Trimethylamine N-oxide (TMAO) is a small organic compound naturally present in fish and seefood or generated by the bacterial breakdown of dietary phosphatidylcholine and carnitine-containing foods within the human gut microbiome. Elevated serum TMAO was previously reported to be associated with an elevated risk for cardiovascular events.

Aim of this study was to investigate the association between plasma levels of TMAO with the Mediterranean diet in a cohort of healthy adults.

Inclusion Criteria:

healthy subjects of both gender

Exclusion Criteria:

• age>65 years
• > BMI 30 kg/m2
• vegetarians
• smokers
• gastrointestinal diseases or complaints
• chronic illnesses or other metabolic diseases (including trimethylaminuria)
• abnormal blood chemistry values indicative of organ dysfunctions
• nutritional supplements, antibiotics or probiotics within 2 months of recruitment

Healthy subjects (n=84) aged 21-50 years with a BMI of 20-29.9 kg/m2, chosen among hospital volunteers and employees from the same geographical area. A sample size of n=40 was determined from a power analysis of a within-subject design to detect a 10% difference of plasma TMAO concentration at alfa<0.05 and β =0.8. Participants were screened by the use of a blood chemistry profile, cell count, and health history questionnaire.