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| Photo Credit: paramountfitness.co.uk |
Acid blockers reduce the diversity of bacteria in the intestines—and that could lead to trouble. In 2014 Americans filled more than 170 million prescriptions for acid
blockers known as proton-pump inhibitors (PPIs) to treat gastric
conditions, including indigestion, peptic ulcers and acid reflux. These
medications are among the top 10 prescribed in the country as a class
and are also available over the counter. Surveys suggest that they are
widely overused, and in such cases, the drugs may do more harm than
good. In fact, two new studies found that PPIs alter gut bacteria in
ways that could increase the risk for dangerous intestinal infections,
adding to a body of research highlighting the drugs' adverse effects. To figure out why people who take PPIs are more likely to get an
intestinal infection, researchers at the University of Groningen and
Maastricht University Medical Center in the Netherlands, as well as the
Broad Institute of Harvard University and the Massachusetts Institute of
Technology, sequenced the bacterial DNA found in the fecal matter of
1,815 people. Doing so gave them a snapshot of the bacteria found in the
subjects' intestines. A comparison of the profiles of subjects taking
PPIs with those who were not revealed that, among other things, PPI
users had less gut bacterial diversity. The researchers, who published their results in the journal
Gut,
found that these differences existed even when PPI users did not have
gastrointestinal conditions, which suggests that the differences were
caused by the drugs rather than simply an artifact of disease. (PPIs are
also prescribed to hospital ICU patients to prevent stress ulcers,
among other uses.) Researchers at King's College London, Cornell University and Columbia
University obtained similar results from a comparably designed study as
well as a small interventional study in which individuals' gut bacteria
were analyzed before and after patients took PPIs for four to eight
weeks. PPIs may limit the gut's diversity by reducing its acidity and thus
creating an environment that is more or less amenable to certain
microbes. And that imbalance could then lead to infection, says Rinse
Weersma, a gastroenterologist at the University of Groningen. The drugs
may induce “a change in the microbiome that creates a niche where
Salmonella or
C. difficile can grow,” he explains. Because a person's microbiome can also influence intestinal
absorption of calcium and other vitamins and minerals, these
drug-induced changes could explain why people who take PPIs are more
likely to fracture certain bones and have nutritional deficiencies.
Although no one yet knows how concerned long-term PPI users should be,
one thing is for sure: “There should be ongoing dialogue and management
between physicians and patients who take these drugs,” says Joel
Heidelbaugh, a family physician at the University of Michigan who
studies PPI overuse. “There are thousands of patients who are on these
drugs indefinitely without needing to be.”
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