Excessive alcohol consumption causes painful hangovers and accompanying headaches, fatigue, and nausea. Drinking alcohol has also been linked to a number of health problems in the human body, including heart disease, cirrhosis, and immune deficiency. One way to avoid those consequences would be to drink less, but researchers in China have introduced another way to mitigate hangovers and other adverse outcomes: a genetically modified probiotic.
In a paper published this week in Microbiology Spectrum, the researchers described their approach and reported that in experiments with mice, the treatment reduced alcohol absorption, prolonged alcohol tolerance, and shortened the animals’ recovery time after exposure to alcohol. alcohol. The probiotic has yet to be tested in humans, but the authors predicted that if it confers the same benefits, it could present a new way to reduce alcohol-induced health problems and liver problems in general.
Meng Dong, Ph.D, of the Institute of Zoology of the Chinese Academy of Sciences, who worked on the study, noted that clinical applications may extend beyond alcohol-related conditions. “We believe that genetically modified probiotics will provide new insights for the treatment of liver diseases,” she said.
The human body primarily uses forms of an enzyme called alcohol dehydrogenase, or ADH, to metabolize alcohol. But some variants are more effective than others: Some studies have found that a form called ADH1B, found primarily in East Asian and Polynesian populations, is 100 times more active than other variants. Previous studies in mice have shown that viral vectors engineered to express ADH1B can speed up the breakdown of alcohol, but that approach has not been shown to be safe in humans.
Motivated by those findings, Dong and his colleagues searched for a safer delivery method, focusing on the probiotic Lactococcus lactis, a bacterium often used in fermentation. They used molecular cloning to introduce the human ADH1B gene into a bacterial plasmid, which was then introduced into a strain of L. lactis. Laboratory tests confirmed that the probiotic secreted the enzyme. The researchers encapsulated the probiotic to make sure it would survive against stomach acid, then tested it on 3 groups of 5 mice, each exposed to different levels of alcohol.
Untreated mice showed signs of intoxication 20 minutes after alcohol exposure. When the mice were placed on their backs, for example, they couldn’t get back up. But in the group that received a probiotic that expressed human ADH1B, half of the mice were still able to roll over an hour after alcohol exposure. A quarter never lost their ability to turn around.
Further tests showed that 2 hours after exposure, blood alcohol levels in the control group continued to rise, while those in the probiotic-treated mice had begun to decline. In addition, the researchers found that the treated mice showed lower levels of lipids and triglycerides in their livers, suggesting that the probiotic could alleviate alcohol-related damage to that organ.
The next step, Dong said, is to investigate whether the potential therapeutic effect of the modified probiotic extends to humans. “We are excited about the improvement of recombinant probiotics in alcohol-induced acute liver and intestinal damage,” said Dong.