Comparison of fecal microbiota among healthy piglets during the weaning transition using barcoded 16S rDNA pyrosequencing

Abstract Text: The objective of this study is to investigate change in the fecal microbiota of healthy piglets during the weaning transition using barcoded pyrosequencing of the prokaryotic 16S rRNA gene. It is believed that the gastrointestinal microbiome changes over time beginning from birth until adulthood in response to changes in diet, environmental stress and diseases. In particular, the weaning process results in reduced metabolic activity, malabsorption of nutrients, and susceptibility to enteric diseases as a consequence of abrupt separation from the sow prior to joining other litters in a different environment. Fifteen crossbred piglets weaned on the day 28 were used in the study. Fecal samples were obtained immediately prior to weaning (4 weeks of age) and after weaning (6 weeks of age), and were subjected to genomic DNA extraction for pyrosequencing analysis. As the piglets underwent the weaning transition a trend toward increased bacterial diversity was observed, based on species abundance as measured by the Shannon-Weaver index. Firmicutes (54.0%) and Bacteroidetes (59.6%) were the most dominant phyla during pre-weaning and post-weaning, respectively. During the weaning transition a distinct shift from Bacteroides sp. to Prevotella sp. as the most abundant genus was observed. Additionally, we detected a number of abundant species in the piglet gastrointestinal tract that have not been reported previously. Clostridium rectum, C. clostridioforme, C. lactatifermentans and Butyricimonas virosa were uniquely detected prior to weaning while Roseburia cecicola and Blautia wexleraewere detected during the post-weaning period only.

Keywords: Bacterial diversity, Piglets, Weaning