Standing next to a person who just ate garlic and got on a bus or into an elevator is a disaster. Similarly, those who unfortunately have too strong armpit odor. Or worse, a careless person farting in public.
Who is the culprit? It is a question that you can see by looking at your face. But have you ever wondered where the body odor really comes from? What chemical compounds are the ultimate culprits in your mouth, under your arms, in your digestive tract and on your socks?
Let’s find out:
The smell in the mouth
In most cases, the cause of bad breath is the bacteria residing in it. The bacteria on your teeth, gums, tongue or in your throat are constantly metabolizing and releasing waste products. These chemicals have an odor and a mixture of smells that creates mouth sores.
The main contribution to the odor in your mouth is volatile sulfur compounds (VSC). Such as hydrogen sulfide (H2S) has the smell of rotten eggs, methanethiol (also known as methyl mercaptan – CH4S) smell of rotten cabbage, and dimethyl sulfide ((CH3)2S) smells similar to garlic.
At a low concentration, the human nose cannot smell these compounds. But the threshold that makes all eyes on the elevator focus on you is not too high. For example, hydrogen sulfide concentration (H2S) up to 0.00047 parts per million could be smelled by human nose.
In addition to the main sulfur-based compounds that cause bad breath, a number of other auxiliary compounds also contribute to the problem, and they may come from the drinks or foods you eat. For example:
– A scientific article in the Journal of Breath Research found 3-mercapto-3-methylbutylformate after drinking coffee, making your breath smell like the smell of cats.
– The breath after you eat garlic comes from allyl methyl sulfide, a product of garlic decomposition.
– After eating meat or fish also causes your breath to give off an unpleasant odor. This is because bacteria break down proteins and create volatile compounds like cadaverine and putrescine. A piece of meat or a fish left out for long periods of time also produces these rotten smells.
The bacteria on your teeth, gums, tongue or in your throat are constantly metabolizing and releasing excess odors.
The stench is when you fart
The sulfur-containing organic compounds are once again responsible for the smell of gas in the digestive tract. The main compound containing sulfur here is hydrogen sulfide (H2S), followed by methanethiol and dimethyl sulfide.
You may wonder, why scientists can detect them. Now, you can easily collect a person’s deflated gas and use a machine called gas chromatography to know the chemical components in it.
But even without such a modern device at hand, scientists can still study the gas mixtures in your digestive tract in a different, rudimentary and more manual way.
A 1998 study in the British Society of Gastroenterology magazine recruited 16 volunteers and gave each person 200g of pinto beans. The scientists then collected air samples in their large intestine with a tube inserted from the anus into the rectum.
In the most special section, two experienced volunteers smelling sulfur-based gases will be invited. The scientists slowly pumped the gas mixture that was collected through a tube three centimeters away from the nose of the two examiners. Each volunteer will take a few breaths, then evaluate the smell they smell on a scale from 1 (no smell), to 8 (very uncomfortable).
This research has produced a surprising result. It is the smell of farting from men and women quite differently. Both volunteers assessed the concentration of hydrogen sulfide (H2S) found in the samples of taller women, and they are significantly more smelly.
The study also revealed that men have more gas in their rectum, so every blow of theirs will get bigger.
Scientists work with a gas chromatograph
The armpit odor
Every square inch of your arm is home to about 1 million bacteria. That’s why, your sweat doesn’t naturally smell, but after it’s metabolized by bacteria, it’s a completely different story.
The armpit odor is generated from a combination of two sulfur-free organic substances. One of them is 3-methyl-2-hexenoic Acid which is described as smelling like goats. The other compound, 3-hydroxy-3-methylhexanoic acid, smells like fennel.
In addition, armpit odor can also come from a sulfur-containing compound 3-methyl-3-sulfanylhexan-1-ol, which smells like onions. The special thing is that the scientists also identified a sulfur-containing compound that smells of fruit in the armpits sweat, but unfortunately, the ratio of this compound is not high, so it does not overpower the difficult odors. bear the other.
Your sweat is inherently odorless, but after it has been metabolized by bacteria, it’s a completely different story.
Once again, sweat is a major factor in foot odor – however, like armpit odor, foot sweat itself has no odor. Its smell comes from the bacteria that grow under your feet.
In addition to the methanethiol compounds listed above, two of the other compounds responsible for the odor in your feet are propanoic acid and isovaleric acid. Propanoic acid is described as having a pungent, sour and rancid odor. While isovaleric acid causes a rancid smell like fermented cheese.