How Does Alcohol Affect Gut Health?

Alcohol is one of the most widely-consumed beverages in the world. Many of us drink at social gatherings, while celebrating major milestones, and even out of sheer boredom. Socially, we’re taught from a young age that alcohol is conducive to a good time, and that, in small amounts, it can even boost our health.

However, while drinking is a customary social behavior, alcohol can have a significant impact on our gut health. In this blog post, we'll explore the ways in which alcohol can harm our gut and provide tips on how we can improve our gut health as we reduce our intake or quit drinking.

The Gut Microbiome: A Complex Ecosystem

The gut microbiome is an intricate and complex ecosystem, home to trillions of microorganisms such as bacteria, viruses, and fungi. These microorganisms play a critical role in maintaining our gut’s health, regulating our immune system, and supporting our overall health and well-being.

In terms of our immune system, the gut microbiome helps distinguish between harmful and harmless bacteria, and it prevents harmful bacteria from entering the bloodstream. An imbalance in the gut microbiome can weaken the immune system, leading to chronic inflammation and autoimmune diseases.

The state of our microbiome has been linked to mental health, with research showing that changes in its composition can affect brain function and behavior. It’s also responsible for producing neurotransmitters such as serotonin, which plays a role in mood regulation. Gut microbiome imbalances have been linked to conditions such as depression, anxiety, and even autism.

Consuming alcohol can disrupt the balance of bacteria in the gut, leading to a decrease in beneficial bacteria and an increase in harmful ones. This imbalance can lead to gut dysbiosis, an unhealthy shift in the gut microbiome that can contribute to a range of health problems.

Dr. Aly Cohen, author of Non-Toxic: Guide to Living Healthy in a Chemical World and founder of The Smart Human health and wellness platform, is an integrative rheumatologist and environmental health expert. According to her, bacteria, mold, and viruses have not evolved to survive contact with alcohol. Drinking can kill good bacteria and disrupt our gut function, which leads to bloating. But bloating is a transient inconvenience — too much drinking can lead to more serious conditions, including small intestinal bacterial overgrowth, autoimmune diseases, or other chronic illnesses.

She stresses the importance of thinking of the gut not just as a tube but also as an immune organ.

The Gut Lining: A Barrier Against Toxins

The gut lining is a critical barrier separating the contents of our gut from the rest of our body. When the gut lining is compromised, toxins and harmful substances can leak into our bloodstream, leading to inflammation and a host of health problems.

Alcohol damages the gut lining, increasing its permeability and allowing harmful substances to leak through. This “leaky gut” often leads to chronic inflammation, which contributes to a range of gut health issues such as irritable bowel syndrome (IBS), celiac disease, and inflammatory bowel disease (IBD). Emerging research has even shown that intestinal permeability is associated with issues outside of the gut, including mood disorders, acne, and arthritis.

To figure out what’s going on, we turned to Dr. Bidhan Das, assistant professor of colorectal surgery with McGovern Medical School at UTHealth Houston. Dr. Das says, “Stomach acid production can be impacted by alcohol. This could decrease the stomach's capacity to eliminate bacteria upon entry, which might permit potentially hazardous bacteria to penetrate the upper small intestine.”

He goes on to explain that the stomach lining contains mucous cells that protect the stomach wall from being harmed from digestive enzymes and acid. “Even just one very excessive drinking session might cause inflammation and lesions in the stomach's mucous cells.”

Finally, Dr. Das shares that based on the latest evidence, compared to non-drinkers or occasional drinkers, those who drink moderately (up to 4 drinks a day) have a 21% increased risk of colorectal cancer. Those who drink heavily (more than 4 drinks a day) have a 52% increased risk of colorectal cancer.

Nutrient Absorption: A Key Function of the Gut

Our gut is responsible for absorbing essential nutrients, such as vitamins and minerals, from the food we eat. However, alcohol can interfere with the absorption of these nutrients, which contributes to nutrient deficiencies seen in heavy drinkers.

