Artist’s Rendition of the Skin Microbiome – Part of Our Second Genome
This interesting TOP 10 LIST OF MICROBIAL FACTS is from Alexandra Carmichael, Director of Community, Product, and Growth at uBiome – just in time for Valentine’s Day.
1. Kissing partners have more bacteria in common on the backs of their tongues than unrelated individuals, but since the similarities aren’t correlated either with kissing technique, nor with how often those involved indulge in a spot of tonsil hockey, we may be unconsciously attracted to partners who have oral microbiomes which match our own.
2. But mating may not be always involve similarity. In 1995 scientists conducted a “sweaty T-shirt experiment”, by getting males to wear T-shirts, then persuading women to sniff them (the shirts, not the guys) the next day in a kind of blind – if somewhat whiffy – test. The shirts’ odors were largely caused by masculine bacteria. The Major Histocompatibility Complex (MHC) is a sophisticated system involved in immune response. Females classified those as most pleasant which came from men whose MHC differed from their own, suggesting that females might be attracted to someone who can give their potential offspring improved immunity, on the basis that two divergent MHC profiles are better than one.
3. Should you share a nice chilled goblet of sparkling wine with your true love this weekend, Spanish researchers believe that bacteria which grew during the wine’s secondary fermentation (yeast and sugar were added just before bottling to create its fizz) affect the size and persistency of the bubbles in your glass. Hic.
4. Dutch researchers persuaded heterosexual partners to share an intimate kiss (presumably not too big an ask), then invited the females to drink a probiotic yogurt drink, and to lock lips and tongues with their paramours for a second time. This passionate procedure helped the scientists estimate the number of bacteria transferred in a 10 second kiss. About 80 million was their conclusion.
5. Certain bacteria in the stomach have been shown to love chocolate almost as much as their human host. Research presented at a 2014 American Chemical Society meeting showed that gut microbes can break down chocolate components into molecules that may reduce stress in the blood vessels.
6. While many women may be aware of their vaginal microbiome, I suspect fewer men might know about the seminal microbiome. Yup, all healthy males have some low level of bacteria in their semen and that’s fine apparently. However a 2008 Italian study suggested that higher levels might play a part in infertility.
7. Cut flowers, frequently given as Valentine’s gifts, will last longer if the water in their vase isn’t allowed to become bacteria-ridden. That’s what causes the unpleasant furry stuff you sometimes find on flower stems in water. One solution? Apparently a few drops of vodka added to the vase, along with a teaspoon of sugar, can do the trick. It creates an antibacterial effect. Change the water, and add more vodka and sugar every other day.
8. Mark O. Martin, an Associate Professor of Biology at the University of Tacoma, Washington, made a Valentine’s Day card for his wife Jennifer by painting a message on a Petri dish using bioluminescent marine bacteria. His words of love glowed in the dark. Beat that Hallmark.
9. In a study of shared oral microbiomes, couples with the most similar salivary microbes were those who kissed at least nine times a day. Bad news for Brits after a survey showed that 20% of UK couples kiss just once a week.
10. Since researchers thought it would be invasive (not to mention rather icky) to take regular stool samples from intimate partners, they instead studied baboons in Kenya. Their 2015 findings revealed that the primates who groomed each other most frequently ended up with the most similar microbiomes, leading them to hypothesise that the more humans hug and hold hands, the more bacteria they’ll have in common.
Happy Valentine’s Day from all of us at uBiome.
Roses are red,
Violets are blue,
If you love your bacteria,
They, too, will love you.
Director of Community, Product, and Growth
Here’s uBiome’s site, where you can learn more about them and order kits to have one or more of your body’s microbiomes sequenced: your gut, mouth, nose, genitals, and skin.
Alexandra’s post includes a coupon for 30% off the price of any kit: LOVE30
She also included a list of further readings in case you want more information on any of these microbial facts:
Information on a new product called AO+ Refreshing Cosmetic Mist caught my eye recently. (Scott, 2014)
It’s a liquid developed by a biotech start up company in Cambridge MA to spray on our bodies in lieu of – or as an adjunct to – taking showers. Showering with most soaps and shampoos kills all the healthy elements of our skin microbiome. The company, AOBiome, says its new living bacterial skin tonic, made of safe live-cultured Nitrosomonas bacteria, replenishes the biome of microscopic organisms that live on our skin.
