The Effects of Type 1 Diabetes Mellitus and Increased Weight on Gut Microbiome and Urine Metabolome Profiles in Children

The investigators will obtain stool and urine samples from subjects aged 7-17 years in 4
groups:

- Group 1: Obese or overweight children within 3 years of diagnosis of T1D

- Group 2: Normal weight children within 3 years of diagnosis of T1D

- Group 3: Obese or overweight children without T1D

- Group 4: Normal weight children without T1D

Type 1 diabetes will be defined according to American Diabetes Association criteria along
with the presence of pancreatic autoantibodies (GAD65, ICA512, or insulin autoantibodies).
Obese and overweight status will be defined by BMI >85th percentile for age and gender
according to CDC criteria.

All subjects will provide one-time stool and first morning urine sample. Overweight or obese
subjects will additionally have a point of care blood glucose and hemoglobin A1c measurement
to ensure that they do not have diabetes.

The investigators will perform 16S rRNA sequencing of stool bacteria and mass spectrometry
measurement of urine metabolites.

Inclusion Criteria:

- Age 7 to 17 years

- Diagnosis of diabetes will be defined by current American Diabetes Association
criteria ° (fasting glucose > 126 mg/dl, 2 hour OGTT glucose > 200 mg/dl; random
glucose > 200 with symptoms of hyperglycemia; or HbA1c > 6.5%)

- Diabetes duration < 3 years

- Presence of pancreatic autoimmunity (GAD65, ICA512, or insulin autoantibody
positivity)

- Adult caregiver willing to actively support study participation

- Signed parental informed consent form and minor child informed assent form

Exclusion Criteria:

- Other significant organ system illness or condition (including psychiatric or
developmental disorder) that, in the opinion of the investigator, would prevent
participation