In Part 1, we looked at the way gut bacteria – the superheroes we’ve known so little about until recently – shape our health. By now, you’re probably aware that we’re entering a whole new paradigm thanks to the discoveries scientists are making. Beyond our genes and our diet, it seems that the microbiome (the collective name for the bacteria that inhabit our body) holds the key to many aspects of our health.

It’s no longer a case of taking a few probiotics to ‘balance your gut flora’, and sort out your bloating. Oh no. There’s so much more to it than this. Partly because 90% of us is actually made up of microbes (not just a handful of bacteria in the gut!)

We know that the more diverse our gut bacteria are, the more resilient we become, and unfortunately our Western diet has already hugely affected our microbiome (perhaps explaining many of the diseases so prevalent today).

So what can you do in practice?

Well, the research is still in its infancy, but there are some rules we can already confidently apply (which the scientists doing this research apply to themselves):

  1. Minimise processed foods. There are two reasons: first because they have generally been cleansed of all bacteria, and secondly because processed food is readily absorbed into the body, leaving no food for our bacteria. The less processed a food is, the more of it gets through the GI tract to the microbiota.
  2. Aim to include raw or lightly cooked plant foods in your diet. The state of ripeness of a food, and the way you cook it also affects whether it gets absorbed straight into your bloodstream, or reaches your gut bacteria, allowing them to work their magic (raw or lightly cooked veg give bacteria more to chomp on than overcooked ones)
  3. Beware of antimicrobial compounds in our diet – e.g. chlorine washes in lettuce might keep undesirables at bay, but will also give beneficial bacteria a hard time.
  4. Don’t overuse hand sanitizers. They have their place but perhaps only in highly sensitive environments – like hospitals.
  5. Be cautious about using antibiotics too readily, as they have been shown to decimate vast swathes of our microbiome (although they are sometimes necessary!)
  6. Aim to have fermented foods like yogurt, kimchi or sauerkraut (check out your local health food shop). They are high in probiotic bacteria and can even change the gene expression of the permanent residents in your gut for the better.
  7. Feed your friendly superheroes: different bacteria thrive off a wide variety of plant fibres, so make sure you include these in your diet:
  • resistant starch, found in bananas*, oats, beans and cold potatoes (when eaten hot, the potato starch tends to get absorbed higher up in the digestive tract, increasing blood sugars.)
  • soluble fibres (from onion, leeks and Jerusalem artichokes), and finally:
  • insoluble fibre (wholegrains and avocados)

Interested in finding out more? Here’s a fantastic article by Michael Pollan which appeared in the New York Times:

Say Hello to the 100 trillion bacteria that make up your microbiome


*For those of you who have heard me warn against having too many bananas (as they have a high glycaemic load, and therefore a high impact on blood sugars), I stand by this! However the greener the banana, the better (so you could use a green banana in a smoothie for example to get the benefit of its fibre).