Patients in the intensive care unit with an imbalanced microbiome are at increased risk for complications and longer ICU stays, according to findings presented at Clinical Nutrition Week 2017 | Anesthesiology News
Image shows bacterial microbiome mapping – a bioartistic experiment.
Paul Wischmeyer, MD, professor of anesthesiology and surgery and director of perioperative research at Duke Clinical Research Institute, in Durham, N.C., who also is part of the ICU Microbiome Project, told meeting attendees that ICU patients experience significant microbiome perturbations and added complications, including acute respiratory distress syndrome (ARDS).
“ICU patients have massive loss of health-promoting bacteria and higher levels of pathogenic species, compared with healthy patients,” Dr. Wischmeyer said. “It is astonishing how rapidly pathogenic bacteria flourish and how this shift to dysbiosis appears to affect a variety of outcomes.”
Dr. Wischmeyer and his colleagues have been examining fecal and oral microbiome samples from 115 ICU patients treated at four hospitals and comparing them with samples from healthy people participating in the American Gut project. In previous research, they found decreases in populations of Bacteroides and Firmicutes, as well as the healthy bacterium, Faecalibacterium prausnitzii, which produces short-chain fatty acids that help preserve normal gut barrier function (mSphere 2016;1. pii:e00199-16). Meanwhile, they discovered increases in the relative abundance of Proteobacteria, a phylum of gram-negative bacteria linked to infections in ICU and hospitalized patients.
ICU patients also tended to lose overall fecal microbiota diversity, with some patients having only one organism compose 95% of their fecal bacteria after a short time in the ICU, he explained.