Result determined after 20 years of research triggering foul-smelling body odors

After 20 years: discovered cause of putrid body odor

After 20 years of research, scientists have discovered why two siblings suffer from a carbonaceous body odor. The cause could affect tens of thousands of people. The experts now hope to be able to develop a drug therapy.

Researchers decrypt the cause of cabbage-like body odor after 20 years

It is not uncommon for people to develop a strong smell of sweat during summer temperatures, or to suffer from bad breath after eating certain foods. But some people exude an unpleasant body odor, although they neither overly sweat nor feed only on garlic, onions and Co. Even two siblings are doing so. They suffer from a kale-like body odor - and nobody knew why for a long time. 20 years ago, the family turned to the University Medical Center Freiburg. Now the researchers have decoded the cause.

Twenty years ago, two siblings, who have been suffering from a kale-like body odor since birth, went to a clinic. Now the researchers have deciphered the cause of the unpleasant odor. (Image: glisic_albina / fotolia.com)

Siblings have suffered from a foul-sulphurous body odor since birth

Foul-sulphurous body odor accompany a boy and his younger sister since their birth, reports the University Hospital Freiburg in a recent release.

Therefore, the family turned to the metabolic outpatient department of the Department of General Pediatrics of the University Hospital Freiburg around 20 years ago.

Professor Karl Otfried Schwab, then head of the consultation hours for metabolic, hormonal and sugar diseases at this clinic, examined the children in detail.

Together with Prof. dr. Jörn Oliver Sass, at that time Head of the Metabolism Laboratory of the University Hospital Freiburg and now Professor at the University of Bonn-Rhein-Sieg, he excludes all known causes of an unpleasant body odor.

Only now, a good 20 years later, have they identified, together with other colleagues from Europe and the USA, a cause for the body odor.

Over 80,000 people worldwide could be affected. The results were recently published in the journal Nature Genetics.

With persistent bad breath to the dentist

Unpleasant breath odor in the mouth is produced in more than 90 percent of cases by bacterial decomposition or inflammation processes.

With the help of comprehensive oral hygiene, bad breath can usually be avoided. Even home remedies such as sage tea can often help to get the problem under control.

"If the dentist does not find it, sufferers should seek out metabolic experts. Behind the smell of the mouth and body can also be metabolic diseases, "said Professor Schwab.

When the metabolism is disturbed, often certain molecules can not be properly degraded and accumulate in the body. Exhaled air, sweat, saliva and urine cause these substances to escape and spread an unpleasant odor.

Cabbage odor has genetic cause

In the case of the two siblings, who turned to the University Hospital Freiburg, the breath smells strongly sulfurous after cabbage.

The researchers of the clinic made a contact to Professor Dr. med. Ron Wevers and dr. Albert Tangerman from Nijmegen, Netherlands, who found elevated levels of methanethiol and dimethylsulfide in exhaled air as well as in urine and blood samples.

The cause of the degradation defect of methanethiol was completely unclear at this time.

Therefore, at the University Hospital Freiburg, a comprehensive comparative gene study in the family of those affected by Professor. Heymut Omran, today at the University Hospital Münster.

The scientists found a genome section, where they suspected the defect in the genome. However, no known human proteins could be identified there which could have explained an inhibition of the degradation of methanethiol.

Over 80,000 people worldwide may be affected

Many years later, a bacteriologist in Nijmegen made a significant contribution. He showed for the first time how methanethiol can be broken down by an oxidase - in bacteria.

When comparing bacterial and human genomes, the researchers finally found the protein that degrades the substances in the body.

All those affected by a Dutch, a Portuguese and a Freiburg family had their DNA mutations in exactly this human protein SELENBP1.

"The function of SELENBP1 might be to keep the concentration of methanethiol low in the air so that the human nose can detect the foul odors of volatile sulfur compounds in the environment," the researchers said, according to a Newsweek report..

"For the Freiburg brothers and sisters and other victims, this protein was not or almost not functional. Therefore, the noxious substances accumulated in the body and led to the unpleasant odor, "said Professor Schwab.

The researchers assume that about one in 90,000 people worldwide carries the hereditary defect. That would correspond to more than 80,000 affected people worldwide. Why the disease has so far only been detected in five people, may have different reasons.

Dietary change can help

"There may be other degradation pathways for these sulfur compounds that we do not know yet. Some sufferers use sprays and perfumes and cover up the smell, they do not even know that they have a disease, "said Professor Schwab.

Whether the genetic defect has a negative effect on the development of affected children is currently unclear, as is the role of the protein SELENBP1 in tumorigenesis and in chronic inflammatory processes.

So far, affected people can get over the unpleasant symptoms by changing their diet. "Of course, we hope that our research will help develop drug therapy at some point in the future. But that's still a long way to go ", says Professor Schwab. (Ad)