by Claire Stevenson
Graduate student in the Committee on Development, Regeneration and Stem Cell Biology
John Alverdy, MD, is a gastrointestinal surgeon and researcher studying the mechanisms by which patients develop infections after surgery and figuring out how best to treat—and prevent—them.
“Research suggests that applying microbiome medicine … to surgical patients will change everything.” Alverdy offered that assessment recently on receiving the Flance-Karl Award for seminal contributions to the field of surgical science. The award was presented at the 103rd Clinical Congress of the American Surgical Association, the most prestigious society in the world aimed at keeping physicians up to date in the field.
Surgical site infections can be debilitating and life-threatening, increasing the risk of death after surgery up to 11-fold, even with advances in medical techniques. Alverdy has committed a large portion of his career to understanding how these infections develop following routine surgery.
He questions the assumption that all infections are caused by bacteria that enter the body during the surgical procedure. “Killing as many threatening microbes as possible prior to surgery, although a common practice, remains questionable from a scientific standpoint,” Alverdy says. His research suggests that the patient’s own microbiome, especially the microorganisms that live in each of our guts, could play a key role in these infections. Perhaps simply keeping our own resident bugs healthy and happy may actually make more sense than broadly eliminating all bacteria.
Microbes can exist in two states, a stable low-growth state and a virulent one, and they transition between these states based on cues from their environment. Alverdy reasoned that our bodies could harbor microbes that are normally innocuous, but which can switch to the harmful state when threatened, as when they have inadequate resources to support growth and reproduction.
In intestinal operations, wounds are normally colonized by gut bacteria. Alverdy and his team demonstrated that alarm signals from the patient’s own tissues and diminishing resources can shift normal bacteria to a more harmful state, significantly impairing healing. Sometimes, these normally helpful bacteria can express enzymes and toxins that cause a leak in the gut repair or other major complications.
Alverdy and his team reasoned it might be more effective to provide local resources to resident bacteria, shielding them from the patient’s alarm signals, in lieu of the traditional broad kill approach with antibiotics. By supporting the health of our normal bacteria, it might be possible to preserve them and thus keep the potentially harmful ones at bay. Alverdy’s lab is thus working to identify the “local public goods” the “good” microbes are missing in their environment and provide these directly to tissues at risk for infection.
Every individual’s microbiome is different, influenced by factors that include diet, travel, medications, and home environment. This could explain why, among patients who have been treated with the same high level of care, some develop infections while others do not. According to Alverdy, “It is time we recognize that any given individual’s disease is biologically unique,” and that, “a one-size-fits all approach to preventing infectious-related complications in surgery … will always be insufficient.”
Work like Alverdy’s, on the microbiome’s role in surgical infections, has the potential to revolutionize patient care. According to him, this could change, “the way we diagnose our patients, our approach to preparing them for surgery, the way we operate, and the way we feed and rehabilitate them postoperatively.” This could even lead to individualized medicine, where each patient’s microbiome is tested prior to surgery and their care is adjusted appropriately. The Duchossois Family Institute’s investment in microbiome research will be a part of turning this vision into a reality.