THE USER’S GUIDE TO…
When you eat, hundreds of different species of microbes chow down, too. So you need adiet to keep them happy – or everything from your mood to your immune system could pay the price. Luckily, science is here to help
01/ WHAT DO MICROBES EVEN DO?
GUT PROTECTION
‘Our bodies are quite clever,’ says Jack Gilbert, a microbiologist at UC San Diego and the director of the Microbiome and Metagenomics Center. Enzymes our bodies make help us digest what we’re able to, then we rely on microbes – mainly bacteria in the colon – to digest the rest. Like you, microbes ‘poop’ out by-products they can’t process. Depending on what they’re eating, these by-products can cause gas and other issues, or their ‘waste’ can be useful things, such as vitamins B and K. A messed-up microbial mix is linked to common digestive ailments as well as Crohn’s disease and ulcerative colitis.
MOOD STABILISATION
The gut is packed with nerves that talk to your brain along the ‘gut-brain axis’, says nutritional psychiatrist Uma Naidoo, author of Calm Your Mind With Food. If you’ve had that butterflies in your stomach feeling (gut) because you were nervous (brain), it makes sense. It goes the other way, too: gut microbes can trigger feel-good signals to the brain.
IMMUNE HELP
When GI-tract microbes produce compounds such as short-chain fatty acids, they help preserve the layers of tissue and mucus that serve as resistance to infections. Your immune system – 70% of which is in your gut – interacts with your microbes, too, learning how to counter other disease-producing invaders in your body. Good microbes may also dampen the inflammatory response at the root of many diseases.
02/ HOW SHOULD YOU FEED THEM?
Your microbial mix is unique, shaped by factors you can’t control (genes, whether you had a natural or caesarean birth, etc) and those you can – like your diet, which makes a huge difference.
EAT MORE…
Fermented foods Yoghurt, sauerkraut, kimchi – all contain living microbes, aka probiotics. The benefits are threefold. ‘You get the food itself, the bacteria that come with the food and the healthy things that the bacteria produce,’ says Keith Summa of Northwestern University’s Feinberg School of Medicine. ‘That would be prebiotic, probiotic and postbiotic.’
Fibre A prebiotic is a type of fibre – and it’s what your microbes eat. They especially adore soluble fibre, found in grains such as oats and barley, beans, apples and citrus fruits. Just know that for some people, more microbial feasting can mean more gas and bloating, says Dr Summa.
Vegetables To diversify your microbiome, eat a variety of plants, says Professor Gilbert. He recommends aiming for 30 different types of fresh veg per week. Sounds ambitious, but even a basic sandwich can contain four: le
