Image credit: Shutterstock/POLIGOONE
Wouldn’t it be nice if there were a simple list of specific foods for a healthy gut?
Well, while aiming for a variety of whole plant foods per week is key for diverse gut bacteria, which promotes better gut health, there are certain foods that are particularly beneficial for your digestive health.
Experts recommend that you eat 30 different plant foods per week. From carrots and kiwis to pulses, here are some of the best foods for gut health that should be in that number.
Fermented foods are foods that have had microorganisms, such as bacteria or yeast, added to them.
The fermentation process is an ancient technique that was used to preserve foods, before the introduction of refrigeration. These days, fermented foods are recommended because of the health benefits they can provide. Gut specialist dietitian Dr Caitlin Hall says:
“Fermented foods like kombucha and kefir, unsweetened yogurt, some cheeses, kimchi, sauerkraut and miso can help to improve the diversity of bacteria in the gut.”
This is because they contain probiotics (beneficial bacteria). This, in turn, can aid digestion.
Almost all cheeses are fermented, but they only retain their beneficial bacteria if they are not heated afterwards – Swiss cheese, Edam, Cheddar or cottage cheese are all good choices for your gut bacteria.
While sourdough bread and tempeh are also classed as fermented foods, they are cooked before eating and this process can mean friendly bacteria is lost, which may mean these foods are no longer a source of probiotics.
This also applies if you cook fermented foods (such as miso), or if you buy long-life, unrefrigerated versions (like some jars of sauerkraut) which are likely to have been heat-treated. So it’s best to stick with fresh, raw varieties to reap the benefits.
Prebiotics are “rocket fuel for your gut microbes,” says Hall. They help to feed the beneficial bacteria in our gut, so it’s important to consume foods containing these alongside fermented foods. Prebiotics are natural fibres found in plants, including most fruit and vegetables.
Hall adds: “Artichokes, asparagus, green bananas, oats, onion, garlic, leeks and chicory root are examples.”
Prebiotics can also be manufactured artificially and added into foods or supplements.
“Some mushrooms, for example fresh button mushrooms and portobello mushrooms, contain a prebiotic carbohydrate called mannitol,” continues Julie Thompson, dietitian and information manager for Guts UK.
“Mushrooms add variety to the diet and some varieties can also contain vitamin D, if they have been left exposed to sunlight.”
Vitamin D is needed for the production of the messaging chemical serotonin – found primarily in the gut – which plays a protective role in your gut.
The NHS says that eating more fibre and roughage from a variety of sources can help digestion and prevent constipation. The recommended daily intake is 30g (1oz) of fibre, but most of us aren’t achieving that. Oats, like other wholegrains, can help you to reach it.
“[Oats are] a very good source of soluble fibre,” explains Fiona Hunter, nutritionist, food writer and supporter of the Love your Gut initiative.
Different types of fibre perform different functions in the bowel. Soluble fibre dissolves in water to form a gel-like substance. This slows down the amount of time it takes for food to travel through the gut, helping us to feel fuller for longer. The gel attracts fluid during digestion, softening stools, helping them to move through the bowel more easily.
Other sources of soluble fibre include apples, citrus fruits, carrots, Brussels sprouts, sweet potato, turnip, aubergine, peas and green beans.
“Slowly introduce fibre to your diet to allow your gut to adjust to increasing levels. If this is done too quickly, it can temporarily result in gas and bloating.”
Like oats, chia seeds are a great source of soluble fibre, with just two heaped tablespoons (around 28g (1oz)) containing 11g (around a third of an ounce) of dietary fibre. Fibre isn’t digested in the small intestine, so, as Hunter says:
“When fibre reaches the large intestine, the bacteria break down the fibre to produce short-chain fatty acids which are beneficial for our health. [This] generates energy and the body uses that energy to strengthen the wall of the large intestine.”
If you’re new to chia seeds, try adding them to cereal or porridge, or mixed into yogurt, or sprinkled on top of a salad.
Unlike chia seeds and oats, asparagus is high in insoluble fibre.
“[Insoluble fibre] passes into your large intestine and absorbs water to create a bulk that produces a larger and softer stool so that when you go [for a poo], it’s easier to pass,” explains Hunter.
