Did you know?
Estimates suggest that 1 in 7 women in the United States is affected by Chronic Pelvic Pain (CPP).
Chronic Pelvic Pain (CPP)
Chronic Pelvic Pain (PP) is persistent pain in the pelvic region lasting six months or longer, often multifactorial, impacting physical and emotional well-being, and associated with various medical conditions.
Research feed 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.
Karen Pendergrass
Overview 
Research Feed 
References Overview
Chronic Pelvic Pain (CPP) presents as persistent, non-cyclical pelvic pain lasting over six months, significantly impairing physical and emotional well-being [1]. It commonly links to conditions like endometriosis, irritable bowel syndrome, interstitial cystitis, and major depressive disorder. Symptoms of CPP vary, including sharp, dull, heavy, or burning sensations. The pain can be continuous or sporadic, with varying intensity levels. Unlike a single disease symptom, CPP is a complex, multifactorial syndrome. The microbiome plays a critical role in influencing immune responses and inflammation pathways. Alterations in gut and urogenital microbial communities may heighten inflammation and disrupt immune regulation, intensifying pain. CPP’s complexity categorizes it as both a symptom, and a unique condition. Diagnosis and treatment pose challenges due to its intricate nature, necessitating a comprehensive, multidisciplinary approach.
What conditions are associated with chronic pelvic pain?
Conditions Associated with Chronic Pelvic Pain
Some of the most common conditions associated with CPP include:
| Condition | Description |
|---|---|
| Endometriosis | A condition where tissue similar to the lining inside the uterus (endometrium) is found outside the uterus, causing pain, especially during menstruation. |
| Interstitial Cystitis/Painful Bladder Syndrome | A chronic condition causing bladder pressure, bladder pain, and sometimes pelvic pain, characterized by urinary frequency and urgency. |
| Irritable Bowel Syndrome (IBS) | A disorder affecting the large intestine, causing symptoms like cramping, abdominal pain, bloating, gas, and diarrhea or constipation. |
| Pelvic Inflammatory Disease (PID) | An infection of the female reproductive organs, often caused by sexually transmitted bacteria, leading to pelvic pain. |
| Pelvic Adhesions | Bands of scar tissue that form between pelvic organs and tissues, causing pain by binding organs that are normally mobile. |
| Fibromyalgia | A condition characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory, and mood issues, which can include pelvic pain. |
| Chronic Prostatitis/Chronic Pelvic Pain Syndrome in Men | A chronic condition in men involving pain or discomfort in the pelvic region and genital area, often associated with urinary symptoms. |
The link between CPP and various conditions underscores the need for a comprehensive evaluation to pinpoint underlying causes. Treatment strategies must address the physical and psychological impacts of the condition. These include pain management, physical therapy, medication, and sometimes surgery.
Research Feed
The role of the vaginal microbiome in distinguishing female chronic pelvic pain caused by endometriosis/adenomyosis
May 9, 2021
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Endometriosis •
Endometriosis
Did you know?
Gut microbiota predict endometriosis better than vaginal microbiota.
Chronic Pelvic Pain (CPP) •
Chronic Pelvic Pain (CPP)
Did you know?
Estimates suggest that 1 in 7 women in the United States is affected by Chronic Pelvic Pain (CPP).
This study examines the role of the vaginal microbiome in distinguishing chronic pelvic pain caused by endometriosis and adenomyosis. Findings highlight specific microbial signatures associated with pain severity, offering potential non-invasive biomarkers for differential diagnosis and targeted therapeutic strategies.
What was studied?
This study investigated whether the composition of the vaginal microbiome could serve as a diagnostic biomarker to differentiate chronic pelvic pain (CPP) caused by endometriosis or adenomyosis (EM/AM) from other causes of chronic pelvic pain syndrome (CPPS) in women. Using 16S rRNA sequencing (V4 region), the researchers profiled the vaginal microbiota of 37 women with EM/AM-associated CPP, 25 with CPPS from other causes, and 66 healthy controls without CPPS. Additionally, the study explored whether combining vaginal microbial markers with serum CA125 could improve differential diagnostic accuracy.
