What drinking coffee every morning does to your gut health
A 2023 study published in the journal Nutrients investigated the association between caffeine, coffee consumption and the colonic microbiome. Results showed the richness of the microbiome to be higher with regular coffee drinkers, who had increased numbers of the helpful Alistipes and Faecalibacterium types (thought to have preventive effects against liver fibrosis and cardiovascular illness), and lower levels of the harmful Erysipelatoclostridium, which causes gut problems. This follows an earlier study where coffee consumption was found to be associated with an increase in bifidobacterium, microbes thought to help with the digestion of fibre and prevent infections.
Coffee also contains plant compounds called polyphenols, a category of compounds naturally found in plant foods, such as fruit, vegetables, herbs, spices, tea, dark chocolate, and wine. 'Polyphenols act as an anti-inflammatory antioxidant,' says Shubrook. 'They can help reduce the risk of cancer by neutralising harmful free radicals, the chemicals that damage cells.'
The specific polyphenol in coffee is known as chlorogenic acid. According to a 2020 study published in Experimental and Clinical Sciences, patients who consumed coffee rich in chlorogenic acid lowered their risk of Type 2 diabetes and non-alcoholic fatty liver disease – they also lost weight. Scientists concluded this was probably related to an increase in intestinal bifidobacteria (one of the 'good' ones).
Established studies have also shown caffeine is good for your gut, stimulating the colon and leading to regular bowel movements. One 1990 study showed that people who drank coffee tended to need the loo 30 minutes after drinking a cup.
In so many ways, the gut appears to love a cup of joe. But is there a best way to prepare and serve your coffee?
Black or with milk?
Experts tend to be unanimous that black coffee is better for you than a cappuccino, latte or flat white. 'Milk has been shown to impede the absorption of polyphenols,' says Julia Kopczynska, a microbiologist at the Polish Institute of Biochemistry and Biophysics in Warsaw who has developed a 'healthy coffee' tool for the company Omni Calculator. 'Adding tonnes of cream or sugar turns your coffee into a dessert. Sugars will do more harm to your blood sugar levels than coffee can do good.'
Which blend should I choose?
There are two main types of coffee bean: Arabica and Robusta. 'Each has different qualities at particular roasting stages,' says Kopczynska. 'Though lighter roasts generally have a higher caffeine content, they preserve more antioxidants than darker roasts. Light-roasted Robusta beans have more antioxidants than the blonde roasts of Arabica coffee.'
Shubrook says her go-to is Exhale Coffee, which is a dark Arabica grown with the highest level of antioxidants. 'It's the perfect black coffee, not at all messed with.'
The length of time the beans have been stored will also influence their polyphenol levels, with a reduction seen in coffee beans stored for 12 months or longer.
What about instant coffee?
Though studies show that instant coffee may contain even more polyphenols and minerals than ground coffee, it also contains 100% more of a chemical called acrylamide – coffee substitutes can even have 300% more. 'Acrylamide forms in coffee during the roasting process, and if people are exposed to it in higher amounts, they could raise their risk of nerve damage and cancer,' says Kopczynska.
There is no cause for alarm, however. 'Coffee consumption, both instant and ground coffee, is not linked to cancer development,' Kopczynska says. 'However, the European Food Safety Authority recommends reducing the amount of acrylamide in our diet. This is why we also recommend classic ground coffee above instant and substitutes.'
How many cups should I drink a day?
A recent study of the centenarians living in the European 'long life' Blue Zones of Sardinia and Ikaria, Greece, revealed that almost all of them drank two to three cups of black coffee a day. 'Presuming a cup of coffee is 8oz/ 220ml, two to three cups is the sweet spot, with five the upper limit,' says Kopczynska.
Before grinding your beans or stamping your loyalty card, it's worth bearing in mind the caffeine content of your drink. 'Although coffee is beneficial, not everyone can metabolise it as efficiently,' says Shubrook. Kopczynska agrees. 'The maximum recommended amount of caffeine is 400mg a day. Anything above 600mg has been linked to insomnia and high blood pressure.'
Advertise with NZME.
