Probiotics have become all the rage recently, and as we learn more about the effects of the gut microbiome on the rest of the body, it is becoming increasingly clear that gut health plays a bigger role than most of us imagined.
Due to the potential widespread impact of the gut microbiome and gut health, the microbiome might play a role in polycystic ovary syndrome. This article explores what recent studies have found about the use of probiotic supplements for PCOS symptoms and various markers of health.
There are some promising results, so read on!
The Effects of Probiotics on Weight Loss, Metabolic Health, and Cardiovascular Health for women with pcos
Women with PCOS tend to struggle with weight gain and insulin resistance, and we are at higher risk for things like high blood pressure, high cholesterol, and heart disease. Ahmadi et al. (2017) used a randomized controlled trial to explore the potential effects of probiotics on these risk factors for women with PCOS. Sixty women of reproductive age with PCOS were recruited from the Taleghani and Emam Reza Clinic in Arak, Iran. The study excluded anyone with type 2 diabetes, active liver disease, or histories of heart or liver failure, and anyone taking any hormonal medications, anti-obesity medications, or antidepressants.
Half of the participants were assigned to the treatment group. This group consumed:
Probiotic capsules containing:
Lactobacillus acidophilus (2x 10^9 CFU/g)
Lactobacillus casei (2 x 10^9 CFU/g)
Bifidobacterium bifidum (2x 10^9 CFU/g)
The other half of the participants were assigned to the control group. This group consumed placebo capsules that looked identical to the probiotic capsules.
Both groups took their respective capsules for 12 weeks.
The table below shows the percent change in measures of metabolic health and cardiovascular health for the placebo and treatment groups after 12 weeks of taking their respective capsules.
The effects of 12 weeks of supplementation with probiotics or a placebo on metabolic and cardiovascular health for women with polycystic ovary syndrome (PCOS). Results compiled from Ahmadi et al. (2017). “-” means there was no statistically significant difference between the changes observed across groups.
In terms of metabolic syndrome indicators, the probiotic group experienced improvements in 4 of the 5 metrics. They experienced about a 3% decrease in fasting blood sugar, a 14% decrease in fasting insulin, almost a 16% decrease in HOMA-IR (a measure of insulin resistance), and a small increase in QUICKI, a measure of insulin sensitivity. The only measure that experienced a decline was HOMA-B, a measure of the function of beta cells, which are the pancreatic cells that produce insulin. The overall improvement in insulin resistance likely also led to improvements in PCOS symptoms and potentially improved the regularity of their menstrual cycles. Unfortunately, this study did not measure these metrics.
Regarding cardiovascular health, the probiotic group experienced an 11% decrease in triglyceride and VLDL cholesterol levels. As we learn more about cholesterol and its links to heart disease, there is increasing evidence that VLDL cholesterol has a stronger link to plaque build-up in arteries than other forms of cholesterol. Similarly, blood triglyceride levels are associated with an increased risk of heart attacks, strokes, and heart disease. The probiotic group also experienced small increases in total cholesterol, HDL cholesterol (generally considered a good form of cholesterol), and LDL cholesterol (typically considered a higher-risk form of cholesterol). However, there were no statistically significant differences between the placebo and probiotic groups for these latter three metrics.
The Effects of Probiotic and Prebiotic Supplementation Body Composition, Metabolic Health, and Reproductive Health for women with pcos
While the study above considered supplementation with just probiotics, three studies experiment with synbiotic supplements - supplements that contain both probiotics as well as prebiotics, which are food sources for probiotics, and measure similar metrics as the study above. The combination of pre- and probiotics may be better than supplementing with probiotics alone because the prebiotics support the supplemented probiotics as well as other probiotics already present in the gut.
Chudzicka-Strugala et al. (2021) recruited 65 overweight or obese women (BMI > 25) with PCOS from patients receiving medical care at the Reproductive Endocrinology & Infertility Clinical Services Department at the Poznan University of Medical Sciences Hospital in Poland.
This study used a randomized controlled trial design, and randomly assigned half of the participants to the placebo group who:
Consumed 4 capsules of placebo daily.
And half of the participants to the treatment group who:
Consumed 4 synbiotic supplement capsules daily. These capsules contained:
Bifidobacterium lactis (W51 and W52)
Lactobacillus acidophilus (W22)
Lactobacillus paracasei (W20)
Lactobacillus plantarum (W21)
Lactobacillus salivarius (W24)
Lactobacillus lactis (W19)
Both groups were counseled on lifestyle changes that included:
Consuming 1400 - 1800 kcal per day based on their individual body compositions
Individualized advice about foods to include or exclude
Encouragement to refrain from consuming alcohol
Encouragement to walk 30 - 40 minutes per day
For all participants, baseline measurements were taken either during the follicular phase of their naturally occurring cycle or after medroxyprogesterone-induced menstruation (for more information on menstrual cycle phases, check out this post).