Who was studied?
The study included 128 premenopausal women attending the gynecology department of Peking Union Medical College Hospital. These were stratified into three groups: 37 women with surgically confirmed EM/AM-associated CPP, 25 women with non-EM/AM CPPS (adhesions, hydrosalpinx, infertility), and 66 women without any chronic pelvic pain. All participants were HPV-negative, had not recently used antibiotics or vaginal products, and were matched for age, gravidity, parity, and contraceptive method to control for confounding variables.
What were the most important findings?
The vaginal microbiome of women with EM/AM-associated CPP exhibited significantly higher alpha diversity than those in the CPPS and healthy control groups. Taxonomic analyses revealed distinct microbial signatures: increased abundance of Clostridium butyricum, Clostridium disporicum, Alloscardovia omnicolens, and Veillonella montpellierensis, alongside a marked depletion of Lactobacillus jensenii, Lactobacillus reuteri, and Lactobacillus iners. These differentially abundant taxa serve as potential microbiome biomarkers.
Diagnostic performance analysis demonstrated that a combination of microbial biomarkers (specifically, a relative abundance of Clostridium disporicum >0.001105% and Lactobacillus reuteri <0.1911349%) yielded 81.08% sensitivity and 52% specificity for identifying EM/AM-associated CPP. When combined with serum CA125 levels, sensitivity increased to 89.19%, although specificity remained unchanged. Functional predictions via PICRUSt revealed enrichment of metabolic pathways such as amino acid metabolism, energy metabolism, and metabolism of cofactors and vitamins in EM/AM patients, along with downregulation of membrane transport and nucleotide metabolism compared to controls. These shifts may reflect microbial contributions to inflammation and pain signaling pathways implicated in EM/AM-associated CPP.
From a microbiome signature standpoint, the enriched taxa—particularly Clostridium disporicum and Alloscardovia omnicolens—emerge as Major Microbial Associations (MMAs) due to their consistent elevation in EM/AM patients. Conversely, Lactobacillus jensenii and L. reuteri, known for their protective, anti-inflammatory properties, are depleted, suggesting their role in maintaining vaginal eubiosis and preventing EM/AM-associated pathogenesis.
What are the greatest implications of this study?
This research provides compelling evidence that the vaginal microbiome harbors discriminative microbial signatures capable of differentiating EM/AM-associated CPP from other forms of chronic pelvic pain. The incorporation of specific microbial biomarkers, particularly when paired with serum CA125, may improve non-invasive diagnostic accuracy, enabling earlier and more targeted therapeutic intervention. Clinically, these findings underscore the potential of microbiome-informed diagnostics for gynecological conditions where conventional markers fall short. More broadly, this study suggests that vaginal dysbiosis, characterized by Lactobacillus depletion and enrichment of saccharolytic and anaerobic species, could be causally linked to EM/AM pathogenesis, possibly via inflammatory or metabolic pathways. Future studies incorporating metagenomic or metabolomic analyses are warranted to functionally validate these microbial associations and to explore the feasibility of microbial modulation as a therapeutic strategy.
Endometriosis
Endometriosis involves ectopic endometrial tissue causing pain and infertility. Validated and Promising Interventions include Hyperbaric Oxygen Therapy (HBOT), Low Nickel Diet, and Metronidazole therapy.
Endometriosis
Endometriosis involves ectopic endometrial tissue causing pain and infertility. Validated and Promising Interventions include Hyperbaric Oxygen Therapy (HBOT), Low Nickel Diet, and Metronidazole therapy.
References
- The role of the vaginal microbiome in distinguishing female chronic pelvic pain caused by endometriosis/adenomyosis.. Chao X, Liu Y, Fan Q, Shi H, Wang S, Lang J.. (Ann Transl Med. 2021)
Chao X, Liu Y, Fan Q, Shi H, Wang S, Lang J.
The role of the vaginal microbiome in distinguishing female chronic pelvic pain caused by endometriosis/adenomyosis.Ann Transl Med. 2021