Effects of removing in-feed antibiotics and zinc oxide on the taxonomy and functionality of the microbiota in post weaning pigsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study used shotgun metagenome sequencing to track the taxonomic and functional evolution of the faecal microbiota in piglets during the first two weeks after weaning. It compared three management strategies: in-feed antibiotics, therapeutic zinc oxide, and no medication, in the context of post weaning diarrhoea (PWD), a major driver of antimicrobial use. The goal was to understand how removing these interventions, as required by new EU regulations, affects the piglet gut microbiota and to inform alternative approaches to controlling PWD.
Who was studied?
The subjects were post weaning piglets housed on commercial farms that routinely use antimicrobials during the post weaning period. Animals were divided into three experimental groups receiving in-feed antibiotics, therapeutic zinc oxide, or no medication. Faecal samples were collected and analyzed across multiple days post weaning and across multiple farms, though the abstract does not give an exact animal count.
What were the most important findings?
Microbiota diversity was affected by day post weaning, treatment, and diarrhoea status, but not by which farm the pigs were on, and composition shifted toward dominance by groups such as Prevotella spp. by day 14. Zinc oxide inhibited E. coli overgrowth, increased abundance of the family Bacteroidaceae, and decreased Megasphaera spp. Pigs treated with antibiotics showed inconsistent taxonomic changes over time, with an overall rise in Limosilactobacillus reuteri and Megasphaera elsdenii. Non-medicated pigs showed virulence-related functions at day 7 post weaning.
What are the greatest implications of this study?
The findings show that zinc oxide has a more consistent, taxonomically defined suppressive effect on E. coli overgrowth than in-feed antibiotics, which produced more variable microbiota changes over time. This distinction is relevant as the EU restricts both interventions and producers seek alternatives to control post weaning diarrhoea. The detection of virulence-related functions in non-medicated pigs early after weaning underscores the vulnerability of the unmedicated microbiota during this period and the need for new, function-informed strategies to manage it.