Did you know that your mouth is home to over 6 billion bacteria? This is according to a review published in Frontiers in Microbiology, which goes on to explain that hundreds of species of oral bacteria usually coexist in a balanced environment, but when conditions change, some types can take over, causing tooth decay or gum disease. Nonetheless, the one species most closely linked to periodontal (gum) disease is Porphyromonas gingivalis, or P. gingivalis.

How Gum Disease Develops

The distinctive nature of periodontal disease (periodontitis) is that it destroys the supporting structures of the teeth — including the gum tissue, 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 around the teeth and ultimately tooth loss.

It all starts with letting bacteria build up on your teeth. This results in gum inflammation, which causes your gums to swell and bleed easily. Plaque — the collection of bacteria — eventually hardens into tartar, which can spread underneath the gumline. As the disease advances, your gum tissue pulls away from the tooth and forms a deep pocket, where more bacteria gather and degrade your supporting bone and ligaments.

The Role of Porphyromonas Gingivalis

Although more than one species of bacteria is involved in causing gum disease, P. gingivalis is the number one opportunist. These microorganisms are classified as gram-negative, anaerobic bacteria that thrive in an environment without oxygen, as the Frontiers in Microbiology review notes. That’s why spaces under your gum tissue are the perfect home for this species, especially the deeper pockets caused by more advanced disease.

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 virulence factors that cause damage to the patient’s cells.

The Relationship Between Periodontal Disease and Systemic Disease

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.

One possible explanation for these connections 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.

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.

Treatment and Prevention

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. You should be brushing 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.