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Characterizing the gut microbiota in females with infertility and preliminary results of a water-soluble dietary fiber intervention study A prebiotic dietary pilot intervention restores faecal metabolites and may be neuroprotective in Parkinson’s Disease Diagnosis of the menopause: NICE guidance and quality standards Causes of Death in End-Stage Kidney Disease: Comparison Between the United States Renal Data System and a Large Integrated Health Care System Factors affecting the absorption and excretion of lead in the rat Factors associated with age at menarche, menstrual knowledge, and hygiene practices among schoolgirls in Sharjah, UAE Cadmium transport in blood serum The non-pathogenic Escherichia coli strain Nissle 1917 – features of a versatile probiotic Structured Exercise Benefits in Euthyroid Graves’ Disease: Improved Capacity, Fatigue, and Relapse Gut Microbiota Regulate Motor Deficits and Neuroinflammation in a Model of Parkinson’s Disease A Pilot Microbiota Study in Parkinson’s Disease Patients versus Control Subjects, and Effects of FTY720 and FTY720-Mitoxy Therapies in Parkinsonian and Multiple System Atrophy Mouse Models Dysbiosis of the Saliva Microbiome in Patients With Polycystic Ovary Syndrome Integrated Microbiome and Host Transcriptome Profiles Link Parkinson’s Disease to Blautia Genus: Evidence From Feces, Blood, and Brain Gut microbiota modulation: a narrative review on a novel strategy for prevention and alleviation of ovarian aging Long-term postmenopausal hormone therapy and endometrial cancer

Nickel Allergy as a Risk Factor for Endometriosis Original paper

Researched by:

  • Karen Pendergrass ID
    Karen Pendergrass

    User avatarKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.

    Read More

Fact-checked by:

  • Karen Pendergrass ID
    Karen Pendergrass

    User avatarKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.

    Read More

March 18, 2025

  • Metals
    Metals

    Heavy metals play a significant and multifaceted role in the pathogenicity of microbial species.

  • Endometriosis
    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.

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  • User avatar
    Karen Pendergrass

    User avatarKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.

    Read More

Researched by:

  • Karen Pendergrass ID
    Karen Pendergrass

    User avatarKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.

    Read More

Fact-checked by:

  • Karen Pendergrass ID
    Karen Pendergrass

    User avatarKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.

    Read More

Last Updated: 2024-12-04

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

Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.

What Was Studied?

This study examined the association between nickel allergy and endometriosis using a population-based nested case-control design. The research aimed to determine whether nickel allergy is an independent risk factor for endometriosis by analyzing a cohort dataset provided by the South Korean National Health Insurance Service (NHIS), which included approximately 1 million individuals. The study was designed to assess causality and improve upon previous correlational studies.

Who Was Studied?

The study included 4,985 women divided into two groups: 997 women with endometriosis and 3,988 controls matched by age and socioeconomic status. The endometriosis group was identified using diagnostic codes, surgery records, and drug prescriptions between 2009 and 2013, while nickel allergy cases were identified between 2002 and 2008 using specific diagnostic and patch test codes.

What Were the Most Important Findings?

The findings revealed that women with endometriosis had a significantly higher prevalence of nickel allergy (0.8%) compared to the control group (0.3%), with an adjusted odds ratio of 2.474 (95% CI: 1.023–5.988; p = 0.044). The study highlights the estrogenic and immune-modulating properties of nickel, suggesting that elevated blood nickel levels associated with nickel allergy may contribute to endometriosis pathogenesis. Both conditions share immunological mechanisms, including cell-mediated hypersensitivity and immune dysregulation. The study also emphasizes the activity of nickel as a metalloestrogen, which may influence endometriosis through its interaction with estrogen receptors. Despite its low clinical prevalence, the findings support nickel allergy as a potential contributing factor to endometriosis, particularly in the context of autoimmune and estrogenic pathways.

What Are the Greatest Implications of This Study?

This study underscores the link between environmental factors, such as nickel exposure, and the development of endometriosis. Identifying nickel allergy as a risk factor paves the way for further research into environmental triggers and immune-mediated mechanisms in endometriosis. These findings could lead to targeted prevention strategies, such as reducing nickel exposure in at-risk populations, and inform therapeutic approaches that address immune and estrogenic pathways in endometriosis management.

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.

Nickel

Bacteria regulate transition metal levels through complex mechanisms to ensure survival and adaptability, influencing both their physiology and the development of antimicrobial strategies.

Metalloestrogens

Metalloestrogens are metals that activate the estrogen receptor in the absence of estradiol.

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