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  • Lab Values
  • Clinical Significance
  • Treatment Options
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Test Code 630

Test Details

TMAO

Trimethylamine N-oxide (TMAO) levels in blood quantified by reverse phase liquid chromatography-mass spectrometry (LC-MS/MS) to help clinicians optimize wellness and longevity related to the interaction between diet and intestinal bacteria.

Methodology

LC-MS/MS

Patient Preparation

  • 8-12 hour fast prior to collection. Patient may drink water, black coffee or tea only (no dairy or sugar).
  • Fish and shellfish should be avoided for 24 hours before testing.

Preferred Specimen

1.0 mL serum collected in a serum separator tube (SST / Tiger Top)

Alternate Specimen

1.0 mL plasma collected in a plasma separator tube (PST/Pearl Top)

Transport Temperature

Refrigerated (ship on frozen cold packs)

Stability

Refrigerated: 7 days

Lab Values

Lab Values

TMAO

  • Optimal: <5.0 umol/L
  • Borderline: 5.0-7.9 umol/L
  • Increased Risk: >7.9 umol/L
Test Details
Clinical Significance

Clinical Significance

TMAO

  • Blood levels of TMAO reflect the relationship between dietary patterns, intestinal bacteria, and health. Dietary precursors such as carnitine, phosphatidylcholine (lecithin), choline, and betaine, which are all found in animal products, are metabolized by certain intestinal bacteria into trimethlyamine (TMA) gas, which is absorbed into the bloodstream and oxidized into TMAO by liver enzymes, primarily flavin monooxigenase.3 Animal studies suggest elevated TMAO has a deleterious effect on cholesterol, sterol, and bile acid metabolism. TMAO levels are associated with longevity and mortality; lower blood levels of TMAO are more favorable than higher levels.

References

  1.  Tan X, Liu Y, Long J, Chen S, Liao G, Wu S, Li C, Wang L, Ling W, Zhu H. Trimethylamine N-Oxide Aggravates Liver Steatosis through Modulation of Bile Acid Metabolism and Inhibition of Farnesoid X Receptor Signaling in Nonalcoholic Fatty Liver Disease. Mol Nutr Food Res. 2019 Sep;63(17):e1900257.
  2. Canyelles M, Tondo M, Cedó L, Farràs M, Escolà-Gil JC, Blanco-Vaca F. Trimethylamine N-Oxide: A Link among Diet, Gut Microbiota, Gene Regulation of Liver and Intestine Cholesterol Homeostasis and HDL Function. Int J Mol Sci. 2018;19(10):3228. Published 2018 Oct 19.
  3. Ke Y, Li D, Zhao M, Liu C, Liu J, Zeng A, Shi X, Cheng S, Pan B, Zheng L, Hong H. Gut flora-dependent metabolite Trimethylamine-N-oxide accelerates endothelial cell senescence and vascular aging through oxidative stress. Free Radic Biol Med. 2018 Feb 20;116:88-100.
  4. Cho CE, Taesuwan S, Malysheva OV, Bender E, Tulchinsky NF, Yan J, Sutter JL, Caudill MA. Trimethylamine-N-oxide (TMAO) response to animal source foods varies among healthy young men and is influenced by their gut microbiota composition: A randomized controlled trial. Mol Nutr Food Res. 2017 Jan;61(1). doi: 10.1002/mnfr.201600324. Epub 2016 Aug 3. PMID: 27377678.
  5. Fu BC, Hullar MAJ, Randolph TW, Franke AA, Monroe KR, Cheng I, Wilkens LR, Shepherd JA, Madeleine MM, Le Marchand L, Lim U, Lampe JW. Associations of plasma trimethylamine N-oxide, choline, carnitine, and betaine with inflammatory and cardiometabolic risk biomarkers and the fecal microbiome in the Multiethnic Cohort Adiposity Phenotype Study. Am J Clin Nutr. 2020 Jun 1;111(6):1226-1234.
  6. Heianza Y, Ma W, Manson JE, Rexrode KM, Qi L. Gut Microbiota Metabolites and Risk of Major Adverse Cardiovascular Disease Events and Death: A Systematic Review and Meta-Analysis of Prospective Studies. J Am Heart Assoc. 2017 Jun 29;6(7):e004947.
Lab Values
Treatment Options

Treatment Options

TMAO

Dietary changes reduce TMAO levels.

  • Chronic consumption of red meat, egg yolks, dairy, and/or supplements high in carnitine or choline increases TMAO levels.
  • Discontinuation of the above dietary sources substantially reduces TMAO within several weeks.
  • Longstanding dietary improvements may potentially improve the intestinal microbial ecosystem, reduce dysbiosis and decrease bacteria that produce TMAO.

References

  1.  Crimarco A, Springfield S, Petlura C, et al. A randomized crossover trial on the effect of plant-based compared with animal-based meat on trimethylamine-N-oxide and cardiovascular disease risk factors in generally healthy adults: Study With Appetizing Plantfood-Meat Eating Alternative Trial (SWAP-MEAT). Am J Clin Nutr. 2020 Aug 11:nqaa203.
  2.  Gertz E, Wang Y, O’Connor L, Campbell W, Bennett B. A Mediterranean-style Eating Pattern Lower in Lean Red Meat Reduced Plasma Trimethylamine N-Oxide in Adults Classified as Overweight or Obese (P08-030-19). Curr Dev Nutr. 2019;3(Suppl 1):nzz044.P08-030-19. Published 2019 Oct 24.
  3. Barrea L, Annunziata G, Muscogiuri G, Laudisio D, Di Somma C, Maisto M, Tenore GC, Colao A, Savastano S. Trimethylamine N-oxide, Mediterranean diet, and nutrition in healthy, normal-weight adults: also a matter of sex? Nutrition. 2019 Jun;62:7-17.
  4. Fu BC, Hullar MAJ, Randolph TW, Franke AA, Monroe KR, Cheng I, Wilkens LR, Shepherd JA, Madeleine MM, Le Marchand L, Lim U, Lampe JW. Associations of plasma trimethylamine N-oxide, choline, carnitine, and betaine with inflammatory and cardiometabolic risk biomarkers and the fecal microbiome in the Multiethnic Cohort Adiposity Phenotype Study. Am J Clin Nutr. 2020 Jun 1;111(6):1226-1234.
Clinical Significance