Supporting data for the systematic review "Why Natural Quorum-Sensing and Anti-Biofilm Inhibitors Fail to Translate." This deposit contains four files. Extraction_Dataset.xlsx: structured compound-level extraction and scoring for the prioritised and lead compounds, with a data dictionary (Online Resource S13). Record_TEH.xlsx: Translational Evidence Hierarchy summaries by pathogen, model/mechanism, and lead compound. Screening_Log.xlsx: PRISMA record cascade, per-database retrieval, and inter-reviewer concordance summaries. Online_Resource_S14_RiskOfBias.docx: domain-level risk-of-bias assessment (SYRCLE for in vivo studies; a predefined checklist for in vitro/ex vivo studies) for the 214 primary and 25 rapid-update studies. Aggregate outputs are provided here; complete per-reviewer decision-level screening files and the fully populated 374-record TEH itemisation were not retained in a form suitable for open deposition and are available from the corresponding author on reasonable request. Licensed CC BY 4.0.