During a fish pedicure, a client's feet are placed inside a tank with small fish called garra rufa.
The fish usually eat plankton but will also eat dead skin in the absence of it.
Authors of the JAMA study warn there are 'inherent risks' associated with fish pedicures.
The study says, 'Tubs and fish cannot be adequately sanitized between people, and the same fish are typically reused for successive persons.
'There are concerns of transmitting infections...several bacteria capable of causing diseases in humans were isollated from batches of garra rufa and waters from 24 fish spas.'