Associate Professor and Campus Alberta Innovation Program (CAIP) Chair for Nutrition, Microbes and Gastrointestinal Health
4-126A Li Ka Shing Ctr for Hlth Rsch Innovation
University of Alberta
Canada T6G 2R3
Diploma: 1999 University of Hohenheim, Germany Food Technology
Ph.D.: 2003 University of Hohenheim, Germany Microbiology
March 2014-now: Associate Professor and CAIP Chair for Nutrition, Microbes, and Gastrointestinal Health, Department of Agricultural, Food & Nutritional Science/Department of Biological Sciences, University of Alberta, Canada.
July 2012-February 2014: Associate Professor at the Department of Food Science and Technology, University of Nebraska at Lincoln, USA.
Sept. 2006-June 2012: Assistant Professor at the Department of Food Science and Technology, University of Nebraska at Lincoln, USA.
August 2004-Sept. 2006: Research Fellow at University of Otago, Department of Microbiology & Immunology, Dunedin, New Zealand in the laboratory of Prof. Gerald. W. Tannock.
May-July 2004: Postdoctoral Fellow at University of North Carolina, Department of Medicine, Chapel Hill, USA in the laboratory of Prof. R. Balfour Sartor.
March 2003-April 2004: Postdoctoral Fellow at University of Otago, Department of Microbiology & Immunology, Dunedin, New Zealand in the laboratory of Prof. Gerald W. Tannock.
Major Responsibilities/Research Interests
Dr. Walter’s research is primarily concerned with the microbial ecology of the human and animal gastrointestinal tract and the metabolic and immunological interactions between the microbiome and its host in relation to health. He views the interrelationship of gut microbes with their host as a symbiosis and is especially interested in the evolutionary processes that have shaped this partnership and the biological outcomes for both the host and the microbes. He is also interested in how environmental factors (such as diet and lifestyle) and historic processes impact the microbial communities in the gut and what consequences their effects have for the host. His research, which is inter-disciplinary and highly collaborative, has resulted in several publications on the evolution of the model gut symbiont Lactobacillus reuteri, the importance of environmental (diet) and host factors (host genotype) on the composition and functionality of the gut microbiota, and the impact of diet on gut microbial ecology in relation to health.
- Clemente JC, Pehrsson EC, Blaser MJ, Sandhu K, Gao Z, Wang B, Magris M, Hidalgo G, Contreras, M, Noya-Alarcon O, Lander O, McDonald J, Cox M, Walter J, Oh PL, Ruiz JF, Rodriguez S, Shen N, Song SJ, Metcalf J, Knight R, Dantas G, Dominguez-Bello MG. The microbiome of uncontacted Amerindians. Science Advances (with research commentary in the Research Highlights of the journal Nature). 1:e1500183 (2015).
- Martinez I, Stegen JC, Maldonado-Gomez MX, Eren AM, Siba PM, Greenhill AR, and Walter J. The fecal microbiota in adults from two non-industrialized regions of Papua New Guinea. Cell Reports (on the cover and with research commentary in the Research Highlights of the journal Nature). 11:527-538 (2015).
- Bindels LB, Delzenne NM, Cani PD, and Walter J. Towards a more comprehensive concept for prebiotics. Nature Reviews in Gastroenterology & Hepatology. 12:303-310 (2015).
- Krumbeck JA, Maldonado-Gomez MX, Martinez I, Frese SA, Burkey TE, Rasineni K, Ramer-Tait AE, Harris EN, Hutkins RW, and Walter J. Introducing the concept of in vivo selection to identify bacterial strains with enhanced ecological performance when used in synbiotic applications. Applied and Environmental Microbiology. 81:2455-2465 (2015).
- Walter. J. Murine Gut Microbiota-Diet Trumps Genes. Cell Host and Microbe. 17:3-5 (2015).
- Leamy LJ, Kelly SA, Nietfeldt J, Legge RM, Ma F, Hua K, Sinha R, Peterson DA, Walter J, Benson AK, and Pomp D. Host genetics and diet, but not immunoglobulin A expression, converge to shape compositional features of the gut microbiome in an advanced intercross population of mice. Genome Biology. 15:552 (2014).
