The gut symbiont Lactobacillus reuteri as a model to study the interplay between diet and phage-host interactions
Dr. Jan-Peter van Pijkeren
December 6 at 12:20pm in the Fralin Auditorium, 102 Fralin Hall
Hosted by Dr. X Luo
JP van Pijkeren received in 1999 his BS-degree in Biotechnology from the Noordelijke Hogeschool Leeuwarden, and in 2002 he received his MS-degree in Microbiology from Leiden University in The Netherlands. In 2007, JP completed his PhD studies in the Alimentary Pharmabiotic Center at University College Cork, Ireland, where he studied cell surface proteins of probiotics. In his postdoctoral studies that he developed Listeria monocytogenes as delivery vehicle of DNA into solid tumors. In a second postdoctoral appointment he developed genome editing tools for use in probiotics. Since 2013, JP is an Assistant Professor in the Department of Food Science at University of Wisconsin-Madison. In the first 5 years of his appointment, he expanded the genome editing tool box in lactobacilli. Currently, JPs research remains centered around probiotic bacteria and focusses on understanding the mechanisms by which bacterial viruses are produced in the gut. Improved understanding of gut fitness is implemented towards the development of next-generation probiotics to deliver therapeutics.
The mammalian intestinal tract contains a complex microbial ecosystem with many lysogens, which are bacteria containing dormant phages (prophages) inserted within their genomes. Approximately half of intestinal viruses are derived from lysogens, suggesting that these bacteria encounter triggers that promote phage production. We show that prophages of the gut symbiont Lactobacillus reuteri are activated during gastrointestinal transit and that phage production is further increased in response to a fructose-enriched diet. Fructose and exposure to short-chain fatty acids activate the Ack pathway, involved in generating acetic acid, which in turn triggers the bacterial stress response that promotes phage production. L. reuteri mutants of the Ack pathway or RecA, a stress response component, exhibit decreased phage production. Thus, prophages in a gut symbiont can be induced by diet and metabolites affected by diet, which provides a potential mechanistic explanation for the effects of diet on the intestinal phage community.