A new study by researchers at University of California San Diego School of Medicine revealed that some over-the-counter medications used to relieve symptoms of heartburn, acid reflux and gastroesophageal reflux disease (GERD) promotes the progression of three types of chronic liver disease.

The study, published in the journal Nature Communication, showed that Proton Pump Inhibitors (PPI) alter the composition of gut microbiome by encouraging the growth of a specific gut bacteria associated with increased risk of liver inflammation and liver injury.

Blocking gastric acids promote liver inflammation

Gastric acids are produced by the stomach to kill ingested microbes. However, these gastric acids in the stomach can regurgitate back up into the esophagus. People suffering from GERD may experience regurgitation, oftentimes accompanied by heartburn. One of the most common treatments for GERD is PPIs, a drug that blocks stomach acid secretions.

Bernd Schnabl, MD, an associate professor at UC San Diego School of Medicine and senior author of the study, noted that blocking the secretion of gastric acids can modify the composition of the gut microbiome. Previous studies already showed that any alterations in the communities of bacteria and microbes living in the guts could influence the risk of liver disease.

For the study, the researchers look into the effects of PPI on mouse models mimicking three common types of chronic liver disease: alcoholic liver disease; non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). The gastric acid production of each group was either blocked by genetic engineering or with a PPI.

The gut microbiome makeup of each mouse model was determined by sequencing microbe-specific genes obtained from the mice’s stool. Interestingly, the researchers observed that mice given with gastric acid blocker had more Enterococcus species of bacteria in their gut. The increased concentration of Enterococcus seems to promote liver inflammation and liver injury, leading to faster progression of liver disease.

PPI-intake could lead to liver cirrhosis

Alcoholic liver disease, NAFLD, and NASH can all lead to Liver Cirrhosis, a condition in which the liver slowly deteriorates and is unable to function. Considered to be the 12th leading cause of death in the United States, liver cirrhosis is responsible for over 38,000 deaths every year.

According to the Centers for Disease COntrol and Prevention, about 3.9 million American adults were diagnosed with liver disease. While the rising prevalence of obesity is mostly responsible for the increased cases of NAFLD, nearly half of deaths caused by liver cirrhosis are related to alcohol abuse.

The researchers noted that not only PPIs could increase the risk of liver cirrhosis, but also other antacids that suppress the production of gastric acids. Due to this, people should think twice before taking over-the-counter PPIs or antacids.