What is this article about?
The gastrointestinal system is home to a thriving and diverse microbial ecosystem otherwise known as the gut microbiome. This community represents an estimated 100 trillion microorganisms, and while the microbiome can consist collectively of up to 1,000 different species, a few dominant bacterial species are the major inhabitants. Comprising 99% bacteria, the microbiome also harbours some yeast, viruses and pathogens that can impact on the wider community. External environmental factors (in particular diet), directly influence microbial balance. Poor nutrition reduces the diversity and alters the finely tuned balance of this gut ecosystem, leading to what is medically termed dysbiosis.