|I took a good whiff of my hairbrush and there was a distinctive smell, so familiar, yet I could not quite put my finger on it.|
This is after a week of not using shampoo. Being isolated in a hotel on a quarantine order, I thought it would be a good chance to give the “no-poo” or “no-shampoo” experiment a try.
“Cheese!” or more specially “blue cheese”.
I figured out. The smell was unique and slightly pungent but not entirely distasteful, somewhat the effect durian has on some people. Some people like it, but some people don’t. But it’s definitely not a smell one associates freshly shampooed hair with.
Besides the smell on my brush, I also noticed that a week without shampooing caused my hair to have more volume, and allowed it stayed in place when I style it with my hands, unlike the frizzy hair I usually have. To my surprise, my hair now felt and looked better.
It made me very curious, what exactly was happening to my hair, that it smelt like the by products of bacteria that ferment cheese.
I googled and found out that the scalp, like the gut, mouth and skin, has its own unique microbiome or colonies of microbes that grow in harmony with one another and with the host substrate. Different from other body sites, the scalp microbiome is characterized by low bacterial diversity and dominated by Cutibacterium acnes, Staphylococcus epidermidis and Malassezia spp. (Saxena et al., 2021).
The scalp is a unique environment, different from the exposed skin. Because of the many strands of hairs on it, it is a humid environment and protected from UV light, and conducive for the growth of unique strains of microbes. It was like your scalp is a garden where you tend strains of bacteria and some fungus, that have developed a symbiotic (or a mutually beneficial) relationship with you.
I googled and found out that some strains of bacteria, make use of the sebum or oil in the scalp, that we naturally produce to moisturize our hair, to make vitamins that are good for hair growth – like biotin, a vitamin that is good for hair growth and scalp health, something our body does not naturally produce but can be bought as supplements from your local drug store.
It intrigued me. You mean the reason why a good diet helps us to have good and strong hair was partly due to good nutrition causing us to produce high quality sebum to feed these bacteria strains, who in turn produce beneficial by products that maintain healthy scalp and hair?
And then, reading more, it appears that dandruff, a condition where flaky skin falls off the scalp, happens when there is more fungal than bacterial growth. So when you don’t take such good care of the garden of your scalp and allow “weeds” or invasive fungus to overwhelm the good bacteria on your scalp, you get hair conditions like dandruff (Saxena et al., 2018) or alopecia (balding) (Barquero-Orias et al., 2021)?
This must be why using the right shampoo, not over washing the hair, and not putting the hair into harsh situations like using chemical and mechanical treatments on them, is good for the hair. We want to maintain an environment that is conducive for good bacteria growth. And that means we want to keep some of these sebum on our hair, and let the scalp and hair be an environment that is conducive to bacterial growth.
And this must possibly be why putting some things like coconut oil on our hair (Saxena et al., 2021), or following other hair care secrets of our grandmothers, is good for the hair, because we are giving additional nutrients to our microbiome, and keeping the microbes happy, means they keep our scalp healthy as well.
This knowledge transformed how I saw my hair. I used to see it as a hassle, which kind of explained my joy when I once shaved it off two years ago. It was then to me one more thing to worry about. But now, I see my scalp and hair in a new light. It is now a mobile or portable garden where I tend to microbes. And when I eat well and treat my hair right, the microbes are kept in good balance and reward me with hair of good texture and which is easy to manage.
I am no longer tending to my hair alone for my own vanity’s sake, but I have microbe partners whose survival and growth are dependent on the decisions I make about my hair and in turn, my health and beauty dependent on them.
Barquero-Orias D, Muñoz Moreno-Arrones O, Vañó-Galván S. Alopecia y microbioma: ¿futura diana terapéutica? Actas Dermosifiliogr. 2021;112:495–502. (https://actasdermo.org/en-alopecia-microbiome-a-future-therapeutic-articulo-S1578219021001487)
Saxena R, Mittal P, Clavaud C, Dhakan DB, Hegde P, Veeranagaiah MM, Saha S, Souverain L, Roy N, Breton L, Misra N and Sharma VK (2018) Comparison of Healthy and Dandruff Scalp Microbiome Reveals the Role of Commensals in Scalp Health. Front. Cell. Infect. Microbiol. 8:346. doi: 10.3389/fcimb.2018.00346 (https://www.frontiersin.org/articles/10.3389/fcimb.2018.00346/full)
Saxena, R., Mittal, P., Clavaud, C. et al. Longitudinal study of the scalp microbiome suggests coconut oil to enrich healthy scalp commensals. Sci Rep 11, 7220 (2021). https://doi.org/10.1038/s41598-021-86454-1 (https://www.nature.com/articles/s41598-021-86454-1)