Study: Mouth bacteria possible culprit of chronic pain

05/27/2025 / By Ava Grace

A 2025 study from the University of Sydney found a strong connection between poor oral health, harmful mouth bacteria and systemic pain disorders like migraines and fibromyalgia.
Four bacteria (Solobacterium moorei, Dialister pneumosintes, Fusobacterium nucleatum, Parvimonas micra) were linked to increased pain, while Mycoplasma salivarium was more common in migraine sufferers.
Harmful oral bacteria trigger systemic inflammation, potentially worsening pain via the “oral-gut-brain axis” where bacterial toxins affect digestion and nervous system function.
Despite evidence, chronic pain patients are often misdiagnosed or dismissed, with oral health rarely considered as a contributing factor.
Improving oral hygiene (brushing, flossing, treating gum disease), reducing sugar intake and consulting dentists may help alleviate chronic pain symptoms.

For decades, millions of women suffering from migraines, fibromyalgia and unexplained chronic pain have been told their conditions are mysterious, untreatable or even psychological. But groundbreaking new research from the University of Sydney suggests the answer may have been hiding in plain sight – inside their mouths.

A comprehensive study published April 9 in Frontiers in Pain Research revealed a disturbing link between poor oral health, harmful mouth bacteria and systemic pain disorders. The study, conducted on nearly 160 women in New Zealand, found that those with the worst oral health suffered significantly higher rates of migraines, body pain and abdominal discomfort. Its findings challenge long-held medical assumptions and could revolutionize how chronic pain is treated.

Researchers identified four specific pathogenic bacteria that were strongly associated with heightened pain levels. These microbes often linked to gum disease and bad breath appear to trigger inflammatory responses that spread far beyond the mouth:

Solobacterium moorei
Dialister pneumosintes
Fusobacterium nucleatum
Parvimonas micra

Women with frequent migraines had notably worse oral health scores than those without. One bacterium in particular, Mycoplasma salivarium, was far more prevalent in migraine sufferers.

This same microbe has been found in patients with temporomandibular joint (TMJ) disorders, further strengthening the case for an oral-systemic pain connection. Even more striking was the finding that every one-point improvement in oral health reduced migraine risk by 5-8 percent. (Related:Research shows amalgam dental fillings expose pregnant women to DANGEROUS mercury vapor levels.)

Mouth bacteria also impact the digestive system

The study also uncovered a troubling relationship between poor oral health and digestive pain, reinforcing the emerging theory of the “oral-gut-brain axis.” Harmful bacteria in the mouth can migrate to the gut, disrupting digestion and triggering inflammation that affects the nervous system. These microbes produce toxins like lipopolysaccharides, which are known to provoke immune responses linked to chronic fatigue and widespread pain.

This discovery could explain why so many fibromyalgia patients also suffer from irritable bowel syndrome and other functional gut disorders. The body’s pain signaling system, already hypersensitive in these conditions, may be further aggravated by bacterial byproducts circulating from the mouth.

Despite mounting evidence, mainstream medicine has been slow to connect oral health with chronic pain. Patients are routinely prescribed painkillers, antidepressants or even dismissed as hypochondriacs, while underlying infections or gum disease go untreated.

The study’s lead researcher, Dr. Sharon Erdrich, noted that bacterial metabolites from the mouth may be entering the bloodstream, amplifying pain signals – yet most doctors never think to check a patient’s dental health. This oversight is particularly egregious given that fibromyalgia, which affected 67 percent of participants in this study, is notoriously difficult to diagnose and treat.

While further research is needed to confirm causality, the study suggests actionable steps for people suffering from chronic pain:

Prioritize oral hygiene: Brush twice daily, floss and consider using a natural antimicrobial mouthwash.
Visit a biological dentist: Seek a professional who understands the systemic impact of oral health.
Address gum disease: Untreated periodontal disease could be fueling inflammation.
Reduce sugar intake: Harmful bacteria thrive on sugar, worsening oral dysbiosis.
Stay hydrated: Saliva helps protect against bacterial overgrowth.

For too long, patients – especially women – have been told their suffering is “all in their head.” Now, science suggests it may actually be in their mouths. The next time a migraine strikes or unexplained pain flares, the solution might not be a pill but a toothbrush.

Visit WomensHealth.news for more similar stories.

Watch Dr. Pam Popper explaining the link between the oral microbiome and blood pressure in this clip.

This video is from the Wellness Forum Health channel on Brighteon.com.

Study: Mouth bacteria possible culprit of chronic pain

Mouth bacteria also impact the digestive system

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