'bacteriotherapy' originates from Greek, specifically the words 'bakterion' and 'therapeia', where 'bakterion' meant 'little rod' and 'therapeia' meant 'healing'.

'bacteriotherapy' changed from Neo-Latin/modern coinage combining 'bacterio-' (from Greek/Neo-Latin 'bacterium' < 'bakterion') and 'therapia'/'therapy' (from Greek 'therapeia' via Latin/Old French) and eventually became the modern English word 'bacteriotherapy' through 20th-century scientific usage.

Initially, the roots referred literally to 'healing related to bacteria,' but over time the compound evolved to mean 'a medical treatment that uses live bacteria or bacterial communities to restore or alter the microbiome.'