Why chronic inflammation could be linked to your gut – and what to do about it
Our gut microbiome, the bustling community of trillions of microbes living deep within our intestines, does more than just help with digest food, it contributes to so many aspects of our health. In recent years, gut health and inflammation have become such popular buzzwords, yet many still don’t realise just how intricately they are linked:
Why is gut health so important?
The gut microbiome is so important, in fact its often called “the second brain.”
Scientists are now realising that when the gut microbiome is out of balance – when the bad bacteria have begun to dominate and kill off the good – it can set off a toxic chain reaction throughout the body. This is chronic inflammation and can be a root cause of many of our most serious illnesses, from cancer to heart disease and diabetes.
So it makes sense that good gut health can translate into improved overall health.
What is inflammation and how is it linked to gut health?
Inflammation is the activation of our immune system, and the reason that the gut is so intimately linked to inflammation is that up to 80 per cent of our immune system lies within our gut.
Yet, inflammation is not always a bad thing. “We do need some inflammation in the body when it’s in response to an infection or acute injury. It’s there to heal us and do a job,” says Dr Emily Porter, a specialist gut dietitian at The Gut Health Clinic in London. “What can become a problem is chronic low-lying inflammation, and this has a direct bidirectional relationship with gut imbalance,” she says.
The problem is that our modern diets and lifestyles can trigger the overgrowth of bad bacteria that, in turn, trigger the immune system to overreact, even if no injury or infection is present.
“These bad bacteria are good at firing up the immune system to think there is an infection and overreact,” says Jack Gilbert, a professor of paediatrics at the University of California, San Diego. “So now you get massive inflammation in your gut, and it gets into the bloodstream and the lymph system so you can end up with joint pain, fatigue, depression, anxiety, allergies, cardiac health problems, asthma and more – it can cause a myriad of problems throughout your system.”
How can you spot inflammation?
Chronic inflammation can cause multiple symptoms, but unfortunately low-grade inflammation might also have no symptoms at all. “There might be no obvious external signs. It’s quite possible, for example, that a lot of children who have a poor diet, don’t get a lot of exercise and suffer from external pollution and stress, could be suffering from low-grade inflammation,” says Gilbert.
If you do have symptoms of inflammation, they can be wide-ranging. According to the experts you can experience:
Skin rashes
Fatigue
Joint aches
Wheezing
Depression and anxiety
Shortness of breath
Feeling bloated
Belching
Flatulence
Changes in bowel habits
Dr Porter says: “if someone comes to the clinic with gut symptoms, we’ll look at the person’s health as a whole to try and unpick the causes, and work out whether they need to see a doctor to rule out a potentially more serious condition.”
How to heal your gut
Here are the nutrition tips you should follow for the best results:
1. Get lots of fruit and vegetables
To maintain a healthy balanced gut microbiome and reduce inflammation, we need to eat much more fibre than most of us do now.
“In our modern world, we don’t consume enough fibre,” says Gilbert. “We need about 50-60 grams a day. This is complex, but basically when bacteria consume plant fibres they release a chemical called butyrate, which is a short-chain fatty acid and a prime fuel for our immune system. If the immune system doesn’t get butyrate it’s like an army not getting enough food, and that’s when you get this chronic inflammation.
“So we need to consume a diverse array of plant fibres – 30 types a week should get you enough plant diversity, and remember that broccoli, sprouts and cabbage are from the same plant species, for example. But very few of us do that. Instead, we eat a lot of saturated fat, a lot of protein and a lot of simple sugars and processed food in our Western diets,” says Gilbert.
Eating 30 different plant foods feeds and encourages a wide range of healthy gut bacteria to grow and flourish. According to Dr Porter: “All the different strains of bacteria have different favourite foods that they use to produce short-chain fatty acids that are beneficial for us and anti-inflammatory. Studies have shown that eating 30 plants a week will also add years to your health span – the period of your life in which you remain healthy.”
2. Eat a wide range of food types
“I encourage people to eat what we call the ‘super six’,” says Porter. “That’s fruit, vegetables, wholegrains, nuts and seeds, beans and pulses, and herbs and spices. If people are eating across these six food groups, we know that is associated with good gut health. Basically if you stick to a Mediterranean-style diet you can’t go far wrong, and that means adding in lean protein like oily fish as well [as] red wine in moderation,” she says.
