Microbiome In Post-Weaning Piglets - Effect Of Pharmasin® Administration
Ulrich Klein
The weaning period is a crucial time in the life of pigs, as the gut microbial composition is still developing. Establishment and maintenance of a beneficial gut microbiota is crucial, since several gut colonizers are pivotal for the establishment of a stable, permanent microbial community. Piglets are frequently exposed to antibiotics post-weaning to treat outbreaks of intestinal and respiratory diseases; thus, it is important to understand how antibiotic administration affects the intestinal microbiota.
Gut microbiome development in pigs - a natural process
In healthy piglets, the diversity of the gut microbiota changes before and after weaning. The major factor influencing shifts in the microbiota of piglets at weaning is transitioning from sow milk to solid feed which contains complex nutrients. Studies have shown that on a bacterial family level, the relative abundances of Bacteroidaceae and Enterobacteriaceae decline, while over time those of Prevotellaceae, Ruminococcaceae, Lachnospiraceae and Succinivibrionaceae increase in weaned piglets as shown in Figure 1.
Figure 1. Gut microbial composition shifts post-weaning
Antibiotic use and effect on microbiota
Antibiotics are a critical tool for fighting bacterial infection in veterinary medicine. Post weaning, pigs are highly susceptible to a number of enteric diseases such as colibacillosis, ileitis, colitis, and Clostridium perfringens infections. Practices that maintain the ability to treat animals but limit the disturbance to the gastrointestinal microbiota are an important component of antibiotic stewardship.
In a study, the effect of Pharmasin® tylosin water medication (treatment dose of 5 mg/kg bodyweight for 7 days, day 0 to day 6) on the microbiome composition in healthy weaned pigs was investigated. Faecal samples were collected from non-medicated pigs (control) and from treated pigs on the same days; prior (day 0) and after Pharmasin® treatment (on day 3, day 7, day 14, day 21, day 28, day 35 and day 42). All samples were analysed with 16S rRNA metataxonomics to identify bacterial composition and diversity.
Bacterial profiles of samples taken from the Pharmasin® treated pigs differed from those taken from non-medicated pigs. Abundance levels of Prevotellacceae, Ruminococcaceae, Lachnospiraceae and Succivibrionaceae were consistently higher in the tylosin-medicated pigs compared to the non-medicated control group (Figure 2). Higher abundances of Prevotellacceae, Ruminococcaceae, Lachnospiraceae and Succivibrionaceae bacteria in the tylosin group are in line with the shift of the microbial composition observed post-weaning and linked to a carbohydrate fermenting microbiota. The decrease in Bacteroidaceae, Peptostreptococcaceae and Clostridiaceae bacteria abundances (Figure 3) further confirms this microbiota shift post-weaning.
Figure 2. Abundance (in %) of Prevotellaceae, Lachnospiraceae, Ruminococcaceae and Succivibrionaceae in the tylosin and control groups
Figure 3. Abundances (in %) of Bacteroidaceae, Clostridiaceae and Peptostreptococcaceae in the tylosin and control groups
Stable and balanced gut microbiome
Treatment with tylosin does not negatively affect the physiological microbiota maturation post-weaning. Pharmasin® tylosin even seems to have a positive effect on the gut microbiota homeostasis and stabilization of the intestinal microbial community.