Can probiotics improve insulin resistance in women with PCOS?

Systematic review highlights the potential of probiotics and synbiotics in enhancing insulin sensitivity and hormonal balance in women with polycystic ovary syndrome.

Study: Effectiveness of Probiotics, Prebiotics, and Synbiotics in Managing Insulin Resistance and Hormonal Imbalance in Women with Polycystic Ovary Syndrome (PCOS): A Systematic Review of Randomized Clinical Trials. Image Credit: Helena Nechaeva/Shutterstock.com

In a recent study published in Nutrients, researchers from Colombia conducted a systematic review to examine the effectiveness of prebiotics, probiotics, and a combination of pro- and prebiotics known as synbiotics in improving insulin resistance and hormonal balance in women with polycystic ovary syndrome or PCOS.

The study focused on assessing outcomes such as insulin sensitivity, hormonal parameters, and lipid profiles from various randomized clinical trials.

Background

Polycystic ovary syndrome is a hormonal disorder that affects women of reproductive age and causes symptoms such as irregular menstruation, excessive androgens, and ovarian cysts. This condition is often associated with metabolic complications, including insulin resistance, increased risk of cardiovascular disease, and higher rates of obesity.

These metabolic effects might also be aggravated by gut microbiota imbalances, which can influence systemic inflammation and insulin signaling.

Although treatments for PCOS frequently involve hormone therapies, these can sometimes exacerbate insulin resistance and metabolic issues, creating a need for alternative treatments.

Emerging research indicates that probiotics and prebiotics, which can positively influence gut bacteria, might offer benefits in managing PCOS symptoms by improving metabolic health and reducing inflammation.

Despite these promising findings, variations in study design and lack of standardization in intervention methods have made it challenging to draw clear conclusions about the effectiveness of pre-, pro-, and synbiotic treatments in PCOS.

About the study

This systematic review aimed to evaluate the impact of pre-, pro-, and synbiotic supplements on insulin resistance and hormonal balance in women with PCOS. The researchers conducted a comprehensive search across numerous medical databases to identify relevant randomized controlled trials.

Eligible studies included those conducted on women who had been diagnosed with PCOS, and involved supplementation with pre-, pro-, and synbiotics for at least eight weeks.

The key parameters assessed included insulin resistance, which was estimated through the Homeostasis Model Assessment for Insulin Resistance or HOMA-IR, as well as fasting insulin, glucose levels, and hormonal markers such as testosterone and sex hormone-binding globulin (SHBG), which is involved in hormonal regulation.

Data on study design, participant demographics, intervention types, dosages, duration, and outcome measures were extracted from the studies. Most interventions included various probiotic strains or prebiotics administered via capsules or beverages.

Synbiotic combinations that included prebiotic fibers, such as inulin, were common across studies. The control groups in the studies typically received placebos, which allowed for comparisons with the active interventions.

The review included a risk-of-bias assessment where domains such as randomization, blinding, and attrition were evaluated for bias.

The researchers stated that the heterogeneity of strains, dosages, and intervention durations across the studies also necessitated a qualitative synthesis rather than a meta-analysis.

Results

The study found that supplementation with pre-, pro-, and synbiotics resulted in improved insulin sensitivity and reduced hormonal imbalances in women with PCOS. The participants who used synbiotics exhibited notable reductions in insulin resistance, with improved fasting glucose and insulin levels compared to control groups.

Probiotic supplementation alone led to moderate improvements in HOMA-IR scores and fasting glucose, although these changes were more pronounced with synbiotics, which combine probiotics and prebiotics.

Furthermore, synbiotic treatments were found to outperform probiotics or prebiotics alone in terms of lipid profile changes, resulting in decreased levels of low-density lipoprotein and triglycerides, along with increased high-density lipoprotein levels. These changes could potentially reduce the cardiovascular risks associated with PCOS.

In addition to metabolic improvements, synbiotic supplementation also showed beneficial effects on hormonal parameters, with increases in SHBG and reductions in free testosterone levels, which are often elevated in PCOS.

Additionally, prebiotic supplements, especially resistant dextrin, also demonstrated improvements in lipid profiles, inflammatory markers, and androgen levels, suggesting benefits for metabolic and endocrine functions.

Although the reviewed studies presented promising outcomes, some inconsistencies were also observed, which the researchers believe were due to variations in intervention duration, probiotic strains, and dosages.

Moreover, short intervention periods in certain studies limited long-term assessments, while the lack of standardization in bacterial strains and prebiotic types complicated the comparisons between studies.

Nevertheless, the review indicated that both probiotics and synbiotics can positively influence metabolic and hormonal markers in PCOS, with synbiotics showing the most significant overall improvements.

Conclusions

Overall, the review indicated that pre-, pro-, and synbiotic supplements offer potential benefits for managing insulin resistance and hormonal imbalances in women with PCOS, with synbiotic interventions showing the most substantial effects.

However, further studies with standardized protocols, diverse populations, and longer intervention periods are needed to validate these findings.

An improved understanding of optimal supplementation could improve PCOS management and quality of life for affected women.