can dysbiosis worsen PCOS symptoms?

Polycystic ovary syndrome (PCOS) is one of the most common hormonal conditions in women of reproductive age, affecting between 6–26% globally. Despite how widespread it is, the exact cause remains uncertain. What we do know is that PCOS is influenced by both our genes and our lifestyle, and it often brings challenges such as irregular periods, acne, excess hair growth, fertility struggles, weight gain, and a higher risk of conditions like insulin resistance and type 2 diabetes.

In recent years, research has started to uncover an important player in this story: our gut microbiome.

Understanding PCOS

PCOS is closely linked to insulin resistance (when the body doesn’t respond properly to insulin, making it harder to control blood sugar) and higher levels of androgens (sometimes called ‘male hormones’ such as testosterone). Together, these can disrupt ovulation and lead to many of the symptoms women experience.

Obesity is also common in PCOS, but it isn’t the whole story. Many lean women also have PCOS, and weight gain often makes symptoms worse. The reasons are complex, and this is where the gut microbiome comes in.

The Role of The Gut Microbiome

Your gut is home to trillions of bacteria, fungi, and other tiny organisms collectively called the gut microbiome. Think of it as a bustling ecosystem that helps break down food, produce vitamins, regulate your immune system, and even influence your mood.

Studies show that women with PCOS often have a less diverse gut microbiome than women without PCOS. This means there’s a smaller variety of helpful bacteria in the gut, which may reduce resilience and make it easier for imbalances to take hold.

Some of the most consistent findings include:

• Lower diversity: Fewer types of bacteria overall.

• Shifts in balance: More of some types (like Bacteroidetes) and fewer of others (like Firmicutes).

• Fewer beneficial bacteria: Lactobacilli and Bifidobacteria, which usually support digestion, immunity, and nutrient absorption, tend to be reduced.

• Changes in gut by-products: The microbiome produces short-chain fatty acids (SCFAs), which play a big role in metabolism, inflammation, and gut health. In PCOS, SCFA levels are often lower, which may contribute to insulin resistance and inflammation.

These shifts don’t just stay in the gut. They can ripple out to affect hormones, metabolism, and even mood through what is known as the gut–brain axis: the two-way communication between your gut and your nervous system.

Why Does This Matter in PCOS?

Gut imbalance, often called dysbiosis, may worsen some of the key features of PCOS:

• Insulin resistance: A disrupted gut lining (sometimes called “leaky gut”) can let inflammatory molecules into the bloodstream, which reduces the body’s sensitivity to insulin.

• High androgens: Insulin resistance can push the ovaries to produce more testosterone, worsening symptoms such as acne, irregular cycles, and excess hair.

• Weight gain: Gut bacteria help regulate appetite, energy balance, and fat storage. Imbalances may make it harder to manage weight.

• Inflammation: Ongoing, low-level inflammation is common in PCOS and may be fuelled by gut changes.

Can Synbiotics Improve Symptoms?

You’ve probably heard of probiotics and prebiotics, but synbiotics are now gaining attention for their ability to combine the two. Probiotics are live, ‘friendly’ bacteria, while prebiotics are the fibres that feed them. Synbiotics bring them together, helping beneficial bacteria to survive, thrive, and play their supportive role in the gut.

Early research suggests that synbiotics may help support blood sugar balance, cholesterol, gut barrier function, and inflammation which are areas that can be relevant for people living with PCOS. For example, one small study found that women with PCOS who took a synbiotic for 12 weeks experienced improvements in certain markers related to insulin and hormone balance. While more research is needed to fully understand this link, these findings are encouraging.

Conclusion

PCOS can feel overwhelming at times, especially with its wide range of symptoms. But by understanding the connection between PCOS and gut health, we open the door to new ways of managing symptoms and supporting overall wellbeing. While research is still evolving, what’s clear is that the gut is a key player in hormonal and metabolic health.

As always, if you’re thinking about trying probiotics or making big changes to your diet, it’s worth chatting to a healthcare professional who understands your unique situation.

Disclaimer: Lifestyle interventions and pharmacological treatments remain the main evidence-based approaches for managing PCOS. Synbiotics are being actively researched and may offer additional support, but they are not a replacement for medical care.

References

Nasri, K., Jamilian, M., Rahmani, E., Bahmani, F., Tajabadi-Ebrahimi, M., & Asemi, Z. (2018). The effects of synbiotic supplementation on hormonal status, biomarkers of inflammation and oxidative stress in subjects with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled trial. BMC Endocrine Disorders, 18, 21. https://doi.org/10.1186/s12902-018-0248-0

Senthilkumar, H., & Arumugam, M. (2025). Gut microbiota: a hidden player in polycystic ovary syndrome. Journal of Translational Medicine, 23, 443. https://doi.org/10.1186/s12967-025-05456-y