Can Probiotics Affect Your Menstrual Cycle?

author avatar Dr. Eric Berg 11/20/2023

Probiotics promote a healthy intestinal microflora, which plays a crucial role in female health and balanced hormone levels. But can probiotics affect your menstrual cycle?

Yes, probiotics can impact the menstrual cycle. Intestinal microbes regulate the metabolism of sex hormones and can lower the risk of excess estrogen linked to various menstrual problems. 


Learn how to build a healthy microbiome to support hormonal balance and discover why taking probiotic supplements can promote healthy menstrual cycles.

Woman holding a calendar

The connection between gut health and menstrual health

The composition of your intestinal microbiota can profoundly impact the regulation and metabolism of estrogen, progesterone, and other hormones involved in menstrual health. 

Estrogen is a crucial female sex hormone that regulates menstrual cycles, reproductive health, and bone metabolism. 

The ovaries are the primary source of estrogen, which enters into the circulation and eventually is inactivated and detoxified by the liver and released into the large intestines for excretion.  

Certain gut bacteria influence hormonal balance by producing beta-glucuronidase, an enzyme that converts inactive estrogen into active estrogen, which is readily reabsorbed into the body. 

Research published in Gut Microbes found that a lack of beneficial gut bacteria, also known as dysbiosis, can significantly impact estrogen levels and result in excessive or inadequate estrogen reabsorption.   

Estrogen dominance is characterized by too much estrogen in the body and is linked to various female health issues, including heavy and prolonged periods, premenstrual syndrome (PMS), and an increased risk of breast cancer. 

Low estrogen levels, on the other hand, are associated with menstrual irregularities such as infrequent or absent periods and can increase the risk of infertility and weight gain. 

In addition, beneficial bacteria release various chemicals that interact with the central and enteric nervous systems and regulate mood and stress levels. This may explain why women with dysbiosis are more likely to experience PMS symptoms such as mood swings and anxiety. 

Watch the video below to learn how estrogen dominance can affect female health. 

Understanding the Women Menstrual Cycle and Estrogen Dominance

Can probiotics affect your menstrual cycle positively?

According to research published by the U.S. Department of Health and Human Services, almost 90 percent of women experience irregular menstrual cycles or uncomfortable period symptoms such as mood swings and abdominal cramps.  

Taking probiotics can help maintain a diverse microbial composition, which supports balanced estrogen levels, regular menstrual cycles, and reproductive health.

Evidence published in Gut Microbes suggests that Lactobacillus species, including Lactobacillus acidophilus and Lactobacillus GG, appear to be the best probiotics to promote balanced estrogen metabolism and menstrual health.

In addition, Bifidobacterium competes with potentially harmful microbes for space and nutrients, which strengthens the intestinal microflora and plays a crucial role in maintaining a balanced vaginal microbiome.

The benefits of probiotics for menstrual health reach far beyond hormonal balance. Many women suffer from persistent gastrointestinal issues such as abdominal cramps, bloating, and diarrhea during their periods. 

Increasing the diversity of gut microbes with beneficial bacteria can improve digestive functionality and ease period-related gastrointestinal symptoms such as loose stools, cramping, and bloating.  

Woman with stomach cramps

Signs of poor gut health

Beneficial microbes in the gut play a fundamental role in digestive and immune system functions, mental health, energy metabolism, and nutrient absorption. 

Factors including frequent antibiotic use, birth control pills, and a diet high in sugar, alcohol, and processed foods can alter the composition of the microbiome.   

Lack of friendly bacteria can result in the overgrowth of potentially harmful bacteria, yeasts, or fungi linked to poor gut health and a wide range of other health issues. 

Here are common signs of poor gut health:

  • Gas and bloating

  • Diarrhea or constipation

  • Frequent infections

  • Fatigue 

  • Unexplained weight gain

  • Depression and anxiety 

  • Food allergies 

  • Nutrient deficiencies 

  • Skin conditions, including fungal acne and psoriasis

  • Poor fat digestion 

If you are concerned about your gut health or have developed symptoms of dysbiosis, it’s crucial to consult a healthcare provider for a thorough evaluation of your symptoms.

Fermented foods

How to build a healthy microbiome

Building a healthy gut microbiome involves increasing microbial diversity by promoting the growth and proliferation of beneficial bacteria. 

Here are some key strategies to help you establish and maintain a healthy microbiome.

Fermented foods

Fermentation creates an optimal environment for beneficial bacteria to flourish which explains why fermented foods such as yogurt, kimchi, sauerkraut, miso, pickles, and kefir are excellent sources of probiotics

Regularly incorporating these foods into your diet is a natural and effective way to support a diverse gut microbiome linked to a lower risk of hormonal imbalances and period-related symptoms. 


