ABSTRACTAlcohol is an essential drug in human life with multiple medical functions, but excessive alcohol intake, even a single episode of binge drinking, can cause serious damage. Reducing alcohol consumption or absorption is a direct way to alleviate the related harm. Alcohol is decomposed successively by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in the liver. Here, we produced a human ADH1B (hADH1B)-expressing probiotic, a recombinantLactococcus lactis, that aimed to enhance alcohol degradation in the intestinal tract after oral administration. Our results showed that the oral hADH1B-expressing probiotic reduced alcohol absorption, prolonged the alcohol tolerance time, and shortened the recovery time after acute alcohol challenge. More importantly, the liver and intestine were protected from acute injury caused by alcohol challenge. Therefore, the engineered probiotic has the potential to protect organ damage from alcohol consumption. Furthermore, this engineered probiotic may have beneficial effects on alcohol-related diseases such as alcoholic fatty liver disease.IMPORTANCEAlcohol plays an important role in medical treatment, culture, and social interaction. However, excessive alcohol consumption or improper alcohol intake patterns can lead to serious damage to health. Aiming to reduce the harm of alcohol consumption, we designed a recombinant probiotic expressing hADH1B. Our results showed that this recombinant probiotic can reduce alcohol absorption and protect the body from alcohol damage, including hangover, liver, and intestinal damage. Reducing alcohol damage is helpful to the health of people with difficulty in abstinence. The engineered probiotic may provide new strategies for treatment and prevention of the negative effects of alcohol, and it also has the potential for widespread application.