A New Approach to Polycystic Ovarian Syndrome via the Gut Microbiome

This article is written by Nick Nation Accredited Practising Dietitian

After presenting to a room full of women living with polycystic ovarian syndrome (PCOS) recently, I thought I’d write a little blog to discuss a new approach to the management of the condition that affects approximately 8-13% of women of reproductive age.

So what is PCOS?

PCOS is a hormonal condition, despite what the name suggests. PCOS doesn’t just affect the ovaries. In fact, diagnosis of PCOS includes 2 out of 3 clinical presentations below:

Hyperandrogenism (e.g. high testosterone)
Oligomenorrhea (infrequent periods) or anovulation (lack or absence of ovulation)
Polycystic ovaries

Factors such as lifestyle, diet, and genetics have been reported to influence the onset of PCOS, however the exact cause is unknown.

We know that an imbalance of two distinct hormones, insulin and androgens (e.g. testosterone) cause the ovaries to work differently. In fact this imbalance can lead to changes in several bodily systems, including:

Anovulation (lack or absence of ovulation)
Polycystic ovarian morphology (PCOM) - multiple cysts on the ovaries
Excess hair growth (hirsutism), alopecia (scalp hair loss), acne
Mood changes
Difficulties with fertility
Weight gain

It’s important to note that symptoms vary between individuals. In fact, just because you’re living with PCOS, it doesn’t mean that you will experience all of the above symptoms.

The Gut Microbiome

The large intestine, affectionately known as the gut, is home to trillions of microbes including bacteria, fungi, viruses and other microscopic living things. The gut works to salvage unabsorbed material from the small intestine. Salts and water are reabsorbed from solid contents, whilst your microbes are busy at work fermenting/digesting most of what’s left.

The curriculum vitae (CV) of the gut microbiome includes making vitamins (e.g. B-vitamins), minerals, hormones, and neurotransmitters (e.g. serotonin & dopamine). The gut microbiome trains and regulates the immune system, and it may also produce important metabolites that prevent against many diseases including:

Irritable Bowel Syndrome and Inflammatory Bowel Disease
Heart health
Type 2 Diabetes
Mental health (e.g. depression & anxiety)
Overweight/obesity

We’re only scratching the surface regarding what constitutes a healthy gut and what our gut microbiome actually does. Currently, our understanding is that bacterial diversity is key. The greater the diversity of bacterial species, the happier the gut. When bacterial diversity is low, this can lead to microbial imbalance (or dysbiosis) which can lead to dysfunction and progression toward a broad spectrum of diseases.

PCOS and the Gut Microbiome

The gut microbiome is so important for your health. However, does this ring true for PCOS-related signs and symptoms…and health conditions linked to PCOS?

Sure does 😊.

Women with PCOS tend to exhibit reduced bacterial diversity (remember, the more diverse the better) and this has been shown in several human and rodent trials. In fact, this lower diversity has been correlated with high androgens, total testosterone levels and excess hair growth, which have all been linked to PCOS.

We think that genetic, hormonal and metabolic factors contribute to the development and progression of PCOS, but we’re not 100% sure (Yurtdas & Akdevelioglu, 2019). It’s certainly not caused by something that you ate that one time. We’re also not sure whether the gut plays a role in the development of PCOS, or whether decreased bacterial diversity is simply a symptom which may worsen PCOS. What we do know is that it’s all connected and I’ve tried to demonstrate this below.

To explore the PCOS-gut connection further, researchers transplanted the faeces (poo) from patients living with PCOS to mice (I know, humans and mice are different, however these studies do offer some great insight). Mice who were transplanted with the poo samples from patients living with PCOS developed insulin resistance, had higher levels of androgens and increased number of ovarian cysts (Zhao et al. 2020). They effectively transplanted PCOS via the poo!

A new approach to PCOS

The PCOS International Consensus Statement recommends lifestyle interventions as a first-line treatment for PCOS. Key areas within this approach include diet, exercise, and behavioural interventions. With regards to diet specifically, the standard Australian diet or the SAD diet (think high salt, high refined carbohydrate) has been linked to hyperandrogenism (high testosterone) and ovulation disorders. Conversely, low glycaemic index (GI) diets can improve insulin resistance and make ovulation and menstrual cycles more regular in people living with PCOS (Zhao et al. 2020).

But what about gut health? We know dietary changes can impact our gut. The more varied the diet, generally the more diverse the gut bacteria and the better PCOS symptom outcomes. Therefore, a new approach to PCOS management should include a strong focus on eating a variety of plant-based ingredients from high fibre sources like fruit and vegetables, nuts and seeds, legumes and beans as well as wholegrains. Recommendations for each of these foods should be individualised, however, a good starting point might look a little bit like this day-on-a-plate below…

Please note, the above day-on-a-plate doesn’t necessarily take into account competing food sensitivities e.g lactose intolerance, or gut-related diseases e.g. inflammatory bowel disease. Best approach your local health professional for more tailored advice in these circumstances.