‘You are what you eat’ is an age-old aphorism, but a more accurate version might be, ‘We are what we feed our microbiome’ – the trillions of different ‘friendly’ bacteria that live in our gut, and on which we rely for maintaining physical health and, it seems, how we feel emotionally, too. These bacteria aid digestion, produce certain vitamins and also impact brain function. Researchers have found that our gut has a direct, two-way connection with our brain through the vagus nerve. Feeling overly stressed, for example, impacts the balance of bacteria in our gut and vice versa – the particular mix of microbes in our gut also influences our stress response.
The same appears true for depression and anxiety, which the authors note can often accompany physical conditions that put our microbiome out of whack. One thing researchers advise is that diversity matters, as bacteria perform different functions. The food we choose to eat is key. Natural and unprocessed are best. Prebiotics – fibre in what we eat – feed friendly bacteria and create the conditions in which they can work for us, so wholegrains and plenty of vegetables are essential.
We can also include probiotics in our diet; foods that are rich sources of healthy bacteria, such as live yogurt, which has been known for thousands of years to have health benefits. There are many other traditionally fermented foods, too, such as kefir, kimchi and sauerkraut, which are becoming more widely available. Reducing refined sugar and exercising also helps our microbiome, and us, flourish. Different foods have different microbia of their own, which helps increase the bacterial diversity inside of us, so diversity in what we eat matters, too.*