PCOS and Hormone Balance: The Gut Connection You Need to Know

If you have PCOS, you already know how unpredictable it can feel. Maybe it's cycles that never seem to follow a pattern, or acne that won't quit, or trying treatment after treatment without finding what works for your body. For years, this has been one of the most frustrating parts of PCOS: wondering why solutions that help others do nothing for you.

You’re not alone. Polycystic ovary syndrome (PCOS) affects 1 in 10 women [1]. And no two cases look alike. 

Researchers are discovering that your gut microbes may be influencing your hormones, metabolism, and symptoms in ways we're only beginning to understand. In this blog, we'll explore how PCOS and gut health are connected, and share some practical ways to support your body if you're living with it.

What is PCOS, exactly?

Polycystic ovary syndrome is the most common hormonal issue in women ages 12 to 51 [2]. It usually shows up around puberty, peaks during the teens through early 30s, and can stick around for life.

It's a condition where hormonal imbalances disrupt your normal ovulation cycle, which can lead to irregular or missing periods, higher levels of androgens (hormones like testosterone), and insulin resistance (when your body doesn't respond well to insulin) [3].

You don't need to have all three to have PCOS, and that's part of what makes it so complex. Some women also experience facial or body hair growth, mood changes, and weight fluctuations [4].

Though PCOS can't be cured, symptoms often improve with the right combination of lifestyle changes, gut health support, and medical treatments [4]. Some women find their symptoms naturally improve or resolve after their reproductive years. Others face ongoing metabolic challenges like insulin resistance and cardiovascular risks into menopause [5]. 

PCOS types explained

Doctors classify PCOS into four main categories (or phenotypes) based on the symptoms you have [6]:

1. Classic PCOS: You have high androgens, irregular periods, and cysts on your ovaries
2. Non-PCO PCOS: You have high androgens and irregular periods, but no ovarian cysts
3. Ovulatory PCOS: You have high androgens and ovarian cysts, but your periods are regular
4. Non-Hyperandrogenic PCOS: You have irregular periods and ovarian cysts, but normal androgen levels

Beyond these, you might also hear about subtypes like insulin-resistant PCOS or inflammatory PCOS. The reality is that most women have a mix of characteristics from different types and subtypes. That's part of what makes PCOS so tricky to manage and diagnose — it’s usually based on your specific symptoms and hormone test results.

The hormone–gut microbiome connection

Researchers are finding that women with PCOS tend to have different gut bacteria than women without it. Studies show that lower diversity and gut imbalances may be associated with hormone disruption and metabolic symptoms like weight changes [7]. 

Hormone recycling and the estrobolome

One reason for the different gut bacteria has to do with an enzyme called β-glucuronidase. Certain gut bacteria produce this enzyme, and its job is to recycle hormones like estrogen and testosterone back into your bloodstream. When β-glucuronidase is overactive, more hormones get recycled instead of being eliminated. This can potentially worsen hormone imbalances in women with PCOS [8].  

Some researchers are now exploring how the estrobolome, the gut's estrogen-regulating microbial community, may also indirectly influence androgen levels.

Hyperandrogenism and gut bacteria

Androgens are a group of hormones that include testosterone, affecting things like energy, muscle mass, and sex drive. In PCOS, elevated androgen levels (hyperandrogenism) are a key feature that can cause symptoms like excess facial or body hair, acne, and irregular periods.

An imbalance in gut bacteria can disrupt how your body processes hormones, potentially making elevated testosterone levels even worse [9].

So what does this mean for you? An imbalanced gut may be more than just a symptom of PCOS. It may be affecting your hormone levels and symptoms. Scientists are still working to fully understand this relationship.

The inflammation and insulin resistance link

Many women with PCOS also experience insulin resistance, meaning the body's cells become less responsive to insulin, which can lead to higher blood sugar and more circulating insulin.

Your gut plays a role in this too.

An imbalanced microbiome can lead to low-grade inflammation and increased gut permeability (a.k.a. leaky gut). This allows bacterial fragments like lipopolysaccharides (LPS), troublemaking molecules, to enter the bloodstream and trigger inflammation throughout the body [10], [11]. 

Inflammation, in turn, can worsen insulin resistance. Some studies have found that specific bacterial populations, like Enterococcus, are more abundant in PCOS patients with insulin resistance [10]. And insulin resistance can stimulate the ovaries to produce more androgens, creating a cycle that fuels many PCOS symptoms [12].

