The team presented their findings at the American Physiological Society’s Physiological and Pathophysiological Consequences of Sickle Cell Disease conference in Washington, Nov. 6-8.
Sickle cell disease is a blood disorder whose symptoms include frequent bouts of pain. Scientists know that gut bacteria play a key role in sickle cell patients’ health, but they haven’t looked at which bacteria might be playing important roles.
Howard researchers decided to characterize the gut microbiome — or bacterial mix — of sickle cell patients by analyzing the bacterial composition of patients’ stool.
They discovered a significant imbalance in patients’ gut microbiome, compared with healthy people. Several species of bacteria were depleted, and there were higher levels of Bifidovacteria, Campylobacter, Veillonella, Actinomyces, Scardovia and Atopobium.
An interesting finding was that sickle cell patients had more anaerobic bacteria, or species that do not need oxygen.
“We here report a major dysbiosis [imbalance] in SCD [sickle cell disease] patients’ microbiota that seems to be driven by the general prevailing ischemic [low oxygen] condition in these patients,” the team wrote.
The team discovered that patients who experienced frequent bouts of pain had higher levels of the bacteria Veillonella. This bacteria can form what’s called a biofilm in the gastrointestinal tract. Dangerous Streptococcus bacteria can attach themselves to the biofilm, which leads to the Streptococcus becoming stronger and more virulent.
All of the patients in the study had been hospitalized for vaso-occlusive crisis, a severe pain event resulting from blocked blood vessels. The researchers said one explanation for the pain events is that high levels of Veillonella could be playing a role in the blood vessel blocking. This could involve red blood cells attaching themselves to the biofilm that Veillonella generates, Dr. Hassan Brim, the first author of the study, said in a press release.
More research is needed to determine how to rebalance gut bacteria to reduce pain, Brim noted.
“Gut microbiome analysis reveals major dysbiosis in sickle cell disease patients with a prevalence of Veillonella strains,” he said at the conference. The team’s research abstract was published in the journal Gastroenterology.