Does Alcohol Affect Gut Bacteria?

Understanding the gut is a complex phenomenon and even with all our advancements in science, we are still learning about the best way to care for it. 

Alcohol is known to be detrimental to our health and wellbeing.6 It is a toxin that, in large amounts, may overwhelm the liver and lead to damage within the gastrointestinal tract (GI) – also known as our gut microbiome.1 

There has been an increase in alcohol consumption over the COVID-19 pandemic, particularly in drinking at home. As a result, people may be drinking far more standard drinks of alcohol per week than they realise. 

So how does alcohol affect our gut bacteria? Are there some types of alcohol that can actually help?

Below, we’ll discuss the relationship between alcohol and gut health, and how you can keep your gut flora happy and healthy.

Alcohol Metabolism and Leaky Gut

Normally, our GI tract is naturally permeable to allow nutrients and minerals to pass through the intestinal lining and into your bloodstream. This also acts as a protective barrier to keep toxins out of your blood and maintain your immune health.9 

Alcohol has been found to weaken this barrier, by damaging the cells that line the intestinal walls leading to a chronic state of intestinal inflammation.8 

This can lead to a condition known as leaky gut syndrome.3  This allows toxins, bacteria, and even food particles to flow out of the GI tract and into the bloodstream.2 

A leaky gut can increase and lead to multiple other health conditions—including diabetes, autoimmune disease, arthritis, allergies, ‘brain fog’, weakened immunity and mental health problems.3 

Having a leaky gut, therefore, affects our gut bacteria by not allowing them to function efficiently and assimilate nutrients on a day-to-day basis. 

Does Alcohol Kill Our Gut Bacteria? 

Alcohol can also kill some types of bacteria and is often used as a disinfectant in domestic products like hand sanitiser and mouthwash.

This can be positive and practical in the modern world. For example, moderate alcohol consumption can help kill bacteria, like salmonella5, which causes food poisoning. However, chronic, heavy alcohol use can also kill the good bacteria your body requires to function well with its effect on stomach acidity and overall digestion. 

Alcohol, Stomach Acidity, and Bacterial Overgrowth 

Our gut contains more than 500 types of good and bad bacteria.4  A healthy gut achieves homeostasis or equilibrium when the good bacteria and bad bacteria balance each other out and work in harmony.4 

Alcohol consumption can increase the number of bad intestinal bacteria or dysbiosis.4  Specifically, alcohol can alter bile-acid metabolism, and, in turn, bile acids can affect intestinal bacteria.8  

Our gut needs to maintain good stomach acidity to digest and assimilate nutrients. If our gut has lower bile acid, this can increase an overgrowth of harmful bacteria due to its effect on our digestion and breakdown of foods, leading to fermentation.

This can increase our risk of poor mental and physical health and lead to a host of symptoms such as bloating Increased fatigue and lack of energy, fluctuations in weight, food allergies and intolerances, skin problems, difficulty regulating emotions, brain fog and more.2 

What is the Best Alcohol for Your Gut? 

Drinking excessively is detrimental to our gut health no matter what type we choose. But there are some types of alcohol that may have protective properties for both our gut bacteria and overall wellbeing.

Red wine is rich in polyphenols—certain antioxidants which may increase good gut bacteria6, and reduce inflammation. These polyphenols may also improve the gut-liver axis that keeps alcohol metabolisation functioning well.8 

Research suggests that just one serving every week or two is enough to benefit your gut. You can also get these polyphenols from different fruits (grapes, strawberries raspberries.8 


In summary, like anything that we consume, alcohol does affect our gut bacteria in certain ways.  If you are a social drinker who rarely has more than a glass or two, alcohol is unlikely to damage your gut and may offer health benefits. 

However, chronic, excessive drinking can damage the lining of our gut, reduce the numbers of beneficial bacteria, reduce our stomach acid, and significantly increase our risk of chronic disease.5,6,7,8 

Our Top Tips for Gut-friendly Alcohol Consumption: 

  1. Hydration is key!  Make sure that you drink enough water before reaching for the alcoholic drink. 
  2. Make sure you aren’t drinking on an empty stomach to avoid an overly acidic gut. Ideally have a balanced meal beforehand.
  3. Kombucha is a great alcohol-free alternative that does wonders for your gut health. It is a fizzy, fermented tea with added healthy gut bacteria. 
  4. Be mindful of your food choices the day after drinking. Choose whole foods that will nourish your gut bacteria and try to avoid the temptation to eat unhealthy meals.
  5. Taking regular probiotics will help to ease the side effects of alcohol. 
  6. Try to consume a variety of different alcohols to improve the diversity of your gut bacteria.

Handpicked content: Why Am I Always Bloated?



    1. Bishehsari, F., Magno, E., Swanson, G., Desai, V., Voigt, R. M., Forsyth, C. B., & Keshavarzian, A. (2017). Alcohol and Gut-Derived Inflammation. Alcohol research : current reviews, 38(2), 163–171.
    2. Bishehsari, F., Magno, E., Swanson, G., Desai, V., Voigt, R. M., Forsyth, C. B., & Keshavarzian, A. (2017). Alcohol and Gut-Derived Inflammation. Alcohol research : current reviews, 38(2), 163–171.
    3. Engen, P. A., Green, S. J., Voigt, R. M., Forsyth, C. B., & Keshavarzian, A. (2015). The Gastrointestinal Microbiome: Alcohol Effects on the Composition of Intestinal Microbiota. Alcohol research : current reviews, 37(2), 223–236.
    4. M C C, C., N L, L., C M, F., J L, G., D, A., C, G., G, C., S H, P., C, M., F S, M., J R, N., M M, T., A L B, G., & A T, V. (2014). Comparing the effects of acute alcohol consumption in germ-free and conventional mice: the role of the gut microbiota. BMC microbiology, 14, 240.
    5. Pandey KB, et al. (2009). Plant polyphenols as dietary antioxidants in human health and disease. DOI:10.4161/oxim.2.5.9498
    6. Patel, R., & DuPont, H. L. (2015). New approaches for bacteriotherapy: prebiotics, new-generation probiotics, and synbiotics. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 60 Suppl 2(Suppl 2), S108–S121.
    7. Rowe, Peter C et al. “Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Diagnosis and Management in Young People: A Primer.” Frontiers in pediatrics vol. 5 121. 19 Jun. 2017, doi:10.3389/fped.2017.00121
    8. Szabo G, Lippai D. Converging actions of alcohol on liver and brain immune signaling. International Review of Neurobiology. 2014;118:359–380. [PubMed] [Google Scholar]
    9. Vancamelbeke, M., & Vermeire, S. (2017). The intestinal barrier: a fundamental role in health and disease. Expert review of gastroenterology & hepatology, 11(9), 821–834.
    10. Bishehsari, F., Magno, E., Swanson, G., Desai, V., Voigt, R. M., Forsyth, C. B., & Keshavarzian, A. (2017). Alcohol and Gut-Derived Inflammation. Alcohol research : current reviews, 38(2), 163–171. 



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