Sharon Erdrich, PhD, highlights oral health's impact on chronic pain

In a recent interview with Contemporary OB/GYN, Sharon Erdrich, PhD, researcher from the School of Pharmacy at the University of Sydney, discussed central sensitisation disorders (CSDs) and her research into how poor oral health and the oral microbiota may influence pain in women with these conditions.

Central sensitisation refers to a phenomenon in which the central nervous system, particularly the brain, becomes hypersensitive to stimuli. As a result, even mild or normally non-painful stimuli are interpreted as painful. This hypersensitivity can cause the pain to be perceived over a larger area than the original stimulus and may continue even after the stimulus has been removed.

Erdrich explained that CSDs involve an amplification of pain signals, and this abnormal processing often leads to a chronic state where patients continue to experience pain despite no apparent physical cause. This kind of pain can even arise from gentle touch, which is not typically painful. Conditions such as migraines, chronic whiplash-associated disorders, irritable bowel syndrome, some forms of lower back pain, and certain temporomandibular joint disorders are now understood to involve central sensitization. One of the key challenges with treating CSDs is that standard painkillers, or analgesics, are usually ineffective, leaving patients to suffer ongoing pain that severely disrupts sleep and daily functioning.

A notable insight from Erdrich’s research is the potential link between the gut-brain axis and pain perception, especially considering the often-overlooked connection between oral health and gut health. Her study focused on women with CSDs and assessed their oral health, oral microbiota, and pain scores. It found that poor oral health was correlated with higher pain levels.

Additionally, specific pathogenic microbes in the oral cavity were associated with both poor oral health and increased pain perception. This was especially pronounced in patients with migraines, potentially because of the anatomical proximity of the mouth to the brain. However, the correlation also extended to generalized body pain and abdominal pain, indicating a broader systemic effect.

Importantly, the study used the Short Form 36, a general health survey, to measure bodily pain, rather than disease-specific tools such as the fibromyalgia scale. The findings point toward a novel connection between the oral microbiome and the nervous system’s role in processing pain — a relationship not yet deeply explored in scientific literature.

Erdrich emphasized that these findings could have significant implications. Since many CSDs are categorized as idiopathic, discovering microbial links offers a potential breakthrough in both understanding and treating these disorders. It may also help validate the experiences of patients who have long struggled with invisible, unexplained pain — often dismissed or misattributed to psychological causes. By identifying modifiable factors such as oral health, this research opens up new avenues for pain management and improving patients’ quality of life.

No relevant disclosures

This video is part 1 of a 2-part series. Check back Monday for part 2.

Reference

Erdrich S, Gelissen IC, Vuyisch M, Toma R, Harnett JE. An association between poor oral health, oral microbiota, and pain identified in New Zealand women with central sensitisation disorders: a prospective clinical study. Frontiers in Pain Research. 2025. doi:10.3389/fpain.2025.1577193