SRA Webinar Series, Workshop, and Round Table Panel Discussion

Understanding Perceptions of Benefits and Risks Posed by Microbiota of Milks

Project Description

Three regional organizations (ROs) of the Society for Risk Analysis (SRA) again partnered in 2017 to address a controversial topic of global significance: Understanding Perceptions and Evidence of Benefits and Risks of Consuming Fresh Unprocessed Milk. The partnering ROs organized a unique risk analysis project beginning with a 2017 webinar series on new scientific evidence and culminating in an international workshop planned for 2020.

RO Project Plan


The safety and health benefits associated with fresh unprocessed milk (raw milk in the US or raw drinking milk in the UK) merit consideration by SRA risk analysis practitioners and stakeholders. In the past (FDA, 2003), risk and attendant uncertainty, but not benefits, were estimated for pasteurized and ‘pre-pasteurized’ milk (not fresh unprocessed milk from licensed dairies intended for consumption as certified raw milk). As scientific knowledge of the impacts of the human microbiome on health and disease continues to advance, the next generation (NextGen) microbial risk assessments cannot continue to exclude the microbiota. The partnering SRA ROs organized this project to include a webinar series to provide necessary context on the microbiota and the history of the ‘milk wars’ for meaningful exercise of analytic-deliberative process in future events with stakeholders from all positions, pro-pasteurization, pro-raw, and neutral.

Phase One - Webinar Series: Microbiota Informing NextGen Risks and Benefits

The partnering ROs organized a 2017 series of 4 webinar sessions, beginning in January and ending in August. The first four webinars were about an hour in duration, with ample time for questions from participants. Podcast recordings of the webinars are posted for the SRA members on the SRA Members Only webpage. Slide sets are available below

Download Slides (PDF) of Microbiota Informing Next-Generation Risks & Benefits - August 2017 Webinar by Peg Coleman and Werner North

Download Slides (PDF) of The Bovine Milk Microbiome - May 2017 Webinar by Dr. Mark McGuire

Download Slides (PDF) of Human Milk: Mother Nature's Prototypical Probiotic Food?  - March 2017 Webinar by Dr. Michelle McGuire

Download Slides (PDF) of Protecting the Human Superorganism - January 2017 Webinar by Dr. Rodney Dietert

Phase Two -  Round Tables and RO Events

The partnering ROs held two Round Table Panel symposia for the 2017 and 2018 SRA annual meetings in Arlington, VA, and New Orleans, LA. Slide sets are available at the links below.

Two events were held by partnering ROs in 2018

Phase Three - Crowdfunding Campaign

A crowdfunding campaign is running through SRA from December, 2018, until February 9th, 2019, to raise funds for preparation of a 'state of the science' manuscripts on benefits and risks of the microbiota of milks, focusing on mechanisms of immune and GI system effects. The manuscripts will be submitted for peer-review to the journal Risk Analysis and a medical microbiology journal.

For more information on the campaign, click on this link:

Phase Four- International Workshop

The partnering ROs plan to organize a 2- to 3-day international workshop in 2020. Stay tuned for updates as planning continues.

