Why a Man’s Nose Is Twice as Dirty as a Woman’s

The truth about the bacteria that live in your nose.

Hello, and a very warm welcome to our first email of 2016! I hope you’re healthy and enjoyed some festive time.

It’s a time of year in the northern hemisphere when many will suffer from head colds, so my commiserations if this includes you right now.


But it does at least provide an ideal opportunity for us to check out a fascinating aspect of your bacterial ecosystem that frequently gets overlooked: your nasal microbiome, one of six sites you can explore with a uBiome test.

Compared to their subterranean cousins downstairs in the gut, the microorganisms of the nasal cavity have been relatively unstudied, which is surprising because they’re potentially important for a host of diseases such as sinusitis, allergies and staph infection.

Speaking of “staph”, it’s crucial to know just what species and strain you’re talking about, for virtually all of us carry members of the Staphylococcaceae family (a bit of a mouthful, or should I say, noseful) up our schnozzes.

Some are harmless while others are frankly pretty unpleasant.

Researchers at the University of Michigan found some types of staph – especially Staphylococcus aureus – in the nasal cavities of all their study participants, but never once found it in oral cavities.

Of course your nose and mouth are both connected to your throat, which is why you’re able to swallow mucus, and boy do you do that in prodigious quantities.

Sorry to report this, but a healthy adult swallows over a litre of mucus every day, much more than enough to fill a bathtub every year.

Some of us (but not all, and more of that in a minute) think of nasal mucus as nasty stuff but it’s actually incredibly useful, acting as a kind of lubricant and moistener, protecting all the bodily tubes it coats.

Snot also acts a bit like flypaper, trapping dust and bacteria before they get into the body.

Moreover it contains antibodies that can help your body recognize invading viruses and bacteria, and enzymes which kill these unwanted guests.

While the great majority of us host Staphylococcus aureus up our noses or on our skin, the one place you really, really don’t want it is in your bloodstream.

Its initials form the last two letters of a scary acronym – MRSA.

Methicillin Resistant Staphylococcus Aureus is a highly dangerous infection which can be acquired in healthcare facilities, particularly if careless and unhygienic insertion of a needle causes a particular strain of skin-borne Staphylococcus aureus to be passed into the blood.

MRSA is a bacteria that is resistant to many antibiotics, sometimes known as “golden staph” because of its distinctive yellow pus.

I know, pretty nasty, right?

Changing the subject to something (slightly) less gross…

You may be interested to know that men’s noses are substantially more bacteria-ridden than women’s.

A 2015 study led by researchers at Johns Hopkins School of Medicine discovered that women had about half as many bacteria in their noses as men did.

The same research, which examined both identical and fraternal twins, found that host genetics played no significant role in nasal microbiota composition, but it did contribute to the density of bacteria in the nose.

So while you don’t inherit the types of bacteria which live in your nose, you do inherit the amount that’s in there.

Finally I know I said you may imagine most people find the whole nasal mucus thing pretty unpleasant, but according to British author Stefan Gates, it could in fact be only a slim majority.

You see, in his 2006 book “Gastronaut”, he explained that 44% of the people he questioned owned up to having eaten and enjoyed their own boogers as adults, a practice which even has its own scientific name – mucophagy.

I was going to say that perhaps we shouldn’t knock it till we’ve tried it.

But like I said, whether you like it or not, you’re already downing a bucketful of the green stuff every week.

Anyway, as long as we’re drinking, let me raise a glass of something a little more sparkly in your direction in order to wish you a very Happy New Year!

Further reading

Anterior nares specimen collection

Eating mucus

Golden staph – the deadly bug that wreaks havoc in hospitals

Methicillin resistant Staphylococcus aureus (MRSA) in the community

Mucus (snot, phlegm) color, function, coughing, and more

Nasal bacteria may be predictor of skin infections

Staphylococcus aureus and the ecology of the nasal microbiome

Stefan Gates

The nasal cavity microbiota of healthy adults

Understanding the nasal microbiome