A Survey on Antimicrobial Resistance Genes of Frequently Used Probiotic Bacteria, 1901 to 2022

Commercial probiotic products may contain ARGs or transferable resistance determinants, although the level of risk varies substantially among product types, bacterial taxa and analytical pipelines.

“Previous studies have shown that commercial probiotic products may contain ARGs or transferable resistance determinants, although the level of risk varies substantially among product types, bacterial taxa and analytical pipelines [15,16,17,18,19,20].”

Mobility, ecological opportunity and recipient compatibility determine whether an ARG becomes a clinically relevant hazard.

“This framework is consistent with the broader horizontal gene transfer (HGT) literature, which emphasizes that mobility, ecological opportunity and recipient compatibility determine whether an ARG becomes a clinically relevant hazard [11,12,16,17].”

The present farm-animal dataset appears less concerning than several reports on broader probiotic or food-associated bacterial collections, where ARGs were frequently detected together with plasmid or iMGE signals.

“the present farm-animal dataset appears less concerning than several reports on broader probiotic or food-associated bacterial collections, where ARGs were frequently detected together with plasmid or iMGE signals [16,17].”

Among ARG-positive samples in a large survey by Tóth et al., 66% were linked to plasmids or iMGEs, although no bacteriophage-linked ARGs were found.

“This profile contrasts with the large survey by Tóth et al., where ARGs were detected in several commonly used probiotic species and, among ARG-positive samples, 66% were linked to plasmids or iMGEs, although no bacteriophage-linked ARGs were found [17].”

Probiotic products and probiotic-associated taxa may carry detectable ARGs, but public-health relevance depends on taxon identity, gene function, genomic context and mobility potential rather than on ARG counts alone.

“previous studies have shown that probiotic products and probiotic-associated taxa may carry detectable ARGs, but that public-health relevance depends on taxon identity, gene function, genomic context and mobility potential rather than on ARG counts alone [15,16,17,18,22,23].”