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Coffee is a brewed drink made from the fruit pits of the coffee tree (Coffea) native to parts of Africa.

Coffee is one of the most popular drinks throughout the world.

Globally coffee consumption amounts to more than 145 million bags of coffee each year. (The World Counts, n.d.)

Its main attraction is its ability to stimulate the brain and central nervous system.

Although coffee does have some beneficial effects, it can be consumed to excess by some people. This can cause some health issues such as anxiety, fatigue, and gastrointestinal effects such as diarrhea.

Every individual has their own tolerance level - some people can't even tolerate a sip, whereas others can consume a strong cup right before bed without adverse effects.


When you drink a cup of coffee, the caffeine is typically absorbed  within twenty minutes from your stomach and small intestine, usually (Heckman et al., 2010)

Caffeine is metabolized in the liver — much of it is broken down into compounds including paraxanthine, theobromine, and theophylline.

Caffeine's number one effect is on the brain. It inhibits the effects of the neurotransmitter adenosine by occupying its receptor sites. Typically, adenosine depresses the central nervous system and promotes sleep. (Mandal, 2019)

During the day, adenosine levels increase, making you more and more tired, and gradually ready to sleep.

By blocking adenosine, caffeine helps you stay awake by reducing tiredness. Drinking coffee can also further stimulate the brain by increasing blood levels of norepinephrine and dopamine, which boosts focus and alertness. (Ferre, 2008)

Gut Health Benefits of Coffee

In healthy individuals, coffee may have beneficial effects on gut health.

Coffee and constipation

Coffee can have a positive effect on the gut microbiome and the activity of the smooth muscle in the intestines. For example, coffee can help to relieve constipation.

In a 2005 study published in the Scandinavian Journal of Gastroenterology, sixteen healthy volunteers were given 280ml of strong coffee or warm water.

The results showed a 45% increase in rectal tone within 30 minutes in the subjects who had coffee, compared to a 30% increase in the subjects who had water. This means that drinking coffee may improve constipation more than drinking water alone. (Sloots et al., 2005)

Coffee and the gut microbiome

Coffee may also be beneficial for the gut microbiome by increasing the metabolism and growth of the bacteria Bifidobacterium spp. Bifidobacteria are one of the first microbes to populate the human gut.

They are believed to have several health benefits, including preventing certain gastrointestinal disorders, such as diarrhea as well as reducing the symptoms of inflammatory bowel disease and promoting colon regularity. (O'Callaghan et al., 2016)

In a 2009 study published in the International Journal of Food Microbiology, sixteen healthy volunteers were given a daily dose of three cups of coffee over three weeks. Fecal samples were examined before and after consumption of the coffee to assess the impact on intestinal bacteria.

Although bacterial profiles were not significantly affected immediately after consumption of coffee, after the three weeks, the subjects showed an increase in the metabolic activity and numbers of the population of Bifidobacterium spp. (Jaquet et al., 2009)

Coffee and the immune system

Drinking coffee may have a beneficial effect on the immune system by lowering levels of circulating inflammatory markers. An elevated level of inflammatory markers may indicate underlying conditions, such as autoimmune conditions, infections, and certain forms of cancer. (Watson et al., 2012)

Potential Risks and Problems

Sometimes, even among healthy people, drinking coffee can cause aggravation, such as stomach pain, acid reflux, and heartburn. (Wendl et al., 1994)

This is due to the natural acid content of coffee beans, which increase when they are roasted or brewed. Coffee may also loosen the lower esophageal sphincter (LES) muscles. (Lohsiriwat et al., 2006)

When functioning normally, these muscles seal the opening between the esophagus and the stomach. When they loosen, this can cause stomach acid to splash up into the esophagus, triggering heartburn and acid reflux. These effects can make drinking coffee a problem for people who suffer from Gastroesophageal reflux disease (GERD).

How to Make Coffee More Gut-friendly

For most healthy people, drinking coffee in moderation is not a problem. However, if you have some discomfort from drinking coffee, and you wish to minimize these issues, you can try taking the following steps.

Choose low-acid coffee varieties

Some varieties of coffee contain more natural acids than others. Types of coffee that have a lower acid content include Indonesian, Brazilian, Sumatran, Venezuelan, Peruvian, Mexican, and Guatemalan.

Try cold-brewed coffee

Cold brewing your coffee can reduce the natural acids by up to 65% because less acid is extracted during the brewing process. To cold brew your coffee, mix your coffee grounds with cold water and let it steep for 12-48 hours, stirring periodically. When the coffee has steeped, filter out the grounds and heat in the microwave.

Add sterilized eggshells to your coffee grounds

Eggshells are alkaline, which means that they can neutralize some of the natural acids found in coffee, reducing its bitter flavor and eliminating discomfort. All you have to do is break up one eggshell and add it to your coffee filter before brewing.

Drink half-decaffeinated coffee

Even if you are a caffeine junky, you can still benefit from drinking half-decaf coffee. It may help to reduce the unpleasant effects such as heartburn and acid reflux, while still offering health benefits. We recommend Swiss water decaffeinated coffee since this doesn't use chemicals to remove the caffeine.

Avoid sugar and artificial sweeteners

Although you may have a sweet tooth, sugar has the potential to promote the growth of bad gut bacteria. Once the balance of good vs. bad bacteria in your gut gets out of kilter, you’re at risk of a depressed immune system and a host of digestive issues.

Artificial sweeteners are just as problematic and can lead to bloating, diarrhea, and yeast overgrowth.

Skip the milk

If you prefer not to drink your coffee black, try it with non-dairy alternatives. This will ensure that the dairy is not the cause of your digestive discomfort. You can replace milk with other options such as flax, rice, almond, coconut, soy, hemp, or cashew milk.

If you are a healthy individual, drinking coffee in moderation can benefit your gut health. If you notice discomfort such as heartburn or acid reflux when you have a cup of joe, you should probably reduce your coffee intake, or try the steps above to reduce the acid content of your coffee.

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Research Citations

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