This does indeed sound novel, interesting – and important!
I started this site to write about how the micro-organisms living in our guts – the gut microbiome – affect the entire body and how to restore your gut – and the rest of you – to good health. See The Gut Microbiome – Our Second Genome. Reading about AOBiome’s brilliant work on restoring our skin’s microbiome, produced a moment of clarity in me – one of those true light bulb moment: It’s not just our gut’s we’re destroying but our other microbiomes as well.
Our usual approach to the bacteria and other micro-organisms living on our skins – and everywhere else we can get to them – is to KILL THEM DEAD. We regard bacteria and their relatives as dangerous and just plain nasty. So this is an entirely new approach – a U turn in how to think about bacteria: The new spray contains billions of cultivated Nitrosomonas eutropha, an ammonia-oxidizing bacteria (AOB) most commonly found in dirt and untreated water in rivers, lakes, and the sea. (Martinko, 2014)
VARIOUS PARTS OF THE HUMAN MICROBIOME
The aggregates of micro-organisms living inside and on our bodies, collectively referred to as the human microbiome or microbiota, make their homes in many places:
In our GI tracts
On the surface of and in deep layers of our skin
On our hair
In the saliva and mucosa in our mouths
In our noses and sinuses
In our urogenital tracts
In the conjunctiva (the lining inside the eyelids and covering the white part of the eye)
OUR SECOND GENOME – THE HUMAN MICROBIOME
Sources: (AOBiome, 2014), (Wikipedia, 2014), and (Baylor College of Medicine, 2013-2014)
There are 100’s of trillions of micro-organisms in the various microbiomes in and on our bodies, our Second Genome.
The number of non-human micro-organisms (bacteria, viruses, fungi, archaea and single-celled leukaryotes) inhabiting a healthy human adult is estimated to outnumber human cells by a ratio of 10 to 1.
The human microbiome contains about 3,000,000 non-human bacterial cells to our 23,000 human cells. (See correction below)
The total number of genes in our microbiome exceeds the number of genes in our human genome by a factor of at least 200.
So, even though the microbial cells making their home in and on us are only 1/10th to 1/100th the size of our human cells, they account for up to 5 pounds of an adult’s body weight.
To date, only a small percentage of the bacteria comprising our human microbiome have been identified.
Correction (8/22/2015): A reader named Stephen sent the following comment:
I just need to point out that you have one fact slightly, but importantly, inaccurate. You cite that:
The human microbiome contains about 3,000,000 non-human bacterial cells to our 23,000 human cells.
When in fact, you should replace the two occurrences of the word “cells” with the word “genes”. This fact is often misunderstood. What it means is that the human genome has about 23k unique genes, whereas the bacteria that inhabit us have about 3x10E6 unique genes, not that there are 3 million genes among them. The point is that the bacteria on our bodies possess incredible functional diversity and can do many things for our bodies that we cannot do ourselves.
And these miniscule critters aren’t invaders trying to harm us. The vast majority of them are necessary and beneficial to us – as we are to them.
Yet for a century, we’ve been unintentionally, but systematically, distorting and destroying the healthy workings of our various microbiomes with processed foods, pharmaceuticals – especially antibiotics, cleaning products, cosmetics, pesticides and herbicides, genetically modified foods and more, resulting in the degradation of our immune systems and huge increases in diseases and chronic medical conditions.
At the same time, and with many of the same products, we’ve also been degrading healthy microbiomes in the soil and our water supplies – making not only humans ill but also wreaking havoc on the other fauna and flora on our planet.
THE HUMAN SKIN MICROBIOME
From the AOBiome website (AOBiome, 2014):
Human skin, a large and heterogenous organ, harbors a fascinating array of species of bacteria, fungi, and other microorganisms. The specific makeup of the skin flora depends on many factors, such as whether the particular skin area is dry, moist, or sebaceous, the age of the host, external conditions, etc. Dry forearms and hairy, moist underarms are very distinct habitats, despite their relative proximity. People living together also seem to share a larger portion of their microbimes than those are not cohabitating, and pet owners share some with their animal companions.
