Effect of probiotics on oropharyngeal and tracheal colonization by pathogenic bacteria before major surgical procedures under general anesthesia

Abstract: Background: Postoperative pneumonia is an acknowledged risk following surgical procedures, for which there is currently no prophylactic treatment. Different methods have been tried with varying results, such as the administration of antibiotics or chlorhexidine to reduce pathogens in the oral flora. This study explores a prophylactic oral treatment with a suspension of two lactobacillus-strains, Lactobacillus plantarum 299 and Lactobacillus plantarum 299v, aiming to reduce pathogenic bacteria in the oropharynx before major surgical procedures under general anesthesia. Methods: Forty-two patients scheduled for surgical procedures with an estimated duration of ≥ 4 hours were randomized into either a study group, rinsing preoperatively with probiotics, or a control group, not rinsing at all. Throat swabs and tracheal secretions were collected at inclusion, immediately after intubation, before extubation and on the first postoperative day. Results: There were few positive cultures overall, and no trends or apparent connections could be seen. The randomization procedure haphazardly allocated all patients with positive start cultures to the study group so that comparison between the groups was impossible. Conclusion: We could not draw any conclusions concerning whether or not prophylactic rinsing with probiotics in the oral cavity reduces oropharyngeal or tracheal colonization by pathogenic bacteria. Further observations regarding probiotic prophylaxis would probably have greater potential among other patient populations such as compromised patients with severe underlying illnesses.