Does alcohol affect your gut health?

Your gut is a complex machine that's fundamental to your health and wellbeing. And when it comes to taking care of it, managing your relationship with alcohol can play an important role.

But what, exactly, is the connection between gut health and alcohol?

"Excess alcohol can have a negative impact on our gut as a whole," says Dr Emily Porter, Bupa Gut Specialist Dietitian at the UK-based The Gut Health Clinic.

Your gut is colonised by trillions of tiny microorganisms (including bacteria, viruses and fungi), known collectively as the gut microbiome, or stomach flora. It helps with things like digesting food, supporting your immune health and even processing alcohol.

"Excess alcohol can have a negative impact on the delicate balance of the gut microbiome," says Dr Porter.

When you drink, your gut microbiome helps you metabolise the alcohol. And when you consume too much of it, this ecosystem can shift towards more unhappy gut bacteria and less beneficial bacteria.

"Alcohol tends to be absorbed higher up in the gut, where it can impact the beneficial gut bacteria," Dr Porter warns.

"When we look at alcohol consumption, we start to see an increase in those less-helpful bacteria, an increase in inflammatory compounds, and impaired immune responses as alcohol intake increases."

And when your gut microbiome is out of balance, it can present several potential gastrointestinal symptoms. According to Dr Porter, gut-related symptoms from consuming too much alcohol can include:

• diarrhoea
• constipation
• gut bloating
• acid reflux or heartburn
• an unsettled stomach.

Signs that you might be overconsuming alcohol can present outside the gut, too.

"Because the gut has so many links to other, wider areas of health, people might notice changes in mood, energy, skin or nails," Dr Porter adds.

Alcohol can also affect how your gut muscles move, so people with existing gut issues (such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD)) may experience worse reactions when consuming too much.

"Food can move through the gut more quickly and worsen symptoms like diarrhoea," says Dr Porter.

The relationship between alcohol and gut health can impact you in a number of longer-term ways.

You may have heard of 'leaky gut syndrome', a theory that proposes a 'leaky' stomach lining can cause various diseases or conditions. While leaky gut itself is not a recognised medical condition, intestinal permeability is.

This occurs when the lining of your stomach is damaged, allowing bacteria or toxins to 'leak' into your bloodstream.¹

The gut is naturally semi-permeable, but inflammation, irritation or certain diseases may worsen it.

As well as reducing your alcohol intake, Dr Porter says that your gut lining can be improved with a healthy, gut-friendly diet that is rich in plant-based fibre.

This largely comes down to small molecules called metabolites, such as short chain fatty acids, that are produced by gut bacteria.

"[They] protect the gut lining, keeping the junctions between the cells of the gut lining healthy, preventing any leakiness," she says.

Gastritis occurs when the lining of your stomach becomes inflamed, leading to symptoms such as tummy pain, nausea and indigestion. This can occur for a number of reasons, including certain medications (like aspirin), infections, stress or excess alcohol consumption.²

"If someone has existing gastritis, alcohol can also exacerbate and irritate this," Dr Porter adds. "People will often notice more abdominal pain, heartburn or reflux if they're having alcohol."

According to Dr Porter, certain compounds that are produced in the gut travel to the liver, and those produced in the liver can travel back to the gut. This two-way relationship is known as the gut-liver axis.

And, Dr Porter claims, "that bi-directional communication is impaired with alcohol".

As well as physical symptoms, there is a link between gut health and mental health. This is underpinned by the gut-brain axis.

"The gut-brain axis is another bi-directional axis that involves cross-talk between the gut and the brain," says Dr Porter.

Dr Porter says that, while everyone responds to alcohol differently, a lot of her patients have reported improvements in their mental health when they cut back (or cut out) alcohol.

"Often, cutting down on alcohol leads to a reduction in anxiety levels and better sleep, both of which help improve gut symptoms, especially if you have a sensitive gut," she says, "as well as improving overall gut health through lowering psychological stress."

In fact, one Melbourne-based study that looked into the diets of people with moderate-to-severe depression found that those who focus on improving their nutrition (such as following a gut-friendly Mediterranean diet) alongside other treatment strategies are more likely to achieve remission from their depression than those who don't.³

According to Dr Porter, alcohol's effect on the gut typically comes down to the amount and concentration of alcohol that you consume. For most people, though, the occasional drink isn't going to harm their gut.

When it comes to maintaining a healthy gut while drinking, it's important to drink in moderation. Australian guidelines for safe alcohol consumption recommend that healthy adults consume no more than:

• 10 standard drinks a week
• 4 drinks in any one day.⁴

It can also help to think about the type of alcohol you're consuming.

"Red wine is high in polyphenols, high in antioxidants," Dr Porter says. So, there may be a small health benefit compared to alternatives.

For mixed drinks, this also means considering the other non-alcoholic ingredients. For instance, while artificial sweeteners may be better for your waistline, they're not ideal when it comes to gut health and alcohol.

One study found that consuming alcohol with diet mixers leads to a higher breath alcohol concentration than drinking it with a regularly sweetened one.⁵

"Sugar slows down how quickly the body is absorbing that alcohol," says Dr Porter.

According to Dr Porter, it's possible to avoid the negative effects of alcohol on your gut (and improve your overall gut health) with a few diet and lifestyle changes.

"We can restore good gut health," she says. "But it tends to be a marathon, not a sprint."

Here are Dr Porter's top 5 tips:

Of course, one of the best ways to avoid the negative effects drinking has on your gut is to reduce your alcohol intake.

If you're struggling to follow the recommended guidelines, Dr Porter recommends tricks like swapping in non-alcoholic alternatives between alcoholic ones.

"That could be sparkling water with frozen berries. Or it might be a fermented tea drink such as kombucha."

When it comes to maintaining a healthy gut, it's important to make sure you're consuming gut-friendly nutrients.

Like any living thing, your gut microbiome needs fuel to survive and thrive. Here, it's important to include a mix of probiotic and prebiotic foods.

Fermented foods contain live cultures that add good gut bacteria in your gut microbiome. These include things like fermented sauerkraut, kimchi, live yoghurt, kombucha and kefir.

Prebiotics provide fuel for the microorganisms in your gut. Here, Dr Porter recommends adding in prebiotic plant-based fibres like onions, leeks, legumes, oats, bananas, asparagus, apples, flaxseeds and avocado.

"Our gut bugs use fibre for fuel, and each type of bacteria tends to like a different type of fibre."

"Having a higher fibre diet can [also] be helpful in managing conditions like depression and anxiety as well as improving digestion."

When it comes to maintaining a healthy gut, diversity is key.

"Instead of using one type of bean, swap to mixed beans," Dr Porter recommends. "Instead of using one type of berry, swap to mixed berries."

"Both of these are easy ways to increase the variety of plant foods in your diet without making any major dietary changes."

If you know that you'll be drinking alcohol, it can help to consume gut-friendly food during the meal before, and even again while you're drinking.

"Food slows down the absorption of alcohol and gives the liver time to catch up in terms of metabolising," Dr Porter says.

Like any engine, your gut needs a lot of care in order to properly function. As well as diet, it will also benefit from lifestyle factors like exercise, stress management and sleep.

"Think about managing stress levels, think about managing sleep, think about staying nice and active," says Dr Porter. "These are really important for improving gut health."