Key Supporting References

  1. Addis MF, Tanca A, Uzzau S, Oikonomou G, Bicalho RC, Moroni P. 2016. The Bovine Milk Microbiota: Insights and Perspectives from –omics Studies. Molecular Biosystems DOI: 10.1039/c6mb00217.
  2. Chen Y, Ross WH, Scott VN, Gombas DE. 2003. Listeria monocytogenes: Low levels equal low risk. Journal of Food Protection 66(4):5707.
  3. Coleman M, Elkins C, Gutting B, Mongodin E, Solano-Aguilar G, Walls, I. 2018. Microbiota and Dose-Response: Evolving Paradigm of Health Triangle. Risk Analysis 38(10):2013-2028.
  4. Coleman, M.E., H.M. Marks, R.C. Hertzberg, M.M. Stephenson. 2017. Mechanistic Modeling of Salmonellosis: Update and Future Directions. Human and Ecological Risk Assessment: An International Journal 23(8):1830-56.
  5. Dietert RR. 2018. A Focus on Microbiome Completeness and Optimized Colonization Resistance in Neonatology. NeoReviews 19(2):e78-88.
  6. Dietert RR. 2017. Safety and risk assessment for the human superorganism. Human and Ecological Risk Assessment 23(8):1819-1829.
  7. Dietert RR. 2016. The Human Superorganism: How the Microbiome is Revolutionizing the Pursuit of a Health Life. Dutton, NY, NY. 341 p.
  8. Dietert RR. 2013. Natural childbirth and breastfeeding as preventive measures of immune-microbiome dysbiosis and misregulated inflammation. Journal of Ancient Diseases & Preventive Remedies. 1(2):1-8.
  9. Fischhoff B, Brewer NT, Downs JS. 2011. Communicating Risks and Benefits: An Evidence-Based User’s Guide. FDA report available at:
  10. Food Standards Agency (UK/FSA). 2018. Advisory Committee on Microbiological Safety of Foods. Interim Assessment of whether the Microbiological Risk Associated with Consumption of Raw Drinking Milk (and Certain Raw Milk Products) Made in the UK has Changed since 2015. ACM/1256. Available at:
  11. Heckman JR. 2017. Securing fresh food from fertile soil, challenges to the organic and raw milk movements. Renewable Agriculture and Food Systems Nov: 1-4. Available at 10.1017/S1742170517000618.
  12. Hunt KM, Foster JA, Forney LJ, Schütte UME, Beck DL, McGuire MK, McGuire MA. 2011. Characterization of the Diversity and Temporal Stability of Bacterial Communities in Human Milk. PLoS ONE 6(6): e21313.
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  15. McGuire MK, McGuire MA. 2015. Human Milk: Mother Nature’s Prototypical Probiotic Food? Advances in Nutrition 6(1):112-123. doi:10.3945/an.114.007435.
  16. National Research Council. 1996. Understanding Risk: Informing Decisions in a Democratic Society. National Academies Press, Washington, DC.
  17. Pouillot R, Klontz KC, and Chen Y. 2016. Infectious dose of Listeria monocytogenes in outbreak linked to ice cream, United States, 2015. Emerg Infect Dis 22(12):2113-19.
  18. Pouillot R, Hoelzer K, Chen Y, Dennis SB. 2015. Listeria monocytogenes dose response revisited-incorporating adjustments for variability in strain virulence and host susceptibility. Risk Analysis 35(1):90-108.
  19. Pricope-Ciolacu L., Nicolau A.I., Wagner M., Rychli, K. 2013. The effect of milk components and storage conditions on the virulence of Listeria monocytogenes as determined by a Caco-2 cell assay, International Journal of Food Microbiology 166(1):59–64.
  20. Quigley L, McCarthy R, O'Sullivan O, Beresford TP, Fitzgerald GF, Ross RP, Stanton C, Cotter PD 2013. The microbial content of raw and pasteurized cow milk as determined by molecular approaches. J Dairy Sci 96(8):4928-37. doi: 10.3168/jds.2013-6688. Epub 2013 Jun 5.
  21. Sassone-Corsi, M, & Raffatellu, M. 2015. No vacancy: how beneficial microbes cooperate with immunity to provide colonization resistance to pathogens. The Journal of Immunology 194(9):4081-4087.
  22. Schanler RJ, Fraley JK, Lau C, Hurst NM, Horvath L, Rossmann SN. 2011. Breastmilk cultures and infection in extremely premature infants. Journal of Perinatology 31(5):335-8.
  23. Stasiewicz MJ, Martin N, Laue S, Gröhn YT, Boor KJ, Wiedmann M, et al. 2014. Responding to Bioterror Concerns by Increasing Milk Pasteurization Temperature Would Increase Estimated Annual Deaths from Listeriosis. J Food Protection 77:696e–712.
  24. Whitehead J, Lake B. 2018. Recent Trends in Unpasteurized Fluid Milk Outbreaks, Legalization, and Consumption in the United States. PLoS currents Sep 13;10. Available at