(P11-063-23) Trimethylamine N-Oxide Is Associated With Dietary Choline Intake, but Not With Egg, Fish, or Betaine Intakes in Toddlers From Vancouver, Canada

Objectives: Trimethylamine N-oxide (TMAO) is a metabolite synthesized from trimethylamine, which is produced by the gut microbiota from dietary choline, betaine, and carnitine. There are also dietary sources of TMAO, such as fish. Circulating TMAO has been implicated with the risk of cardiovascular disease in adults, but little is known about TMAO in children. The objective of this study was to determine the relationships between plasma TMAO concentrations and dietary precursors (choline, individual forms of choline, and betaine) and plasma choline metabolites (free choline, betaine, and dimethylglycine) in toddlers.

Methods: Participants (n=133) were from a randomized controlled trial of fatty acid supplementation between ages 1 and 2 years in Vancouver, Canada. Plasma TMAO, choline, and choline metabolite concentrations were quantified by LC-MS/MS. Dietary information was collected by three non-consecutive day food records (usual intake) and one 24-hour recall before blood collection (recent intake). Daily nutrient intakes were estimated using the Canadian Nutrient File and USDA database of choline.

Results: Plasma TMAO concentrations were (median [IQR]) 1.65 (1.12-2.44) µmol/L at age 1 year and 1.91 (1.32-2.70) µmol/L at age 2 years. TMAO concentrations did not differ by age, sex, or ethnicity. Plasma TMAO concentrations were unrelated to usual and recent egg and fish intakes. At age 1 year, TMAO concentrations were positively associated with usual intakes of phosphocholine (ρ=0.205; P=0.036) and sphingomyelin (ρ=0.199; P=0.042). At age 2 years, TMAO concentrations were positively associated with recent intakes of total choline (ρ=0.210; P=0.039) and phosphatidylcholine (ρ=0.316; P=0.002). TMAO concentrations were not associated with plasma choline metabolites.

Conclusions: TMAO concentrations were not associated with egg or fish intake in toddlers. Positive associations between dietary choline intakes and TMAO concentrations were found, but were inconsistent among choline forms. Additional research is needed to confirm these findings in larger pediatric populations.

Funding Sources: Funding was received from BC Hospital Children’s Hospital, NSERC. The funders had no role in the study design and data analyses.