Cleveland Free Times June 16-22, 1999
A scientific debate rages over an unproven theory linking a bacterium in milk to Crohn's disease -- a debilitating intestinal disorder affecting at least four million people worldwide.
BY LISA CHAMBERLAIN
Dr. Rodrick Chiodini went on a treasure hunt. Like most people who embark on an improbable journey, the hunt took over his life, changing it irrevocably. Unlike most treasure hunters, he found what he was looking for.
While working on his Ph.D. in microbiology at the University of Connecticut, Chiodini developed an expertise on a bacterium, Mycobacterium paratuberculosis (Mp), that causes a debilitating intestinal disorder in cattle. The disease in cows, identified more than a century ago by Heinrich Johne, is characterized by diarrhea, excessive weight loss, reduced milk production and ultimately death.
Named after its identifier, Johne's disease (pronounced YO-neez) in cattle is similar to Crohn's disease in humans (pronounced kronz). This chronic inflammatory disease of the gastrointestinal tract also results in severe diarrhea, excessive weight loss and -- for humans, who live a lot longer than cows -- debilitating abdominal pain, rectal bleeding, bowel obstruction, fistulas and abscesses. Chronic Crohn's will likely lead to surgery for removal of inflamed intestine, as well as a lifetime of harsh drug therapy that often doesn't work.
The possibility of a connection between Johne's disease in cattle and a similar gastrointestinal condition in humans had been suggested as early as 1913, but for 70 years, every attempt to locate the bug in human Crohn's patients failed. Despite the negative results, the similarities between Johne's in cattle and Crohn's in humans proved too compelling to ignore.
So in 1981, Chiodini went looking for the elusive bacterium, successfully isolating Mp -- the cause of Johne's disease in cattle -- in the intestine of six people suffering from Crohn's disease. Chiodini's discovery -- seemingly the microbiologist's equivalent of unearthing a buried treasure -- turned out to be a Pandora's box. For the first time, Chiodini's research implicated contaminated milk as a possible cause of a debilitating, sometimes fatal, gastrointestinal disease.
The Crohn's connection
"The public should know that there are a number of medical researchers and veterinary researchers that are concerned about the implications of this organism," says Mike Collins, a doctor of veterinary medicine and microbiology at the University of Wisconsin. Collins has been leading a three-year international study on the possible connection between Mp and Crohn's disease, the results of which are not yet available.
"This organism basically resides in animal populations, mainly ruminants, and it causes a disease in those ruminants that looks very much like Crohn's disease [in humans]. But we don't know what, if any, the consequences are when this organism spills over to the human community. We don't know how that might happen, the frequency or the consequences. But we need to figure this out as quickly as possible. There's sufficient scientific evidence to cause concern."
This seemingly banal statement summarizes a raging, eye-crossing scientific debate among a core group of researchers that has yet to come to the public's attention. The debate over the possibility that a bacterium originating in cows might cause Crohn's disease in humans has fueled merciless professional attacks, closed-door meetings and a lot of behind-the-scenes hand-wringing.
What it has not fueled is well-funded research by either the government or the dairy industry. The little research that has been undertaken has been on shoestring budgets, yielding debatable results. Very few researchers have been able to culture the bug from Crohn's patients, grow it in the laboratory or detect an immunological response to it. Conflicting research has been reported from every corner of the globe. The only certainty in the whole matter is that it is a very controversial, unproven theory.
Critics of the theory then use the inconclusive r