The Microbiome

The human gut harbours a vast number of microbes, including bacteria, viruses, archaea and fungi. Each of us host 10 times as many microbial cells for each human cell and that they can weigh up to 2 kg/4 lbs. This microbial community of 100 trillion cells are formed by a diverse array of groups of several thousand species and strains. They form an ecological community known as the “microbiota”.

Microbes traditionally get a bad press but less than a tiny fraction of the millions of species are harmful to us. Many are crucial to our health playing a role on a number of metabolic functions and keeping our immune system healthy.

The composition of the microbiota has been correlated with, and may play an important role in, a range of diseases and conditions. These are as diverse as autoimmunity, IBS, allergies, diabetes and obesity. The microbiome can also be influenced by and in turn determine how we respond to medicines. It is often not clear in humans whether changes to microbes are causing or resulting from disease – but experimental work in animals has shown that at least in some instances they can promote disease.  These findings are driving an interest in understanding the functions of the microbes inhabiting the human body and their consequences on health. Some now argue that we should now describe the gut microbiota as an “organ” that provides key physiological functions.

“Each of us host 10 times as many microbial cells for each human cell and that they can weigh up to 2 kg/4 lbs.”

We all possess a unique set of microbes a bit like a fingerprint

Our microbiome is very personal to us and research shows that there are great variations among individuals in the number and variety of microbial species that live in the gut. Microbes begin populating the human body from birth and throughout our lives they are affected by what we eat and our environment. Research has shown that microbiota of extant hunter-gatherer populations are much more diverse than those of people living in rich urban areas, with some hunter gatherer tribes hosting twice as many bacterial genes as the average westerner.

“We know that microbial diversity is very important for our health.”

A diverse microbiome

On-going research is trying to identify the important microbial species and in what proportion they should exist in our guts and overall bodies to maintain our health and overall wellbeing. Initial indications show that microbial diversity is key.  A less diverse microbiota is often associated with a less health or diseased state. If we can understand the drivers of microbial diversity we can aim to develop therapies to promote diversity and maximise our health.