Probiotic Expert: Dr. Greg Leyer
It is difficult to spend much time in the probiotic industry without hearing the name “Dr. Greg Leyer”.
Dr. Gregory Leyer, PhD has dedicated the entirety of his 25-year career to the research and development of innovative probiotic solutions. His passion for probiotic advancement has not only made him a critical component of UAS Labs, but a world-renowned expert, educator and speaker in the field.
Learn more about Dr. Greg’s background and influence on the probiotic industry below.
Background
A graduate of the University of Wisconsin-Madison, Greg Leyer received his M.S and Ph.D. in Food Microbiology and Toxicology. There he studyed the pathogenesis of various organisms including Clostridium botulinum and Salmonella typhimurium.
His post-graduate career has since focused on the beneficial effects microbes have on humans.
Dr. Leyer started his career at Abbott Nutrition in Medical Nutritional Product Development, focusing on innovative probiotic solutions for adults and children. He then held several positions at Danisco-DuPont Nutrition and Health, including Global Probiotic Technical Director and Global Business Development Director–Consumer Healthcare, all with an emphasis on probiotics.
After his time at Danisco-DuPont, Dr. Gregory Leyer brought his wealth of experience to UAS Labs.
Current Role & Responsibility
Dr. Leyer currently operates as the Chief Scientific Officer (CSO) of UAS Labs. His activities span research, quality, regulatory affairs, operational technical support, strategy development, customer technical service, and comprehensive instructional training.
To continue driving the industry and UAS Labs forward, Dr. Greg’s research focus encompasses the areas of probiotic formulation, bioprocess development, application development, and clinical sciences.
However, Dr. Greg’s passion for the development of high quality probiotics goes far beyond his corporate experience.
Leadership & Involvement
With 25 years in the industry, Dr. Greg has made an impact on probiotic research that will last a lifetime.
To-date he has authored or co-authored 24 publications in the areas of probiotic clinical results, application know-how, safety parameters, and holds patents in the field. (Publications listed below)
Dr. Greg is also an active professional member of both the International Probiotic Association (IPA) and International Scientific Association for Probiotics and Prebiotics (ISAPP). He has played a prominent role in discussions with the FDA on behalf of the IPA regarding microbial New Dietary Ingredients guidelines. These discussions continue to take place as the regulatory requirements and guideline interpretations are a hot topic.
Dr. Greg has also made his mark as a renowned speaker in the nutraceutical industry.
Dr. Leyer attends most nutraceutical tradeshows around the world. He provides industry professionals with updates on probiotic clinical research and the progression of the probiotic industry as a whole. See below a list of presentations Dr. Greg has given at major events over the past couple of years:
Recent Industry Presentations
2018
- “Weight Management Probiotic Superstrain: BNR17™” at Supply Side West
- “The Emerging Role of Gut Microbes in Cardiovascular Health” at Probiota Americas
- “Probiotic Manufacturing Excellence” at Vitafoods Europe
2017
- “Probiotic Benefits: From the Inside Out!” at Supply Side West
- “Helping the FDA Move Probiotics Forward” at the ISAPP
- “Evidence-based Approach to Supporting Heart Health” at Vitafoods Europe

Involvement Outside the Industry
Outside of the professional sphere of the probiotic and nutraceutical industry, Dr. Greg has held a notable presence in the public domain as well. Dr. Greg has taken numerous opportunities to educate the general public about probiotic cultures and probiotic digestive health through a variety of outlets:
Television News Features
Radio
Webinars

It is Dr. Greg Leyer’s passion for health and wellness and probiotic development that has spurred an abundance of probiotic advancement within the past three decades. His commitment to thorough clinical research has not only driven UAS Labs forward, but the entire industry!
If you are looking for a probiotic company led by world-class scientists who are passionate about providing science-centered probiotics, consider UAS Labs. Our team of scientists led by Dr. Gregory Leyer continue to pioneer the probiotic frontier. Our researchers have verified the benefits of four patented probiotic strains:
- L. acidophilus DDS®-1 for digestive support
- Heart Health Probiotic LRC™
- Weight management Probiotic BNR17™
- Spore-forming probiotic, ProDURA®.
