The Microbiome and Polycystic Ovary Syndrome (PCOS)

PCOS is a common disorder affecting hormone levels, menstrual cycles, and ovaries. It has many causes, including genetics, hormones, and environment. Recently, the gut microbiome has been found to play a role in PCOS.

The Gut Microbiome: An Overview

The gut microbiome consists of trillions of microorganisms, like bacteria, viruses, and fungi, living in the digestive tract. These microbes help with digestion, vitamin production, immune system regulation, and protection against harmful bacteria. Factors such as diet, genetics, environment, and medication can affect the gut microbiome. An imbalance in these microbes, known as dysbiosis, is linked to various health issues, including metabolic disorders and mental health problems.

The Microbiome-PCOS Connection

Studies have shown that the gut microbiome differs between people with PCOS and those without it. This suggests that gut imbalances may contribute to PCOS in several ways:

  1. Metabolic Dysfunction
    • Insulin Resistance: About 70% of people with PCOS have insulin resistance. The gut microbiome can affect insulin sensitivity through the production of short-chain fatty acids (SCFAs) like butyrate. A lack of SCFA-producing bacteria in PCOS can lead to poor insulin sensitivity.
    • Obesity: The gut microbiome influences energy balance and fat storage. Certain gut bacteria can increase calorie absorption and fat storage, leading to obesity, which worsens insulin resistance and hormone imbalances in PCOS.
  2. Hormonal Imbalance
    • Androgen Excess: The gut microbiome can affect hormone levels. Dysbiosis may increase the reabsorption of androgens (male hormones), leading to symptoms like excess hair growth and acne in PCOS.
    • Oestrogen Metabolism: The gut microbiome also impacts oestrogen levels. Dysbiosis can lead to higher oestrogen levels, disrupting the hormonal balance needed for normal ovarian function.
  3. Chronic Inflammation
    • PCOS is linked to low-grade chronic inflammation. Gut dysbiosis can increase gut permeability, allowing harmful substances into the bloodstream, triggering inflammation and worsening insulin resistance and androgen excess.
  4. The Gut-Brain Axis and Its Influence on PCOS
    • The gut-brain axis is the communication network between the gut and the brain. Gut bacteria can produce neurotransmitters like serotonin and dopamine, influencing mood and brain function. Dysbiosis can affect neurotransmitter levels and increase gut permeability, leading to systemic inflammation and mood disorders like anxiety and depression in PCOS.

Implications for Treatment and Management

Understanding the role of the gut microbiome in PCOS suggests new treatments, such as:

  1. Dietary Modifications: Eating a diet high in fibre and low in refined sugars can promote beneficial gut bacteria and reduce inflammation.
  2. Probiotics: Supplements containing beneficial bacteria, like Lactobacillus and Bifidobacterium, can improve insulin sensitivity and hormone levels in PCOS.
  3. Prebiotics: Foods that promote the growth of beneficial bacteria, like chicory root and garlic, can help manage PCOS symptoms.
  4. Faecal Microbiota Transplantation (FMT): Transplanting stool from a healthy donor to restore gut microbiota is an emerging treatment that shows promise for PCOS.

Polyphenols and Gut Microbiota

Plant compounds called polyphenols can also help by promoting beneficial bacteria and reducing harmful ones. Examples include:

  • Anthocyanins: Found in berries, they may improve ovarian function and support gut health.
  • Catechins: Found in green tea, they can reduce inflammation and improve hormone profiles.
  • Resveratrol: Found in grapes and berries, it can enhance insulin sensitivity and support overall gut health.