This issue of Microbiology Australia is on the topic of probiotics. The word ‘probiotic’ meaning ‘for life’ is derived from Latin ‘pro’ and Greek ‘bios’. According to the World Health Organization and the Food and Agriculture Organization of the United Nations, probiotics are defined as ‘live microorganisms which when administered in adequate amounts confer a health benefit on the host’1, while a very similar definition, albeit with the term ‘body’ (i.e. not plant), is used by the US National Institutes of Health: ‘. . . live microorganisms that are intended to have health benefits when consumed or applied to the body.’2.