A study recently presented at the American Transplant College shows that the gut's microbiome plays a significant role in whether a transplant recipient will develop a viral infection of not.

“Our results confirm and extend the novel association between the gut microbiome and the development of viral infections from stem cell transplant recipients to solid organ graft recipients,” Dr. John Lee and colleagues wrote in the abstract. “Altogether, these findings support targeting the gut microbiota as a strategy to prevent and/or treat viral infections.”

Dr. Lee works in the division of nephrology and hypertension at Weill Cornell Medicine in New York. His collaborators were infectious disease specialists from the Sloan-Kettering Cancer Center.

“Recent studies suggest that the gut microbiome plays a critical role in protecting its host from infections beyond Clostridium difficile,” Dr. Lee wrote. “Notably, butyrate-producing bacteria may be beneficial to gut health and have recently been associated with lower rates of respiratory tract infections in bone marrow transplant recipients.”

In the study, researchers looked at the relationship between butyrate-producing gut bacteria and the future development of viral infections in kidney recipients. Samples were collected from 115 kidney recipients two weeks following transplantation surgery.

Researchers said they profiled the gut microbiome using 16S rRNA gene-deep sequencing of the V4-V5 hypervariable region. The next step was determining the likelihood of patients with less than 1% relative abundance of butyrate-producers developing one of three very common viral infections within two years of transplantation. The viruses were BK viremia, cytomegalovirus viremia and respiratory tract (RV) infections.

The patients who had a low abundance of butyrate-producers were at significantly increased risk for developing RV infections than those who had a high abundance of butyrate-producers. Of the 115 individuals studied, 23 patients developed RV infections while 22 developed BK viremia and 15 developed CMV viremia; Fifty developed at least one out of the three.

The study results indicate the need to monitor the risk of infection closely in both solid organ transplant recipients and stem cell recipients, researchers say.

Along with viruses, solid organ recipients are also at greater risk of contracting a Clostridioides difficile infection. The illness is caused bybacteria that causes bloody diarrhea and other intestinal complications. It poses greater risks for solid organ recipients.

A team of researchers from Columbia University Irving Medical Center in New York discussed the prevalence of CDI in solid organ transplant patients during the American Transplant College. Of 2.622 recipients, 8.5% experienced CDI within a year of transplant.

Of those cases, 64% were considered severe. Pancreas recipients had the highest rate of CDI at 12.5%. Lung, liver, heart and kidney followed in that order. The media time of transplant to CDI was 56 days, and nearly 30% of patients had recurrent CDIs.

All patients had a twofold increase in the chance of death. Since CDI is especially dangerous for solid organ recipients, researchers indicated "Novel strategies to prevent and effectively treat CDI in SOT are urgently needed," in the abstract.