According to Kopczynska, a home-brewed cup of coffee contains between 70mg and 140mg of caffeine, depending on the bean and brewing method. Meanwhile, the average high street coffee has 180mg of caffeine. Others can be higher: a medium Costa cappuccino in Britain has 325mg – almost your entire recommended daily allowance in one cup.
You may also be surprised to hear that most espressos are lower in caffeine than other types of coffee: the caffeine found in 30ml espressos from three major British coffee chains ranges from 33mg to 75mg. (But a cup of espresso is also a far smaller amount of liquid than a latte or a cappuccino.)
How should I prepare my coffee?
How you fix your beans preserves different compounds, those which are beneficial, and the ones which are less good for you. Brewed coffee contains cafestol and kahweol, chemicals known as diterpenes. 'Cafestol and kahweol are known for their anti-inflammatory, anti-diabetic, anti-cancer, and polyphenol-preserving properties,' says Kopczynska. 'These are 30 times higher in unfiltered coffee.'
On the other hand, she says, unfiltered coffee contains oils that have been shown to raise cholesterol levels. 'Filtered coffee not only contains fewer coffee oils but also contains less caffeine compared to unfiltered coffee brewing methods.'
If you can get around the fiddliness of using an Aeropress, a 2023 study published in the journal Foods revealed this method to be the best for preserving polyphenols. 'In our study, the lowest total polyphenol content was found in the coffee from the French press (133.9g gallic acid/litre) and the highest was observed in the Aeropress brew (191.29g gallic acid/litre),' wrote the authors. 'Of all the highest antioxidant potential and polyphenol content was observed in the brew made in the Aeropress.'
Can I make my coffee healthier?
Adding natural spices – as opposed to sugars or syrups – can bring extra health benefits. 'Cardamom is an anti-inflammatory and regulates blood sugar levels,' says Kopczynska. 'Ginger, a natural painkiller, improves digestive health and lowers cholesterol. If you're using milk, turmeric added to a latte is known for its beneficial effects on metabolism and the immune system.'
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
NZ Herald
20-05-2025
- NZ Herald
What drinking coffee every morning does to your gut health
A 2023 study published in the journal Nutrients investigated the association between caffeine, coffee consumption and the colonic microbiome. Results showed the richness of the microbiome to be higher with regular coffee drinkers, who had increased numbers of the helpful Alistipes and Faecalibacterium types (thought to have preventive effects against liver fibrosis and cardiovascular illness), and lower levels of the harmful Erysipelatoclostridium, which causes gut problems. This follows an earlier study where coffee consumption was found to be associated with an increase in bifidobacterium, microbes thought to help with the digestion of fibre and prevent infections. Coffee also contains plant compounds called polyphenols, a category of compounds naturally found in plant foods, such as fruit, vegetables, herbs, spices, tea, dark chocolate, and wine. 'Polyphenols act as an anti-inflammatory antioxidant,' says Shubrook. 'They can help reduce the risk of cancer by neutralising harmful free radicals, the chemicals that damage cells.' The specific polyphenol in coffee is known as chlorogenic acid. According to a 2020 study published in Experimental and Clinical Sciences, patients who consumed coffee rich in chlorogenic acid lowered their risk of Type 2 diabetes and non-alcoholic fatty liver disease – they also lost weight. Scientists concluded this was probably related to an increase in intestinal bifidobacteria (one of the 'good' ones). Established studies have also shown caffeine is good for your gut, stimulating the colon and leading to regular bowel movements. One 1990 study showed that people who drank coffee tended to need the loo 30 minutes after drinking a cup. In so many ways, the gut appears to love a cup of joe. But is there a best way to prepare and serve your coffee? Black or with milk? Experts tend to be unanimous that black coffee is better for you than a cappuccino, latte or flat white. 'Milk has been shown to impede the absorption of polyphenols,' says Julia Kopczynska, a microbiologist at the Polish Institute of Biochemistry and Biophysics in Warsaw who has developed a 'healthy coffee' tool for the company Omni Calculator. 