Disturbance in the oropharyngeal microbiota in relation to antibiotic and proton pump inhibitor medication and length of hospital stay

The aim of this study was to investigate the appearance of a disturbed oropharyngeal microbiota during hospitalization and explore the patient characteristics that maybe associated with such a disturbance. Oropharyngeal swabs were collected from 134 patients at hospital admission and every 3–4 days thereafter. The samples were cultivated to determine the presence of a disturbed microbiota, which, in turn, was subcategorized into respiratory tract pathogens, gut microbiota and yeast species. Demographics, medical history data and hospitalization events were compared. The percentage of disturbed oropharyngeal microbiota increased significantly with length of stay (LOS). Receiving antibiotic treatment during the hospitalization tended to be associated with a disturbed microbiota (OR 2.75 [0.99–7.60]). Proton pump inhibitor (PPI) medication and receiving antibiotics before hospitalization were associated with the development of a disturbed oropharyngeal microbiota with colonization of gut pathogens (OR 3.49 [1.19–10.2] and OR 4.52 [1.13–18.1], respectively), while acute hospital admission was associated with a lower risk of colonization of gut pathogens (OR: 0.23 [0.074–0.72]). The risk of developing a disturbed oropharyngeal microbiota increased with LOS in hospitalized patients. PPI medication and receiving antibiotics before hospitalization were independent risk factors for developing oropharyngeal colonization of gut pathogens.