Here are some of the most common microorganisms that reside on our skin:
Propionibacteriaare the most prevalent on sebaceous, or oily skin, such as nostrils, scalp, upper chest and back. They are lipophilic anaerobes, decomposing oily sebum secreted by our glands, producing propionic acid. Although they are present in infants and babies, they become more dominant around the onset of puberty, as the sebaceous glands increase their output. One of the bacterial strains, Propionibacterium acnes, is thought to be responsible for inflammation of the glands that can lead to acne.
Staphylococcihave their name derived from Greek word for grape, as their colonies resemble grape clusters. They reside predominantly in the moist areas of the body, such as the armpit, the elbow crease, etc. As aerobic bacteria, they produce lactic acid that lowers the pH of the skin and controls growth of other microorganisms. They are particularly prevalent on the skin of babies and infants, their relative abundance decreasing with age. While normally harmless, certain species of staphylococci, such as S. aureus, can act as human pathogens. Methicilin-resistant S. aureus (MRSA) infections are a difficult public health problem in hospitals and beyond.
Corynebacteriaare rod-shaped, and mostly innocuous. They also prefer moist environments, such as the navel, or back of the knee. They grow slowly, even when the food is abundant.
Betaproteobacteriaare a diverse group, which includes Nitrosomonas, currently excluded from human skin. They are the most prevalent group in the dry areas, such as the forearms. Also, these are the bacteria that the dog owners have the most in common with their dogs
Malassezia– as fungi, Malassezia get a honorable mention. They are found on our skin in large quantities, and are typically harmless, but certain species can cause dandruff or skin discoloration.
NITROSOMONAS BACTERIA IN DIRT
Ever wonder why horses love to roll around in dirt? We know horses, like humans, sweat a lot. We also know how unpleasant our skin can feel – and smell – after we’ve worked up a sweat. David Whitlock, the M.I.T.- trained chemical engineer who invented AO+, theorized that horses dirt bathe to manage their sweat. He reasoned, “The only way that horses could evolve this behavior was if they had substantial evolutionary benefits from it.”
The goal of using AO+ spray is to encourage the growth of a healthy colony of probiotic bacteria on the skin. This probiotic bacterial colony will then act as a built-in cleanser, deodorant, anti-inflammatory and immune booster by feeding on the ammonia in our sweat, converting it into nitrite and nitric oxide.
Scientists at AOBiome hypothesize that humans also had healthy, mutually beneficial, colonies of ammonia-oxidizing bacteria (AOB), such as Nitrosomonas eutropha, living on our skins. These AOBs regulated our nitrogen metabolism. Then in the 20th century, we began regarding all bacteria as dangerous and started trying to scrub them all away. (AOBiome, 2014)
THE HYGIENE HYPOTHESIS
The Hygiene Hypothesis – also called the Biome Depletion Theory or the Lost Friends Theory – states that a lack of early childhood exposure to infectious agents, symbiotic microorganisms (eg, probiotic gut flora – referred to as Our Old Friends), and parasites increases susceptibility to allergic diseases by suppressing the natural development of the immune system. In particular, the lack of exposure is thought to lead to defects in the establishment of immune tolerance. (Wikipedia, 2014).
The Hygiene Hypothesis is consistent with the destruction of the ammonia oxidizing bacteria (AOB) on our skins. Many ingredients in most of our personal care products have been found in laboratory tests to inhibit or have been found toxic to AOB: sodium lauryl sulfate, sodium coco-sulfate, castile-type soaps, and amine oxides (such as lauryl dimethyl amine oxide). AOBiome’s laboratory is still in the process of testing the AOB toxicity of other ingredients commonly found in soaps, shampoos, skin creams, and deodorants.
