Oral Carnitine Challenge Test Guides Personalized Nutrition for CV Patients

Investigation on Clinical Application of Oral Carnitine Challenge Test as a Guidance of Personalized Nutrition for Patients With Cardiovascular Disease

The investigators plan to use the recently developed oral carnitine challenge test (OCCT) as a tool to exam individual's trimethylamine N-oxide (TMAO) production capacity from their gut microbiota. By using data collected by OCCT, the investigators defined subjects as high-TMAO producer or low-TMAO producer and apply low carnitine/choline diet as dietary intervention for the high-TMAO producers. After dietary intervention for two months, the investigators conducted OCCT for the participants and compare the TMAO production capacity before and after the dietary intervention.

Patients diagnosed with cardiovascular disease at the CV clinics are being recruited to undergo the Oral Carnitine Challenge Test (OCCT) to assess the TMAO production capacity of their gut microbiota. Participants identified as high-TMAO producers will be invited to partake in a two-month vegetarian diet intervention, supervised by a registered dietitian, followed by a three-month period of reverting to their regular diet. The OCCT will be conducted before and after the vegetarian diet intervention, as well as after the diet recovery phase. Fecal samples will be collected and analyzed at the baseline, in the second month, and in the fifth month of the study.

Inclusion Criteria:

• Patient with risks of cardiovascular disease (CAD) or CAD patients proved by coronary angiography

Exclusion Criteria:

• age < 20, hx of GI surgery, hx of malignancy, antibiotic or probiotic or carnitine supplement use within one month, liver cirrhosis, end stage chronic renal disease