April 9 (UPI) -- Stool transplants effectively treat bacterial infections in the colon by boosting levels of specific molecules that help protect bowel cells, according to a study published Friday by Gastroenterology.
The molecules, called microRNA, act as messengers carrying instructions from DNA for the production of proteins in the body, with many implicated in common human disorders.
Clostridium difficile, the bacteria behind C. diff infections in the bowel, interferes with microRNA, preventing production of proteins that protect cells in the colon and bowel -- often causing severe diarrhea and potentially life-threatening inflammation in the colon -- study co-author Christos Polytarchou said in a press release.
"MicroRNAs are characterized as master regulators of gene expression. A single microRNA can modulate multiple RNA and protein molecules, affecting a vast array of cell functions," said Polytarchou, an associate professor of science and technology at Nottingham Trent University in England.
More than 220,000 cases of C. diff are reported in the United States each year, and roughly 12,000 die as a result of the bowel infection, which usually occurs in hospitals in older patients on antibiotics, according to the Centers for Disease Control and Prevention.
Stool transplants, also known as fecal microbiota transplants, or FMTs, are a common treatment for recurrent C. diff and are designed to repopulate the gut with microbes from a healthy person.
After a healthy stool sample is produced, it is mixed with water and administered to the bowel via the mouth straight into the stomach or a colonoscopy, through the rectum.
Although the approach is effective in at least 80% of cases in treating the condition, little still is known about how it works, the researchers said.
For this study, the research team, which also included investigators from Vanderbilt and Clemson, tested blood samples collected from people with C. diff who received FMTs at multiple hospitals in Britain and the United States.
Four and 12 weeks after undergoing FMTs, study participants' blood showed evidence of 64 microRNAs, the six most of common of which were found to be suppressed as a result of C. diff infection, the researchers said.
FMTs effectively reversed the suppression of these microRNAs, allowing them to serve their function producing proteins designed to protect cells on the bowel walls, according to the researchers.
Study co-author Dr. Tanya Monaghan said that while not much is known about how FMT works at the molecular level, the treatment could be refined.
Now, "we have discovered a new mechanism by which the transplants work, which will now help us to develop a new method of therapeutics," said Monaghan, clinical associate professor of gastroenterology at the University of Nottingham.