Toxins are poisonous substances released by many types of pathogenic (harmful) bacteria. These toxins are the causes of many different types of disease.
A witch tossed in (toxin) some poison to make whoever drank the potion feel ill.
Examples of toxins
1. Botulinum neurotoxins cause the deadly food poisoning disease botulism
2. Clostridium tetani produces tetanus toxin, which leads to a fatal condition known as tetanus