Fresh Mouth Battles Migraine: Surprising Link Between Oral Hygiene and Chronic Pain

The University of Sydney conducted a recent study which was published in Frontiers in Pain Research and has identified a fascinating association between oral wellness and chronic pain in women suffering from central sensitization disorders, including fibromyalgia, migraine, and irritable bowel syndrome (IBS).

Significance of the Study

Researchers are working to discover the mysteries behind nociplastic pain—a type of pain that doesn’t come from visible injury or inflammation, but from changes in how the brain and nervous system process pain signals. This type of pain is experienced in conditions like fibromyalgia and migraines, where people may feel constant, spreading pain without any markable physical damage.

Approach and Procedures

Researchers conducted a secondary analysis involving 158 non-smoking women in New Zealand between 2021 and 2022. They assessed self-reported oral health, oral microbiota (using metatranscriptomic sequencing), and pain levels—including body pain, migraines, and abdominal pain. Data were collected through standardized clinical health questionnaires and saliva samples, with microbiota analyzed at multiple taxonomic levels.

Principal Observations

Women with poor oral health were 60% more likely to report moderate to severe body pain and 49% more likely to suffer from migraines.

Various microbiological studies revealed numerous oral bacteria associated with pain and inadequate oral hygiene, which include:

• Parvimonas micra

• Solobacterium moorei

• Dialister pneumosintes

• Fusobacterium nucleatum

• Mycoplasma salivarium (linked to migraine)

• Gardnerella vaginalis (associated with low oral health scores)

During the analysis, Bifidobacterium, commonly considered a probiotic, was found to be positively associated with pain but linked in a negative direction with oral hygiene, challenging its traditional classification as a beneficial bacterium.

Microbial activity

The investigation uncovered microbial activity in pain perception, focusing on biological pathways that describe how bacterial activity is related to chronic pain. Key mechanisms include:

1. Synthesis of neuroactive compounds: Microbes can initiate the release of compounds like CGRP (calcitonin gene-related peptide), VEGF (vascular endothelial growth factor), and substance P. These molecules mediate pain and inflammation.

2. Immune activation leading to inflammation: Bacteria will initiate the immune system and promote inflammatory responses that contribute to pain.

3. Release of Endotoxin: Gram-negative bacteria release endotoxins (e.g., LPS) that initiate inflammatory responses in the stream, leading to the amplification of pain

Commensal Microbiota and Oral Health

Resident oral bacteria play a vital role in maintaining oral health by inhibiting the multiplication of harmful pathogens and thus sustaining microbial balance.

Participants with better oral hygiene manifested a higher amount of beneficial (commensal) bacteria and reported lower pain levels, supporting the idea that oral eubiosis—a balanced microbiome—may help protect against chronic pain.

Clinical and Public Health Implications

These findings identify oral health as a potentially modifiable risk factor in chronic pain management. Recognizing the need for:

• Incorporating oral hygiene into pain management.

• Promoting clinical-based epidemiological study on the oral microbiome–pain relationship

• Promotion of public health measures emphasizing the relationship between oral and systemic health

Oral Hygiene as a Health Strategy

Routine habits like toothbrushing, flossing, using mouthwash, and regular dental check-ups support a healthy oral microenvironment by reducing plaque and maintaining microbial balance.

Meticulous oral hygiene not only prevents dental issues like cavities and gum disease but also contributes to overall health and may help decrease chronic pain.

MedBound Times connected with Dr. Neelima Narayanan, and she shared her insights on this matter:

This ground-breaking research showcases the oral microbiome as an important factor in chronic pain, emphasizing the need to incorporate oral health into broader approaches to women’s health and chronic pain management.

References:

1. Chaphalkar, Anushree. "Poor Oral Health Linked to Migraine, Chronic Pain in Women." Medscape, April 15, 2025. https://www.medscape.com/viewarticle/poor-oral-health-linked-migraine-chronic-pain-women-2025a10008xp.

2. University of Sydney. 2025. "Poor Oral Health Linked with Body Pain and Migraines in Women." April 10, 2025. https://www.sydney.edu.au/news-opinion/news/2025/04/10/poor-oral-health-linked-with-body-pain-and-migraines-in-women--.html.

3. Erdrich, Sharon, Joanna E. Harnett, and colleagues. 2025. "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 6: Article 1577193. https://www.frontiersin.org/articles/10.3389/fpain.2025.1577193/full.​

4. The Week News Desk. 2025. "Bad Teeth, Bad Pain? How Oral Health Could Be Fueling Your Migraines." The Week, April 14, 2025. https://www.theweek.in/news/health/2025/04/14/bad-teeth-bad-pain-how-oral-health-could-be-fueling-your-migraines.html.

_MSM