When food synergy breaks: Failure-mode mapping and a stage-gated evidence pipeline for functional food bioactive combinations

Background Food-bioactive combinations are increasingly explored to enhance functionality beyond single compounds, yet synergy remains difficult to reproduce, compare, and translate into food applications. An emphasis on positive interaction findings may leave synergy breakdown under food-relevant conditions underexamined. More fundamentally, synergy is better understood as a conditional outcome shaped by composition, ratio, matrix interactions, processing, digestion, and microbiome-mediated transformation. Scope and Approach Against this background, this review shifts the focus from synergy generation to synergy breakdown, defined as loss, reversal, material narrowing, or reclassification of a model-supported interaction after a prespecified food-relevant challenge. We distinguish effect, exposure, and system synergy and map failure modes across the food-to-gut continuum, including composition drift, matrix binding and sequestration, process- and storage-induced ratio changes, digestion-stage reclassification, and microbiome-dependent switching. The interaction itself is the unit of validation, with ingredients and product formats providing food-system context for testing. The framework combines a claim-routed stage-gated evidence pipeline with MISE-Food (Minimum Information for Synergy Evidence in Foods), an author-proposed provisional reporting framework. Key Findings and Conclusions Fragility may help explain why some synergy claims fail to progress toward practical use despite a strong initial response. Robustness remains claim-specific and requires retaining a model-supported interaction across every prespecified claim-relevant challenge. The framework distinguishes apparent, fragile, and robust synergy from “robustness not assessed” and uses GO, REVISE, and NO-GO decisions to guide interpretation and next steps. Together, these elements connect interaction trajectories to evidence-aligned claim wording and product or quality-control specifications, while in vivo , human, and regulatory substantiation remains separate and claim-dependent.