July 23 (UPI) -- Viruses and inflammatory bowel diseases, including ulcerative colitis and Crohn's disease, have a key connection, according to a study with mice.
Scientists studied prokaryotic viruses inhabiting bacteria in the intestine known as bacteriophages -- or phages -- and determined they are altered during inflammatory disease. These findings, which researchers said could lead to new kinds of treatment for the conditions, were published Monday in the journal Nature Microbiology.
The Centers for Disease Control and Prevention reports that an estimated 1.3 percent of adults in the United States -- 3 million people -- reported inflammatory bowel disease in the digestive track in 2015, a sharp uptick in cases from the two million reported in 1999.
Researchers in the new study found that phage communities change randomly, which is a genetic signature suggesting an inflammatory environment.
"Phage numbers are elevated at the intestinal mucosal surface and increase in abundance during inflammatory bowel disease, suggesting that phages play an unidentified role in IBD," lead author Breck Duerkop, an assistant professor of immunology and microbiology at the University of Colorado Anschutz Medical Campus, said in a press release.
Other researchers have studied whether environmental factors cause persistent inflammation of the intestine, because microbial communities are critical to maintaining intestinal health.
But Duerkop said most studies have focused chiefly on bacteria rather than the viruses inside them.
"We hypothesize that inflammation or other host defenses alter phage abundances during colitis," researchers wrote in the new study. "Such stresses could produce ecological disturbances in the intestinal environment, driving alterations within the viral community."
Viruses may be killing off beneficial bacteria in the intestine and allowing "bad actor" bacteria to cause inflammation and bowel disease, the researchers said.
"What we see in mice is consistent with what we see in humans with IBD," Duerkop said.
Duerkop believes viruses could be used to eliminate certain bacteria to prevent inflammation.
"We could promote the growth of good bacteria -- a kind of phage therapy," Duerkop said. "We could perhaps use phages as markers to identify someone predisposed to developing these diseases. While there is clearly more research to do, the potential is very exciting."