Conventional Approaches to Gastritis May Not Be the Best
Juanita Merchant
Photo: Marcia Ledford |
If you need to soothe the burning pain of gastritis, reducing the amount of
acid in your stomach may seem like a good idea. But scientists at the U-M Medical
School have learned it could be the worst thing you can do.
In a series of recent experiments with laboratory mice, U-M scientists found
that antibiotics were actually the best way to treat an inflamed stomach and
kill the bacteria that cause gastritis. Mice treated instead with prescription
drugs called proton pump inhibitors or PPIs, which block acid production and
often are used to treat gastritis in humans, had more bacteria and developed
more inflammatory changes in their stomach linings than untreated mice.
“The inflammatory response, which triggers overproduction of hydrochloric
acid, is the stomach’s primary response to bacterial colonization,”
says Juanita L. Merchant, M.D., Ph.D., a Howard Hughes Medical Institute assistant
investigator and associate professor of internal medicine and physiology. No
matter what type of bacteria causes the problem, gastritis is a serious medical
condition which, if untreated, can lead to peptic ulcers and stomach cancer.
“Inflammation of the stomach lining coincides with production of peptides
called cytokines, which stimulate production of a hormone called gastrin. Gastrin
triggers parietal cells in the stomach lining to produce more hydrochloric acid,
which kills off most invading microbes. If you inhibit gastric acid production,
you interfere with the stomach’s natural defense mechanism against invading
bacteria.”
Since Merchant wanted to study the relationship between other bacteria and gastric
acid, Helicobacter pylori, bacteria that 75 percent of people with gastritis
test positive for, were excluded from the study. H. pylori is the only bacterial
organism in the stomach that cannot be killed by hydrochloric acid.
Without controlled clinical trials, Merchant says she can’t say whether
the results would be exactly the same in humans. But since reduced gastric acidity
does appear to make the mammalian stomach more vulnerable to bacterial invasion
and gastritis, Merchant suggests physicians may want to re-evaluate the long-term
use of proton-pump-inhibiting drugs in their patients.
“The bottom-line message is that a two-week course of antibiotics to treat
the inflammation is essential for a successful cure,” Merchant adds. “Once
you get rid of the inflammation, the gastric acid levels should return to normal.”
In addition to the Howard Hughes Medical Institute, the research was supported
by the National Institutes of Health. Linda C. Samuelson, Ph.D., associate professor
of physiology in the Medical School, developed the strain of transgenic mice
used in the experiments. Former U-M post-doctoral fellows Gabriele Rieder, Ph.D.,
and Amy Ferguson, Ph.D., collaborated in the study.
Results of the research were published in the January 2002 issue of Gastroenterology.
—SFP
Read the complete story at:
www.med.umich.edu/opm/newspage/stomachacid.htm
A press release from the Howard Hughes Medical Institute is available at: http://www.hhmi.org/news/merchant.html
 
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