Researchers from the University of California, San Diego, enrolled nearly a dozen people in a study to examine how skin care products like antiperspirant, lotion, moisturizer, and foot powder affect the microbial and molecular diversity of the skin. As they report in BMC Biology, the researchers collected samples from 11 volunteers who for the first three weeks only used a light body wash and then for the next three weeks applied select products to particular sites. For the last three weeks, they returned to their typical skin care routine.
When the researchers analyzed these samples using mass spectrometry and 16S rRNA sequencing, they found compounds from these skincare products persisted on the skin for weeks. At the same time, they report the lotion and moisturizer didn't have too much of an effect on the skin microbiome, though the antiperspirant and foot powder did. Those products, they report, led to an increase in the microbial diversity present — possibly due to changes in nutrient and moisture levels, as Scientific American notes.