The Skin Microbiome: pH

The water we shower and bathe in may impact our skin microbiome, but we don’t generally just rinse off with water. We use soaps and shampoos as well. How could they impact the microbiome of the skin? Let’s take a look.

Normal healthy skin has a pH range of 5.4 to 5.9. At that pH, the body maintains a normal microbiome. Researchers examined the pH of shampoos and soaps in about 100 different products. Most soaps were highly alkaline with a pH that averaged between 9 and 10. Shampoos fared much better with most in the 6 to 7 pH range.

Will the exposure to these products damage the skin microbiome? If it does, will it be temporary? After all, the exposure will be limited depending on the length of the shower or bath. We don’t have all the answers on that. The closest I’ve seen to sequential testing was a multi-country study that found that the skin pH was still elevated six hours after washing with soap. The rise was less than a single point; still, the actual impact on the microbiome wasn’t evaluated. There’s still much we don’t know.

We’re still not done with the skin microbiome so we’ll finish this up on Saturday.

What are you prepared to do today?

        Dr. Chet

References:
1. Int Microbiol. 2019 Mar;22(1):1-6. doi: 10.1007/s10123-018-00049-x.
2. Indian J Dermatol. 2014 Sep-Oct; 59(5): 442–444. doi: 10.4103/0019-5154.139861.
3. International J of cosmetic science. 2006 DOI: 10.1111/j.1467-2494.2006.00344