Use of the probiotic Lactobacillus plantarum 299 to reduce pathogenic bacteria in the oropharynx of intubated patients: a randomised controlled open pilot study

Abstract

Introduction: Ventilator-associated pneumonia (VAP) is usually caused by aspiration of pathogenic bacteria from the oropharynx. Oral decontamination with antiseptics, such as chlorhexidine (CHX) or antibiotics, has been used as prophylaxis against this complication. We hypothesised that the probiotic bacteria Lactobacillus plantarum 299 (Lp299) would be as efficient as CHX in reducing the pathogenic bacterial load in the oropharynx of tracheally intubated, mechanically ventilated, critically ill patients.

Methods: Fifty critically ill patients on mechanical ventilation were randomised to either oral mechanical cleansing followed by washing with 0.1% CHX solution or to the same cleansing procedure followed by oral application of an emulsion of Lp299. Samples for microbiological analyses were taken from the oropharynx and trachea at inclusion and at defined intervals thereafter.

Results: Potentially pathogenic bacteria that were not present at inclusion were identified in oropharyngeal samples from eight of the patients treated with Lp299 and 13 of those treated with CHX (p = 0.13). Analysis of tracheal samples yielded similar results. Lp299 was recovered from the oropharynx of all patients in the Lp299 group.

Conclusions: In this pilot study, we found no difference between the effect of Lp299 and CHX used in oral care procedures, when we examined the effects of those agents on colonisation of potentially pathogenic bacteria in the oropharynx of intubated, mechanically ventilated patients.

Figure 1

Results of oropharyngeal cultures. Number of patients with and without emerging enteric bacteria, not identified at inclusion. No new enteric species (ie, taxa not found at inclusion) appeared in 65% (15 of 23) of the patients in the Lp299 group compared with 38% (8 of 21) in the control group.

Figure 2

Distribution of the findings of emerging enteric bacteria. On the first days of ICU care, identified emerging enteric species were twice as many in the control patients. Despite a gradual decrease in the number of patients remaining in the study (similar in both groups), new cases of tracheal infection appeared in the latter part of the study period, primarily in the control group.