How PCOS affects daily life: the Tiny Health and Mira study

The science is compelling, but what does this actually look like day to day? 

In a 2024 Tiny Health and Mira study of 366 women with PCOS, 94% reported gut health issues, and 69% experienced moderate to severe symptoms. The most common were bloating (72%), diarrhea (46%), excessive gas (44%), constipation (38%), abdominal cramping (35%), and acid reflux or heartburn (31%).

These symptoms aren't just uncomfortable, they're disruptive. More than half of participants (57%) said their productivity suffered because of PCOS, and 40% had taken days off work to deal with symptoms.

The emotional toll is real too. Sixty percent said PCOS made them feel less attractive, 50% reported not liking the way their body looked, and 33% were afraid to talk to friends and family about it.

If any of this sounds familiar, it's not in your head.

Can addressing gut health help with PCOS?

Research suggests it might. Hormone treatments that support estrogen balance have been shown to reduce overactivity of β-glucuronidase in the gut [13]. 

The more diverse your gut bacteria, the better. Greater diversity is linked to better insulin sensitivity and less inflammation [12], [14]. 

What does all of this research mean for your health? It could mean better hormonal balance, healthier blood sugar levels, and fewer symptoms.

Here are two interventions that show promise for women with PCOS:

Probiotics

Early research suggests probiotic strains like Bifidobacterium lactis may influence sex hormone levels through the gut-brain connection [9]. For women with PCOS, this could potentially help address some of the most frustrating symptoms tied to hormone imbalances, like irregular cycles, acne, and excess hair growth. 

Diet

Based on emerging animal data, what you eat has a stronger effect on your gut bacteria than PCOS itself [15], so a healthy diet does matter. In fact, it can improve hormonal and metabolic markers in women with PCOS. In mouse studies, adjusting the balance of protein, carbs, and fat changed gut bacteria in ways that reduced androgen production and improved reproductive function [15]. If this finding translates to humans, it could possibly help with regulating your cycle and improving fertility.

The science is still developing, but the potential is there. Gut-focused approaches offer a new way to think about managing a condition that is often misunderstood.

5 ways to support your gut when managing PCOS  

Living with PCOS comes with real challenges, but your gut health is one area where you have control. Here are some practical steps you can take today.

1. Focus on fiber-rich foods: Eat a variety of vegetables, fruits, whole grains, and legumes. These foods help manage blood sugar and feed your beneficial bacteria.
2. Choose plant proteins: Include more plant-based protein sources like beans, lentils, tofu, tempeh, and nuts in your diet to support helpful microbes.
3. Consider probiotics: Look for multi-strain formulations containing Lactobacillus and Bifidobacterium species. Talk to your practitioner about what might work for you.
4. Add prebiotic foods: Include garlic, onions, leeks, asparagus, bananas, and oats in your meals to feed friendly bacteria.
5. Consider a Gut Health Test: Understand how your β-glucuronidase activity and LPS levels may be impacting your symptoms. 

It’s always best to work with your practitioner when you're switching up or changing your wellness routine.

Fertility support: track your cycle with PCOS 

While you're working on gut health, tracking your cycle can also help, especially if you're trying to conceive. PCOS is one of the most common causes of infertility. Understanding your cycle can be challenging when it’s irregular. Women with PCOS may experience multiple luteinizing hormone (LH) peaks or hormonal variations that make ovulation even harder to predict [16].

If you’re trying to conceive, helpful tools like Mira can help you track your cycle with actual numbers instead of best-guesses. Their at-home fertility monitor uses quantitative technology to track key fertility hormones (LH, E3G, PdG, and FSH) with numerical results and personalized data. It shows your body's patterns rather than just a positive or negative result. 

For women with PCOS who are trying to get pregnant, this level of precision can make all the difference in identifying your fertile window.

Finding your way forward

PCOS is complex, and for too long, women have been left without clear answers about why their bodies respond the way they do. The emerging research on gut health doesn't solve everything, but it does offer a new lens, one that provides deeper insight into how our microbes play a part in the hormonal and metabolic puzzle.

Whether you're newly diagnosed or have been navigating PCOS for years, exploring the gut connection might be a valuable addition to your wellness approach. 

Our Tiny+ Adult Membership can help you see what's actually going on, like your β-glucuronidase activity and LPS levels, and where to focus. It includes a session with a microbiome specialist who can walk you through your results, and your personalized Action Plan with recommendations for diet, supplement, and lifestyle changes to support your microbiome.