Antibiotic Treatment Early in Pigs' Lives Has Long-Lasting Effects09 October 2015
This study by Dirkjan Schokker and colleagues, published in PLoS One, found that use of antibiotics early in piglets' lives has long-lasting effects on their gut microbiota composition and immune system.
The efficient uptake of nutrients and maintenance of immune homeostasis are major prerequisites for a healthy pig gut.
Immediately after birth, the gut of piglets is colonised by microbiota derived from the sow and the environment. From studies in model organisms (rodents), but also in pigs, it has become clear that this primary colonisation is important for the right development and programming of the animal’s local and systemic immune system.
Since at this stage the necessary regulatory and epigenetic processes underlying gut immune homeostasis have probably not been fully programmed yet, the composition and diversity of the colonising microbiota is highly susceptible to environmental variations.
Experimentally induced changes in early life environmental factors have been associated with variations in the microbial composition at later ages, with variations in immune characteristics, and with differences in the susceptibility to immunological disorders.
In intensive pig husbandry systems, antibiotics are frequently administrated during early life stages to prevent respiratory and gastro-intestinal tract infections, often in combination with stressful handlings.
The immediate effects of these treatments on microbial colonisation and immune development have been described recently. In this study, researchers looked at whether the early life administration of antibiotics has long-lasting effects on the pig’s intestinal microbial community and on gut functionality.
The specific objective was to identify and characterize changes in the composition and diversity of the microbiota in the lumen of the gut and the concomitant (immunological) effects in intestinal tissue at 51 and 172 days after the environmental intervention.
To do that, the researchers used community-scale analysis of gut lumen microbiota and genome-wide transcriptome profiling of intestinal tissue.
To investigate the long-lasting effect of early-life treatment, piglets were divided into three different groups receiving the following treatments:
- no antibiotics and no stress,
- antibiotics and no stress, and
- antibiotics and stress.
All treatments were applied at day four after birth. Sampling of jejunal content for community scale microbiota analysis, and jejunal and ileal tissue for genome-wide transcription profiling, was performed at day 55 (~8 weeks) and day 176 (~25 weeks) after birth.
Antibiotic treatment in combination with or without exposure to stress was found to have long-lasting effects on host intestinal gene expression involved in a multitude of processes, including immune related processes.
The results obtained in this study indicate that early life (day 4 after birth) perturbations have long-lasting effects on the gut system, both in gene expression (day 55) as well as on microbiota composition (day 176).
At day 55 high variance was observed in the microbiota data, but no significant differences between treatment groups, which is most probably due to the newly acquired microbiota during and right after weaning (day 28).
Based on the observed difference in gene expression at day 55, the researchers hypothesised that due to the difference in immune programming during early life, the gut systems respond differently to the post-weaning newly acquired microbiota. As a consequence, the gut systems of the treatment groups develop differently.
The researchers said that this finding opens avenues to steer gut development and other processes through modulation of the microbial colonisation process in the early days of an animal’s life.
You can view the full report and author list by clicking here.