The mix of bacteria in the gut may predispose some kidney transplant patients to urinary tract infections, according to a study presented at Kidney Week 2018.
About one in five patients experience a urinary tract infection after kidney transplantation, said John Lee, MD, MS, a transplant nephrologist at New York Presbyterian Hospital—Weill Cornell Medical Center. These infections can usually be successfully treated with antibiotics, but in rare circumstances they can have serious consequences like graft loss and death, he noted. Finding ways to prevent such infections could help improve outcomes.
To examine how gut bacteria may contribute to the risk of urinary tract infection, Lee and his colleagues used DNA sequencing to assess the abundance of Escherichia and Enterococcus bacteria in fecal samples from 169 kidney transplant recipients during the 3 months after their transplantations. They found that 36 patients experienced urinary tract infections with Enterococcus species and 36 experienced urinary tract infections with Escherichia species during that period. Patients in whom these urinary tract infections developed were more likely to have a greater proportion of the corresponding bacteria in their gut, and the strain of bacteria in the urine was similar to that found in the gut, suggesting that the gut is likely the source of infection.
“Our data suggest people who have gut dysbiosis are at increased risk of developing urinary tract infections,” Lee said. “People with recurrent urinary tract infections had the worst gut dysbiosis.”
Nephrologist Dominic Raj, MD, professor of medicine, biochemistry, and genetics, and of biostatistics and epidemiology at George Washington University in Washington, DC, said it’s not surprising that bacteria from the gut might be contributing to these infections, noting that it’s “not uncommon for bacteria from stool to migrate to the urinary tract.”
Lee cautioned that the findings are preliminary and must be confirmed, but if they are confirmed, it may suggest that modifying the gut microbiome could decrease the risk of urinary tract infections.
“If people with recurrent urinary tract infections have a gut dysbiosis that seems to predict urinary tract infections, then maybe you could use a prebiotic or probiotic approach to prevent that problem, rather than treat subsequent infections as they come up with a continued course of antibiotics,” Lee explained.
He noted studies have found that fecal transplantation may help reduce urinary tract infections (1). But this field is evolving rapidly to test other targeted therapies, like giving patients beneficial bacteria (probiotics) or prebiotics, the types of fiber needed to feed beneficial bacteria in the gut. Raj noted a study in Nature that found giving neonates both lactobacilli and prebiotics reduced sepsis by one-third (2).
Lee noted the importance of members of the collaborative effort to conduct this project: Manikkam Suthanthiran, MD, from Weill Cornell Medicine; Eric Pamer, MD, from Memorial Sloan Kettering Cancer Center; and Iwijn De Vlaminck, PhD, from Cornell University. Testing whether such gut-targeted approaches might be useful in preventing or treating urinary tract infections is the next step for this research, if the results are verified, Lee said.
In addition to aiding research on the role of gut microbes in kidney disease and infection, Raj predicts that DNA sequencing of bacteria will eventually change the way clinicians diagnose infections.
“We are not going to wait for the culture to come,” Raj said. “We are going to rely on DNA testing to identify the bacteria.”
References
- 1.↑
Raseen T , et al.. Fecal microbiota transplantation for recurrent Clostridium difficile infection reduces recurrent urinary tract infection frequency. Clin Infect Dis 65; 10:1745–1747.
- 2.↑
Pinaki P , et al. A randomized synbiotic trial to prevent sepsis among infants in rural India. Nature 2017; 548: 407–412.
Gut Microbiota Dysbiosis Is a Novel Risk Factor for Urinary Tract Infections in Kidney Transplant Recipients. Kidney Week 2018 Oral Abstract 007.
