Your 10-Step Gut Makeover Plan.


Improving the diversity of the trillions of bacteria that live in your gut (38 trillion if you want to be precise) is increasingly being seen as not just useful for easing gut complaints such as bloating and IBS type symptoms, but as the key to achieving overall good health.

Around 1,500 species of bacteria have been identified in the gut microbiota (a mixture of bacteria, yeasts and fungi found in the digestive tract) so far and study after study is increasingly showing how important that its diversity is in maintaining good health – rather than this idea of having “good” and “ bad” bacteria, which gives people the idea that popping a probiotic can cancel out eating a bad diet (it can’t).

The microbiome affects everything from general immunity, irritable bowel syndrome (IBS), bloating and inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis, to the stiffness of the arteries in heart disease, kidney disease, skin conditions and even mental health disorders such as depression.

Research has linked the gut microbiota with the health of just about every organ in the body and it’s very important for building a strong immune system.

It is only early days in that we are still yet to determine whether intervening on the gut microbes can improve the health of our other organs with diets targeting the gut microbes, but that’s where the science is heading - it’s looking promising in many areas including our mental health.

The intestine is 9 metres long and 70 per cent of our immune system lies within the intestine so clearly its essential to our immunity. We also know that the microbiota produces molecules that get into our blood and can ‘talk’ to our brains and other organs.

With so many scientific studies being published at break-neck speed, here are some basic principles and useful practical tips for achieving a healthy gut microbiome based on the very latest (non-faddy) science.

  1. Think diversity rather than good and bad bacteria.

    The first thing to realise is that you need to eat as wide a range of plant-based foods as possible,’ advises Megan. ‘In clinic, I advise people to aim for 30 different plant-based foods – that’s nuts, seeds, wholegrains, legumes and fruit and veggies – a week. It’s really best not to fixate on eating just one category of those foods but aim to get something from all those groups. Research has suggested that if you are having less than 10 of these plant-based foods a week your microbial diversity isn’t very strong. Try to vary the foods you eat from week to week and always be open to trying new things.

  2. Eat fibre -rich foods to ‘feed’ gut bacteria.

    Fibre found in certain (but not all) high fibre foods contain prebiotics which ‘feed’ the beneficial or ‘good’ bacteria which live in your gut. Foods that contain beneficial prebiotics include beans, pulses, artichoke, legumes and Brussel sprouts- quite a wide range of fruits and vegetables so don’t get fixated on certain ones. However, Megan says: ‘Not all fibre acts as a prebiotic per say – some types are indigestible for bacteria and some other types of fibre don’t exclusively feed the beneficial bacteria such as bifidobacteria so don’t meet the definition of a prebiotic.

    Current Department of Health guidelines recommend we should be eating 30g of fibre a day, but most of us are only eating 19g. I believe we should be aiming even higher and eat 50g of fibre a day as in the Mediterranean diet - it sounds a lot but it’s not if you’re basing the bulk of your diet on whole plant-based foods. In some countries in rural areas people manage to eat in excessive of 80g of fibre a day.

    Fibre is a Holy Grail nutrient – if you can increase the amount you eat - it will benefit pretty much every organ in your body including your heart, my advice is to increase it gradually though to give your body time to adjust to it.

  3. Include healthy ‘fermented’ foods in your diet every day.

    Fermentation involves bacteria or yeast - to make foods such as yoghurt, kefir (a traditional homemade fermented drink made from milk that contains live bacteria) and kombucha (made from fermented tea, sugar, bacteria and yeast). They generally contain a wide range of different types of bacteria so are believed to be beneficial for the gut microbiome. I try and eat fermented foods every day, kefir is the fermented food with the most scientific evidence behind it.

    Kefir has around 20 different types of bacteria and yeast in it – the diversity is much great than yoghurt. I drink 100ml of kefir a day – it’s really easy to make yourself. You buy the kefir grain and add milk and put on the work bench to ferment for around 12 hours and it’s ready to drink.

    Other popular healthy fermented foods include kimchi, a type of spicy Korean pickled cabbage and sauerkraut, a fermented cabbage.

    One thing to be aware of is that many fermented foods are also high in FODMAPs, which are not well-tolerated by some people with IBS and may trigger gut symptoms. Chocolate, bread and beer are also technically fermented foods, but clearly don’t all have the same health benefits!