Our team has also developed a rich research packet to support our private label probiotics including our Children’s probiotic formula.
If you plan to attend a nutraceutical tradeshow in the future, be sure to visit UAS Labs for an opportunity to meet world-renowned probiotic expert and Chief Scientific Officer of UAS Labs, Dr. Gregory Leyer, PhD. Or contact our team today to discover how UAS Labs can meet your probiotic needs from Strain to Solution™.
Publications
- Barrangou, R., Briczinski, E.R., Traeger, L.T., Loquasto, J.R., Richards, M., Horvath, P., Couˆte´-Monvoisin, A-C, Leyer, G., Rendulic, S., Steele, J.L., Broadbent, J., Oberg, T., Dudley, E.G., Schuster, S., Romero, D.A., and R.F. Roberts. 2009. Comparison of the Complete Genome Sequences of Bi_dobacterium animalis subsp. lactis DSM 10140 and Bl-04. J. Bact. 191(13): 4144 – 4151.
- Daniel, C., Poiret, S., Goudercourt, D., Dennin, V., Leyer, G., and B. Pot. 2006. Selecting lactic acid bacteria for their safety and functionality by use of a mouse colitis model. Appl. Environ. Microbiol. 72(9): 5799 – 5805.
- Engelbrektson, A., Korzenik, J.R., Pittler, A., Sanders, M.E., Klaenhammer, T.R., Leyer, G., and C. Kitts. 2009. Probiotics to minimize the disruption of faecal microbiota in healthy subjects undergoing antibiotic therapy. J. Med. Micro. 58: 663-670.
- Engelbrektson, A.L., Korzenik, J.R., Sanders, M.E., Clement, B.G., Leyer, G., Klaenhammer, T.R., and C.L. Kitts. 2006. Analysis of Treatment Effects on the Microbial Ecology of the Human Intestine. FEMS Microbial Ecology. 547: 239-250.
- Flickinger, E. A. , B. W. Wolf, K. A. Garleb, J. Chow, G. J. Leyer, P. W. Johns, and G. C.Fahey, Jr. 2000. Glucose-Based Oligosaccharides Exhibit Different In Vitro Fermentation Patterns and Affect In Vivo Apparent Nutrient Digestibility and Microbial Populations in Dogs. J. Nutr. 130: 1267-1273.
- Henriksson, A., Ouwehand, A.C., and G. Leyer. 2009. Probiotics that alleviated symptoms of functional bowel disorders. Aus J Diary Technol. 64(1): 138-141.
- Kihm, D.J., G.J. Leyer, G.H. An, and E.A. Johnson. 1994. Sensitization of Heat-Treated Listeria monocytogenes to Added Lysozyme in Milk. Appl. Environ. Microbiol. 60: 3854-3861.
- Leyer, G. and P. Kolakowski. 2004. Probiotic Applications in the Dairy Industry. Pol. J. Nat. Sci. 2:121-128.
- Leyer, G.J., and E.A. Johnson. 1990. Repression of Toxin Production by Tryptophan in Clostridium botulinum type E. Arch. Microbiol.154: 443-447.
- Leyer, G.J., and E.A. Johnson. 1992. Acid Adaptation Promotes Survival of Salmonella sp. in Cheese. Appl. Environ. Microbiol. 58: 2075-2080.
- Leyer, G.J., and E.A. Johnson. 1993. Acid Adaptation Induces Cross-Protection Against Environmental Stresses in Salmonella typhimurium. Appl. Environ. Microbiol. 59: 1842- 1847.
- Leyer, G.J., and E.A. Johnson. 1997. Acid Adaptation Sensitizes Salmonella typhimurium to Hypochlorous Acid. Appl. Environ. Microbiol. 63(2): 461-467.
- Leyer, G.J., L.L. Wang, and E.A. Johnson. 1995. Acid Adaptation of Escherichia coli O157:H7 Increases Survival in Acidic Foods. Appl. Environ. Microbiol. 61: 3752-3755.
