How gut health affects hormones and your menstrual cycle

Your gut isn’t just for digesting food; it’s a powerhouse that influences nearly every system in your body, including your hormonal health. Often referred to as the "second brain," your gut microbiome plays a pivotal role in regulating mood, immunity, and even your menstrual cycle. For women, gut health can have a profound effect on hormonal balance, especially in conditions like PCOS (Polycystic Ovary Syndrome) and menstrual irregularities. 

 

In this article, we explore the connection between gut health and hormones, their impact on your menstrual cycle, and the steps you can take to support both of them naturally. 

Understanding the gut-hormone connection

 

The gut microbiome is home to trillions of bacteria that help regulate key bodily functions, including hormone metabolism. 

 

Hormone metabolism and regulation

 

The gut plays a crucial role in metabolising and recycling hormones, including oestrogen and progesterone, two female sex hormones. A group of gut bacteria known as the estrobolome plays a specific role in processing oestrogen. When gut bacteria are imbalanced, it can lead to excess oestrogen circulating in the body, contributing to symptoms like bloating, mood swings, and irregular periods. 

 

The gut-liver axis

 

The liver works closely with the gut to detoxify and clear hormones from the body. When the gut microbiome is out of balance, it may affect how efficiently the liver clears hormones, especially oestrogen. This can contribute to oestrogen dominance, which is linked to PMS (Premenstrual syndrome), heavy periods, and fibroids. 

The gut-brain axis

 

The gut communicates with the brain through the vagus nerve, influencing the release of hormones like cortisol and serotonin [1]. Cortisol, the stress hormone, can directly affect menstrual cycle regularity, while serotonin is essential for mood stability, explaining why gut imbalances can also trigger emotional PMS symptoms. 

 

The effect of gut health on the menstrual cycle

 

 

Imbalances in the gut, like dysbiosis (an overgrowth of harmful bacteria) or leaky gut, where bacteria and toxins can enter the blood steam from the intestine, can throw your hormones off balance, which inevitably disrupts your menstrual cycle. Find out more about these imbalances and how they can impact your menstrual cycle. 

 

Gut imbalances and irregular cycles

 

Dysbiosis can impair hormone regulation, leading to irregular ovulation or anovulatory cycles [2] (where the egg is not released from the ovary). A compromised gut lining (leaky gut) may also allow toxins into the bloodstream, increasing systemic inflammation, which negatively impacts hormone function. 

 

PMS, Cramping, and Mood Swings

 

Poor gut health is often associated with increased inflammation, which may worsen PMS symptoms like cramping, breast tenderness, and mood instability. When gut bacteria aren't producing enough short-chain fatty acids (SCFAs), which reduce inflammation, PMS symptoms can become more severe. 

 

Digestion and Hormonal Excretion

 

Slow digestion or chronic constipation can delay hormones from being excreted from the body, causing oestrogen to recirculate back around the bloodstream. This can cause an excess of oestrogen in the body. Supporting digestion through diet and adequate hydration is essential to maintaining hormonal balance. Regular bowel movements = better hormone balance! 

 

PCOS and gut health: What’s the link?

 

PCOS affects up to 10% of women of reproductive age [3] and is characterised by hormonal imbalances, insulin resistance, and irregular periods. Emerging research shows a strong link between PCOS and gut health [4]. 

 

Gut microbiota and PCOS