Wondering about that pungent smell? Scientists have now come up with an answer.

Everyone has a unique body odor (or BO, as it's commonly called). It may be subtle for some people, but most of us get really conscious when our body stinks. It is a very natural and common occurrence and mostly occurs due to several bacterias, dirt, and sweat within our bodies.

To narrow down the cause of body odor, researchers at the University of York in England decided to do some work. To begin, they isolated a particular microbe that lives in the armpit. These microbes release a byproduct called "thioalcohol" when they react to the skin's specific components.

Now, not all the microbes in the body are the odor offender. Staphylococcus hominis, to be precise, is one armpit-dwelling bacteria which contributes majorly in producing BO.

Our bodies have two types of sweat glands: eccrine glands, and apocrine glands. Eccrine glands are present in most parts of the body, and they open directly to the skin, whereas apocrine glands are present in body parts with hair follicles—like armpits, groin, and inside the ears. The apocrine sweat releases an odorless compound called Cys-Gly-3M3SH. But when Staphylococcus hominis react with this compound, they release an enzyme that converts Cys-Gly-3M3SH to smelly thioalcohol 3M3SH. This also explains why private parts and armpits smell funny, but not the other parts of the body. Also, eccrine and apocrine glands become functional only when we reach puberty. That's why children do not have body odor issues.

According to Professor Gavin Thomas, a senior microbiologist in the York research team, "The bacteria take up the molecule and eat some of it, but the rest they spit out, and that is one of the key molecules we recognize as body odor.”

To confirm S. hominis as the main culprit, the team transfered the enzyme into Staphylococcus aureus, another microbe. It started emanating foul odors, too.

The researchers also suggested that only a few Staphylococcus members carry the BO enzyme and that, most likely, people inherited them from an ancient primate microbial ancestor nearly 60 million years ago.

The research, which was a collaboration with Unilever, can help the deodorant and antiperspirant companies to focus on making products that will target only the particular enzyme-releasing microbes.

Besides microbes and sweat, there can be few other reasons behind our body odor:

  • Diet—Some pungent smelling foods like onion, garlic, and fish can release compounds in our sweat, making the BO worse.
  • Medical Conditions—Diabetes, kidney conditions, some rare genetic conditions may cause a distinct body odor. 
  • Stress—Stress causes apocrine glands to produce more sweat, which may explain the sudden rise in odor in difficult situations.
  • Excessive sweating—This condition is also known as hyperhidrosis, which makes a person sweat more, especially in hands, palm, feet. This condition is common and can be treated.

Body Odor Treatment

Most of the time, body odor does not indicate any serious ailment. It can be treated with maintaining proper hygiene, antiperspirant, diet, and stress reduction.

"It could be a hygiene issue, it could be that you've become tolerant to the form of antiperspirant deodorant you're using, or it could signify something is happening," says Niket Sonpal, an assistant professor of clinical medicine at Touro College of Osteopathic Medicine in New York City. "If switching up your deodorant and stepping up your hygiene habits isn't helping, it's worth checking in with your doc."

To summarize, if you do not sense a sudden change in your odor, then maybe just let the bacteria enjoy its meal!