Participants followed their respective plans for 3 months, and then measurements were retaken. The table below contains the percent change in each metric measured for the placebo group and the probiotic + prebiotic group.
The effects of three months of diet and lifestyle changes and supplementation with either a synbiotic (probiotics + prebiotics) or a placebo on body weight, body composition, reproductive hormones, metabolic health, and cardiovascular health. Results compiled from Chudzicka-Strugala et al. (2021). “-” means there was no statistically significant difference between the changes observed across groups.
Given that both groups followed a calorie-restricted diet and added in physical activity, it is not surprising that both groups experienced reductions in body weight, BMI, body fat percentage, and various body measurements like waist and hip circumference.
Interestingly, the group consuming probiotics and prebiotics experienced bigger decreases in weight, BMI, and waist circumference than the placebo group. Improvements in gut health led to bigger effects of diet and exercise!
While the placebo group did not experience any reductions in total testosterone or the Ferriman-Gallway score (a measure of excessive facial and/or body hair growth), the supplement group experienced reductions in both of these measures. Excessive body hair is one of the most frustrating symptoms of PCOS, so it is pretty exciting to see that synbiotic supplementation could play an important role in reducing this symptom.
The placebo group experienced reductions in luteinizing hormone (LH), which is often high in women with PCOS. However, this group also experienced a reduction in follicle-stimulating hormone, which can be low relative to LH in women with PCOS. Thus, it is not clear that these changes, in combination, are necessarily helpful, and indeed, the LH to FSH ratio remained unchanged for the placebo group.
Unfortunately, neither group experienced improvements in measures of metabolic health like fasting blood glucose or fasting insulin, and neither group experienced improvements in cholesterol levels. Both groups did experience a decrease in triglycerides, suggesting some improved cardiovascular health from the lifestyle modifications.
Hariri et al. (2023) followed a similar protocol with lifestyle modifications and a synbiotic supplement. Like the previous study, they found no effects of supplementation on cholesterol levels, nor did they find any effects of supplementation on triglycerides or c-reactive protein, a measure of inflammation.
Darvishi et al. (2021) also studied the effects of synbiotic supplementation on women with PCOS. This study recruited 68 overweight or obese women with PCOS from the General Gynaecology Clinic Department at the Alzahra Hospital in Iran. Like the previous study, this study also used a randomized controlled trial, and randomly assigned participants to either:
The control group who:
Consumed one placebo capsule containing starch each day after lunch
Or the treatment group who:
Consumed one synbiotic capsule that contained:
Lactobacillus casei
Lactobacillus rhamnosus
Lactobacillus bulgaris
Lactobacillus acidohilus
Bifidobacterium longum
Streptococcus thermophilus
fructooligosaccarides (an inulin-type prebiotic).
Both groups took their respective capsules for 8 weeks.
Unlike Chudzicka-Strugala et al., neither group made adjustments to their diets or their activity levels.
The table below shows the percent changes in various metrics across the 8 weeks of the intervention.
The effects of 8 weeks of supplementation with a synbiotic (probiotics + prebiotics) on body weight, body composition, metabolic health, and cardiovascular health for women with polycystic ovary syndrome (PCOS). Results compiled from Darvishi et al. (2021). “-” means there was no statistically significant difference between the changes observed across groups.
Interestingly, the placebo group experienced increases in body weight and BMI and increases in fasting glucose, fasting insulin, and HOMA-IR (a measure of insulin resistance), indicating worsened metabolic health. They also experienced increases in total cholesterol and LDL cholesterol alongside decreases in HDL cholesterol, all indicating worsened cardiovascular health.
These trends of the placebo group have been seen in other studies because women with PCOS often experience worsened body composition, metabolic health, and cardiovascular health over time in the absence of any intervention. For this study, however, I question whether the starch used in the placebo capsule contributed to these results. I would be curious to see how their metrics would have changed if provided with a non-starchy placebo, given the tendency of women with PCOS to exhibit insulin resistance and reduced carbohydrate tolerance.
While the placebo group experienced worsened health, the group consuming the probiotic + prebiotic supplement experienced decreases in body weight, waist circumference, hip circumference, waist-to-hip ratio, waist-to-height ratio, fasting insulin, and HOMA-IR (a measure of insulin resistance). All of these trends indicate improved body composition and improved metabolic health. While the body composition changes were small, they were still the opposite trend experienced by the control group, and they were simply the result of taking a supplement, in the absence of any diet or exercise intervention.
