A common clinical practice may be inadvertently harming patients, according to research published in the European Respiratory Journal. The team of Michigan Medicine researchers behind the study suggest that administration of antibiotics with activity against anaerobic bacteria has a profound effect on the gut microbiome and, ultimately, an adverse impact on critically ill patients.
In the paper, researchers found that, in critically ill patients, the practice of early administration of anti-anaerobic antibiotics is commonplace – about two-thirds of the 3,032 patients observed in the study’s cohort received such treatment.
With support from the Weil Institute, along with funding from the National Institutes of Health, the researchers conducted a retrospective single-center cohort study of 3,032 critically ill patients, comparing those who did and did not receive early anti-anaerobic antibiotics. By comparing ICU outcomes in all patients, and changes in gut microbiota in 116 of the patients, they found that those who received anti-anaerobic antibiotics early in their hospital course had worse outcomes, whether measured in overall survival, infection-free survival, or pneumonia-free survival.
The authors also found dramatic consequences of these antibiotics on the gut microbiome – during hospitalization, patients who received anti-anaerobic antibiotics had decreased initial gut bacterial density, followed by increased expansion and domination of the microbiome Enterobacteriaceae (a genus of common bacteria, many of which are pathogenic and cause opportunistic infections in immunocompromised hosts).