Porter also recommends expanding our dietary choices beyond the standard options we always reach for.
“Eat prebiotics like onions, garlic and leeks, brightly coloured fruits and veg, and especially beans and pulses – they’re my hero foods. Try to add in rather than take away – so oats are good, but add in a seed and nut mix to make them even more nutritious. Brown bread is good, but if you go for a granary style you’re going to get a bit more fibre, protein and seeds as well. Rather than just having brown pasta, try quinoa, bulgur wheat, wholegrain couscous and buckwheat. The key thing is diversity,” she says.
3. Include fermented foods in your diet
Numerous studies have shown that fermented foods such as kimchi, sauerkraut (pickled cabbage), kefir (fermented milk), kombucha, live yogurt, pickles and miso are incredibly valuable for your gut health.
“Research has shown that to get the most benefit from eating a high-fibre diet, you have to prime the microbiome with a fermented food diet,” says Gilbert. “We’re not entirely sure why, but we think it’s because fermented foods contain a lot of bacteria that our ancestors used to consume, as they didn’t have fridges to preserve things. So our immune systems, which keep a record of everything they see, say, ‘Oh, I know these guys, they’re safe,’ and we have this amazing situation where they dampen down inflammation and encourage the proliferation of good bacteria in our gut.”
4. Eat foods rich in polyphenols
There is growing evidence showing that dietary polyphenol may directly modulate the gut microbiome, increasing beneficial microbial species or decreasing harmful ones. High quantities of polyphenols can be found in all berries, carrots, cocoa, 70 per cent dark chocolate, tea and coffee, beans, green tea, olives and soy.
“If you eat the rainbow by choosing lots of different-coloured foods, you’ll be eating ‘polyphenols’, a beneficial chemical found in highly pigmented foods. Polyphenols are loved by our gut bacteria, and transformed by them into helpful anti-inflammatory chemicals,” says Porter.
Polyphenols are also good for blood sugar control and may reduce the risk of heart disease.
5. Limit ultra-processed foods
Processed foods aren’t very nourishing for your gut as they tend to contain a lot of fat, sugar, salt and preservatives. “There are suppressed levels of nutrients associated with those foods as they’re generally processed to make them more shelf stable,” says Gilbert. “They’re good at providing us with calories, but not the nutrients that our bodies need. A lot of processed foods also promote the growth of bacteria that love simple sugars, and you end up with too many bad bacteria growing, encouraging inflammation.”
Porter emphasises that it’s about finding a balance, rather than cutting foods out altogether. “We don’t want to demonise food. Food is about more than health, it’s celebration, it’s social and it’s connection. Generally, we advise having less of those [ultra-processed] foods, or just having them once in a while or balancing them with healthier additions. So, for example, if you’re having a croissant for breakfast, maybe have some strawberries with it.”
How exercise, stress and sleep play a role
It’s not just a poor diet that can imbalance our gut – our lifestyles, including stress, sleep and exercise, also play a major role. Our brain and our gut are in constant communication, so if we feel stressed or anxious that will impact on the gut, and similarly if the gut is inflamed that can also make us feel depressed.
“We’ve done studies that have shown that stress induces inflammation throughout the body,” says Gilbert. “We looked at farmers who go through periods when they are making money and periods when they are quite poor, and during the periods when they are poor, their bodies become inflamed because of the stress caused by worrying about money. Then, when they have money, their bodies go back to normal. Psychological stress causes your brain to release the hormone cortisol, which changes how your immune system works and promotes the growth of bad bacteria. Then, of course, when you’re stressed you’re more likely to eat bad food, and it’s a continuous cycle.”
When it comes to exercise, we’ve evolved to do this daily, so it’s not enough to go to the gym once a week. Exercise also promotes the growth of good bacteria, which dampen down inflammatory responses. It’s is also brilliant for stress. Sleep allows our body to recover and repair, and makes it less likely we’ll eat badly and get stressed as well.
The lesson of the gut is that everything is connected – we can’t cheat on our mental or physical health.
