It happens to most people at one time or other – they eat too much or indulge in too much alcohol and don’t feel well the next day. If they drank too much alcohol, they may be hung over with a headache, an upset tummy and fatigue that make it hard to crawl out of bed. Not a pleasant scenario, especially if they have to be somewhere the next day. Interestingly, bacteria that live in the gut may impact how quickly a person recovers from “tipping the bottle” too much. Here’s why. There are a number of reasons people feel bad after over-imbibing alcohol. For one, alcohol is a diuretic that increases urination, leading to dehydration. Plus, overindulging can lead to fluctuations in electrolytes like sodium, potassium and chloride and blood sugar level that contribute to fatigue, nausea and headache. In addition, most people don’t sleep well after an evening of drinking so they don’t awaken feeling refreshed. Inside the body, alcohol is metabolized into various products that may play a role in the unpleasant symptoms of a hangover. Initially, it’s broken down into acetaldehyde and then to acetate. Acetate is completely non-toxic. It’s the intermediate product acetaldehyde that triggers many of the symptoms associated with a hangover. Plus, not everyone breaks down alcohol to acetate quickly. If they’re a “slow metabolizer,” acetaldehyde can hang around longer leading to a more severe hangover. Alcohol also irritates the lining of the stomach, increasing acid production. This can lead to inflammation of the stomach lining, a condition known as gastritis. Alcohol also appears to harm the gut in another way. A study showed that it alters gut bacteria in a way that could increase the risk for alcohol-related problems. This study showed that alcoholics have lower levels of three types of gut bacteria – bifidobacteria , lactobacilli and enterococci compared to controls – but after supplementing with probiotics for five days, their levels of bifidobacteria and lactobacilli went up. What’s more interesting is their liver enzymes decreased after being mildly elevated prior to supplementing with probiotics. Elevated liver enzymes in a drinker are usually a sign of liver inflammation from alcohol exposure. The fact that their liver enzymes dropped after the probiotics likely means there was some improvement in liver inflammation in these subjects after supplementing their gut flora with beneficial bacteria. It appears that alcohol has the unwanted effect of upsetting the delicate balance of the digestive tract and the bacterial residents that live there. This may be why the symptoms of a hangover stick around even after the alcohol has been metabolized and blood alcohol level returns to zero. A healthy, balanced gut may have the capacity to better deal with overindulgences, whether it’s food or alcohol. The key is to achieve and maintain a healthy gut balance. A number of factors can rob the gut of healthy bacteria including too much alcohol, a diet rich in processed foods, certain medical conditions and some medications, especially antibiotics. The other way is to replenish the gut bacteria that these factors alter, essentially “fill in” with the right bacteria. Doing so could help people who overindulge feel better faster.  Of course, the best way to prevent a hangover is not to drink too much but it’s always good to have a back-up plan.