APD6: the antimicrobial peptide database is expanded to promote research and development by deploying an unprecedented information pipeline.

The global antibiotic resistance issue constitutes a driving force for developing host defense antimicrobial peptides (AMPs) into a new generation of antibiotics. To facilitate this development, we report the antimicrobial peptide database version 6 (APD6) with (i) the consolidated database platform, (ii) the most comprehensive AMP information pipeline (AMPIP), and (iii) the expanded wheel of function. As of 18 March 2025, the APD6 platform housed records for 5188 peptides, including 3306 natural, 1380 synthetic, and 239 predicted AMPs with systematic classification schemes for each group. Based on the refined dataset, we present an updated view and findings on natural AMPs. Natural AMPs provide a fundamental dataset for peptide design and predicting potential AMPs. While current artificial intelligence prediction of AMPs is limited to activity and hemolysis, the APD6 provides new positive and negative datasets (e.g. pH, salt, serum effects, and resistance) for building advanced AI prediction models to identify more robust antibiotics. The AMPIP covers information ranging from peptide discovery, in vitro/in vivo activity and toxicity data, to clinical trials. In addition, the APD6 (available at https://aps.unmc.edu) contains an expanded wheel of peptide functions (e.g. anticancer and antidiabetic), allowing for developing peptide therapeutics outside the antibiotic arena.