The European Food Safety Authority’s (EFSA’s) Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) has issued an opinion on Bacillus species used in animal production as microbial feed additives or as the source of other feed additives, mainly enzymes.

Noting that the main “concern for humans, and, to a lesser extent livestock, associated with Bacillus is a capacity for toxin production,” the FEEDAP Panel cautions that the capacity for toxin production and the nature of the toxins produced is “unevenly distributed over the genus, occurring frequently in some species and more rarely in others.”

According to the panel, the selection of strains belonging to the B. cereus taxonomic group for direct use in animal production is considered inadvisable. For other species, “concerns appear to be associated to the production of surfactin like-lipopeptides, although the relation between the presence of these compounds and/or other toxic factors and the risk of illness in humans has not yet been established.”

The panel also concluded that “in the absence of animal models shown to be able to distinguish hazardous from non-hazardous strains,” it relies on the use of “in vitro cell-based methods to detect evidence of a cytotoxic effect . . . If the strain proves to be cytotoxic it is not recommended for use.”