The Cleanliness Paradox: Why Being Too Clean Might Be Making You Sick

Do you remember being a child? Really remember it?

Playing in the garden until your knees were brown with mud. Eating a piece of fruit straight off the tree, maybe giving it a quick wipe on your shirt if you were feeling fancy. The dog licking your face and nobody panicking about it. Drinking from the garden hose. Building sandcastles and inevitably getting some in your mouth.

And somehow — we were fine. More than fine, actually. Most of us were remarkably healthy little humans.

Now think about today. Antibacterial hand wash at every sink. Sanitiser on every counter. Antibiotics at the first sign of a sniffle. Surfaces wiped down with products that kill 99.9% of all bacteria. And yet — allergies, autoimmune conditions, asthma, eczema, IBS, and chronic inflammation are at record highs. Especially in children.

Something doesn't add up.

The hygiene hypothesis

Scientists noticed this paradox decades ago and gave it a name: the hygiene hypothesis. The idea is this — our immune systems are designed to be trained by exposure to microorganisms from early childhood. When we grow up in environments rich in diverse bacteria (soil, animals, fermented foods, outdoor play), our immune systems learn to distinguish between genuine threats and harmless substances.

When we grow up in overly sterile environments, that training doesn't happen. The immune system, with nothing real to fight, starts picking fights with things it shouldn't — pollen, dust, certain foods, even the body's own tissues. The result? Allergies, intolerances, autoimmune conditions.

We didn't get sick playing in the mud as kids. The mud was, in a very real sense, making us stronger.

Germs are not the enemy

Here's the reframe that changed everything for me: bacteria are not inherently bad. The vast majority of the bacteria in and on your body are either neutral or actively beneficial. Your skin, your mouth, your gut — all teeming with microbial life that keeps you healthy, balanced, and protected.

The enemy isn't bacteria. The enemy is the wrong bacteria, in the wrong place, in the wrong quantities. And ironically, our obsession with killing all bacteria indiscriminately is creating exactly that problem. When you wipe out everything — good and bad alike — you leave a vacuum. And nature, as they say, abhors a vacuum. Something will fill it. Often, it's the opportunistic bacteria that cause problems.

What antibiotics do to your gut

I want to be clear: antibiotics save lives, and there are absolutely times when they're necessary. But they are also one of the most significant disruptors of the gut microbiome we know of. A single course of antibiotics can reduce gut microbial diversity by up to 30%, and for some people, full recovery takes months — or never fully happens without deliberate intervention.

If you've had a course of antibiotics recently, your gut microbiome needs rebuilding. Fermented foods are one of the most effective ways to do that — introducing diverse beneficial bacteria and giving your gut the raw material it needs to recover.

The case for a little dirt

I'm not suggesting you stop washing your hands before you cook or after the bathroom. Basic hygiene matters. But there's a meaningful difference between sensible hygiene and the kind of antibacterial paranoia that's become normal in modern life.

Let your kids play in the garden. Get a dog if you can — research consistently shows that children who grow up with dogs have more diverse gut microbiomes and lower rates of allergies. Eat food that's been grown in real soil. And eat fermented foods — because they reconnect you, in the most direct way possible, with the microbial world your body was always meant to live alongside.

Coming full circle

There's something beautifully ironic about fermentation. In a world that's terrified of bacteria, fermented food asks you to trust them. To let them do their work. To understand that not all microbes are threats — that some of them are, quite literally, keeping you alive.

When I open a jar of sauerkraut and smell that sharp, alive, tangy scent, I feel connected to something ancient. To the children we were, playing in the mud without a care. To generations of humans who understood, instinctively, that the natural world — bacteria and all — was not something to fear but something to work with.

Your gut remembers. Feed it accordingly.

Explore our range of raw, living fermented vegetables at Fermentastic — and make friends with the good guys. 🦠🌱