Bonitos with low content of malodorous trimethylamine as palliative care for self-reported Japanese trimethylaminuria subjects.

Trimethylaminuria is caused by excessive malodorous trimethylamine excreted via urine and body secretion by decreased hepatic flavin-containing monooxygenase 3 (FMO3) metabolic capacity for transforming non-odorous trimethylamine N-oxide. This study investigates foodstuff first in healthy volunteers for palliative care for self-reported Japanese trimethylaminuria subjects. Urinary excretion of total trimethylamine in volunteers was determined by gas chromatography under daily food intake or after ingestion of selected fish premeasured for total trimethylamine content. Frequency of individuals showing apparently <40% FMO3 metabolic capacity was 3.8% in 365 Japanese volunteers who suffered from self-reported malodor. Bonitos, especially red flesh, had the lowest total trimethylamine content (approximately 1 micromol per g tissue) among salmon, tuna, swordfish, sea bream or cod in this study. Mean excretion ratio of total trimethylamine in 8 h-urines from six healthy volunteers was approximately 90% after loading test by ingesting bonito (200 g) resulting in less than 2 micromol of free trimethylamine/mmol creatinine excreted in volunteers harboring high FMO3 metabolic capacity, in contrast to approximately 40% after ingestion of 200 g cod. These results in healthy volunteers suggest that bonito may be one of the best nutrient sources and palliative care for self-reported Japanese trimethylaminuria subjects.