More Bowel Bacteria Found in Digestive Diseases 
Fri Mar 29, 1:19 PM ET By Karla Gale NEW YORK (Reuters Health) - People with 
inflamed bowels have more bacteria in their colons than healthy individuals, 
and the amount of bacteria increases with the severity of disease, according 
to the results of a study.      
Little is known about the bacteria that interact with the mucosal lining of 
the intestines, the researchers note. To investigate, they studied the 
bacterial content--or flora--of colon tissue samples from 305 patients with 
bowel inflammation and 40 healthy individuals. Patients with inflammation 
included 28 with colitis that improved within 2 months, 104 with 
indeterminate colitis, 119 patients with ulcerative colitis, and 54 with 
Crohn's disease. Colitis is a general term for inflammation of the colon. 
Ulcerative colitis and Crohn's disease, known collectively as inflammatory 
bowel disease (IBD), are more serious, chronic conditions. Dr. Alexander 
Swidsinski of Charite Humboldt Universitat in Berlin, Germany, and colleagues 
tested the biopsied tissue for the presence of bacteria. They found that the 
concentration of mucosal bacteria increased progressively with the severity 
of illness. Concentrations were highest in those with Crohn's disease. The 
type of bacteria found did not differ significantly among the groups. 
"Surprisingly, concentrations of mucosal bacteria were higher in non-inflamed 
than inflamed mucosa," the investigators note in a recent issue of the 
journal Gastroenterology. The ability to prevent bacteria in feces from 
closely contacting the epithelial surface, or lining, of the colon is 
disturbed in patients with IBD primarily due to local inflammatory changes, 
the researchers conclude. The findings suggest the patient's response to the 
bacteria, rather than the infectious agent itself, is responsible, they add. 
Dr. Jonathan Braun of the University of California, Los Angeles School of 
Medicine, suggests in an accompanying editorial that the inflammatory 
disorder appears to enhance the ability of bacteria to adhere to epithelial 
cells. In an interview with Reuters Health, Braun theorized that bacterial 
concentrations are lower over areas of inflammation because those epithelia 
have been sloughed off, resulting in fewer binding sites for bacteria. 
Overall, however, "people with this disease may be colonized with bacteria 
that are better at binding to and invading epithelial surfaces," he said. 
"Another idea is that structures onto which bacteria bind may be more highly 
expressed in people with these diseases." The implication, he added, is that 
more microbial binding puts individuals at risk for the disease. Braun said 
the new findings demonstrate "a greater need for understanding the details of 
bacterial biology in the gut and a level of interaction between the gut 
bacteria and the lining of the intestine that we previously hadn't 
appreciated." More detailed understanding will help clinicians assess and 
treat this category of intestinal diseases, he added. SOURCE: 
Gastroenterology 2002;122:44-54, 228-230.