The supplement did not have any significant effect on any measure of cardiovascular health.
The results of this study call into question the "calories in, calories out" model of weight loss. Caloric consumption did not change, but the treatment group still saw modest decreases in body composition, suggesting that eliminating gut dysbiosis and improving gut health can potentially lead to weight loss.
The Effects of Probiotics on Reproductive Hormone Levels and Symptoms of PCOS
While many studies of PCOS patients do not directly measure symptoms of PCOS like acne and hirsutism (excessive growth of hair on the face and body), a study by Arab et al. (2020) does measure these things. This study recruited 99 women with PCOS from the Arash Women's Hospital in Tehran, Iran. Participants were aged 19 to 37 years old, with body mass indexes of 25 or higher (associated with being overweight or obese). As usual, this study excluded participants with other health challenges including diabetes, lung, pancreatic, kidney, liver, or cardiovascular disease, or any autoimmune diseases.
50 of the participants were randomly assigned to the probiotic group. This group consumed:
2 capsules per day, which contained 7 strains of beneficial bacteria, including
Lactobacillus acidophilus (ATCC: 4357) 3 × 10^10 colony-forming units (CFU)
Lacticaseibacillus casei (ATCC: 393) 3 × 10^9 CFU
Lactobacillus bulgaricus (ATCC: 11842) 5 × 10^8 CFU
Lacticaseibacillus rhamnosus (ATCC: 7469) 7 × 10^9 CFU
Bifidobacterium longum (ATCC: 15697) 1 ×10^9 CFU
Bifidobacterium breve (ATCC: 15700) 2 × 10^10 CFU
Streptococcus thermophilus (ATCC: 19258) 3 × 10^8 CFU)
21 mg inulin, a prebiotic that can support beneficial gut bacteria
The control group took two placebo capsules each day which contained 250 mg starch and 250 mg maltodextrin.
Each group took their respective capsules for 12 weeks.
The table below shows the percent change in reproductive hormones for the probiotic and placebo groups.
The effects of 12 weeks of synbiotic (probiotics + prebiotics) supplementation on women with polycystic ovary syndrome (PCOS). Results compiled from Arab et al. (2020). “-” means there was no statistically significant difference between the changes observed across groups or for that group alone.
Women with PCOS tend to have elevated luteinizing hormone (LH) and in particular, LH is high relative to follicle-stimulating hormone (FSH). Thus, we want interventions that lower the ratio of LH to FSH. In this study, neither group experienced statistically significant changes in FSH, and both groups experienced increases in LH, which is the opposite of what we want to see. The increase in LH to FSH ratio was statistically significant for the probiotic group, but not the placebo group.
The probiotic group did not experience any changes in total testosterone levels, sex hormone-binding globulin, or free androgen index. The placebo group experienced an increase in their levels of total testosterone and free androgen index and decreases in sex hormone binding globulin. In this sense, if the probiotic helped the probiotic group prevent worsening hormonal imbalances, then we could consider this a benefit of probiotic supplementation, even though they did not experience changes themselves. Both groups experienced an increase in DHEAS, which is another androgen hormone.
In terms of symptoms of PCOS, the probiotic group experienced statistically significant changes in the percentage of participants experiencing different categories of acne, while the placebo group did not. In particular, the probiotic group saw an increase in the percent who had no acne and a decrease in the percent who had severe acne.
Pre- and post-intervention acne severity for women with polycystic ovary syndrome (PCOS) taking either a probiotic supplement or a placebo for 12 weeks. Results compiled from Arab et al. (2020).
The placebo group also experienced small changes in the percentage experiencing different levels of hirsutism, while the placebo group did not. After the intervention, the probiotic group had a larger percent with no hirsutism and smaller percentages with mild or moderate hirsutism. The percentage with severe hirsutism did not change.
Pre- and post-intervention hirsutism (excessive facial and/or body hair growth) severity for women with polycystic ovary syndrome (PCOS) taking either a probiotic supplement or a placebo for 12 weeks. Results compiled from Arab et al. (2020).
It is quite interesting that this study did not find beneficial effects of probiotics on lab-measured hormone levels, but did observe positive effects of probiotic supplementation in terms of the symptoms of PCOS. This suggests that a healthy gut may play a role in symptoms, regardless of hormone levels. It also suggests that more studies of women with PCOS should measure symptoms, and not just lab values.
