Common drugs for gastric reflux and heartburn could contribute to liver injury and even worsen chronic liver disease, research by US researchers has found.
Scientists at the University of California San Diego School of medicine looked at proton pump inhibitor (PPI) drugs that are taken by about 10 per cent of Americans to block the stomach acid secretions that cause frequent heartburn, acid reflux, and gastroesophageal reflux disease.
PPIs can cut acid production, which happens automatically in our stomaches as well as in response to eating, by as much as 90 per cent. But they can cause side effects including pain, constipation, nausea and vomiting.
Now, the US researchers have found evidence in both mice and humans that suppressing stomach acid changes specific gut bacteria in a way that can cause liver injury and worsen three times of chronic liver disease.
“Since we found previously that the gut microbiome — the communities of bacteria and other microbes living there — can influence liver disease risk, we wondered what effect gastric acid suppression might have on the progression of chronic liver disease,” Bernd Schnabel, the senior author of the study, said in a report published by the university.
“We found that the absence of gastric acid promotes growth of Enterococcus bacteria in the intestines and translocation to the liver, where they exacerbate inflammation and worsen chronic liver disease.”
The growth of the Enterococcus bacteria “promoted” liver inflammation and liver injury, which “progressed” three types of liver disease in mice – alcoholic liver disease, non-alcoholic fatty liver disease and steatohepatitis, which is a type of fatty liver disease.
PPIs are commonly prescribed to people with existing liver disease, as well as those with acid reflux and frequent heartburn. And liver disease is becoming more common due to the rise in obesity levels around the world. Acid reflux disease, meanwhile, is more common among older people, in part because of the gradual weakening of the lower oesophagael sphincter muscle due to ageing.
The university’s report said, however, that a controlled clinical trial would be needed to definitively show that PPI use raised the risk of chronic liver disease in humans.