Submitted to: Infection and Immunity
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/19/2012
Publication Date: 6/1/2012
Citation: Li, R.W., Wu, S., Li, W., Hill, D.E., Urban, Jr., J.F., Navarro, K., Couch, R.D. 2012. Alterations in the Porcine Colon Microbiota Induced by the Gastrointestinal Nematode Trichuris suis. Infection and Immunity. 80(6):2150-2157. Interpretive Summary: Parasitic infections have a significant economic impact on the livestock industry. Helminth parasite Trichuris suis has the potential to play an important role in human health as well. In this study, we characterized the porcine proximal colon microbiota in response to an experimental T. suis infection using metagenomic tools. Our results suggested that the infection in pigs induced a profound change in the composition of the proximal colon microbiota and led to a severe disruption in the metabolic potential of the gut microbial ecosystems. Our findings provided a scientific basis to formulate a concurrent administration of T. suis eggs with selected probiotic bacterial populations that are altered in the colon microbiota by infection to ameliorate any negative influence of the worm on human and animal physiology.
Technical Abstract: Helminth parasites have evolved to regulate host immunity to ensure their survival through mechanisms that dampen host inflammation. These properties have been recently exploited therapeutically to treat human diseases. The bio-complexity of the intestinal lumen would suggest that interactions between parasite and intestinal microbiota would also influence inflammation. In this study, we characterized the porcine proximal colon microbiota in response to Trichuris suis (whipworm) infection using 16S rDNA-based and whole genome shotgun (WGS) approaches. A 21-day T. suis infection in pigs induced a profound change in the composition of the proximal colon microbiota. The abundance of four of the 15 phyla identified, such as Proteobacteria, was changed in infected pigs. Approximately 10% of genera were significantly altered by infection. Notably, reduced Succinivibrio abundance in infected pigs implied that T. suis infection altered carbohydrate metabolism in the proximal colon microbial ecosystem. Conversely, Mucispirillum was significantly increased in infected pigs suggesting that mucosal disruption induced by parasite infection and feeding perturbed this ecological niche. Infection led to a significant shift in the metabolic potential of the proximal colon microbiota. Approximately 26% of all metabolic pathways indentified were affected by infection. Two important functional categories repressed by infection were carbohydrate metabolism and lysine biosynthesis. Furthermore, changes in pathogen associated pathways suggested that T. suis infection could impact subsequent infection and modulate host-pathogen interactions. Our findings should facilitate development of strategies for parasitic control in pigs and humans and optimize successful helminth therapy to reduce inflammation.