It is well-established that persons with type 1 diabetes (T1D) are at an increased risk for morbidity and mortality related to bone fracture due to poor bone health, however we do not fully understand the mechanism behind the increased fracture risk. We are examining bone health and the microbiome in adolescents and young adults with type 1 diabetes to better understand the reasons behind this increased risk.

This pilot study aims to look at measures of bone health, the gut microbiome and measures of glycemia/glycemic variability in those with preclinical and clinical diabetes. Our primary and secondary outcomes are to characterize these variables, with our long term objectives to better understand the natural history of bone health in T1D, help characterize the etiology of worse bone health in those with T1D, and try to identify potential time periods for intervention.

Inclusion Criteria:

- Willing and able to comply with study protocol

For participants with type 1 diabetes (T1D):

- T1D diagnosed clinically by an endocrinologist as documented in medical records.

Exclusion Criteria:

• use of oral or parenteral antibiotics within 3 months
• use of probiotics/prebiotics/synbiotics within 3 months of enrollment; persons who eat yogurt will be asked to stop for 30 days prior to stool collection
• use of medications that will affect bone, including glucocorticoids, bisphosphonates
• chronic medications (other than insulin for those with T1D or a stable dose of thyroid hormone)
• uncontrolled chronic gastrointestinal disease including celiac disease (persons with T1D will be screened for celiac disease with a Tissue Transglutaminase Antibody (tTG)/Immunoglobulin A (IgA) if not done in prior 2 years)
• known genetic syndrome that predisposes the participant to fracture (such as osteogenesis imperfect) or skeletal dysplasia that would affect skeletal assessment (such as hypochondroplasia)
• pregnancy
• Any other condition that in the opinion of the investigator would jeopardize the safety or rights of the subject participating in the study or would make it unlikely the subject could complete the study

Additional Exclusion Criteria for Healthy Controls:

• Presence of any diabetes autoantibody
• Presence of any type of diabetes or hyperglycemia (HbA1c≥5.7%)

Type 1 Diabetes