PAR-25-211
Enhancing Mechanistic Research on Precision Probiotic Therapies (R61/R33 Clinical Trial Optional)
Summary
Briefing: PAR-25-211 — Precision Probiotic Therapies Mechanistic Research
Research Focus
This funding opportunity supports mechanistic research to understand why probiotic responses vary dramatically between individuals and to develop precision probiotic interventions tailored to person-specific characteristics. The core problem is that probiotics—living microorganisms such as bacteria and yeast administered as therapeutics—show inconsistent clinical effects across populations and trials, limiting their clinical utility. The program seeks research that identifies and characterizes host biological patterns (native microbiome composition, immune system function, sex, diet, age, genetic background, lifestyle, and health history) that predict probiotic responsiveness and define responder subgroups. The R61 phase (1–2 years) funds observational or secondary data analysis studies to correlate host factors with probiotic clinical effects. The R33 phase (up to 3 additional years) supports mechanistic studies in animal models or human subjects to establish causality of identified factors. This is not a clinical efficacy or effectiveness trial program; it targets fundamental understanding of interindividual variation and development of predictive tools and strategies to address complexity in precision probiotic design.
At-a-Glance
- Who can apply: Institutions eligible for NIH R-series grants; applications must align with NCCIH, NIA, NIDCR, or NCI missions.
- Funding & project length: Not stated; combined R61/R33 should not exceed 5 years total. R61 phase is 1–2 years.
- Award mechanism: R61/R33 exploratory/developmental phased award (milestone-driven; R33 transition not guaranteed).
- Key dates: Applications open May 2, 2025; earliest start June 2, 2025; NOFO expires June 3, 2027.
- Best fit for: Microbiome researchers, nutritionists, immunologists, geneticists, and computational biologists studying gut microbiota, host–microbe interactions, and dietary or lifestyle factors affecting probiotic response in aging, cancer, oral health, or women's health populations.
Key Facts
Deadline
Wed, June 2, 2027
Posted
Thu, October 31, 2024
Max Duration
5 years
Keywords
Research Areas
Gotchas (3)
R61 phase limited to 1 or 2 years, but combined R61/R33 cannot exceed 5 years—applicants must carefully plan total project duration across both phases
95%
Source Text
“The first phase, funded by the R61, will provide for 1 or 2 years of support... The combined R61/R33 should not exceed 5 years.”
Transition from R61 to R33 phase is NOT automatic and depends on multiple criteria including peer review, milestone completion, program priorities, and fund availability—not all applications will cont
98%
Source Text
“Transition to the R33 phase requires administrative review by NIH staff and is not guaranteed. Approval of the transition to the R33 phase will be based on the original R61/R33 peer review recommendations, successful completion of transition milestones, any proposed changes to the R33 research based on R61 findings, program priorities, and availability of funds. It is not expected that all applications will continue to the R33 phase.”
R61 phase restricted to observational or secondary data analysis studies only; mechanistic studies requiring primary data collection must wait for R33 phase
98%
Source Text
“The first phase, funded by the R61, will provide for 1 or 2 years of support to identify host biological patterns (e.g., native microbiome, immune system, sex, diet, age, genetic background, lifestyle, or health history) that are correlated with differences in probiotic clinical effects using observational or secondary data analysis studies.”