The human gut contains up to 1,000 species of bacteria, collectively known as the gut microbiome. Maintaining harmony in the gut microbiome is key for looking after our gut health and overall wellbeing.
Research shows that imbalances in the gut microbiome, also known as dysbiosis, may increase the risk of gastrointestinal conditions like ulcerative colitis and irritable bowel syndrome (IBS), as well as diabetes, obesity, depression, and heart disease.
Here, we’ll explore 10 surprising things that can harm your gut health.
1. Lacking diet variety
Eating a varied diet is one of the most effective ways to improve your gut health – but research shows it’s an area where many of us fall short.
In fact, over half of Brits lack variety in their diet, with many of us eating an average of just six meals on rotation. Other research has found that 75% of the world’s food supply comes from only 12 plants and five animal species.
In this study, people who regularly ate over 30 different types of plant foods per week had more diverse and healthy gut microbiomes than those who ate 10 or fewer plant types a week. The good news is that studies show that changing your diet can positively impact gut microbiome after only a few days.
There are plenty of ways to add more variety to your diet, for example, by experimenting with different cuisines and eating with the seasons. To learn more, check out our article; What are the benefits of adding more variety to your diet?
2. Not getting enough prebiotics
Prebiotics are a type of fibre that passes through the body undigested. They’re needed to grow gut-friendly bacteria, known as probiotics, that help to maintain the gut’s natural balance.
For example, in this study of obese women, taking a daily prebiotic supplement for three months promoted the growth of healthy gut bacteria.
Once consumed, prebiotics ferment and produce short-chain fatty acids, which are the main source of food for cells that line the colon. Keeping these cells happy and well-fed strengthens the gut barrier – helping to protect against harmful bacteria and viruses. In turn, this can reduce inflammation and the risk of diseases, including colon cancer.
For further reading, you might like to read our article; What’s the difference between probiotics and prebiotics? Or, for tips on how to up your intake, check out these 13 prebiotic foods to add to your diet.
3. Drinking too much alcohol
When it comes to gut health, drinking too much alcohol can lead to gut microbiome imbalances.
This study compared the gut microbiome of alcoholics with healthy individuals who consumed little to no alcohol. It found that gut dysbiosis (an unbalanced gut microbiome) was present in 27% of those who were alcoholics, but not in any of the healthy individuals.
Another study found that drinking 100ml of gin daily decreased the number of beneficial gut bacteria.
This doesn’t mean you have to cut alcohol out entirely if you don’t want to. However, research suggests that some options are better than others. Interestingly, research has found that drinking red wine in moderation can actually have a beneficial impact on gut health. Experts have put this down to the polyphenols found in red wine. These are plant compounds with powerful antioxidant properties.
If you’re looking to reduce your alcohol intake, you might find our articles, How to make healthier drink choices and 10 tips to stay alcohol-free beyond dry January, useful.
4. Frequent antibiotic use
Antibiotics are important for treating infections and diseases and work by killing bacteria or preventing them from multiplying. However, research has identified some potential drawbacks to using them.
This is because antibiotics affect both good and bad bacteria. In fact, studies show that just a single course of antibiotics can negatively affect the diversity of gut bacteria.
Other research has found that while most bacteria return after one to four weeks following antibiotic treatment, their numbers often don’t return to previous levels. This study found that a single dose of antibiotics reduced the diversity of one of the most dominant good bacteria groups and increased the number of negative bacteria – and the effects remained for up to two years.
Most of us will need antibiotics from time to time, but it can help to limit use where possible.
5. Artificial sweeteners and added sugar
The NHS advises that added sugars, such as those found in table sugar, syrups, and fizzy drinks, shouldn’t make up more than 5% of the energy we get from our daily diet – the equivalent of around 30g a day. However, research shows that many of us consume around double this amount, which can affect gut health.
Diets high in added sugar have been found to lead to imbalances in the gut microbiome. This study examined the effects of a high-sugar, high-fat diet on mice over four weeks. The mice’s gut microbiomes changed significantly, with numbers of specific segmented filamentous bacteria (SFB) falling sharply. We know from research that SFB microbes play a key role in maintaining a healthy immune system.
Other research has linked high intake of sugar and soft drinks with a higher risk of ulcerative colitis, a type of inflammatory bowel disease. Meanwhile, people who ate more vegetables were found to have a lower risk.
Check out our article, 9 simple ways to cut back on added sugar, for ideas on how to reduce your intake.