'Adding tonnes of cream or sugar turns your coffee into a dessert. Sugars will do more harm to your blood sugar levels than coffee can do good.' Which blend should I choose? There are two main types of coffee bean: Arabica and Robusta. 'Each has different qualities at particular roasting stages,' says Kopczynska. 'Though lighter roasts generally have a higher caffeine content, they preserve more antioxidants than darker roasts. Light-roasted Robusta beans have more antioxidants than the blonde roasts of Arabica coffee.' Shubrook says her go-to is Exhale Coffee, which is a dark Arabica grown with the highest level of antioxidants. 'It's the perfect black coffee, not at all messed with.' The length of time the beans have been stored will also influence their polyphenol levels, with a reduction seen in coffee beans stored for 12 months or longer. What about instant coffee? Though studies show that instant coffee may contain even more polyphenols and minerals than ground coffee, it also contains 100% more of a chemical called acrylamide – coffee substitutes can even have 300% more. 'Acrylamide forms in coffee during the roasting process, and if people are exposed to it in higher amounts, they could raise their risk of nerve damage and cancer,' says Kopczynska. There is no cause for alarm, however. 'Coffee consumption, both instant and ground coffee, is not linked to cancer development,' Kopczynska says. 'However, the European Food Safety Authority recommends reducing the amount of acrylamide in our diet. This is why we also recommend classic ground coffee above instant and substitutes.' How many cups should I drink a day? A recent study of the centenarians living in the European 'long life' Blue Zones of Sardinia and Ikaria, Greece, revealed that almost all of them drank two to three cups of black coffee a day. 'Presuming a cup of coffee is 8oz/ 220ml, two to three cups is the sweet spot, with five the upper limit,' says Kopczynska. Before grinding your beans or stamping your loyalty card, it's worth bearing in mind the caffeine content of your drink. 'Although coffee is beneficial, not everyone can metabolise it as efficiently,' says Shubrook. Kopczynska agrees. 'The maximum recommended amount of caffeine is 400mg a day. Anything above 600mg has been linked to insomnia and high blood pressure.' Advertise with NZME. According to Kopczynska, a home-brewed cup of coffee contains between 70mg and 140mg of caffeine, depending on the bean and brewing method. Meanwhile, the average high street coffee has 180mg of caffeine. Others can be higher: a medium Costa cappuccino in Britain has 325mg – almost your entire recommended daily allowance in one cup. You may also be surprised to hear that most espressos are lower in caffeine than other types of coffee: the caffeine found in 30ml espressos from three major British coffee chains ranges from 33mg to 75mg. (But a cup of espresso is also a far smaller amount of liquid than a latte or a cappuccino.) How should I prepare my coffee? How you fix your beans preserves different compounds, those which are beneficial, and the ones which are less good for you. Brewed coffee contains cafestol and kahweol, chemicals known as diterpenes. 'Cafestol and kahweol are known for their anti-inflammatory, anti-diabetic, anti-cancer, and polyphenol-preserving properties,' says Kopczynska. 'These are 30 times higher in unfiltered coffee.' On the other hand, she says, unfiltered coffee contains oils that have been shown to raise cholesterol levels. 'Filtered coffee not only contains fewer coffee oils but also contains less caffeine compared to unfiltered coffee brewing methods.' If you can get around the fiddliness of using an Aeropress, a 2023 study published in the journal Foods revealed this method to be the best for preserving polyphenols. 'In our study, the lowest total polyphenol content was found in the coffee from the French press (133.9g gallic acid/litre) and the highest was observed in the Aeropress brew (191.29g gallic acid/litre),' wrote the authors. 'Of all the highest antioxidant potential and polyphenol content was observed in the brew made in the Aeropress.' Can I make my coffee healthier? Adding natural spices – as opposed to sugars or syrups – can bring extra health benefits. 'Cardamom is an anti-inflammatory and regulates blood sugar levels,' says Kopczynska. 'Ginger, a natural painkiller, improves digestive health and lowers cholesterol. If you're using milk, turmeric added to a latte is known for its beneficial effects on metabolism and the immune system.'
