Genetically engineered probiotics could help speed up alcohol recovery, study suggests

13 Apr 2023 --- Chinese researchers have developed a probiotic that reduces alcohol absorption, prolongs alcohol tolerance and shortens recovery time after alcohol exposure in mice. The authors note that the engineered probiotic can protect organ damage from alcohol consumption, but it needs to be verified whether it works on humans.

Alcohol is metabolized to acetaldehyde by alcohol dehydrogenase (ADH) and converted to carbon dioxide and water in the liver, catalyzed by acetaldehyde dehydrogenase (ALDH). 

The researchers produced a human ADH1B-expressing probiotic, an ADH enzyme more active than other variants. They used the food-grade probiotic Lactococcus lactis – a bacterium used in the dairy industry – and altered it to express the ADH1B enzyme, aiming to enhance alcohol degradation in the intestines after consumption. 

“Our study highlights that mice treated with the genetically engineered probiotic to express ADH1B recovered from alcohol exposure faster than untreated mice without health problems,” author Meng Dong, Ph.D. at the Chinese Academy of Science’s Institute of Zoology, tells NutritionInsight. 

The researchers genetically engineered the probiotic L. lactis to express the ADH1B enzyme in enhancing alcohol degradation.“As a drug delivery system, Lactococcus lactis has great potential to deliver therapeutic proteins or peptides to combat diseases, especially gastrointestinal-related diseases.” 

Health benefits of probiotics 
Dong believes genetically engineered probiotics will provide new ideas for treating liver diseases and that clinical applications may extend beyond alcohol-related conditions. 

“In our opinion, live biotherapeutic products based on probiotics are of great application value, which can carry a variety of active proteins or peptides to treat multiple diseases.” 

“We have already investigated the role of genetically engineered probiotics that express TGFBR2 extracellular domain, GLP-1, in the treatment of liver fibrosis and diabetes,” she continues. 

“Currently, we are actively investigating the role of engineered probiotics expressing factors related to the immune surveillance in cancer.” 

Scientists from the University of California recently revealed how chronic use of alcohol may adversely affect the gut microbiome, which changes by the release of acetates by the liver. 

Consumers across the globe are also keen to learn more about probiotics, driven by demands for gut health, feeling better and immunity support.

Set up of the study 
With molecular cloning, the research team introduced the gene for human ADH1B into a bacterial plasmid introduced into a strain of L. lactis. Lab tests confirmed that the probiotic secreted the enzyme. 

Next, the team encapsulated the probiotic and tested it on three groups of five mice, exposing each group to different levels of alcohol. 

Two hours after alcohol exposure, blood alcohol levels in mice treated with the probiotic dropped, while in the control group, these continued to rise.The article, published in Microbiology Spectrum, showed that mice untreated with the probiotic showed signs of drunkenness within 20 minutes of alcohol exposure. The researchers tested this with a “righting reflex,” determining if mice could get back on their feet after placing them on their backs. 

Half of the mice in the group that received the engineered probiotic were able to right themselves an hour after alcohol exposure, while a quarter never lost this reflex. Moreover, alcohol recovery time also decreased in this group.

Two hours after alcohol exposure, blood alcohol levels in the control group continued to rise, while those in the probiotic-treated mice began to fall. The researchers found that treated mice also showed lower levels of lipids and triglycerides in their livers, suggesting that the probiotic could alleviate alcohol-related damage to that organ. 

Commercial applications 
The researchers note that the resulting probiotics are safe and easy to use, have a mature industrial production system and have low production costs. 

Dong highlights that the researchers are keen to work with the pharmaceutical industry to see their product “become a commercial product to treat alcohol-related diseases, such as alcoholism and alcoholic fatty liver.” 

UK-based research previously flagged that alcohol consumption is a risk factor for cardiovascular disease, regardless of quantity. 

“The strength of this research is that it presents a convenient and safe way to replenish active enzymes,” adds Dong. However, “the major limitation is that the expression of recombinant ADH1B is not high enough. Therefore it is still needed to optimize the level of ADH1B.”

The next step, Dong concludes, 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 the acute alcohol-induced liver and intestinal damage.” 

By Jolanda van Hal