Hair Loss Is Not Just Hormonal: A 2026 Study Suggests Your Scalp Microbiome May Play a Role

A new 2026 research paper suggests that common hair loss may not be purely hormonal—but also linked to changes in the tiny ecosystem inside your hair follicles.

This article explains what that means, in plain English.

TL;DR (from Dr Gwen Adey)

• Hair loss is still mainly caused by genetics and hormones

• But the environment inside the hair follicle may also change

• A common scalp fungus (Malassezia) is reduced in hair loss

• This may allow imbalance and inflammation to develop

• This doesn’t change treatment yet—but it may shape future approaches

The study

This article summarises:

Miao et al. (2026)

Alterations in the Hair Follicle Bacteriome and Mycobiome in Androgenetic Alopecia

👉 Full paper:

First, a simple idea: your hair follicle is an ecosystem

Most people think of hair loss like this:

Hormones shrink the hair → hair gets thinner → eventually stops growing

That’s still true.

But this study suggests something extra:

Each hair follicle also has its own microbiome—a mix of bacteria and fungi living inside it.

Just like your gut has a microbiome, so does your scalp.

And in healthy hair follicles, that microbiome is balanced.

What the researchers found

The study compared people with hair loss to those without.

They looked deep inside the hair follicle—not just the scalp surface.

The key result:

• Bacteria stayed mostly the same

• Fungi changed significantly

👉 In simple terms:

Hair loss was linked to a fungal imbalance, not a bacterial one

The most interesting finding: a missing fungus

In healthy follicles:

• The most common fungus is called Malassezia

In hair loss:

• Malassezia levels were much lower

Wait—aren’t fungi supposed to be bad?

Not always.

We often hear about fungi causing:

• Dandruff

• scalp irritation

But this study suggests something more subtle:

In the right balance, some fungi may actually be helpful

Think of it like your gut:

• You don’t want no bacteria

• You want the right balance of the right ones

The same may be true for your scalp.

What happens when that balance is lost?

As hair loss progresses, the study found:

• More types of microbes appear

• The environment becomes less stable

The researchers describe this as:

“Niche collapse” — the follicle loses its normal balance

A simple way to think about it:

• A healthy follicle = well-managed garden

• A hair loss follicle = weeds start to take over

Why would this happen?

The study suggests a few reasons:

• Hair follicles shrink (this is already known in hair loss)

• Oil (sebum) changes in composition

• The structure of the follicle changes

All of this can make the follicle:

Less able to support its normal, healthy microbiome

An important insight: the whole scalp may be affected

Interestingly, the study found:

• These microbiome changes happen across the whole scalp

• Not just the areas where hair is thinning

So why does hair loss only happen on the top?

The answer:

Some follicles (like those on the crown) are more sensitive to hormones.

So:

Hair loss may happen where two things overlap:

• Hormonal sensitivity

• Microbiome imbalance

Why this could matter

At the moment, most treatments focus on:

• Hormones (like finasteride)

• Stimulating growth (like minoxidil or PRP)

This study suggests something new:

The environment inside the follicle itself may also matter

In the future, this could lead to treatments that:

• Support the scalp microbiome

• Restore balance inside the follicle

• Reduce inflammation more precisely

Important: this does NOT change treatment yet

This is where it’s important to stay grounded.

This study:

• Does not prove cause and effect

• Does not test treatments

• Does not show that changing the microbiome regrows hair

For example:

Shampoos like ketoconazole (Nizoral) are sometimes used in hair loss care.

This study does not show they are harmful.

It simply suggests:

The scalp microbiome is more complex than we previously thought

Final perspective

Hair loss is still mainly driven by:

• Genetics

• Hormones

But this research suggests something more:

The hair follicle is not just shrinking—it may also be losing its internal balance.

Seen this way:

Hair loss may be partly a problem of the follicle’s ecosystem

That’s a subtle shift—but potentially an important one.

If future research confirms it, it could change how we think about treatment.

Summary from Dr Gwen Adey

This study doesn’t overturn what we know about hair loss.

But it adds a new layer.

It suggests that alongside hormones, the health of the follicle environment itself may play a role.

That’s not something we currently treat directly.

But in the future—it might be.

Want help understanding your hair loss?

If you’re not sure what’s causing your hair loss, the first step is a proper diagnosis.

At Growth Factor Hair Clinic, consultations focus on:

• Understanding your specific type of hair loss

• Explaining your options clearly

• Creating a plan that makes sense for you

👉 You can book a consultation to explore your options