Tag Archive for: showers

The Skin Microbiome: Skincare and Cosmetics

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While the state of the current pandemic has restricted the ability to socialize to any great degree, it may turn out to be beneficial for the skin microbiome. Be honest. If you don’t have to go to work or out into the public, do you still maintain the same personal grooming practices? Do you put on all your makeup? Based on what people say in virtual meetings, the answer is no. Why is that beneficial for the skin microbiome?

The final potential insult to our skin microbiome is from products we willingly use. Most people apply some form of skincare and/or cosmetic products every day, plus deodorant or anti-perspirant, haircare products, moisturizers, and a plethora of make-up products. Here’s the key point: most of these products contain anti-microbials to maintain the safety of the product before use. That means when applied to the skin, they could also impact the microbiome of the skin.

After reading a review article on the state of research on the entire gamut of skincare products, several researchers outlined the type of research that should be done. While encouraging, that means that not much has been done. I couldn’t find any research that directly examined the impact of skin and cosmetic products on the skin microbiome. We just don’t know.

Strategies for Healthy Skin

There are several things we can do to indirectly help our skin.

  • Drink one-half your body weight in ounces of liquid every day.
  • Take 1 to 4 grams of omega-3 fatty acids every day. There are many reasons to take your omegas, but one is to help reduce the production of inflammatory hormones.
  • Take a probiotic with several types of bacteria with a prebiotic every day. They contribute to a healthy immune system and internal microbiome.
  • There are several supplements that may also contribute to the health of the skin including biotin, vitamin C, and collagen. They may not affect the skin’s microbiome, but starting with a healthier surface may be beneficial.
  • Regular exercise increases blood flow to all areas of the body, including the skin. That can deliver nutrients and help remove waste products.

The Bottom Line

Our skin microbiome is part of our first line of defense against microbial invaders. At this point, there’s not enough research to know whether the skincare routines we’ve become accustomed to are beneficial, harmful, or at least neutral. Is that worth stopping all skincare and cosmetic products? Should we stop taking showers? I don’t think we need to do any of those, but if we start paying more attention to the products we use and make better choices in selecting them, that may give us an edge while science catches up with this amazing part of our immune system.

What are you prepared to do today?

        Dr. Chet

Reference: Int J Cosmet Sci. 2020 Apr;42(2):116-126. doi: 10.1111/ics.12594.

The Skin Microbiome: pH

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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

The Skin Microbes: What They Eat

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When we talk about the microbiome of the digestive system, it’s well-known what they eat: sugar. That’s also mostly true for the skin’s microbiome, although those microbes eat other substances as well. In today’s Memo, we’ll cover the types of bacteria and where they’re located. Then we’ll look at their diet.

The Microbes of the Skin

It may come as no surprise that the type of bacteria and other microbe depends on the location. That makes sense: what may grow well in moist areas may not grow well in dry areas.

The sebaceous sites on the head and torso are dominated by species of bacteria that like fatty environments. Remember that sebum is primarily a type of fat, so the type of bacteria that will grow in that area has to be able to thrive in that environment. The Propionibacterium species dominates in the oil glands.

The moist and humid sites contain bacteria such as Staphylococcus and Corynebacterium species. They thrive in the bends of the elbow and the feet, as well as other locations.

Bacteria are not the only important microbes in our microbiome; there are plenty of fungi as well, and I know how gross that may seem to some readers, but try to think about how much you like mushrooms. They’re there to do a job: protect us. The genus Malassezia are found at core body and arm sites. The feet are more diverse in fungi species: Malassezia, Aspergillus, Cryptococcus, Rhodotorula, Epicoccum species as well as others. Here’s something that may comfort some of you: bacteria were the most abundant and fungi were the least abundant.

What about viruses? They seem to be specific to the individual without any single virus dominating. Based on the longitudinal studies of the skin microbiome, they remain largely stable for as long as two years, the length of the longest studies. Pretty amazing considering how the seasons change in places like here in Michigan.

