The Metabolic Fate of Isotopically‐Labeled Trimethylamine‐ <i>N</i> ‐oxide (TMAO) in Humans
Bibliographic record
Abstract
Although trimethylamine‐ N ‐oxide (TMAO) is associated with chronic disease risk, little is known about the metabolic fate of orally consumed TMAO. As part of a randomized, controlled cross‐over study, healthy young men (n=40) consumed 50 mg deuterium‐labeled methyl‐d9‐TMAO (d9‐TMAO) and TMAO metabolites were measured in plasma, urine, stool and muscle. Plasma d9‐TMAO comprised ~75% of total TMAO at 2 h and remained elevated after 6 h. d9‐trimethylamine (d9‐TMA) and d6‐dimethylamine (d6‐DMA) became enriched in plasma with averages of 52% and 3% of total TMA and DMA, respectively, at 6 h. d9‐TMAO was excreted more rapidly during 0–6 h than 6–24 h, comprising 67% and 52%, respectively, of urinary TMAO. No d9‐TMAO was detected in feces. Interestingly, d9‐TMAO and d9‐TMA were detected in skeletal muscle (n=6) at 6 h, and the enrichment ratio of d9‐TMAO:d9‐TMA was influenced by a genetic variant in flavin‐containing monooxygenase ( FMO3 G472A). The heterozygous GA genotype had lower muscle d9‐TMAO:d9‐TMA than the homozygous wildtype GG genotype. In conclusion, orally consumed TMAO is rapidly absorbed, is metabolized in part to TMA and DMA, and is taken up by skeletal muscle, where evidence of impaired conversion of TMA to TMAO among carriers of the FMO3 472A variant allele is observed. Support or Funding Information Egg Nutrition Center, Beef Checkoff through the National Cattlemen's Beef Association, Canadian Institutes of Health Research Postdoctoral Fellowship.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".