The Fish malodor syndrome, also known as the Fish odor syndrome or Trimethylaminuria (TMAU) is a rare metabolic disorder, a genetic disorder characterized by the presence of abnormal amounts of the dietary-derived tertiary amine, trimethylamine, in the urine, sweat, and breath, and other bodily secretions such as reproductive fluids, causing people who suffer from TMAU to emit the smell of rotting-fish (trimethylamine itself has the powerful aroma of rotting fish), and this gives the sufferer a highly objectionable body odor (body malodor), which can be destructive to the personal, social, and work life of the sufferers, some people with trimethylaminuria have a strong odor all the time, but most have a moderate smell that varies in intensity over time. People suffer from Fish malodor syndrome do not have any physical symptoms, and typically appear healthy, it has nothing to do with personal hygiene, TMAU is more common in women than men,
The fish malodor syndrome causes a defect in the normal production of the enzyme Flavin containing monooxygenase 3 / FMO3, The flavin-containing monooxygenase (FMO3) protein family consists of a group of enzymes that catalyze chemical reactions via the bound cofactor flavin. These reactions involve oxidation of heteroatoms, particularly nucleophilic atoms such as the nitrogen of amines.
When FMO3 is not working correctly or if not enough enzyme is produced, the body is unable to metabolize trimethylamine from food sources, the body loses the ability to properly breakdown trimethylamine (TMA) from precursor compounds in food into trimethylamine oxide / TMAO (non-odorous metabolite) through a process called N-oxygenation (trimethylamine-oxidase deficiency). Trimethylamine then builds up and is released in the person's urine, sweat, and breath, giving off a strong fishy odor, especially after consumption of cholin-rich foods, this malodor varies depending on many known factors, including diet, hormonal changes, other odors in the space, and individual sense of smell.
TMAU is a life-disruptive disorder caused by both genetic and environmental factors, living with TMAU is challenging, and it can adversely affect the livelihood of
adults who have it and their families, children with this condition could face rejection or a lack of understanding from their friends during school or at play
Trimethylamine is a product of decomposition of plants and animals. It is the substance mainly responsible for the odor often associated with unpleasant smell fish, some infections, and bad breath, trimethylamine is flammable tertiary amine has a strong "fishy" odor in low concentrations and an “ammonia-like” odor at higher concentrations, it is a gas at room temperature
The flavin-containing monooxygenase 3 (FMO3) protein family consists of a group of enzymes that catalyze chemical reactions via the bound cofactor flavin. These
reactions involve oxidation of heteroatoms, particularly nucleophilic atoms such as the nitrogen of amines.
There are two major subtypes of fish malodor syndrome :
- That are related to a dysfunction of the normal enzyme activity due to genetic, hormonal, or inhibitory-chemical influences;
- That are arised from substrate overload of the enzyme activity (normal or depressed) such as an excess of dietary precursors of trimethylamine or variations in the gut microflora resulting in enhanced liberation of trimethylamine.
Treatment
There is no perfect cure for trimethylaminuria, and treatment options are limited, it is possible for some people suffer from TMAU live relatively normal, healthy lives without the fear of being kept away / avoided from other people because of their unpleasant odor.
Ways of reducing the fish malodor syndrome :
Fighting Fish Odor Syndrome !
- Reduce the intake of precursors of trimethylamine (TMA) by avoiding foods such as eggs, legumes, certain meats, fish, and foods that contain the amino-acid: choline found in fish, eggs, beans, and organ meats, carnitine, nitrogen, and sulfur (low protein diet), limiting lecithin, a common food additive that also occurs naturally in eggs, soybeans, and corn.
- Avoid broccoli and greens, broccoli and other dark green vegetables contains indole-3-carbinol (I-3-C) which inhibits breakdown of TMA.
- Increasing the intake of water, and taking a good probiotic to increase the number of friendly bacteria in the intestinal tract.
- Taking low doses of antibiotics to reduce the amount of bacteria in the gut, or a short course of neomycin and metronidazole to reduce the activity of the gut micro flora.
- Using slightly acidic detergents with a pH between 5.5 and 6.5.
- Gene therapy with replacement of the human gene for FMO3.
- Daily intake of gut absorbents like charcoal, ion-exchange resins, or copper chlorophyllin to modify the gut flora to reduce the bacterial species responsible for the conversion of precursors to trimethylamine, may be of significant use in improving the quality of life of individuals suffering mild forms of TMAU, but not always success.
- Incorporate micro-organisms "engineered" with human FMO3 into the gut flora,
- To oxidize any trimethylamine released to its non-odorous N-oxide,
- Provide riboflavin supplements, a precursor of the FAD cofactor for flavin monooxygenase function, in an attempt to maximize any residual activity,
- Use "malodor suppressants" in hygiene products to disguise the offensive smell of trimethylamine.
- Behavioral counseling to help with depression and other psychological symptoms
- Genetic counseling to better understand their condition.