What the Skin Microbes Eat

The skin provides a cool and acidic environment for its residents. The primary nutrients are protein and fats. The microbes have adapted to what’s available in the sebaceous glands, the sweat, and the dead skin cells of the stratum corneum.

For example, the anaerobe P. acnes can survive and thrive by using protein enzymes to break down the amino acids found in the dead skin cells of the corneum stratum. Not only that, they have lipases to breakdown the triglycerides in sebum to use fat as a fuel as well as provide the means for the bacteria to adhere to the skin.

The lipids that can be liberated from the oily sebum and the stratum corneum are also used by the fungi for lipids as they cannot manufacture their own lipids. The Staphylococcus spp. have developed several strategies to survive the dry areas of the body. They’re tolerant of the high salt content of the skin and can use the nitrogen group from urea as a nitrogen source. They also produce chemicals that can break down the stratum corneum to extract nutrients from there as well.

As the researchers who wrote the review paper said, “the skin harbors a heterogeneous community of microorganisms that each have distinct adaptations to survive on the skin.”

The Bottom Line

As you can tell from this week’s memos, the skin microbiome is not just a few bacteria that decided to take up residence and are along for the ride; they have adapted to their environment to survive. How are they impacted by the water we bathe in, the soap we use, and the chemicals we use to look and smell better? That’s what I’ll write about next week.

What are you prepared to do today?

        Dr. Chet

Reference: Nature Reviews doi:10.1038/nrmicro.2017.157

The Skin Microbiome: Anatomy

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The skin microbiome is amazingly complex. Not only do we have all the beneficial bacteria and other microbes, we also have microbes that can be beneficial or damaging depending on how we treat the skin. Let’s begin with location: where are all these microbes located? For that, we need to understand a little bit about the structure of the skin.

The skin is the largest organ of the body and is constructed of two different layers: the outermost or the epidermis and an inner layer called the dermis. The outermost layer called the stratum corneum is composed of dead cells that are chemically crosslinked with each other and with cells below to provide a true barrier. As they’re sloughed off, they’re replaced.

To say “skin is skin” does this organ a disservice. It varies in different locations in the body and provides amazing microenvironments based on UV light exposure, pH, temperature, moisture, and sebum content. What is sebum? That’s the product of sebaceous or oil-producing glands, primarily located on the face, the chest, and the back. The sebum provides a coating that repels water and provides an antibacterial shield to hair and skin.

There are also areas of the body that are moist such as under the arms, between the toes, and in other more private areas. Those areas contain sweat glands which modify the pH of the skin and make it more acidic. That created an unfavorable environment for the growth of some bacteria and other organisms.

That’s the anatomy of the skin. The next question is what type of bacteria and other microbes are found on the skin and exactly what do they eat? We’ll cover that on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Nature Reviews doi:10.1038/nrmicro.2017.157

No More Showers!

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If you saw a book called Clean, you probably wouldn’t think the author decided not to take any more showers. But you would be wrong, because that’s exactly what Dr. James Hamblin announced he would do about five years ago in a magazine article. Over time and a whole lot of research, the article became the basis for his book. In an interview I read with the author, he’s constantly irritated because the most frequent question he gets when people find out he hasn’t taken a shower in five years is “Do you stink?” My thought is if that you’re close enough to ask the question, you probably should know the answer, even with social distancing.

His primary concern over taking showers is our addiction to cleanliness, which is something I’ve thought about as well. (Never fear, I’m not going to quit taking showers.) His concern is with the microbiome of the skin. We all hear research on the microbiome within the digestive system just about every day, but the microbiome of our skin is actually the first line of defense in our immune system. Whatever we do to our skin affects the microbiome of our skin. With all the various soaps, detergents, and shampoos, as well as the chlorine that’s in most water treatment systems, that has to have some impact. Is the impact good or bad?

That’s what we’re going to take a look at in this week’s memos. Could how we treat our skin microbiome impact our immune system? We’ll look at the state of research to date.

What are you prepared to do today?

        Dr. Chet

Reference: Clean The New Science of Skin. James Hamblin. Penguin Random House. 2020.