Fermented foods for PCOS

Gut health and fermented foods are hot topics, but what about fermented foods for PCOS? In this article, we will demystify gut health and fermented foods and their link to PCOS. Keep reading to learn more and whether you need kimchi, sourdough or yoghurt in your life!

What are fermented foods?

The fermentation process to preserve food and drinks is an ancient technique. During fermentation, microorganisms like bacteria, yeast or fungi convert the sugars into alcohol or acids. These act as natural preservatives and improve the taste and texture of fermented foods, leaving them with a distinctive and intense flavour. 

How do fermented foods impact gut health?

Our large colon in our gastrointestinal tract digests and absorbs food and naturally contains trillions of microorganisms (or gut microbiota) that help us break down all of our food and support our overall health and wellbeing. Our gut microbiota is ‘like a fingerprint’. It is specific and unique to every person.

Imbalances in our gut microbiota (gut dysbiosis) can be caused by many different factors. These include getting older, taking antibiotics, illnesses such as irritable bowel syndrome or inflammatory bowel disease or following an episode of food poisoning or surgery. Even significant life events that have caused huge amounts of stress and low mood can have an impact on the balance of your gut microbiota. 

Fermented foods may contain beneficial microorganisms that can support our gut health by potentially helping restore any imbalances in the bacteria in our large colon. Fermented foods also contain other fibres known as prebiotics, which we know as beneficial to support our gut microbiota by continuing to feed our ‘good’ bacteria. 

Does PCOS impact gut health?

Our gut microbiota living in our large colon is related to various metabolic pathways including our immune system, carbohydrate metabolism and influence insulin sensitivity. As already mentioned our gut health is affected not only by what we eat but other internal and external factors.

Existing medical conditions such as PCOS may impact gut health. Research studies suggest that insulin resistance and altered sex hormones may affect the diversity and composition of gut microbiota in people with PCOS. 

Most importantly the gut microbiota can influence the brain directly via the vagus nerve, which travels from the brain to the gut. This is known as the brain-gut axis. When we’re stressed and/or anxious, our brain sends signals to the gut. This switches on the sympathetic (‘fight or flight) nervous system and can raise the sensitivity of the gut, known as visceral hypersensitivity.  This can subsequently increase the risk of making us more susceptible to low moods and depression

PCOS can display as a collection of symptoms including; acne, oily skin, lack of or irregular periods, lack of ovulation, excess hair growth, insulin resistance, increased testosterone levels and fertility issues. These symptoms can in themselves cause stress and anxiety and therefore impact our gut health. 

With a better understanding of the role of gut microbiota in PCOS, interventions including prebiotics, probiotics, and synbiotics (pre- and probiotics combined) may be considered as future treatment options. 

Top 5 fermented foods

Ready to introduce more fermented foods into your diet? Here are our top 5 fermented foods for PCOS.


Yoghurt is a food produced by the bacterial fermentation of milk. Yoghurt contains live, active cultures of lactobacillus bacteria and is a good source of protein and calcium. Take a look at our dedicated article if you’re curious about dairy for PCOS.

Try combining yoghurt with granola and berries for a tasty breakfast or snack, or add to a smoothie for a creamy texture.

Miso Paste

Miso paste is a fermented soybean paste. Miso is a Japanese staple ingredient with a deep umami flavour. Miso gives deep, savoury notes to soups, fish, meat and vegetable dishes. It is incredibly versatile and delicious.


Sauerkraut is created via the natural lactic acid fermentation of salted, shredded cabbage. Try adding sauerkraut to a salad or a sandwich, or add as a tasty side to many dishes. Or, if you prefer to cook with sauerkraut, you can add it to stocks or soups although this may reduce the prebiotic effects.


Kefir is a fermented milk drink, similar to yoghurt. Like yoghurt, you can add it to smoothies or even just drink it solo.


Many people forget but olives are actually a fermented food. They are a great snack or can be added to pizza, salads or even sandwiches.

Key takeaways: Fermented foods for PCOS

Whilst the evidence for fermented foods for PCOS is compelling, more research is required. It is also important not to overhaul your entire diet in a short space of time. Take it one change at a time, especially if the fermented food is new to you, to allow time for your body to adapt. However, if you are immune-compromised please discuss this with your medical team or GP.

Sophia Boothby RD Author at The PCOS Collective

Lead Author | Head Dietitian | Registered Dietitian


Sophia is a Registered Dietitian working as a Specialist Community Dietitian within a London NHS Teaching Hospital specialising in gut health such as irritable bowel syndrome (IBS) and the low FODMAP diet, type 2 diabetes, PCOS, and cardiac rehabilitation. Sophia offers 1:1 PCOS support in our virtual PCOS clinic.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top