Safety of microbial food cultures: an update

Fermentation is probably one of the oldest food science technologies, used for over 10,000 years by mankind. More recently, however, fermented food products are becoming the new trend in product development, and new combinations are proposed for introduction in the food chain.
Is it something to be assumed safe by design? Most certainly not. Microbial food cultures are considered to be safe based on their traditional historical use, but they are not safe per se. They are safe if used properly in traditional food matrices, but crossover fermentation, as suggested by a team at Wageningen University,¹ is not safe by design.

Lactic acid bacteria are beneficial on dairy matrices, but some are considered spoilers on meat products. Caution and proper risk assessment prior to usage is therefore mandatory, as failure to do so can have severe if not fatal outcomes, as seen most recently in the US with the fatal sepsis of a neonate following probiotic strain ingestion.² There were warning signals, but unfortunately they were not heeded.³