BY Lucy Taylor September 12, 2019
From the inside of our gut to the surface of our skin, our bodies are host to thriving communities of microbial life. These microbes - which are so small that they can only be viewed under a microscope - make up the human microbiome.
While it's commonly quoted that these microbial cells outnumber our own human cells by a factor of 10, scientists now believe that the ratio is likely closer to one-to-one(1), meaning for every cell of your body, there’s a microbial cell to match it. In fact, an adult’s microbiome weighs in at around 200g, which is roughly the same as a large orange!
The most diverse and abundant community of microbes live in our gut, which is referred to as the gut microbiome. We live in harmony with our gut microbes; we provide them with food and a nice place to live, and they repay the favour by protecting our body from invasion from disease-causing microbes, help us to extract energy from our food, and even synthesise certain vitamins. In recognition of their vital role in maintaining our health, some scientists believe the gut microbiome should be reclassified as an additional organ of the body (2), just like the lungs or kidneys.
While the types and numbers of microbes we host in our gut generally remains stable over time, a number of factors can disrupt this balance, such as taking a course of antibiotics, excessive stress, or major changes to our diet. A disruption to our gut microbiome which negatively affects our health is referred to as ‘dysbiosis’, and is associated with a number of diseases, including inflammatory bowel disease (3), asthma (4), and even obesity (5). More than 2000 years ago, a Greek physician named Hippocrates is credited with saying ‘All disease begins in the gut’ (6), and it is now widely accepted by modern science that the influence of the gut microbiome extends far beyond our digestive tract.
As scientists unravel the complex relationship between the health of our gut microbiome and many aspects of our health and wellbeing, there is an emerging role for clinically researched probiotic products to support a range of conditions, including our mood, immunity, and even bone health.