Oyster mushroom (Pleurotus ostreatus) extract made Staphylococcus aureus far more sensitive to antibiotics, expanding inhibition zones from 0–8 mm to 15–20 mm under antibiotic stress. The extract suppressed the bacterial stress-response gene uspA while delivering high levels of bioactives, including 63 mg/dL flavonoids and 29 mg/dL tannins. Instead of killing bacteria outright, the mushroom shifted how microbes respond to drugs, hinting at a food-derived way to reinforce existing antibiotics when resistance starts creeping in.