- Leyer, G., Li, S., Mubasher, M., Reifer, C., and A. Ouwehand. 2009. Probiotic effects on cold and in_uenza-like symptom incidence and duration in children. Pediatrics 124;e172-e179.
- Ouwehand, A.C., Søndberg Svendsen, L., and Leyer, G. 2011. Probiotics: from strain to product. In: Probiotics and health claims (Kneifel and Salminen Eds.) J. Willey & Sons, Inc.
- Paineau, D., Carcano, D., Leyer, G., Darquy, S., Alyanakian, M.A., Simoneau, G., Bergmann, J.F., Brassart, D., Bornet, F., and A.C. Ouwehand. 2008. Effects of seven potential probiotic strains on speci_c immune responses in healthy adults: a double-blind, randomized, controlled trial. FEMS Immunol Medical Microbiol. 2008 Jun;53(1):107-13.
- Pariza, M.W., Gillies, K.O., Kraak-Ripple, S.F., Leyer, G., and A.B. Smith. 2015. Determining the safety of microbial cultures for consumption by humans and animals. Regul Toxicol Pharmacol. 73:164-171.
- Polewski, MA, Krueger, CG, Reed, JD, and G. Leyer. 2016. Ability of cranberry proanthocyanidins in combination with a probiotic formulation to inhibit in vitro invasion of gut epithelial cells by extra-intestinal pathogenic E. coli. J. Functional Foods. 25: 123-134.
- Putaala, H., Barrangou, R., Leyer, G.J., Ouwehand, A.C., Bech Hansen, E., Romero, D.A. and N. Rautonen. 2010. Analysis of the human intestinal epithelial cell transcriptional response to Lactobacillus acidophilus, Lactobacillus salivarius, Bi_dobacterium lactis and Escherichia coli. Ben Micro September 2010; 1(3): 283-295.
- Ringel, Y., Ringel-Kulka, T, Maier, D, Carroll, I, Galanko, J, Leyer, G, and O.S. Palsson. 2011. Probiotic Bacteria Lactobacillus acidophilus NCFM® and Bifdobacterium lactis Bi-07 Versus Placebo for the Symptoms of Bloating in Patients with Functional Bowel Disorders—a Double-blind Study. J. Clin Gastro. 45 (6): 518-525.
- Rousseaux, C., Thuru, X., Gelot, A., Barnich, N., Neut, C., Dubuquoy, L., Dubuquou, C., Merour, E., Geboes, K., Chamaillard, M., Ouwehand, A., Leyer, G., Carcano, D., Colombel, J-F., Ardid, D., and P. Desreumaux. 2007. Lactobacillus acidophilus modulates intestinal pain and induces opiod and cannabinoid receptors. Nat. Med. 13(1): 35-37.
- Sanders, ME, Klaenhammer, TR, Ouwehand, AC, Pot, B, Johansen, E, Heimbach, JT, Marco, ML, Tennila, J, Ross, RP, Franz, C, Page, N, Pridmore, RD, Leyer, G, Salminen, S, Charbonneau, D, Call, and I Lenoir-Wijnkoop. 2014. Effects of genetic, processing, or product formulation changes on ef_cacy and safety of probiotics. Annals NY Acad Sci. ISSN 0077-8923.
- Sanders, ME, Merenstein, DJ, Ouwehand, AC, Reid, G, Salminen, S, Cabana, MD, Paraskevakos, G, and G. Leyer. 2016. Probiotic use in at-risk populations. J Amer Pharma Assoc. 56: 680-686.
- Shah, N.P., Ding, W.K., Fallourd, M.J., and G. Leyer. 2010. Improving the stability of probiotic bacteria in model fruit juices using vitamins and antioxidants. J Food Sci. 75 (5): June/July: M278–M282
- Waller, P., Gopal, P., Leyer, G., Ouwehand, A., Reifer, C., Stewart, M., and L. Miller. 2011. Dose-response effect of Bi_dobacterium lactis HN019 on whole gut transit time and functional gastrointestinal symptoms in adults. Scand J Gastro. 46(9):1057-64.