Alcohol damages the lining of our gut, as discussed above, making it difficult for our body to absorb nutrients properly. This can lead to deficiencies in key nutrients such as B vitamins, which can impact our overall health and well-being.

Here are a few of the most common nutrient deficiencies that result from prolonged alcohol use:


1. Vitamin B1 (thiamine) deficiency. Commonly referred to as thiamine, vitamin B1 plays a central role in our overall health. It’s primarily responsible for converting the nutrients from the foods we eat into energy, fueling the body's numerous cellular activities. More importantly, it's vital for the nervous system's proper functioning, ensuring that nerve signals are transmitted efficiently and effectively. Chronic alcohol consumption has been proven to interfere with thiamine's absorption and utility in the body. This interference can manifest in several ways, including memory loss, muscle weakness, and fatigue.

2. Folate (vitamin B9) deficiency. Folate, or vitamin B9, is crucial for the body's cellular functions, especially DNA synthesis and cell division. This vitamin is instrumental during periods of rapid growth, such as pregnancy and infancy. Alcohol, which interferes with the body's absorption mechanisms, poses a threat to our folate levels. A deficiency in folate can lead to severe consequences, including anemia and fatigue, and in pregnancy, it can lead to birth defects.

3. Vitamin B6 deficiency. Similar to other B vitamins, B6 is a powerhouse essential for a plethora of metabolic processes, particularly protein metabolism. Moreover, it plays a pivotal role in neurotransmitter synthesis, ensuring the nervous system functions seamlessly. However, consuming alcohol can inhibit our body's ability to utilize and absorb this vitamin — resulting in confusion, mood changes, and weakened immune function.

4. Vitamin D deficiency. Vitamin D, the "sunshine vitamin," is paramount for maintaining bone health and bolstering immune function. Its primary role is to facilitate the absorption of calcium, ensuring that our bones remain strong and resilient. Alcohol's disruptive influence affects the liver and kidneys, organs vital for vitamin D conversion into its active form. A vitamin D deficiency paves the way for bone disorders like osteoporosis and a compromised immune system, making individuals more susceptible to infections.

5. Magnesium deficiency. Magnesium, an often-overlooked mineral, plays a role in over 300 enzyme reactions within the body, from muscle and nerve regulation to the synthesis of proteins. Alcohol has a diuretic effect, leading to increased excretion of essential nutrients like magnesium. A sustained deficiency can result in symptoms such as muscle cramps, irregular heartbeat, and even mental disorders.

6. Zinc deficiency. Zinc, a trace element, is responsible for myriad physiological functions, from wound healing to DNA synthesis, and most notably, immune system operations. Alcohol's consumption can hinder the body's ability to absorb and use zinc effectively. A deficiency in zinc doesn't just compromise immunity: it also affects skin health, leading to brittle skin and nails, hair loss, and a decreased ability to taste or smell.

Gut Motility: A Critical Factor in Digestion

Gut motility refers to the rate at which food moves through our digestive system. Most of us rarely think of our food moving through the digestive tract when we eat because this process is involuntary (we don’t have to give it any thought at all!). However, we may notice impaired gut motility when we have symptoms like constipation, bloating, and abdominal pain.

Alcohol is known to slow gut motility, leading to digestive problems and changes in bowel movements. This can make it more difficult for our body to remove waste, which may contribute to gut health issues over time.

According to Dr. Das, “High alcohol content beverages (more than 15% alcohol volume) can delay stomach emptying, which can result in bacterial degradation of the food, and cause abdominal discomfort.”

Tips for Maintaining a Healthy Gut

Alcohol can undoubtedly have negative impacts on gut health, and on our overall well-being. We seldom think of the gut as the key to our immune system, but prioritizing gut health and developing a healthier relationship with alcohol allow us to feel and function at our best.

If you’ve consumed alcohol to excess in the past, there’s good news — we promise! It’s possible to undo the negative effects of alcohol on the gut and heal your gut lining. Here are some tips to help you keep your gut healthy.

