At the time of birth the human body is sterile- it has no bacteria in the system and with the first breath and first feed bacteria reach the breathing and intestinal passage respectively. Most people may be unaware that this is vital not only for their well-being but also for survival. These bacteria play a vital part in our health and defence against diseases. We have a close relationship with the microbes in various parts of the body such as the skin mouth and digestive tract. This is known as the microbiome. The balance of bacteria in these areas is