Microbes and Microbiota: Benefits and Risks

Third of Five Reasons to Follow SRA

Connect with SRA specialty groups to learn more about opportunities to engage in inter-disciplinary collaborations related to assessing, communicating, and managing risks.

The Society for Risk Analysis (SRA) currently recognizes 16 specialty groups that represent substantive or disciplinary area of interest relating to risk analysis. The interdisciplinary nature of risk analysis requires representation of diverse disciplines on risk analysis teams, including the natural sciences (biology, chemistry, ecology, microbiology, etc.), social sciences, mathematics and statistics, law, and decision sciences. See list of SRA specialty groups, contacts, and websites appended.

This blog describes examples of both well established and newly formed specialty groups of interest to SRA members, as well as some of their activities. Only SRA members are eligible to participate in elections for the officers serving the specialty groups, as described in their charters. Some activities of specialty groups are free and open to the public.

 SRA Specialty Group Chairs. See appended list for contacts.

SRA Specialty Group Chairs. See appended list for contacts.


An essential element of most risk assessments is a qualitative or quantitative description of the doses of a hazard (for example, a chemical, physical hazard, or microbial pathogen) that cause beneficial or adverse responses in humans or the environment. DRSG members examine scientific data and generate dose-response models to predict the chance of responses from experiments administering measured doses of hazards to human volunteers, animals, or in vitro systems including cell and organ cultures. Dose-response modeling is crucial to determining safe doses unlikely to cause adverse responses to chemicals and microbes. Strong scientific evidence would include knowledge of the underlying causal mechanisms for the responses, understanding of how responses increase in frequency or severity with increasing dose, and implications for regulatory choices to minimize risk.

DRSG members have interests in:

  • methods to assist in analyzing the benefits of measures that are expected to alter risks to chemical, physical, and microbial hazards;

  • advancing the integrated use of mechanistic, animal, and epidemiologic data to estimate risks at lower doses than can be directly assessed in animal toxicology or human studies; and

  • providing opportunities for vigorous interdisciplinary exchange in our sponsored symposia and teleseminars led by invited speakers.

DRSG is a large and well established SRA specialty group active since 1993. DRSG hosts open teleconference meetings each month (first Tuesday of the month from 12:00-1:00 PM Eastern time). DRSG plans and hosts free open teleseminars on first Tuesdays in March, June, and September. Instructions for joining the electronic mail notification list are available on the DRSG website. SRA members and non-members are welcome to participate in DRSG monthly meetings and teleseminars.

Due to SRA’s emphasis on interdisciplinary collaborations, many specialty groups organize joint events and joint projects. The Dose-Response and Microbial Risk Analysis groups recently supported a joint symposium at the annual SRA meeting that resulted in a publication entitled Microbiota and Dose Response: Evolving Paradigm of Health Triangle in the SRA journal Risk Analysis.

 Figure 2. People with  healthy microbiomes  ( blue ovals ,  rightmost dose-response curve ) can  ingest significantly more pathogens before becoming ill  than those with  microbiomes disrupted by antibiotics  ( red ). Coleman et al., 2018.

Figure 2. People with healthy microbiomes (blue ovals, rightmost dose-response curve) can ingest significantly more pathogens before becoming ill than those with microbiomes disrupted by antibiotics (red). Coleman et al., 2018.

The authors introduce key studies that demonstrate protective effects of natural gut and nasal microbes (microbiota) and the unintended loss of the protective microbiota with antibiotic treatment. The figure from this paper depicts a family of dose-response curves for human salmonellosis. The horizontal axis represents increasing dose of salmonella bacteria from less than 100 on the left to more than 10 million on the right. The vertical axis represents increasing chance of developing salmonellosis at administered doses from zero to 1 (100%) at the top of the figure. People whose natural microbiota is disrupted by antibiotics (red ovals) are sensitive to much lower doses of pathogens than people with healthy microbiota. Health benefits of the natural microbiota are biologically relevant to assessing, communicating, and managing microbial risks.

Risk and Development Specialty Group (RDSG)

The RDSG is a recent addition to the SRA list of specialty groups that serves as a focal point for crucial topics including risk and sustainable development, risks associated with poverty, risks of economic growth, risk and distributional equity, risk and international development assistance, and at-risk youth and community development. These topics can engage risk analysts with expertise in many disciplines, including health, environment, economics, engineering, decision making, communication, and law and policy. Major debates from global to local scales interact deeply with issues of risk, development, and social justice.

Risk Communication Specialty Group (RCSG)

RCSG is a large and well established group that focuses on the communication of risk information between technical and lay audiences. Typical members are interested in: perceptions of risk; public participation; mass media coverage of risk; emotionality, trust and credibility; social influence; and evaluation related to risk -communication activities. The purpose of the group is to facilitate the exchange of ideas and knowledge among practitioners, researchers, scholars, teachers, students, and others to encourage collaborative research, provide leadership, build scholarship, and play an active role in advancing the field of risk communication.

SRA members interested in the RCSG consider conflicts over beliefs, values, and interests, as well as misunderstandings and misrepresentations of scientific uncertainty, communicating uncertainty and consensus amid controversy, and acknowledging and debunking misinformation.

SRA and National Academies of Sciences, Engineering, and Medicine

Many SRA specialty group members also contribute more broadly to interdisciplinary work through service on National Academies of Sciences, Engineering, and Medicine committees and colloquia. The National Academies are private, nonprofit institutions that provide expert advice on some of the most pressing challenges facing the nation and the world. Their work helps shape sound policies, inform public opinion, and advance the pursuit of science, engineering, and medicine. Over many decades, the National Academies have earned a solid reputation as the nation's premier source of independent, expert advice on scientific, engineering, and medical issues. Search for reports from committees and colloquia of the National Academies that can all be downloaded for free.

 Download for free  here .

Download for free here.

A particularly timely report of interest to many SRA members and their favorite specialty groups is The Science of Science Communication III: Inspiring Novel Collaborations and Building Capacity: Proceedings of a Colloquium. Many different academic, governmental, and industry centers consider methods for good practice in communicating about science. SRA and the National Academies also work to communicate uncertainty so crucial to understanding risk and risk information. This report will be the topic of a future blog.

Ready to connect with an SRA Specialty Group?

No matter what your own training or disciplines of interest, you can connect with any of the SRA Specialty Groups listed below to better understand the science and research included and excluded from assessments, communications, and regulations and policies about risks facing our communities and the world. Email addresses for contacts and links to websites for each specialty group are appended.

The SRA Specialty Groups offer a diverse program of symposia, round table panels, posters, and workshops at the SRA annual meeting in New Orleans from December 2nd through 6th. Early registration saving apply until the end of October.

Questions and comments about SRA and its specialty groups are welcome. You are welcome to click on the button at the top of this blog to subscribe to receive email notifications of new posts.

 Click  here  for more information about registering for this year’s annual SRA meeting in New Orleans (12/2-12/6).

Click here for more information about registering for this year’s annual SRA meeting in New Orleans (12/2-12/6).