She recommends the Bristol stool chart as a useful resource for checking stool consistency.
“We should be aiming for something that’s quite soft and large and you can pass quite easily, without straining,” she says. “You should have a bowel movement ideally every 24 hours. If you don’t go for more than three days, you’re constipated.”
Hunter and Thompson emphasise the importance of staying hydrated for a healthy gut.
“If you’re not drinking, the fibre can’t do its job,” Hunter explains. Instead, your body will absorb fluid from the contents of your large intestine, which can cause your stools to become hard and difficult to pass.
What’s more, stools that are sitting around in your large intestine aren’t great for your gut microbes. To avoid this, aim for around 1.5 litres (two and a half pints) of fluid per day, but you may need more depending on your circumstances.
Why not invest in a measuring water bottle or download a water tracking app to keep tabs on how much you’re drinking?
Thompson says: “Nuts and seeds can also be a source of fibre and add variety to your diet. However, because of their high calorie content, limit your portion size to a small handful.”
Why not add some walnuts to a colourful salad or sprinkle pumpkin seeds on your porridge?
Garlic has been found to have a range of benefits for gut and wider health, including feeding the friendly gut bacteria that are thought to support your immune system.
There is also some evidence that it can work against unhelpful changes in gut bacteria that are linked to obesity. Research suggests that a garlic extract taken for three months increases gut microbe diversity in people with high or raised blood pressure.
Some of the research into garlic and gut health has been carried out on mice, so more research based on humans is still needed, including into whether there are any differences in the impact of garlic supplements compared with whole garlic as a food on gut health.
Closely related to garlic is the leek, which Hunter explains provides similar benefits, since they both contain a prebiotic fibre called inulin.
However, if you have irritable bowel syndrome (IBS), you may find that foods in the onion family, like garlic, can worsen symptoms due to being high in fructan. Fructan is a type of fermentable sugar (or FODMAP) which is poorly absorbed in the small intestine, so can aggravate the gut and cause symptoms in some people.
If you have IBS or a related condition, speak to a dietitian before adding or removing these from your diet.
Not only does it taste nice, but this drink has been proven to be beneficial for our gut health. A 2019 study showed people who drank red wine had a wider variety of gut bacteria compared with those who drank other alcoholic drinks.
The reason is in the grape skins. When red wine is being made, the skins are left in contact with the grape juice whilst it ferments into wine. Grape skin has lots of polyphenols (natural antioxidant compounds found in plants), which feed gut microbes and help them to reproduce.
Overall, alcohol can still damage your health and the NHS recommends drinking no more than 14 units of alcohol per week. But if you’re going to drink alcohol, red wine is the gut-friendly choice (along with a glass of water, of course).
Or if you’re celebrating a special occasion with bubbles, pink champagne, like rosé wine (both are produced either by allowing the skins to stay in contact with the grape juice for a short time, or by blending in a small amount of red wine), contains more polyphenols than standard champagne.
While it’s a myth that carrots will help you to see in the dark, their ability to support your gut health is not. This is thanks to their high fibre content. In fact, as Thompson says:
“Carrots are the vegetable that people in the UK get most of their fibre from, compared with all the other fruits and vegetables they eat.”
Part of the same family as parsnips, a portion (80g (2.8oz)) of carrots contains more than 2g (0.07oz) fibre, which is more than a tenth of the recommended daily amount.
And it doesn’t just have to be fresh. “Frozen and tinned are also suitable options, so it doesn’t need to be expensive,” says Thompson.
In fact, she suggests that adding a portion of frozen or tinned mixed vegetables is an easy way to include several different veg in your meal, to support good gut microbe diversity.
Pulses are gaining recognition for being both a cheap and healthy addition to the diet – the United Nations has even designated an annual World Pulses Day to raise awareness of their benefits.
Supporting your gut health is one of these. Thompson says: “Pulses, which include lentils, peas and beans, contain prebiotic carbohydrates called oligosaccharides – they benefit and feed our gut microbes.”
However, these are one of the FODMAPs which can be hard to digest and trigger symptoms in people with IBS.
