Probiotics and the envisaged role in treating human infertility Original paper

Researched by:

  • Divine Aleru ID
    Divine Aleru

    User avatarI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.

July 3, 2025

  • Women’s Health
    Women’s Health

    Women’s health, a vital aspect of medical science, encompasses various conditions unique to women’s physiological makeup. Historically, women were often excluded from clinical research, leading to a gap in understanding the intricacies of women’s health needs. However, recent advancements have highlighted the significant role that the microbiome plays in these conditions, offering new insights and potential therapies. MicrobiomeSignatures.com is at the forefront of exploring the microbiome signature of each of these conditions to unravel the etiology of these diseases and develop targeted microbiome therapies.

  • Female Infertility
    Female Infertility

    Female infertility is a multifactorial condition affecting 10-15% of women of reproductive age, often caused by underlying conditions like Bacterial Vaginosis (BV), PCOS, Endometriosis, and Pelvic Inflammatory Disease (PID). Microbiome-targeted interventions (MBTIs) offer a promising approach to restoring balance, improving fertility outcomes, and addressing root causes.

Researched by:

  • Divine Aleru ID
    Divine Aleru

    User avatarI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.

Last Updated: 2025

Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.

Divine Aleru

I am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.

What was reviewed?

This review article comprehensively examines the emerging role of probiotics in the context of human infertility, focusing on both male and female reproductive health. The authors synthesize current evidence on how the human microbiome, particularly the urogenital and gastrointestinal microbiota, influences fertility, and detail the mechanisms by which probiotics, especially strains of Lactobacillus and Bifidobacterium, may contribute to fertility restoration. The review covers the historical development of probiotic therapy, the interaction between probiotics and prebiotics (synbiotics), and the multi-faceted ways in which probiotics maintain immune homeostasis, suppress pathogenic bacteria, and support reproductive tract health. Special emphasis is placed on infertility related to bacterial vaginosis, oxidative stress, obesity, hormonal disturbances, and complications during IVF or pregnancy, highlighting the microbiome’s pivotal role in reproductive success.

Who was reviewed?

The review synthesizes studies involving a broad spectrum of populations relevant to infertility: reproductive-age men and women, including those with obesity, advanced age, bacterial vaginosis (BV), polycystic ovary syndrome (PCOS), and those undergoing assisted reproductive technology (ART) such as IVF. Both human clinical trials and animal model studies are included to elucidate probiotic effects on sperm quality, testicular histopathology, vaginal microbiota balance, pregnancy outcomes, and menopausal infections. The article integrates findings from diverse ethnic, age, and health backgrounds, reflecting the complex interplay between host factors, microbiome composition, and fertility outcomes.

Most important findings

The review highlights that a balanced microbiome, particularly the dominance of Lactobacillus species in the female genital tract, is strongly associated with reproductive health and fertility. In women, disruption of this balance (dysbiosis) and overgrowth of pathogens such as Gardnerella vaginalis are linked to BV, infertility, increased risk of pre-term birth, and complications in ART. Probiotic supplementation demonstrates efficacy in restoring vaginal microbiota, reducing BV recurrence, and promoting favorable reproductive outcomes. In men, probiotics can mitigate the negative effects of obesity and oxidative stress on sperm quality and testosterone levels, potentially enhancing fertility. Notably, animal and human studies show that probiotics can reverse testicular tissue injury, improve sperm parameters, and maintain reproductive hormone levels. Furthermore, probiotics are associated with reduced inflammation in PCOS, improved IVF outcomes, and better management of menopausal vaginal infections. The review underscores the need to identify precise probiotic strains, optimal dosing regimens, and combination strategies for maximal clinical benefit.

Key implications

The findings suggest that probiotics could serve as adjunct or alternative therapies for infertility management in clinical settings, offering a microbiome-targeted approach to both prevention and treatment. For women, maintaining a Lactobacillus-dominant vaginal microbiota may reduce infertility risk, improve ART success, and prevent recurrent BV and related complications. For men, probiotics offer a natural means to counteract infertility associated with metabolic dysfunction and aging. However, the review also notes that further in vivo studies are necessary to standardize administration methods, dosing, strain selection, and combination therapies before widespread clinical adoption. Integration of microbiome analysis into fertility assessments and treatment personalization could significantly advance reproductive medicine.

Probiotics

Probiotics are live microorganisms that offer significant health benefits when administered in adequate amounts. They primarily work by modulating the gut microbiome, supporting a balanced microbial ecosystem. Probiotics have been shown to improve gut health, modulate immune responses, and even influence metabolic and mental health disorders. With growing evidence supporting their therapeutic potential, probiotics are increasingly recognized for their role in treating conditions like irritable bowel syndrome (IBS), antibiotic-associated diarrhea (AAD), and even mental health conditions like depression and anxiety through their impact on the gut-brain axis.

Infertility

Infertility is the inability to conceive after 12 months of regular, unprotected sex. It affects both men and women and can be due to various physical, hormonal, or genetic factors. Treatments include medication, surgery, assisted reproductive technologies, and lifestyle changes.

Bacterial Vaginosis

Bacterial vaginosis (BV) is caused by an imbalance in the vaginal microbiota, where the typically dominant Lactobacillus species are significantly reduced, leading to an overgrowth of anaerobic and facultative bacteria.

Bacterial Vaginosis

Bacterial vaginosis (BV) is caused by an imbalance in the vaginal microbiota, where the typically dominant Lactobacillus species are significantly reduced, leading to an overgrowth of anaerobic and facultative bacteria.

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects women of reproductive age, characterized by irregular menstrual cycles, hyperandrogenism, and insulin resistance. It is often associated with metabolic dysfunctions and inflammation, leading to fertility issues and increased risk of type 2 diabetes and cardiovascular disease.

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