The worldwide incidence of autoimmune diseases has been steadily growing over the past decades, making them a significant public health concern. This increase is attributed to changes in our environment, diet, and lifestyle. Autoimmunity is the result of a dysregulated immune response against one’s own body. The origin of this abnormal behavior of the immune system is presumed to be multifactorial, involving both environmental and genetic elements, but one very interesting hypothesis is that changes in your microbiomes, known as dysbiosis, confuse your immune system and potentially cause autoimmunity. We’re going to explore the link between oral dysbiosis manifesting as dental infections and autoimmune disorders.

The oral microbiome is the second largest in your body after the gut microbiome, with over 700 bacterial species; each drop of saliva has an average of 1 billion bacteria. Most of them are harmless, but even minor imbalances in this complex microenvironment can cause illnesses. Various types of dental infections arise from such imbalances; these include:

• Dental caries or cavities: They are caused by bacteria breaking down your enamel, causing infection and tooth decay.
• Gum infections: They can be just a mild inflammation causing discomfort, which is gingivitis, or a severe, chronic infection that involves the underlying bone and results in loss of teeth, which is periodontal disease.
• Abscesses: These are pus-filled cavities usually at the root of a tooth, resulting from the progression of a root canal infection.
• Specific bacterial, viral, and fungal infections, like tonsillitis, pharyngitis, thrush, and herpangina.

Chronic dental infections are often overlooked when looking for the cause of systemic illnesses, but oral dysbiosis has been demonstrated to be a major factor in the pathogenesis of various autoimmune diseases, either by causing chronic inflammation or by molecular mimicry.

Oral dysbiosis and chronic inflammation

Overgrowth of harmful bacteria in your mouth doesn’t only cause dental issues; bacteria can reach your bloodstream during dental manipulation or through minor cuts in your gums. These bacteria will trigger an immune response and cause widespread systemic inflammation. The chronic inflammation that results from long-term exposure to the harmful bacteria from your mouth will eventually cause immune dysregulation, and your body will start attacking itself, manifesting as autoimmunity, like systemic lupus, Hashimoto’s thyroiditis, multiple sclerosis, and many other autoimmune disorders.

Molecular mimicry

Some bacteria have proteins that are similar to proteins found in your body, which confuses your immune system, causing it to attack your body following dental infections. Rheumatic fever is an example of this process. Streptococcus pyogenes, the culprit bacteria in strep throat and tonsillitis, possesses a protein that is structurally similar to a human protein found in the heart, brain, and joints. Your immune system is usually unable to overcome this similarity and starts to attack your organs as a consequence of the throat infection, producing the symptoms of rheumatic fever.

Periodontitis and rheumatoid arthritis

The connection between periodontal disease and rheumatoid arthritis (RA) is perhaps the most evident example of the connection between dental infections and autoimmune diseases. This connection was extensively studied in the last two decades, revealing a strong association between Porphyromonas gingivalis, the most commonly isolated bacteria in periodontitis, and the development of RA. P. gingivalis is the only known bacteria that produces an enzyme called peptidylarginine deiminase (PAD). This enzyme is capable of modifying structural proteins in your joints, making them a target for your immune system, which triggers the autoimmunity that eventually shows up as rheumatoid arthritis.

The role of gut dysbiosis

The microbiomes in your mouth and gut are closely related; we swallow between one and two liters of saliva every day, so an imbalance in your oral microbiome will disrupt your gut microbiome, causing gut dysbiosis, which is linked to multiple autoimmune conditions like inflammatory bowel diseases, celiac disease, psoriatic arthritis, and type-1 diabetes.

Simple steps to reverse the damage

Keeping good oral hygiene by brushing and flossing regularly and choosing a healthy anti-inflammatory diet rich in healthy fats and antioxidants, coupled with regular visits to your dentist, are steps you could take right now to improve your oral health and avoid dental infections and their complications.

Different from the traditional medicine approach to treat autoimmune conditions symptomatically only by suppressing the immune system, which leaves you susceptible to dangerous infections, we search for the root of autoimmune conditions, which includes careful dental evaluation looking for hidden infections in your mouth that could be triggering your condition, potentially sparing you the harmful effects of medical therapy. These are the benefits of having both your dentist and your doctor working together.