Scoop
05-05-2025
- Scoop
Gut Microbiome Link To ADHD Reinforced In Scientific Review
Press Release – University of the Sunshine Coast The link between a gut imbalance and symptoms of Attention Deficit/Hyperactivity Disorder has been further supported by a University of the Sunshine Coast scientific review. The paper, published in Neuroscience, reviewed more than 280 studies and found mounting evidence that the immune system, neuroinflammation and a disturbed balance of bacteria in the gut played a role in ADHD symptoms. Lead author Naomi Lewis said two types of bacteria were particularly implicated: the Bacteroides species and Faecalibacterium. 'What we found was that there are compositional differences in the types of bacteria in the gut that may contribute to inflammation, brain functioning differences, and symptoms, in ADHD,' Ms Lewis said. In particular, certain Bacteriodes species that may improve the integrity of the intestinal barrier were found in less abundance in people with ADHD. 'Similarly, low levels of Faecalibacterium in the gut, also implicated in ADHD, has been linked with inflammatory conditions. 'Systemic inflammation cuts through the blood-brain barrier and can cause neuroinflammation, potentially from a very young age.' Ms Lewis said although ADHD was highly heritable, there were still environmental links to the severity of symptoms. 'It's important to remember there is a lot of complexity here, so no one thing is causing ADHD,' she said. 'Genetics still play a major role, but this research suggests you may want to look at the best support for minimising inflammation, particularly going into pregnancy.' 'The research in this space is still quite limited, but what we do know is that gut health plays an enormous role in mental health and neurological conditions,' Ms Lewis said. 'Gut bacteria can affect neurological processes in the brain, impacting behaviour and emotional regulation.' Co-author, UniSC Nutrition and Dietetics senior lecturer Dr Anthony Villani, said the review added to the global understanding on the impact of the gut microbiome on mental health. 'Most studies have found children with ADHD have poorer diets, with more added sugars and more processed foods compared to those without. 'But whether that is cause or affect we don't know, but there is certainly a need for more research,' Dr Villani said. Across the hundreds of papers reviewed, the evidence supports adopting lifestyle choices that nurture the gut microbiome. This includes minimising antibiotics, stress, and alcohol, saturated fats and refined sugar, eating more fibrous foods such as whole grains, fruits, vegetables, legumes and nuts – or adopting a Mediterranean-type diet as much as possible.
Scoop
05-05-2025
- Scoop
Gut Microbiome Link To ADHD Reinforced In Scientific Review
The paper, published in Neuroscience, reviewed more than 280 studies and found mounting evidence that the immune system, neuroinflammation and a disturbed balance of bacteria in the gut played a role in ADHD symptoms. Lead author Naomi Lewis said two types of bacteria were particularly implicated: the Bacteroides species and Faecalibacterium. 'What we found was that there are compositional differences in the types of bacteria in the gut that may contribute to inflammation, brain functioning differences, and symptoms, in ADHD,' Ms Lewis said. In particular, certain Bacteriodes species that may improve the integrity of the intestinal barrier were found in less abundance in people with ADHD. 'Similarly, low levels of Faecalibacterium in the gut, also implicated in ADHD, has been linked with inflammatory conditions. 'Systemic inflammation cuts through the blood-brain barrier and can cause neuroinflammation, potentially from a very young age.' Ms Lewis said although ADHD was highly heritable, there were still environmental links to the severity of symptoms. 'It's important to remember there is a lot of complexity here, so no one thing is causing ADHD,' she said. 'Genetics still play a major role, but this research suggests you may want to look at the best support for minimising inflammation, particularly going into pregnancy.' 'The research in this space is still quite limited, but what we do know is that gut health plays an enormous role in mental health and neurological conditions,' Ms Lewis said. 'Gut bacteria can affect neurological processes in the brain, impacting behaviour and emotional regulation.' Co-author, UniSC Nutrition and Dietetics senior lecturer Dr Anthony Villani, said the review added to the global understanding on the impact of the gut microbiome on mental health. 'Most studies have found children with ADHD have poorer diets, with more added sugars and more processed foods compared to those without. 'But whether that is cause or affect we don't know, but there is certainly a need for more research,' Dr Villani said. Across the hundreds of papers reviewed, the evidence supports adopting lifestyle choices that nurture the gut microbiome. This includes minimising antibiotics, stress, and alcohol, saturated fats and refined sugar, eating more fibrous foods such as whole grains, fruits, vegetables, legumes and nuts – or adopting a Mediterranean-type diet as much as possible. The paper is called
