Scientific Colloquium 29 - Decoding the Microbiome: From Knowledge Gaps to Actionable Regulatory Science

Background

The role of the microbiome in human and animal health is one of the most rapidly advancing areas within life sciences, with growing relevance for food and feed safety risk assessment. Microbiome-related considerations are already emerging in current safety assessments for example in the areas of pesticides, novel foods or food and feed additives, and regulatory applications directly involving complex microbial community products are expected in the near future. Despite these developments, the methodological tools, evidence standards and regulatory science frameworks needed to systematically incorporate microbiome data into the risk assessment remain scarse and difficult to implement. Existing guidance was not developed with microbiome endpoints in mind, and risk assessors currently lack the methods and data that would enable to address microbiome-related questions consistently and robustly.

EFSA and the broader regulatory science community have made significant investments in mapping these gaps and have collectively documented where the science is insufficient for regulatory purposes. The 2026 Scientific Colloquium on Microbiomes builds on this foundation, starting from the documented gaps and exploring what actions are needed to address them, in what order and by whom.

The colloquium addresses two domains where microbiome-related regulatory science challenges are most pressing within food and feed domains. The first is the assessment of chemicals such as pesticides, food and feed additives, and contaminants where the gut microbiome may both be a target of chemical-induced effects with consequences for host health and may also play a role in modulating chemical exposure through biotransformation. The second is the safety assessment of biological and microbiome-based products such as complex microbial feed additives and next-generation probiotic products, where the product itself intentionally aims to modulate the host microbiome and where current assessment frameworks may be insufficient. Both domains are addressed from a human and animal health perspective. The environmental microbiome such as soil, aquatic and other environmental microbial communities, is not addressed in this colloquium. EFSA intends to address environmental microbiome assessments in a subsequent dedicated initiative.

The colloquium is co-organised by EFSA and INRAE, with the French organisation also leading the World Microbiome Partnership, reflecting the importance of international collaboration in advancing microbiome regulatory science.

Objectives of the event

The overarching objective of the colloquium is to assess the maturity of available microbiome science relative to regulatory risk assessment needs, and to define what actions are required to bridge the gap between existing scientific knowledge and its use in food and feed safety risk assessments.

The colloquium is designed to produce three specific outputs:

• Output 1 — A structured maturity assessment for each domain addressed, distinguishing what is approaching sufficient regulatory science readiness, what requires further development and tailoring for risk assessment integration, and what requires longer-term research investment.
• Output 2 — A set of priority regulatory science actions, structured around three specific questions: what adversity criteria and evidence standards are needed before microbiome endpoints can be incorporated into regulatory decisions; what methods, data and reporting standards must be established for regulatory submissions involving microbiome data; and whether and how existing regulatory tools can be adapted to integrate microbiome-related endpoints.
• Output 3 — A gap-closing action plan identifying who does what and when, distinguishing what falls within EFSA's and partners' direct regulatory science remit, what requires international coordination, and what requires longer-term research investment that regulatory science organisations should advocate for.

Structure of the event

Following the opening plenary session where introductory presentations will be shared, participants will break into four parallel discussion groups addressing specific domains:

Break-out Group 1 | Chemicals and the Microbiome — Human Health Risk Assessment

Break-out Group 2 | Chemicals and the Microbiome — Animal Health Risk Assessment

Break-out Group 3 | Biological and Microbiome Products — Human Health Risk Assessment

Break-out Group 4 | Biological and Microbiome Products — Animal Health Risk Assessment

The outcome of the discussion groups will be presented in a final plenary moderated panel discussion on Day 2, designed to formulate the conclusions of the event. EFSA will issue a short report collecting and summarising the discussions following the event which will be published together with the presentations shared at the event.

Who should attend?

The event is intended for scientists, regulatory experts and other stakeholders with expertise at the interface of microbiome science and risk assessment Participation is limited to a maximum of 120 participants, including speakers and other experts already identified by EFSA and co-organisers. Given the colloquium's focus on producing actionable regulatory science outputs, participation is specifically sought from experts who combine scientific knowledge of microbiomes with experience or familiarity of risk assessment processes. Academic researchers with strong connections to regulatory science questions are also welcome. Representatives of national competent authorities, international organisations, research institutions and industry are all encouraged to apply. A selection process will ensure sufficient representation of relevant fields of expertise, stakeholder groups and geographical balance.

On-line registration

The registration form can be found at link

Please note that registration may close once the maximum number of participants is reached or, at the latest, by 14 September 2026 at 12.00 CEST. After closure of registration, applicants will be informed whether they have been selected for participation.

Organisational details

The event will be held in person in Brussels, Belgium on 23-24 November 2026 (Day 1: 09:00–18:00 CET; Day 2: 09:00–13:00 CET). English will be the language of the event, and no interpretation will be provided.

Online participation is not foreseen — please register for this event only if you are able to attend in person.

There is no fee for participation, however participants are responsible for covering their own expenses related to travel and accommodation. Further organisational details will be communicated to selected participants.

Contact

Do not hesitate to contact the organising committee at scientific.colloquia [at] efsa.europa.eu for more information.