Probiotic Supplements and Menstrual cycle Regularity
Menstrual cycle regularity is often considered to be a woman's 6th vital sign. And for women with PCOS, our cycles are usually especially sensitive to changes in our mental and physical health. It is surprising to me that so few studies exploring the effects of probiotics on women with PCOS track menstrual cycle regularity. Fortunately, Kaur et al. (2022) did track menstrual cycle regularity and found positive effects of supplementation for some participants.
This study recruited 104 participants from the Gynaecology Out-Patient Department (OPD) at the Postgraduate Institute of Medical Education and Research in India.
Participants were split into:
A treatment group, who consumed capsuled containing 10 billion colony forming units (CFU) consisting of the following probiotic strains and prebiotics:
Lactobacillus acidophilus
Lactobacillus rhamnosis, UBLR-58
Lactobacillus reuteri, UBLR-87
Lactobacillus plantarum, UBLP-40
Lactobacillus casei, UBLC-42
Lactobacillus fermentum, UBLF-31
Bifidobacterium bifidum, UBBB-55
Fructo-oligosaccharide (100 mg)
And a control group who consumed similar capsules containing maltodextrin.
For the first two months, all participants took 1 of their respective capsules per day. For the next four months, all participants took two capsules per day.
The table below reports the changes, if any, experienced by participants in each group.
The effects of 6 months of supplementation with either a probiotic or placebo on menstrual cycle regularity, metabolic health, and body composition for women with polycystic ovary syndrome (PCOS). Results compiled from Kaur et al. (2022). “-” means there was no statistically significant difference between the changes observed across groups.
There was a significant reduction in participants with irregular menstrual cycles and polycystic ovaries among the probiotic group, and the number of participants with regular menstrual cycles more than doubled among probiotic users. It should be noted, however, that 37 out of the 52 participants in the probiotic group still experienced irregular periods at the end of the study period, as shown in the graphs below. While the use of probiotics did help some women achieve menstrual cycle regularity, probiotics should not be seen as a cure-all for menstrual and fertility challenges for women with PCOS.
The effects of 6 months of probiotic supplementation (or placebo) on menstrual cycle regularity for women with polycystic ovary syndrome (PCOS). Irregular periods are a hallmark of PCOS and contribute to infertility struggles.
When considering the effects of probiotics on androgen hormones, we see that those taking the probiotic dietary supplements experienced reductions in total testosterone, which tends to be elevated in women with PCOS. Neither group, however, experienced a change in DHEAS, another important androgen hormone.
In terms of metabolic effects, the placebo group actually experienced an increase in fasting blood sugar (a negative change), while the probiotic group experienced no change in fasting blood sugar. Both groups experienced decreases in fasting insulin levels, but only the probiotic group experienced a decrease in HOMA-IR, a measure of insulin resistance. Women with PCOS almost always have some degree of insulin resistance driving their symptoms, so any intervention that reduces insulin resistance can help reduce PCOS symptoms and improve overall health.
Lastly, in terms of weight management, the probiotic group experienced decreases in weight, waist circumference, hip circumference, waist-to-hip ratio, and body mass index. While the placebo group also experienced reductions in some of these measures, the probiotic group experienced larger reductions for all measures.
Probiotic and Prebiotic Supplements and Mental Health
While most studies stick to measuring objective things like fasting glucose and body weight, Jamilian et al. (2018) chose to focus on subjective measures of well-being in addition to several objective health measures. Mental health challenges are common among women with PCOS, so assessing the effects of supplements on indicators of mental health is important. This study recruited 60 females with PCOS aged 18 - 40 years old.
Participants were divided into a treatment group who took capsules containing:
Lactobacillus acidophilus
Lactobacillus reuteri
Lactobacillus fermentum
Bifidobacterium bifidum
200 micrograms of Selenium
And a control group who took placebo capsules that were a similar shape and size to the probiotic capsules.
Both groups took their respective capsules for 12 weeks.
The effects of 12 weeks of supplementation with a probiotic + selenium or a placebo on measures of mental health, reproductive hormones, hirsutism (excessive facial and/or body hair), and measures of inflammation. Results compiled from Jamilian et al. (2018). “-” means there was no statistically significant difference between the changes observed across groups.
Neither group of participants experienced significant reductions in body weight or BMI.
However, the probiotic + selenium supplement was associated with both physical and mental health benefits. The study used three measures of mental health: The Beck Depression Inventory, the General Health Questionnaire, and the Depression, Anxiety, and Stress Scale. For all three measures, lower scores indicate better mental health. While the control group's scores decreased by about 1.4% to 1.9%, the treatment group experienced reductions ranging from 3.1% to 7.1%.