Many people turn to artificial sweeteners when looking to reduce their sugar intake or daily calories. Artificial sweeteners are added to all sorts of everyday foods and products, including fizzy drinks, sweets, toothpaste, and chewing gum. However, while sweeteners can be helpful when cutting back on sugar, research suggests they may also affect the balance of beneficial bacteria in your gut.
In this study, when mice ate the artificial sweetener saccharin, the numbers and types of bacteria in their guts changed – including a reduction in some beneficial bacteria. Another study found that people who consume artificial sweeteners have different gut bacteria profiles than those who don’t.
That said, further research is needed to confirm these findings, as some studies suggest that the effects of artificial sweeteners on gut bacteria are only present in some people.
6. Not eating fermented foods
Many fermented foods, such as kefir and tempeh, are fantastic sources of probiotics, which are known to improve gut health.
In this study, kefir improved lactose digestion in 15 people with lactose intolerance – a condition caused by an inability to digest sugars in dairy products, which can cause symptoms like cramps, bloating, and diarrhoea. Other studies have found that miso can improve digestion, and reduce gas, constipation, and antibiotic-related bloating and diarrhoea.
In this study, when healthy adults followed a diet containing fermented foods for 10 weeks, their gut microbiome diversity increased. As a result, research has found that diets low in fermented foods may lead to declines in gut microbiome diversity and negatively impact gut health.
If you’d like to add more fermented foods to your diet, check out our articles; 8 fermented foods for gut health and How to make your own fermented foods at home.
7. Not getting enough exercise
Staying active is important for overall health and helps to reduce the risk of various health conditions like stroke, diabetes, and heart disease. However, research has found that exercise can also affect the gut microbiome and improve gut health.
This study found that professional rugby players had a more diverse gut microbiome and twice the number of bacterial varieties compared to a control group of non-athletes matched in age, gender, and body size.
Another study of active and non-active women found that those who were physically active had higher amounts of health-promoting gut bacteria. The results suggest that regular exercise, even at low-to-moderate intensities, can be beneficial.
If you’re yet to find a form of exercise you enjoy, head over to the fitness and exercise section of our website. Here, you’ll find information on everything from walking, cycling, and swimming, to team sports.
8. Smoking
We all know that smoking is bad for health. Smoking causes harm to nearly every organ in the body and significantly increases the risk of various health conditions, including stroke, heart disease, and lung cancer.
Cigarette smoke is also one of the main environmental risk factors for inflammatory bowel disease, which is caused by ongoing inflammation in the digestive tract. For example, studies have found that smokers are twice as likely to develop Crohn’s disease compared to non-smokers. Meanwhile, this study found that quitting smoking increased gut microbiome diversity.
If you’d like support to quit smoking, check out our article; 7 tips for quitting smoking.
9. A lack of good-quality sleep
Getting enough, good-quality sleep is key for overall health. During sleep, the body rests and repairs itself and, as a result, research has linked sleep deprivation with a higher risk of several health conditions – including stroke, heart disease, and a weakened immune system.
It’s also been found to impact gut health. Studies suggest that the gut follows a daily circadian-like rhythm. And when this rhythm is disrupted – for example, through a lack of sleep or eating late at night – research has noted harmful effects on the gut microbiome.
This study compared the effects of two nights of sleep deprivation (around four hours sleep per night) with two nights of normal sleep duration (8.5) in men. It found that those who were sleep-deprived had higher amounts of gut bacteria associated with weight gain, obesity, and type 2 diabetes.
If you’ve been struggling to sleep well recently, head over to the sleep and fatigue section of our website. Here, you’ll find information on everything from coping with insomnia to creating a bedtime routine.
10. High stress levels
Research has found that high amounts of stress can impact gut health by increasing gut sensitivity, reducing blood flow, and impacting the balance of gut bacteria.
Animal studies have found that different types of stress, including isolation and heat stress, can reduce gut diversity.
Another study found that high stress levels reduced the amount of gut-friendly bacteria and increased potentially harmful bacteria.
For ideas on how to manage stress, check out our articles; 9 simple stress relieving activities and 7 tips for coping with stress and anxiety.
Final thoughts…
An unbalanced gut can significantly impact our overall health and how well we feel. However, the good news is that there are plenty of ways to take charge of your gut health – and many are simple too.
For further reading, head over to the gut health section of our website. Here, you’ll find information on everything from the best foods for digestion to the gut-brain connection.
What steps have you taken to boost gut health? Have you been inspired to make any changes? We’d love to hear from you in the comments below.