Alcohol allows bacteria to infiltrate into liver

Alcohol allows gut bacteria to migrate to the liver, promoting alcohol-induced liver diseases, reveals a new study.

According to the researchers, natural gut antibiotics are diminished by alcohol and leave mice more prone to bacterial growth in the liver, exacerbating alcohol-induced liver disease.

"Alcohol appears to impair the body's ability to keep microbes in check," said senior author Bernd Schnabl from University of California, San Diego School of Medicine in the US. 

"When those barriers breakdown, bacteria that don't normally colonise the liver end up there, and now we've found that this bacterial migration promotes alcohol liver disease. Strategies to restore the body's defenses might help us treat the disease," Schnabl added.

The study was published in Cell Host & Microbe.

REG3G deficiency promotes progression of alcohol-induced liver disease. 

For the study, mice engineered to lack REG3G and fed alcohol for eight weeks were more susceptible to bacterial migration from the gut to the liver than normal mice who received the same amount of alcohol, the researchers discovered.

REG3G-deficient mice also developed more severe alcoholic liver disease than normal mice.

To find methods for stemming the tide of liver-damaging microbes, researchers tried experimentally bumping up copies of the REG3G gene in intestinal lining cells grown in the lab. 

They found that more REG3G reduced bacterial growth. likewise, restoring REG3G in mice protected them from alcohol-induced fatty liver disease, a condition that precedes liver cirrhosis, or end-stage liver disease.

Not only do patients with alcohol dependency have lower levels of REG3G than healthy people, they also have more bacteria growing there, the study found.