In terms of sex hormones, the treatment group experienced a 21.4% reduction in testosterone and a 5.1% increase in sex hormone-binding globulin (SHBG). SHBG binds free testosterone, reducing the effects of this androgen hormone. Both of these changes likely contributed to the reduction in the modified Ferriman-Gallway score experienced by the treatment group. This is a measure of hirsutism, or excess hair growth on the face and body, resulting from high male hormones.
Lastly, the study considered several measures of cardiovascular health and overall antioxidant capacity. For all measures, the treatment group experienced improvements, while the placebo group experienced some changes that were actually in the wrong direction.
This study shows the positive effects of probiotic supplementation across several different categories of health, suggesting that probiotics are helpful for overall health, as well as for PCOS, specifically.
Take Home Points
For women with PCOS, probiotic supplementation may:
Improve mental health
Improve menstrual cycle regularity
Reduce symptoms of PCOS like acne and hirsutism
Increase weight loss when reducing calories
Contribute to weight loss without reducing calories
Improve metabolic health by reducing insulin resistance
The effects of probiotic supplementation on cardiovascular health appear to be limited.
The effects of probiotic supplementation on reproductive hormone levels were inconsistent across studies.
While probiotics are helpful for some women with PCOS, not all women experience substantial benefits from supplementation.
While these studies focused on probiotic supplementation, fermented foods are also a great source of probiotics! Check out this stew and this breakfast bowl that contain fermented foods.
Always talk to your healthcare provider before starting any supplementation program!
About the author
Kelly Grogan, Ph.D., NTM, is a holistic nutrition therapist who is passionate about helping females with PCOS. She currently manages her own PCOS with nutrition and lifestyle tools that she developed through extensive review of the scientific literature on PCOS interventions.
disclaimer
This post is not intended to diagnose or treat any medical issues. It is intended for informational purposes only. I am not a medical practitioner. Always consult a trusted healthcare provider with any questions you may have about a medical condition or treatment and before starting any new healthcare regimen.
References
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Arab A, Hossein-Boroujerdi M, Moini A, Sepidarkish M, Shirzad N, and Karimi E. 2022. Effects of probiotic supplementation on hormonal and clinical outcomes of women diagnosed with polycystic ovary syndrome: A double-blind, randomized, placebo-controlled clinical trial. Journal of Functional Foods, 96:105203, https://doi.org/10.1016/j.jff.2022.105203
Chudzicka-Strugała I, Kubiak A, Banaszewska B, Zwozdziak B, Siakowska M, Pawelczyk L, Duleba AJ. 2021. Effects of Synbiotic Supplementation and Lifestyle Modifications on Women With Polycystic Ovary Syndrome. The Journal of Clinical Endocrinology & Metabolism, 106(9):2566–2573, https://doi.org/10.1210/clinem/dgab369
Darvishi S, Rafraf M, Asghari-Jafarabadi M, and Farzadi L. 2021. Synbiotic Supplementation Improves Metabolic Factors and Obesity Values in Women with Polycystic Ovary Syndrome Independent of Affecting Apelin Levels: A Randomized Double-Blind Placebo-Controlled Clinical Trial. International Journal of Fertility and Sterility, 15(1):51-59. doi: 10.22074/ijfs.2021.6186.
Hariri Z, Yari Z, Hoseini S, Mehrnami A, Abhari K, and Sohrab G. 2023. Effects of Synbiotic-Containing Bacillus coagulans (GBI-30) on the Cardiovascular Status of Patients With Polycystic Ovary Syndrome: A Triple-blinded, Randomized, Placebo-controlled Study. Clinical Therapeutics, 45(10):e193-e199. doi: 10.1016/j.clinthera.2023.07.024.
Hariri Z, Yari Z, Hoseini S, Abhari K, Sohrab G. 2024. Synbiotics as an ameliorating factor in the health-related quality of life in women with polycystic ovary syndrome. A randomized, triple-blind, placebo-controlled trial. BMC Women's Health, 24(1):19. doi: 10.1186/s12905-023-02868-1.
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Kaur I, Suri V, Sachdeva N, Rana SV, Medhi B, Sahni N, Ahire J, Singh A. 2022. Efficacy of multi-strain probiotic along with dietary and lifestyle modifications on polycystic ovary syndrome: a randomized, double-blind placebo-controlled study. European Journal of Nutrition, 61(8):4145-4154. doi: 10.1007/s00394-022-02959-z.