The Oral Microbiota as Reservoir for Systemic Opportunistic Pathogens

Introduction The dental biofilm offers a protected environment for bacteria during systemic antibiotic treatment and may consequently be a source of reinfection. The concentration of antibiotic needed for inhibiting the growth of bacteria within a dental biofilm has been estimated to be 250 times greater than for planktonically growing bacteria (1). Chronic obstructive pulmonary disease (COPD) exacerbations cause pain and discomfort for the patient, healthcare resources and an increased usage of antibiotics. Smaller studies indicate that the act of advanced dental cleaning may lower the risk of reinfected COPD, but this needs to be validated in a larger randomized study to promote clinical implications.

COPD is a growing health problem worldwide. In 2020, COPD is projected to rank fifth in terms of burden of disease and third in terms of mortality (2). Assessment of COPD is based on the patient´s level of symptoms, exacerbation history and severity of spirometric abnormality. In a randomly selected Swedish cohort, the prevalence of COPD was 16.2%, and 34% of the COPD patients had never smoked (3). Unfortunately, none of the existing medications for COPD has been shown conclusively to modify the long-term decline in lung-function, but COPD patients are usually prescribed β2-adrenerg receptor agonists and anticholinergics (2). For acute exacerbations, the patients have oral steroids and antibiotics, typically doxycycline and amoxicillin. Importantly, two smaller (n=20 per group) pilot studies (4,5) have reported a lower frequency of exacerbations in COPD patients that have received advanced dental cleaning, suggesting that the oral microbiome might constitute a reservoir that infects the lungs in COPD. There is a need of studies based on larger cohorts in order to claim that dental treatment should be added to the treatment regime of COPD, to decrease the frequencies of exacerbations and thereby minimize physical suffering as well as related costs.

Hypothesis The hypothesis of this project is that adding advanced dental cleaning to established COPD treatment regime delays and lowers the frequency of exacerbations by eliminating a source of reinfections.

Aim The overall aim of this project is to investigate if the treatment of COPD can be optimized by adding advanced dental cleaning to the established treatment regime and thereby eliminate a source of reinfections.

The specific aim is to investigate if adding advanced dental cleaning to COPD treatment can (i) lower the number of exacerbations and (ii) improve the COPD symptoms the coming 6 and 12 months. In an effort to explain the underpinning mechanism we will collect oral dental biofilm samples at baseline and follow up in the treatment and control group to investigate changes in the composition of the biofilm.