As they are a hot, humid and closed area, belly buttons become perfect places for bacteria to appear. Washing with soap and water solves the problem in most cases.
Every year, thousands of people turn to Google with an unexpectedly common question: “Why does my belly button smell bad?” According to researchers and health experts, the most likely explanation is simple: the bacteria. But the science behind this surprisingly widespread concern reveals much more about the human body than many realize.
Bacteria thrive in hot, humid and closed spacesand the belly button is one of the most neglected microenvironments in the body. When these microbes feed on dead skin cells, oils and sweat, they release gases and volatile compounds that produce odor. Humans, who have evolved to notice the smell of decay or infection, are particularly sensitive to these odors.
A pioneering study of the belly button microbiome, led by researchers at North Carolina State University, has illustrated just how biologically rich the belly button can be. By collecting samples from attendees of two science festivals in the US, scientists analyzed 60 samples and found more than 2300 bacterial species and it is estimated that around 1400 of which may be completely new to science, according to the report on the project.
Although some types of bacteria appeared consistently in many people, the overall diversity was immense. Some participants even harbored ultra-rare species, including a microbe previously found only on Japanese soil, despite the individual never having traveled abroad.
Given this microbial diversity, it is not surprising that the belly button can occasionally release an odor. In most cases, a thorough wash with warm soapy water should resolve the issue. However, even a clean belly button can sometimes harbor an unexpected problem. Doctors note that some people develop omphaloliths, which are dark, hardened masses made up of dead skin, hair, and sebum. Although harmless, need to be removed to reduce irritation and odor.
Persistent odor, pain, or discharge, however, may signal an underlying medical problem. Fungal infections caused by Candida overgrowth are relatively common in the navel and easily treated with antifungal creams. Cysts can also form in or near the belly button, ranging from benign cysts caused by trapped skin cells to urachal cysts, which are rarer and refer to remnants of fetal anatomy that occasionally produce fluid.
Healthcare professionals emphasize that the best way to prevent odor is simple hygiene: wash the area regularly and then dry it completely.
