Ancient Egyptians treated infected wounds with moldy bread more than 4,000 years before penicillin was officially discovered.

Medical papyri, particularly the Ebers Papyrus dating to approximately 1550 BCE, document various treatments using organic materials to combat infection. These ancient texts describe applying moldy bread and soil to open wounds to prevent decay and inflammation. Although the Egyptians lacked understanding of bacteria, their empirical observations led them to develop an effective medical practice that preceded modern microbiology by thousands of years.The treatment's success came from fungi in the Penicillium genus, which naturally colonize decaying grain. These molds produce secondary metabolites called antibiotics to eliminate competing bacteria in their environment. When applied to human wounds, these metabolites inhibit bacterial cell wall synthesis, stopping infection from spreading.It wasn't until 1928 that Sir Alexander Fleming at St. Mary's Hospital in London formally identified penicillin after observing similar antibacterial properties in a Petri dish. Before this 20th-century breakthrough, many ancient cultures—including those in Greece and Serbia—also used moldy cheese or bread for topical healing. Egyptian records remain among the earliest documented evidence of humans successfully using natural antimicrobial agents.Modern analysis of skeletal remains from the Nile Valley has revealed traces of tetracycline, another antibiotic, likely ingested through fermented grain used in beer production. This suggests that ancient Egyptian diet and medical practices provided consistent, though unintentional, exposure to life-saving fungal compounds. Their use of moldy bread demonstrates a sophisticated grasp of natural remedies aligned with modern pharmacological principles.