Prebiotics are indigestible fibers that are fermented by gut microbes. This fermentation process releases large amounts of short-chain fatty acids (SCFAs), which serve as the primary fuel source for beneficial bacteria.

Foods including garlic, onions, leeks, asparagus, flaxseed, and artichokes are rich in prebiotic fibers that promote the growth and proliferation of healthy bacteria.

Probiotic supplements

While prebiotic and probiotic foods play a crucial role in supporting a diverse microbiome, many people don’t consume enough fermented and fiber-rich foods to maintain optimal levels of good bacteria. 

“Poor gut health can profoundly impact overall health and well-being,” explains Dr. Berg. “Probiotic supplements are an effective strategy to populate your gut with good bacteria and promote microbial diversity.”  

Probiotic supplements are widely available and can be taken as pills, capsules, powders, or in liquid form. 

To get the most out of taking probiotics, it’s recommended to opt for a supplement that contains several well-researched bacterial strains, including Lactobacillus and Bifidobacterium.

In addition, opt for a product that contains at least 60 billion colony-forming units (CFUs), which indicates how many viable microorganisms each serving contains. 

Supplements with fewer CFUs may not deliver adequate amounts of beneficial bacteria into the gut, leaving you at risk of an imbalanced gut microbiota. 

Female reproductive system

Other benefits of probiotics for women’s health 

The female reproductive system is densely populated by microbes, and promoting bacterial diversity with probiotics has been associated with a healthy vaginal microbiome.

Beneficial bacteria help prevent the proliferation of fungi and yeasts in the vagina, which significantly lowers the risk of Candida overgrowth and urinary tract infections.

A study published in the Journal of Ovarian Research suggests that probiotics promote metabolic health and lower the risk of insulin resistance, a key factor in the development of polycystic ovary syndrome (PCOS).

In addition, certain probiotic strains produce antimicrobial substances that can inhibit the growth of harmful bacteria on the skin, which supports a diverse skin microbiota.

Maintaining adequate concentrations of beneficial bacteria on the skin’s surface can help prevent skin conditions linked to microbial overgrowth and hormonal imbalances, such as acne, fungal infections, rosacea, and psoriasis.   

Probiotic supplement on a wooden spoon

Key takeaways

Can probiotics affect your menstrual cycle? Yes, probiotics help regulate and metabolize estrogen, which supports female sex hormone balance and regular menstrual cycles.  

Increasing microbial diversity with probiotic supplements and pre- and probiotic-rich foods can help alleviate period-related symptoms, including mood swings, abdominal cramping, and gastrointestinal issues such as bloating and diarrhea. 

Additional resources


1. Can probiotics cause hormonal changes?

Yes, probiotics can help restore and maintain a diverse gut microbiome, which plays a crucial role in regulating hormonal balance. 

Beneficial gut microbes produce an enzyme called beta-glucuronidase, which influences whether inactive estrogen is reabsorbed or excreted. An imbalanced microflora can lead to excessive or inadequate estrogen reabsorption, which can contribute to hormonal changes.  


2. Can probiotics affect your menstrual cycle?

Yes, probiotics have been found to promote hormonal balance linked to regular menstrual cycles and a lower risk of period-related symptoms such as premenstrual syndrome (PMS), abdominal cramps, breast tenderness, and mood swings. 

3. How do probiotics affect your menstrual cycle?

Probiotics enhance the body’s ability to balance estrogen, a crucial female sex hormone that regulates menstrual cycles. 

Supporting a diverse microbiome with probiotics helps promote healthy menstrual cycles and vaginal health and is associated with a lower risk of heavy bleeding, mood swings, and PMS. 

4. How can a poor microbiome throw off your menstrual cycle?

The gut microbiome plays a vital role in the metabolism of hormones, including estrogen and progesterone, which are essential for regular menstrual cycles. 

A poor microbiota can affect hormone levels and potentially lead to absent or irregular periods. 

5. What is the best type of probiotic for hormonal health?

Evidence suggests that Lactobacillus strains, including Lactobacillus acidophilus and Lactobacillus GG, can enhance estrogen metabolism and support hormonal balance. 

In addition, Bifidobacteria compete with potentially harmful bacteria for nutrients and space, which helps prevent an imbalanced microflora linked to hormonal imbalance.  

6. Can probiotics improve PMS symptoms?

The gut microbiome communicates with the central nervous system, and probiotics have been found to influence neurotransmitter production and mood regulation, potentially improving mood-related PMS symptoms such as irritability, anxiety, and depression.

7. What fermented foods are beneficial for hormonal balance?

Fermented foods such as sauerkraut, miso, kimchi, natto, kombucha, kefir, and yogurt are excellent sources of probiotics strains such as Lactobacillus and Bifidobacterium, which have been found to promote hormonal balance in women. 







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