Stay Hydrated

Our bodies, which are approximately 60% water, heavily depend on adequate hydration for cellular function, temperature regulation, digestion, and, as mentioned above, detoxification. Toxins and waste products are more efficiently removed from our system when we are well-hydrated. This ensures a smoother metabolic process and aids in mitigating inflammation, especially in the gut.

Dr. Cohen highlights the importance of consuming filtered water as much as possible, as chemicals (like plastics) can make their way into tap water. Such contaminants not only disturb our bodily functions but also hamper the delicate balance of our gut flora. Filtered water offers a solution by providing a cleaner, safer source of hydration, devoid of many of these potential hazards.

Eat a Healthy Diet

A diet rich in whole foods (fruits, vegetables, and whole grains) can help support a healthy gut microbiome and gut lining. These foods provide essential nutrients, fiber, and antioxidants, which collectively support a flourishing microbiome and a robust gut lining. By prioritizing whole foods, we also avoid many of the food additives found in processed and pre-packaged foods. These additives, as Dr. Cohen suggests, may disrupt the gut's natural environment and potentially damage its lining. This, in turn, could pave the way for various digestive disorders and systemic health issues.

Focus on Prebiotics and Probiotics

Dr. Shoshana Ungerleider, board certified internal medicine physician in primary care and host of the TED Health Podcast, discussed the importance of probiotics and prebiotics for gut health. “Taking probiotic supplements or consuming foods high in probiotics, such as yogurt, kefir, or kimchi, can help restore the balance of healthy gut bacteria,” she says. “Prebiotic foods, such as garlic, onions, and asparagus, can also feed beneficial gut bacteria.”

Furthermore, Dr. Das wants our readers to know that “all parts of the body can heal naturally.” Using probiotics (after consulting with your physician) can “repopulate the ‘good’ bacteria and change the balance of the microbiome in such a way that your gut lining has a better support system, which, in turn, will support your overall immunity.”

Avoid Irritants

“Avoiding foods that irritate the gut lining, such as spicy or acidic foods, can help promote healing,” says Dr. Ungerleider. “Similarly, avoiding alcohol, smoking, and nonsteroidal anti-inflammatory drugs (NSAIDs) can also reduce inflammation and promote gut health.”

Alcohol can erode the mucosal layer of the gut, potentially leading to ulcers. Smoking has a myriad of toxins that adversely impact gut health. NSAIDs, commonly used for pain management, can sometimes cause gastric irritation or even bleeding. By minimizing or eliminating these irritants, the gut has a fighting chance to reduce inflammation and initiate a healing process.

Manage Stress

We’re all stressed out these days, and unfortunately, this stress can wreak havoc on our gut if not properly managed. According to Dr. Cohen, stress changes the acidity and alkalinity of the gut, which can throw off the balance of good and bad bacteria.

To counteract this, relaxation activities such as meditation, deep breathing exercises, and even hobbies can prove invaluable. Regular physical activity also plays a dual role: it not only helps manage stress but it can stimulate gut motility, aiding digestion and preventing constipation.

Get Enough Sleep

“Sleep is essential for gut health, as it allows the body to repair and regenerate the gut lining,” Dr. Ungerleider says. Each of us should aim for 7-9 hours of sleep each night to heal the gut lining and keep it in good shape.

During these hours of rest, the body focuses on repair and regeneration, and the gut lining is a prime focus. The cells rejuvenate, the mucosal barrier strengthens, and any potential damage — alcohol-related or otherwise — starts its healing process.

Take a Break

Taking a break from alcohol, even if we’re not ready to go sober, can give the gut a chance to heal and recover. Consider easing off alcohol for a few weeks or months to help support gut health. Reframe’s challenges — like Dry January, Sober Spring, or 1,000 Hours Dry — are an excellent way to do so with the support of the Reframe community. You’ll find effective, science-backed coping mechanisms and discover ways to enjoy life beyond alcohol.