How alcohol affects bacteria in the mouth

You may be wondering whether alcohol-based mouthwash is better than normal mouthwash? Or how drinking alcohol is affecting your oral health. Well, you’ve come to the right place! In this article we discuss the effect of alcohol on your oral health, and the oral microbiome.


Oral health is an important aspect of a person's overall well-being. Decades of research has now shown important associations between oral diseases like gum disease and cavities with increased risk of overall disease, such as cardiovascular disease, diabetes, arthritis, and even Alzheimer’s disease. Unfortunately, these associations have also come with the misconception that killing all oral bacteria is the way to prevent disease. The truth is that alcohol can cause significant harm to your oral and overall health, for multiple reasons that we cover below.

Alcohol and hydration

Saliva is a key component of oral health. You produce almost 1 liter of saliva per day! This saliva keeps your teeth coated in antimicrobial peptides and antibodies that keep them healthy, and protect your gums by reducing the load of harmful bacteria. Saliva is critical to your

Ever had a night of drinking and wake up with extremely dry mouth? That’s the alcohol causing dehydration. Alcohol is a diuretic, which means it causes your body to remove fluid throughout your organs, leading to dehydration. Saliva is composed of 99% water! Dehydration significantly reduces the amount of saliva you make, and impacts your mouth.

Alcohol and the oral microbiome

Alcohol can also harm your dental health by destroying good bacteria in your mouth, leaving your teeth and gums vulnerable to infection and disease. Alcohol is a potent antibacterial agent that will almost certainly kill any bacteria it comes into contact with. Unfortunately, this also means that it will kill the bacteria that fight against other bacteria.

Our mouths are full of good bacteria that help keep us healthy, these bacteria are part of a community of microbes known as the oral microbiome. These bacteria protect not only our mouths, but also the rest of our body! The healthy bacteria counteract the bad bacteria that can cause disease. The oral microbiome can easily become imbalanced, which can lead to oral disease and overall disease.

One research study found that self-reported moderate or heavy drinkers had different oral microbiome compositions than people who rarely drank or did not drink at all. The people who reported drinking more often had reduced levels of healthy bacteria compared to people who drank less. Additionally, a study of over 39,000 people found that alcohol drinking frequency was associated with increased risk of periodontal disease. Increased levels of harmful bacteria can also increase your risk of systemic diseases like heart disease and some cancers.

Does alcohol kill bacteria in the mouth?

Yes, alcohol affects the bacteria in your mouth, but getting rid of these bacteria is not always a good thing. Drinking can significantly alter the microbiome towards dysbiosis.

If I drink alcohol, what can I do to repair my microbiome?

  1. Drink plenty of water after drinking alcohol. Hydration can help counteract some of the dehydrating effects of alcohol.
  2. Chew xylitol gum. Chewing gum and eating lozenges can increase salivation. Saliva is an important component of preventing oral disease.
  3. Use dental probiotics to replenish beneficial bacteria. You can read more about our research on dental probiotics and how you can best use them to improve oral health.
  4. Keep to an oral hygiene routine.


In summary, yes. Alcohol can kill the majority of bacteria in the mouth, but this is usually a bad thing as you need beneficial bacteria to keep you healthy.

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