OSU One Health research targets swine microbiome to reduce antibiotic reliance

Monday, March 18, 2024

Media Contact: Sydney Trainor | Communications and Media Relations Specialist | 405-744-9782 | sydney.trainor@okstate.edu

When piglets are 3 weeks old, they are weaned. This change abruptly switches their diet from liquid of a sow’s milk to a solid diet which they eat for three months until they are market ready.  

The change in diet is a highly stressful period for piglets, making them susceptible to infection, diarrhea and other problems. If the piglets can be managed effectively during that phase, limiting infection and sickness, then they are usually healthy during the rest of production.  

Traditionally, infection treatments are to give piglets antibiotics. However, the mass use of antibiotics causes antibiotic resistance, which has become a One Health problem affecting both animal agriculture and human medicine.  

Dr. Joy Scaria, OSU’s Walter R. Sitlington Endowed Chair in Infectious Diseases, has been awarded a $385,000 U.S. Department of Agriculture grant to investigate microbiome-targeted interventions for swine gastric disorders over three years.

The collaborative study includes researchers from Auburn University and Iowa State University who, along with OSU, split the total grant of $770,000 aimed at developing antibiotic-reducing treatments for healthy swine.    

“We know that when a healthy complex gut microbiome is present, then these diarrheal issues like E. coli infection do not happen. So, in mature pigs, E. coli infection is not an issue. We see that in human medicine too,” Scaria said. “A lot of diarrheal infections happen in the infant stage, and as we age, and we develop a healthy microbiome, unless something disastrous happens, we don't get diarrheal infections. That is this pattern between what you're seeing in human medicine, as well as animals.” 

The team is applying lessons learned from human medical practice for animal agriculture.  

Scaria’s research is directly applying this research for improving swine health, but there are broader impacts that also address the issue of mitigating antibiotic resistance in agriculture, and human health.  

These infections are an issue for humans as well because if microbes in animals develop resistance, those resistances transfer to humans through contaminated pork, or by workers getting exposed, and then is spreading in the environment.  

“Reducing antibiotic resistance generally in the environment and the food production system is critical for our well-being,” Scaria said. “In this case, the underlying science is more or less the same because there's a lot of overlap between pig microbiome and the human microbiome.”  

A  study published in 2019 by The Lancet estimated that 1.27 million deaths were directly caused by drug resistance they also estimated that globally, 4.95 million deaths were associated with bacterial antimicrobial resistance, including both deaths directly caused by AMR and those indirectly associated with it. 

According to the Center for Disease Control and Prevention the COVID-19 pandemic attributed to 1.1 million deaths as of Sept. 12, 2023. 

“Antibiotic resistance now is sort of considered as a silent pandemic, that takes out five million people every year,” Scaria said. “By 2050, if we don't do anything, it will become like close to 75 million per year. It's a huge problem of boiling and simmering, and we really need to address it. So, alternatives to antibiotics in all spheres of treatment, both in human as well as agriculture is critical.”  

In human health, fecal microbiota transplant, where microbiomes from healthy adults are transferred to infected individuals, has shown effectiveness in treating Clostridium difficile infection. 

“It's a major issue in human medicine because when people take antibiotics for some other infection or surgery, it causes collateral damage, and then this species called  Clostridioides difficile which is otherwise, is not a problem, blooms and then causes infection,” Scaria said. “Since your trigger is antibiotic usage, using more antibiotics aggravates the problem so in response to that, prior doctors have tried taking fecal material from a healthy donor and transplanting it into the patient and it resolves the issue. We now know that fecal transplantation can work as the alternative to antibiotic treatment in both humans and animals.” 

Pigs have served as a model for human medicine, particularly in understanding C. difficile infection due to their diverse microbiome. However, implementing this approach on a large scale in production settings proves challenging due to batch-to-batch variations and concerns regarding the transfer of other infections during the process. 

The question the team is looking to solve is: Can they identify the species responsible for suppressing these pathogens? If so, can they make a defined mix of species instead of transferring the whole feces?   

“The goal is to try a defined mix of beneficial bacteria from adult fecal microbiome and then try this as an antibiotic treatment during post weaning diarrhea in piglets so that they don't need to be treated with antibiotics, and then we can reduce mortality,” Scaria said.  

For this study, Scaria has developed a cultural library healthy microbiota from piglets. He will also be using artificial intelligence to analyze the genomes of this bacteria, to create multiple combinations of a defined mix reduce the number of initial targets and then transplant this in the piglets in the post weaning phase and see how that compares to fecal microbiota transplantation. 

This research is directly helping to build critical mass in OSU in the microbiome research advancing OSU’s land-grant mission enhancing human and animal health research.  

“Before the SARS-CoV2 pandemic, many outside of scientific circles gave little thought to the vital connection between the health of animals, the health of humans, and pathogens in the environment. But years before, OSU had already chosen One Health as a critical interdisciplinary research focus,” said Dr. Kenneth Sewell, OSU vice president for research. “By investing in this emphasis, and the related Microbiome Initiative (now federally funded as the Oklahoma Center for Microbiome Science), we were able to bring Dr. Scaria to OSU. 

“His unique research program is able to isolate exactly which microbes are responsible for specific health effects — going beyond correlation to observe direct causation. We are excited to see the tremendous health impacts that will result from Dr. Scaria’s groundbreaking research.”