samples were collected at home and frozen promptly for analysis.

Most important findings

Children with diabetes showed a clearly shifted fecal microbial ecology versus controls, with lower within-group similarity and markedly lower between-group similarity on DGGE—supporting a disease-associated community structure difference. Quantitatively, diabetes was associated with decreased Firmicutes and Actinobacteria, increased Bacteroidetes, and a significantly reduced Firmicutes: Bacteroidetes ratio. At genus/group level, diabetes was characterized by higher Clostridium, Bacteroides, and Veillonella, alongside lower Lactobacillus, Bifidobacterium, Prevotella, and the Blautia coccoides/Eubacterium rectale group—taxa often discussed as lactic-acid and butyrate-linked, barrier-supporting guilds. Importantly for a microbiome-signatures database, several signals tracked glycemia: Bifidobacterium and Lactobacillus (and the Firmicutes: Bacteroidetes ratio) correlated negatively with plasma glucose, while Clostridium correlated positively with glucose and HbA1c; multivariable models highlighted lower Bifidobacterium and Lactobacillus as predictors of higher glucose, and lower Firmicutes :Bacteroidetes ratio plus higher Clostridium as predictors of higher HbA1c.

Key implications

This work supports a recognizable, clinically relevant gut microbiota signature in pediatric type 1 diabetes—one marked by a lower Firmicutes:Bacteroidetes ratio, depletion of Bifidobacterium/Lactobacillus and putative butyrate-associated groups, and enrichment of Clostridium/Bacteroides/Veillonella—alongside correlations with glycemic control. For clinicians, the practical takeaway is not “microbiome test equals diagnosis,” but that microbiota patterns plausibly intersect with barrier biology and metabolic regulation, making them candidates for risk stratification research and adjunctive interventions (dietary, pre/probiotic, or other microbiota-modulating strategies). The small sample size and cross-sectional design limit causal inference, so these signatures should be treated as hypothesis-generating biomarkers rather than targets ready for routine care.

Citation

Murri M, Leiva I, Gomez-Zumaquero JM, Tinahones FJ, Cardona F, Soriguer F, Queipo-Ortuño MI. Gut microbiota in children with type 1 diabetes differs from that in healthy children: a case-control study. BMC Medicine. 2013;11:46. doi:10.1186/1741-7015-11-46