The study was halted due to low enrollment exacerbated by COVID-19.

The pilot study is designed to investigate the acute and chronic effects of the diet supplement tauroursodeoxycholic acid (TUDCA) on endothelial function in participants with type 2 diabetes mellitus.

This is a pilot study designed to investigate the effect of two doses of TUDCA on endothelial function.All subjects will receive 500 mg/day in a one week run-in period and then 1750 mg/day in one week treatment period. The study will consist of four visits (screening visit and three study visits), and last up to 2 weeks for individual subjects, depending on the time between visits. It is estimated that the study will last two years from IRB approval through data analysis.

Inclusion Criteria:

• Type 2 diabetes mellitus defined as fasting glucose greater than or equal to 120 mg/dL, HgA1C ≥6.5% or ongoing treatment with hypoglycemic medication.
• Willing to give written informed consent and able to understand, to participate in and to comply with the study requirements.

Exclusion Criteria:

• Women lactating or pregnant. All women with childbearing potential will undergo a urine pregnancy test at each visit to exclude pregnancy.
• Treatment with an investigational product within the last 30 days.
• Clinically evident major illness of other organ systems, including end-stage cancer, renal failure, or other conditions that in the opinion of the principal investigator make a clinical study inappropriate.
• Inability to provide informed consent.
• Clinical instability that would preclude withholding medications as determined by the study physician.