  4. Always buy ‘live’ yoghurts.

    Although there are millions of different types of yoghurts on the market – not all of them contain beneficial gut bacteria. Look out for the cartons that are labelled as containing ‘live cultures’, it doesn’t really matter if they are full fat or made from skimmed milk, although full fat yoghurts have been shown to protect the bacteria from stomach acid so may have the edge, but that’s a mechanistic benefit rather than a superiority of the bacteria in the yoghurt.

  5. Avoid artificial sweeteners if you can.

    Although artificial sweeteners may help you reduce your calorie intake – they may also destroy the diversity of your gut microbiome.

    All the evidence coming from animal studies suggests that artificial sweeteners are probably not a great thing to include in your diet in large amounts. ‘Whether it’s better to have sugar instead of sweeteners, if you want something sweet depends on a number of things, including your weight and medical history. A small, 30g chocolate bar is perfectly fine to include - food is meant to be enjoyed- but regularly over doing it with a big bag of sweets is not a great idea. As boring as it sounds – it’s all about balance.

  6. Swap your diet stables around regularly.

    If you eat rice try eating wild rice, quinoa or buckwheat – try to get more ancient grains on your plate. Even eating yellow and green peppers as well as red ones all helps. If you’re buying chickpeas – why not buy a tin of four bean salad instead and get butter beans, red kidney beans and black beans too? Likewise, with pasta – try whole wheat versions or lentil pasta or Konjac pasta (although don’t binge on this as it can cause bloating and stomach upsets).

  7. Take a probiotic – but only if you are taking antibiotics or IBS.

    There isn’t any evidence that taking a probiotic supplement confers health benefits to healthy people, but there are studies that show specific strains of bacteria can help treat certain conditions. For instance, if you’re taking antibiotics, one strain of yeast called saccharomyces boulardi taken at a dose of 10 billion colony-forming-units (CFUs) twice daily can dramatically reduce the incidence of diarrhoea associated with taking antibiotics, which affects around 30 per cent of people who take them. You would need to take them throughout the course of your treatment and for a few days after wards for them to be effective. It’s quite specific and prescriptive though – not just any probiotic will have that effect and not just any dose.

    For IBS there are 4 probiotic supplement products on the market which have been proven to be effective in treating IBS symptoms, Symprov, Alflorex, Bio-Kult and VSL#3. Although I wouldn’t go as far as to say that they would work for everybody with IBS as this is based on one single study. When researchers have pooled the results of all studies together, they have found that probiotics reduce symptoms by 20 per cent, so it’s not that impressive really.

  8. Don’t try the low FODMAP diet on your own.

    You may have heard a lot about how the low FODMAP diet (basically avoiding a type of poorly absorbed carbohydrates that are found in certain foods such as onions , garlic, lentils, brassicas, cabbage, cauliflower, broccoli and wheat), can ease IBS symptoms such as bloating, wind and diarrhoea and be tempted to try it, but I would warn that it’s not something that should be undertaken without the supervision of a trained-dietitian.

    The low FODMAP diet can be very useful for some types of IBS but it shouldn’t be the first port of call, as it’s very complex. Also, it should only be followed for 4 to 6 weeks and then FODMAPs should be systematically re-introduced with the help of a dietitian so that you can identify what your tolerance is of certain FODMAPs. Many FODMAP are essentially prebiotics so by cutting them out you could be starving your gut bacteria - this is why attempting it must be done with a dietitian.

    In some cases, this can be somewhat offset by taking a probiotic supplement (one study from my research team used VSL#3).

  9. Eat like a Mediterranean to boost your mood.

    This is an emerging area, but we have seen in some dietary interventional studies that eating a high fibre (50g of fibre a day) Mediterranean style diet made up of fruit, vegetables, legumes, extra virgin olive oil and wholegrains can improve depression scores in some people. That's not to say that people taking medication should stop taking their pills - rather that eating a high fibre Med diet alongside taking their medication may improve their mood.

  10. Don't go low carb.

    We are really quite worried about the ramifications about the trend for eating a low carbohydrate diet, because fibre is a type of carbohydrate. In the short term you can lose weight, but you can also damage your gut bacteria, which might in the long term have consequences such as an increased risk of colon cancer.