The encouraging news is that AOBiome has found ingredients that ARE compatible with ammonia oxidizing bacteria. Their goal is to test, certify and develop a variety of hygiene products with these ingredients – including soaps and shampoos. (AOBiome on facebook, 2013-2014)
WHY IT’S GOOD TO HAVE COLONIES OF THESE BACTERIA ON OUR SKINS
Here’s an explanation of why restoring healthy colonies of this bacteria on our skins is important – from the AOBiome website (AOBiome, 2014):
Modern hygiene has selectively depleted the natural balance of the skin microbiome particularly affecting AOB. By restoring the appropriate AOB levels, we believe a range of human health conditions could be impacted. AOBiome is interested in exploring potential physiologic effects including:
Improving skin architecture
Before the advent of anionic surfactants,Nitrosomonaswould have colonized our skin, our sweat glands in particular, constantly secreting low amounts of NO. Due to their particular sensitivity to detergents, however, they have been eradicated from our skin microbiome. As a consequence, we are dermatologically and systemically NO-deprived – in a mildly pro-inflammatory state, with a number of our systemic NO-mediated regulatory mechanisms out of balance. This deprivation may contribute to a number of skin conditions, such as eczema, psoriasis, potentially also neuropathies, and more. AOBiome aims to re-introduceNitrosomonasto our skin’s bacterial flora, restoring natural NO levels, stabilizing the NO-dependent signaling pathways and alleviating symptoms resulting from NO imbalance.
Nitrosomonas are naturally occurring in most aquatic and soil environments and seem to totally lack pathogenic potential, as indicated by the absence of pathogenicity factors and also evidenced by the complete lack of human infections reported to date. SinceNitrosomonasdepend on ammonia and urea for their growth, their numbers on the skin are necessarily limited, and are naturally regulated by the amount of sweat the body produces. This ensures that the amount of NO produced would be relatively low, without any adverse effects. Because of its reactivity, the Nitrosomonas-produced NO will exert most of its effects locally, in the skin of the host. If desirable, however, one could eliminate the bacteria using a simple soap treatment.
AOBiome’s scientists have also found that using concentrated AO+ led to a hundredfold decrease of Propionibacterium acnes, bacteria associated with acne breakouts. And they have found that a two week treatment with a formulation of AOB heals skin ulcers on diabetic mice. (Scott, 2014)
ARE WE GOING TO GIVE UP SHOWERING?
AOBiome says NO. The probiotic bacteria in AO+ Refreshing Cosmetic Mist thrive in water so you can use it and also continue showering – just not lathering yourself up with soap or shampoo that will kill those useful bacteria. The ammonia oxidizing bacteria in AO+ can survive limited exposure to the chlorine and chloramine added to municipal water supplies to purify them. From the company’s facebook page (AOBiome, 2013-2014):
Our research shows that daily application along with normal showering in regular tap water produces a sustained level of AOB on skin. In our initial cosmetic study we showed that AOB are detectable and present in 95% of cases with daily showering and application and that AOB continue to survive in 60% of subjects for up to 7 days without additional applications as long as shampoo is not used. This is the basis for our recommendation that you apply AO+™ Refreshing Cosmetic Mist daily as part of your usual personal hygiene routine.
A note for those of you who’ve read the New York Times Magazine article, “My No-Soap, No-Shampoo, Bacteria-Rich Hygiene Experiment” (Scott, 2014), and came away from it thinking the choice will be between using the ammonia oxidizing bacterial spray or showering:
The article’s author was using the spray and not showering for 28 days as part of a clinical trial for AOBiome. When she started showering again but not also using the spray, the colony of ammonia oxidizing bacteria on her skin was quickly destroyed by showering with soap.
When the Company has succeeded in bringing to market an AOB-friendly shampoo and AO+ Refreshing Cosmetic Mist is also readily available, we should be able to both shower and wash our hair with these products while maintaining a healthy colony of AOB. And when an AOB-friendly skin cream has been developed and approved for marketing to the public, we’ll also be able to nurture our AOB colonies by using it.
SAVING OUR SKINS – FIGURATIVELY AND LITERALLY
As Michael Pollan wrote in an excellent article last year titled Some of My Best Friends Are Germs (Pollan, 2013):
As a civilization, we’ve just spent the better part of a century doing our unwitting best to wreck the human-associated microbiota.
Now this brilliant biotech company, AOBiome, is working on a big piece of the solution to our ills. If you want to be wowed by the work they’re doing, take a look at their website.