What's really going on down there: bacteria, pH, and why it matters

Let's talk about something most of us were never really taught properly: the vaginal microbiome.

It sounds clinical, but it's simple — and once you understand it, a lot of things (odour, itching, that “off” feeling after a big night out or a sweaty gym session) start to make a lot more sense.

You have a whole ecosystem down there

The vagina isn't sterile — it's home to a living community of microorganisms, dominated by a family of bacteria called Lactobacillus. These “good” bacteria produce lactic acid, which keeps the vaginal environment naturally acidic, sitting at a pH of around 3.8 to 4.5.

That acidity isn't an accident. It's your body's built-in defence system — an environment that's inhospitable to a lot of the bacteria and yeast that cause irritation, odour, and infection. When the balance of good bacteria drops, or the pH shifts out of that ideal range, that's when problems like bacterial vaginosis or yeast infections tend to show up.

So what throws it off balance?

Plenty of everyday things can disrupt this delicate ecosystem, including:

• Heat and moisture — tight, non-breathable fabrics trap warmth and sweat, creating an environment where unwanted bacteria and yeast can thrive

• Scented products — fragranced soaps, sprays, wipes, and douches disrupt the natural pH and strip away protective bacteria

• Douching — the vagina is self-cleaning; internal washing does more harm than good

• Antibiotics — these can wipe out good bacteria along with the bad

• Your period — menstrual blood is less acidic, so pH naturally shifts during your cycle

• Sweat and damp clothing — sitting in a wet swimsuit or workout gear for too long

None of this means you're doing something wrong. Most disruptions are temporary, and your body is generally very good at re-balancing itself.

Small habits that support balance

The good news: supporting a healthy microbiome doesn't require anything complicated.

• Choose breathable fabrics. Natural, breathable materials allow airflow and help moisture escape, rather than trapping it against the skin.

• Skip the scented stuff. Your vulva doesn't need fragranced soap — plain water, or a gentle, fragrance-free wash, is enough.

• Change out of damp clothing promptly after a swim or workout.

• Wash your underwear with a gentle, fragrance-free detergent and skip fabric softener, which can leave a residue that irritates skin and reduces breathability.

• Leave the douching to nobody. Ever.

When to see a doctor

Occasional shifts in odour or discharge are normal. But if you're noticing a strong, persistent smell, unusual discharge, itching, or discomfort that doesn't settle, that's worth a conversation with your GP or gynaecologist rather than self-diagnosing. These symptoms can have a few different causes, and getting the right one treated properly matters more than guessing.

Where fabric comes in

This is exactly why we chose bamboo modal for our underwear. It's naturally breathable and moisture-wicking, which means less heat and dampness trapped against the skin over the course of a day — one small factor, among many, in keeping things comfortable down there.

It's not a fix-all, and no piece of clothing is a substitute for good habits or medical care when you need it. But we figure: if you're going to wear something against your skin every single day, it might as well be doing you a favour.

This article is general information, not medical advice. If you have ongoing symptoms or concerns about vaginal health, please speak with a healthcare profession