Fish Odor Syndrome or Trimethylaminuria: Causes, Symptoms, Treatment

Fish Odor Syndrome which is also known by the name of trimethylaminuria is a rare genetic disorder in which the body is unable to process a compound called trimethylamine. This chemical is found in many food products and is normally absorbed by the body and eliminated but in some people this ability of processing or absorbing trimethylamine is absent which results in the chemical being eliminated from the body through sweat, breath and urine giving a pungent smell which is similar to that of a rotten fish or garbage.

Fish odor syndrome or trimethylaminuria may become quite embarrassing for individuals, especially who go outside for work and other social activities. Fish odor syndrome or trimethylaminuria tends to get worse in females at the time of their menstrual periods. Trimethylamine is about in abundance in choline rich foods like eggs, wheat, and certain meats. The best way to prevent fish odor syndrome or trimethylaminuria is by eating less of the choline rich food and foods that are low in calories.

The cause of fish odor syndrome or trimethylaminuria can be better understood if we understand a little bit of the digestive system of the body. There are quite a few bacteria present in the stomach which help digest food like eggs, beans, and other seafood which are rich in choline. During this process of digestion they release a chemical called trimethylamine.

Under normal circumstances, this trimethylamine is converted to an odorless trimethylamine oxide by an enzyme found in the liver called FMO3. Majority of people have the gene called FMO3 which helps in the production of the enzyme FMO3 but in some cases this gene is either completely absent or is defective and unable to work properly allowing a gradual buildup of trimethylamine in the body.

This results in the trimethylamine to be released from the body through urine, sweat and breath resulting in Fish odor syndrome or trimethylaminuria. In most of the cases of Fish Odor Syndrome, the faulty FMO3 gene is inherited from both parents.

There are also certain other causes of Fish odor syndrome or trimethylaminuria. These causes are presence of certain proteins in excess or an increase in the bacteria in the stomach that produces trimethylamine. Some cases of fish odor syndrome or trimethylaminuria have been linked to kidney or liver dysfunction which results in the FMO3 enzyme not working properly resulting in Fish Odor Syndrome.

Females are more likely to get fish odor syndrome or trimethylaminuria than males as the sex hormones of females tend to aggravate the symptoms. Fish odor syndrome or trimethylaminuria in females is typically worse around the menstrual periods, upon taking a contraceptive pill, or around menopause. Additionally stress and unhealthy diet have also found to be a cause for development of fish odor syndrome or trimethylaminuria.

Apart from having a strong pungent smell in the sweat, urine, saliva, and certain vaginal fluids there are no additional symptoms caused by fish odor syndrome or trimethylaminuria. The intensity of the odor may vary and sometimes the affected individual may have a very strong smell but at other times they tend to have much mild smell.

The smell from fish odor syndrome or trimethylaminuria usually begins in childhood and slowly starts to become apparent, although in some cases it has begun in adulthood as well. In some children, fish odor syndrome or trimethylaminuria may be temporary and gradually as the child grows the smell slowly goes away.

Fish odor syndrome or trimethylaminuria is normally diagnosed through a urinalysis which measures the amount of trimethylamine and trimethylamine oxide in the body. If the level of trimethylamine is more than trimethylamine oxide then the diagnosis is confirmed of fish odor syndrome or trimethylaminuria.

This test is usually done after giving the patient food rich in choline for best result to diagnose fish odor syndrome or trimethylaminuria. In some cases gene testing may also be done to see whether there are any abnormalities in the FMO3 gene causing fish odor syndrome or trimethylaminuria.

As of now there is no definitive treatment for fish odor syndrome or trimethylaminuria except for certain lifestyle and dietary changes. There are also certain medications that can be prescribed to reduce the amount of trimethylamine in the body.

Some of the dietary and lifestyle changes that can be made for fish odor syndrome or trimethylaminuria are:

Avoiding foods that are rich in choline like cow milk, eggs, liver, peas, beans, peanuts, broccoli, cabbage, cauliflower, and seafood. For females who are pregnant or planning to get pregnant a consultation with a nutritionist or a dietician is recommended who can formulate a diet plan best suites for the patient with less choline containing foods.

Taking low doses of antibiotics may help with eliminating the bacteria which form trimethylamine from the stomach resulting in less buildup of trimethylamine in the body and thus reducing the symptoms of fish odor syndrome or trimethylaminuria. It should be noted here that the antibiotics should be taken in small doses and for a short period of time in order to avoid antibiotic resistance. Additionally, one can use laxatives to speed up the bowel movements so that less trimethylamine is present in the body to help with fish odor syndrome or trimethylaminuria.

There are certain supplements which can be taken in small amounts to reduce the symptoms of fish odor syndrome or trimethylaminuria like charcoal 750 mg for about 10 days two times a day, riboflavin supplements to enhance FMO3 enzyme so that more and more amounts of trimethylamine is converted to its oxide and odorless form and reduce the symptoms of fish odor syndrome or trimethylaminuria.

There are also certain other lifestyle measures that one can incorporate in the daily routine like when exercising trying less weights so that there is less amount of sweat produced to help with the symptoms of fish odor syndrome or trimethylaminuria.

Fish odor syndrome or trimethylaminuria may be an embarrassing condition for many people and may lead to depression and social withdrawal. This is where counseling from a psychologist may help a great deal in patients to cope up with the symptoms of Fish Odor Syndrome.