You may have heard of the gut-brain axis, whereby the gut microbiome strongly and directly affects the activities, development and permeability of the brain. The mechanism behind it is poorly understood, but its existence is well documented.

Numerous studies have shown that animals brought up in sterile environments behave very differently to their normal counterparts, and do not deal with stress very well (we’re not talking a quick wipe down with alcohol gel here, we’re talking dedicated facilities, and layers of decontamination measures to provide several generations that conclude with an animal that the labs can reliably describe as “germ-free”).

Studies have also shown that mice who are raised germ-free, and then get a fecal transplant from normal mice, start behaving in a measurably similar way to their donor mouse – in other words, they start acting like a normal mouse once they’ve had some normal mouse faeces implanted into their intestines. Which is probably as gross as it sounds, but it does the job.

In humans, elderly people with a more diverse microbiome have been shown to be more social, perform better on cognitive tests and show a stronger ability to cope in stressful situations. Given that sociability has been shown to play an important role in happiness by itself, there seems to be compounding effects of maintaining your gut bacteria.

From the evidence available, it seems that a diverse microbiome is key to happiness, health, sociability and staying young.

How do I diversify my gut microbes?

  • Diversity of diet is strongly linked to diversity of gut microbiome – eat a variety of vegetables, fruit, nuts and seeds.
  • Sources of protein should vary, whether you’re a vegan, vegetarian or carnivore. Make sure you’re not eating the same things every week to fulfil your protein requirements. Peanuts, nuts, beans, tofu, and many other plant-based products are all great sources of protein that also support gut health.
  • Get carb-smart by replacing pasta and white rice with potatoes, brown rice and other wholegrains.
  • Probiotics may be helpful, particularly after antibiotic use or gut illness.
  • Fermented milk products, kefir, and sauerkraut all make great sources of healthy gut bacteria.