Strain matters in probiotic selection

Steve Lerner, Ph.D., and head of marketing and product management at Christian Hansen Animal Health and Nutrition, spoke recently on the concept that probiotic strain matters at the National Cattlemen’s Beef Association’s Winter Reboot conference.

“By law, all direct fed microbial products must include on their labels the genus and species that they purport to contain,” Lerner said. “Unfortunately, knowing the genus and species of the organisms in the package really doesn’t give you nearly enough information about which of those direct-fed microbial products is going to be an effective probiotic. It’s the strain of the organism that’s most important and that’s why we say strain matters.”

According to Lerner, a strain is an individual organism and it has trillion upon trillions of nearly identical clonal copies. He said probiotic users must understand the relative magnitude of genetic diversity that exists for different types of organisms.

“In truth, it’s that variation in genetics that enables us to select the best individuals for a specific purposes,” he said. “If we look at the genetic diversity of types of animals from mice to people to chimpanzees, we find that genetically speaking, mice differ from humans by about 10% and chimpanzees are closer to us with 96% similarity. If we were to compare individual humans at the level of DNA base pairs, then humans are about 99.9% one to another.”

For other traits like Bacillus subtilis—a gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants and humans—there is as much as an 18% genetic diversity and where that diversity exists is incredibly important.

“If we focus on Bacillus subtilis, we know there are 3,722 genes that control every function of that organism and based on scientific research, we know that there are over 1,000 of those genes that are divergent, that is to say that individual strains of the same genus and species can differ across an array of over 1,000 functional genes,” Lerner explained. “Where those differences exist must be considered when choosing an individual for a particular purpose. There is a 66% genetic divergence in the capacity to produce antimicrobial peptides, which is what gives some organisms their capacity to compete in their environment against potentially pathogenic strains. We want to select strains that, based on their genetics, have the best set of gifts that enable them to deliver truly probiotic results.”

Lerner said when measuring probiotics in populations of animals, whether it is their effect in beef steers or a herd of dairy cattle, chickens or pigs, there is a noticeable shift toward positive distribution and a reduction in variation. He said research studies have shown a shift toward heavier carcass and an increase of about 20 pounds average daily gain per animal studied.

According to Lerner, in one study where 30 calves were exposed to Clostridium perfringens—a gram-positive, spore-forming anaerobic bacteria that is normally found in the intestines of humans and animals—eight of the 30 calves succumbed to the infection. The percentage of normal scores were significantly higher for the group of calves that received an effective probiotic.

“When we look at survival, only four of the control calves survived, whereas eight of the 10 calves on the effective probiotic survived and all of the calves on our best probiotic survived the challenge,” he said. “What we believe is for producers who want those in their care to have the best opportunity to achieve their full potential, absolutely nothing feels better than a normal and stable herd, lot, flow or flock.”

Lacey Newlin can be reached at 620-227-1871 or [email protected].