- Spinler JK, Sontakke A, Hollister EB, Venable SF, Oh PL, Balderas MA, Saulnier DM, Mistretta TA, Devaraj S, Walter J, Versalovic J, Highlander SK. From prediction to function using evolutionary genomics: Human-specific ecotypes of Lactobacillus reuteri have diverse probiotic functions. Genome Biology and Evolution 19:1772-1789 (2014).
- Frese SA, MacKenzie DA, Peterson DA, Schmaltz R, Fangman T, Zhou Y, Zhang C, Benson AK, Cody LA, Mulholland, Juge N, and Walter J. Molecular characterization of host-specific biofilm formation in a vertebrate gut symbiont. PLoS Genetics. 9:e1004057 (2013).
- Cullender TC, Chassaing B, Janzon A, Kumar K, Muller CE, Werner JJ, Angenent LT, Bell ME, Hay AG, Peterson DA, Walter J, Vijay-Kumar M, Gerwirtz AT, and Ley RE. Innate and adaptive immunity interact to quench microbiome flagellar motility in the gut. Cell Host and Microbe (on the cover and with commentary in same journal). 14: 571-581 (2013).
- Martínez I, Muller CE, and Walter J. Long-Term Temporal Analysis of the Human Fecal Microbiota Revealed a Stable Core of Dominant Bacterial Species. PLoS ONE. 8(7):e69621 (2013).
- Walter J, Martínez I, and Rose DJ. Holobiont nutrition: Considering the role of the gastrointestinal microbiota in the health benefits of whole grains. Gut Microbes. 4(4): 340-346 (2013).
- Martínez I, Perdicaro DJ, Brown AW, Hammons S, Carden TJ, Carr TP, Eskridge KM, and Walter J. Diet-induced alterations of host cholesterol metabolism are likely to affect gut microbiota composition in hamsters. Applied and Environmental Microbiology. 79:516-524 (2013).
- Martínez I, Lattimer JM, Hubach KL, Case JA, Yang J, Weber CG, Louk JA, Rose KJ, Kyureghian G, Peterson DA, Haub MD, and Walter J. Gut microbiome composition is linked to whole grain-induced immunological improvements. ISME Journal. 7:269-280 (2013).
- Oh, P.L., Martínez, I., Sun, Y., Walter, J., Peterson, D.A., and Mercer, D.F. Characterization of the Ileal Microbiota in Rejecting and Non-Rejecting Recipients of Small Bowel Transplants. American Journal of Transplantation (with commentary in Nature Reviews Gastroenterology and Hepatology). 12:753-762 (2012).
- Davis, L.M., Martínez, I, Goin, C., Walter, J., and Hutkins, R.W. Barcoded Pyrosequencing reveals that consumption of galacto-oligosaccharides results in a highly specific bifidogenic response in humans. PLoS ONE. 6:e25200 (2011).
- Walter, J., and Ley R.E. The human gut microbiome: ecology and recent evolutionary changes. Annual Reviews of Microbiology. 65:411-429 (2011).
- Walter, J., Britton, R. A., and Roos, S. Microbes and Health Sackler Colloquium: Host-microbial symbiosis in the vertebrate gastrointestinal tract and the Lactobacillus reuteri paradigm. Proceedings of the National Academics Sciences USA. 108: Suppl. 1:4645-4652 (2011).
- Frese SA, Benson AK, Tannock GW, Loach, DM, Kim J, Zhang M, Oh PL, Heng NCK, Patil PB, Juge N, MacKenzie DA, Pearson BM, Lapidus A, Dalin E, Tice H, Goltsman E, Land M, Hauser L, Ivanova N, Kyrpides NC, and Walter J. The evolution of host specialization in the vertebrate gut symbiont Lactobacillus reuteri. PLoS Genetics (with commentary in Nature Reviews in Microbiology). 7(2): e1001314 (2011).