These key places you shouldn't forget to clean when you shower, according to a study

2023-11-03 14:10:00

What if grandma was right? And if it really had to insist, or at least not forget to polish certain hidden areas of the body to maintain healthy skin? To test this hypothesis, a research team from George Washington University (GW) conducted a study on the skin microbiotathe results of which recently appeared in the journal Frontiers in Microbiology (Source 1).

Keith Crandall, a professor of biostatistics and bioinformatics at GW and co-author of the study, says his grandmother always asked the children in her family to “rub behind the ears, between the toes and in the belly button.” The researcher then hypothesized that these “hot spots” are washed less often than the skin on the arms or legs, and can therefore harbor different types of bacteria.

The researchers here solicited the participation of their students to test this hypothesis: 129 students collected their own samples by dabbing certain moist and naturally oily regions of the body, such as the area behind the ears, the spaces between the toes, and the navel. At the same time, they also dabbed “control” areas such as the calves and forearms. The students then extracted and sequenced the DNA from the 579 samples obtained, to compare the microbes in the different buffered zones.

Less microbial diversity in oily areas that are difficult to access

The researchers thus noted that the forearms and calves, two areas often cleaned thoroughly in the shower or when bathing, presented a greater microbial diversity, and therefore potentially healthier microbial flora que the so-called “hot spots” areas, between the toes, in the navel or behind the ears.

This study thus demonstrates that the composition of the skin microbiota varies depending on the areas of the skin, partly due to intrinsic factors (presence of hair making the skin more oily for example), but also environmental (friction, UV rays, humidity, temperature…). Moreover, “washing habits or skin care products can also disrupt bacterial communities differently and play a role here, since one might expect certain areas like the calves and forearms to be washed and lubricated more often than others”, note the researchers in their conclusion.

“When certain harmful microbes take over the microbiota (understand, they take over, Editor’s note), they can unbalance health”, explained Keith Crandall in a press release (Source 2). “If the microbiota leans in favor of harmful microbes, skin diseases such as eczema or acne can result”, warns the researcher.

Maintaining sufficient hygiene in naturally oily areas could thus contribute to maintaining a healthy microbiota, provided that not to use products too aggressivewhich undermine the hydrolipidic film which protects the skin barrier. Everything is in the measure between lack and excess of hygiene.