Probiotics may pose a risk to animal and human health

Probiotics may not be as beneficial to animal and human HEALTH as people think, according to a new Kansas State University study. In most cases, probiotics are considered beneficial organisms for gut health in animals and humans.

Raghavendra Amachawadee, assistant professor of beef and dairy cattle therapy at the State College of Veterinary Medicine, and his team found that the bacterial species Enterococcus faecium, which is found in several commercial swine and cattle products, may be a source of antibiotic resistance, the report said.

“While probiotics are beneficial bacteria, some types of bacteria can have unintended negative effects,” Amachawady says in a press release. “Our study showed that Enterococcus faecium carries genes that confer resistance to antibiotics widely used in human medicine. Feeding such foods to animals raises the possibility that genes can be passed on to pathogenic bacteria and make them resistant to antibiotics that can be inherited by humans.”

For now, he says it's only a theoretical possibility. There is no evidence that such transmission actually occurs in the gut and subsequent human exposure.

The study used whole genome sequencing to assess virulence potential, identify antimicrobial resistance genes, and analyze phylogenetic relationships of E. faecium strains from commercial probiotics for pigs and cattle.

“Because the use of antibiotics creates resistance in bacteria, which is a major public health issue, manufacturers are looking for replacements for antibiotics,” Amachawady says in a press release. "Most commercial probiotic products contain live bacteria that benefit animals by improving the balance of bacteria in the gut."

The study suggests that in the future, probiotic products may need to be tested for antimicrobial resistance genes before being sold for use in beef and dairy cattle.

The study, funded in part by a grant from the National Pork Council, involved researchers from the Departments of Animal Science and Industry, Diagnostic Medicine and Pathobiology, and the U.S. Food and Drug Administration's Center for Food Safety and Applied Nutrition in Laurel. state of Maryland.

“Estimation of virulence potential, susceptibility and antimicrobial resistance of Enterococcus faecium strains isolated from commercial probiotic products for pigs and cattle based on whole genome sequencing” was published recently in the Journal of Animal Science.