<Copper is a natural antimicrobial material that, when added to pig feed, may promote the growth and health of the animals. Researchers at Texas Tech University in Amarillo recently looked into whether copper could be used to improve gut health and reduce the shedding of microbes into the environment, as pigs can tolerate high levels of the metal.>This week in Microbiology Spectrum, researchers found that adding small copper-containing beads to pig feed can effectively deliver the metal to the animal’s gut. According to Dr. Alexandra Calle, the senior author of the study, the copper is released slowly in the animal’s system, remaining in the gastrointestinal tract for a longer period of time instead of being quickly absorbed in the stomach. In the laboratory, Calle and her team discovered that exposing Salmonella to the copper bead solution resulted in reduced shedding of microbes to the environment, which can contribute to better overall health.lted in a significant decrease in the bacterial pathogen population. They were hopeful that their animal experiments would also demonstrate the effectiveness of the copper beads in reducing microbial pathogens in the gut.
The researchers divided a group of 48 6-month-old pigs, with an equal number of male and female pigs, into two groups. During the second week of a 3-week study, one group was fed normal feed while the other group was fed feed with added copper beads. Feces were collected from the pigs throughout the experiment, and copper levels were measured using atomic spectroscopy. Additionally, microbial species were identified using 16s RNA sequencing.
Lead researcher Calle and her colleagues…Leagues chose 2 families of bacteria to examine as indicators of how copper affected the gut microbiome. One family was Enterobacteriaceae, a group of microbes that includes Salmonella, Shigella, Escherichia coli, and others, some of which can be pathogenic. The other family consisted of lactic acid bacteria, which have been associated with health and nutritional benefits. Animals in the experimental group had approximately 20 times more copper in their feces compared to the control group. Once they stopped receiving copper, their metal levels returned to normal. These measurements confirmed that the copper had an impact.The metal was effectively delivered. Analyses of the microbial populations revealed that the addition of copper resulted in increased levels of Enterobacteriaceae and decreased levels of lactic acid bacteria in the control group. This was not the expected outcome for the researchers. Calle mentioned that their goal was to lower the levels of Enterobacteriaceae, but the opposite occurred. She believes that the reduction of lactic acid bacteria by copper made it easier for Enterobacteriaceae to colonize the gut. However, despite these results, the researchers remain optimistic. This was their initial attempt at the experiment.Calle stated that the purpose of the project is to create a “pre-harvest intervention” to improve the gut health of animals before they are slaughtered for food. The next step is to use the beads to target harmful microbes and maximize the benefits of gut health. The research was published in the Mic journal and was authored by Mariana Fernandez, Jonathan Thompson, and Alexandra Calle.The article “Biology Spectrum” was published in 2024 and can be accessed at DOI: 10.1128/spectrum.04280-23.