For those who can tolerate them, “tinned varieties are a suitable option, which can reduce the cost of cooking them. Using the liquid from the tin in a dish increases the prebiotic content of that meal,” Thompson adds.
She says that pulses offer a cheaper way to make a meal go further and suggests adding them to stews to bulk them out.
Trying to catch an avocado at the perfect ripeness might be frustrating, but the gut health benefits they provide aren’t. Hall says avocados are a digestion-promoting food that help your bowel movements to stay regular.
This is due to their fibre and potassium content. The fruit is also low in fructose – a natural sugar which can cause digestive discomfort in some people – so it’s less likely to cause gas.
Kiwis are high in both soluble and insoluble fibre, which we know are beneficial for regular bowel movements. Thompson says: “They draw water into the gut to prevent constipation.”
What’s more, evidence shows eating the whole kiwi – the skin as well as the flesh – can boost your fibre intake even more.
“The skin provides a third of the fibre in a kiwi. You might want to consider eating two per day; this would provide a third of your daily fibre requirement,” explains Thompson.
Not keen on the furry texture of the skin? “It might help to think of it like the skin on a peach,” says Thompson.
“The best way to eat a kiwi with the skin on is to wash it, cut off the ends and then cut it into segments lengthways. This means a lower surface area of your mouthful of kiwi will be skin.”
She says prunes have a similar effect on the bowel. “However, prunes may be less well tolerated by some people with gut issues, such as IBS. So kiwi fruit is a good alternative.”
Perhaps unsurprisingly, root ginger is a gut-friendly choice. It has a long history of being used for medicinal purposes, such as alleviating digestive issues. It has even been found to reduce stomach cramps, speed up the movement of food through your digestive system, prevent flatulence and bloating and ease nausea.
Herbs and spices are also one of Dr Megan Rossi’s super-six plant food groups that she recommends including in your diet. The Gut Health Doctor suggests we aim for something from each of the six groups each day.
If you don’t have ginger to hand, try switching your usual cuppa for a ginger tea – an effective home remedy for an upset stomach.
There’s nothing fishy about this. Hall is an advocate for oily fish, which includes salmon, mackerel, sardines and trout, and its health benefits. In particular, the omega-3 fatty acids found in oily fish can positively influence our gut bacteria.
Omega-3 increases bacteria in the gut that produce short-chain fatty acids. These chemicals are important for many of the body’s processes and short-chain fatty acids (especially butyrate) play an important role in colon health and can help to reduce our risk of diseases like bowel cancer.
Current guidelines state that we should be eating two portions of fish per week, one of which is oily.
Many factors, from stress and sleep, can affect our gut health and so can the foods we eat. In turn, this affects our overall health; for example, because a healthy gut helps to regulate your immune system.
Hunter says: “We are what we eat.” Imagine you’re a high-performance car, she says – if you put rubbish fuel into it, you’re not going to get good performance.
This is why a healthy eating and a balanced diet are so important. Hunter explains that it helps us to live longer but also to stay healthier for longer.
While it’s important to make positive choices as early as you can in life, she says:
“It’s never too late to make changes to your diet. Your digestive system can become a little more sluggish [as you get older],” adds Hunter. “We only have one body, so we’ve got to look after it.”
A few additions to your diet can make improvements to your health. For more ways to look after yourself, check out these food tips to help you sleep.
Fiona Hunter has a BSc (Hons) Nutrition and a postgraduate diploma in Dietetics. She started her career as a dietitian in the NHS, then joined Good Housekeeping magazine. Currently, Hunter works as a consultant for food manufacturers, retailers and public relations agencies, with her work having been featured in national newspapers and magazines, as well as on TV and radio.
Julie Thompson is a dietitian who has worked in the NHS and is information manager for the Guts UK charity, which provides information and research on digestive diseases. Thompson is also a member of the Gut Microbiota for Health Expert Panel of the British Society of Gastroenterology.
Dr Caitlin Hall is a gut health dietitian, with a PhD in neurosciences and gut microbiology. She is passionate about the real-world applications of gut-brain axis research, including microbiome-based interventions that improve physical and mental health. She works as chief dietitian and head of clinical research at myota – a gut health company specialising in prebiotic fibre blends.
The best advice on preparing and painting your ceiling from a professional.
