The Connection Between Porphyromonas Gingivalis and Gum Disease

Periodontal disease begins as gingivitis, an infection of the gums caused by a build-up of bacterial plaque on the teeth and gum line. If left untreated, it can progress to periodontitis, or advanced gum disease, where plaque spreads below the gum line and hardens into tartar. The resulting inflammation destroys the supporting structures of the teeth, including the bone that holds your teeth in their sockets and the ligaments that connect the teeth to the bone. According to the Centers for Disease Control and Prevention, when not treated, the acute inflammation caused by periodontal disease can lead to pocket formation between the teeth and gum tissue, trapping bacteria and food debris. Periodontitis can ultimately lead to tooth loss.

Porphyromonas gingivalis, or P. gingivalis, is a species of bacteria that is closely associated with gum disease. It is classified as a gram-negative, anaerobic bacteria that thrives in an environment without oxygen, as noted in a Frontiers in Microbiology review. That's why the spaces under your gum tissue are the perfect home for this species, especially the deeper pockets caused by more advanced periodontal disease.

Although more than one species of bacteria is involved in causing gum disease, P. gingivalis is the number one culprit. It is present in many people with healthy mouths, but is usually kept in check by commensal (“friendly”) bacteria. However, an imbalance of bacteria in the mouth can allow this opportunistic bacteria to thrive. 

The Frontiers in Microbiology review points out that this species of bacteria is found in 85.75% of plaque samples taken from under the gumline of patients with chronic periodontitis. And because these bacteria have the ability to bypass some of your body's immune responses, they can easily invade. In addition, P. gingivalis has something called “virulence factors” – characteristics that allow it to cause damage to your cells.

A recent Biomedical Journal article reports that the list of diseases with possible connections to periodontal disease is growing. It includes:

• Diabetes and insulin resistance.
• Cardiovascular disease.
• Respiratory infections.
• Alzheimer's disease.
• Gastrointestinal and colorectal cancers.

Some adverse pregnancy outcomes have also been linked to periodontal disease. However, the article warns that a cause and effect relationship has not been fully established, and studies are ongoing.

P. gingivalis has also been found to correlate with systemic health problems like atherosclerosis (narrowed arteries), Alzheimer’s disease, diabetes, rheumatoid arthritis autoimmune disease and adverse pregnancy outcomes. That leaves some experts wondering if P. gingivalis could be the missing link between periodontal disease and systemic diseases like these.

One possible explanation is that bacteria such as P. gingivalis produce endotoxins that could directly contribute to systemic diseases. These bacteria may enter the bloodstream following dental surgery or other procedures. And in those with damaged gum tissue due to advanced gum disease, it is much easier for oral bacteria to enter the bloodstream during everyday oral hygiene. Indeed, the bacteria has been found in tissues all over the body, suggesting it can spread from the mouth.

There may also be an indirect link related to the body's inflammatory response. Oral inflammation can create systemic inflammation throughout the body, and conversely, inflammation in the body could affect oral inflammation. This is frequently evident in people with diabetes, where uncontrolled blood sugar levels can predispose one to periodontal disease, and likewise, periodontal disease can negatively affect blood sugar levels. Similarly, because Alzheimer's disease is the result of inflammatory processes, periodontal disease could increase a person's risk for Alzheimer's. Conversely, compromised oral hygiene in a person with Alzheimer's can increase their risk for periodontal disease.

If you have any signs of gum disease, such as bleeding, sore or swollen gums, it's an indication that you need to reexamine your oral hygiene routine. Brush thoroughly twice a day with a soft-bristled brush, making sure you clean well around and under the gumline. Daily flossing is a must. 

See your dentist for dental cleanings at least twice a year to remove hardened tartar before it damages your gums or allows pockets to form. If periodontal disease has reached the stage of deep pockets and bone loss around the teeth, your dentist may recommend periodontal surgical procedures to stop further progression of the disease.

You may always have billions of bacteria in your mouth, but with good oral hygiene practices and regular dental visits, you limit the risk of P. gingivalis causing periodontal disease.

This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to be a substitute for professional advice, diagnosis or treatment. Always seek the advice of your dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.