What causes food poisoning?

Food poisoning primarily occurs from the consumption of foods contaminated with pathogenic bacteria, viruses, or their toxins. When food is contaminated, harmful microorganisms can multiply and, if ingested, can lead to various gastrointestinal issues and other illnesses. Pathogenic bacteria such as Salmonella, E. coli, and Listeria are common culprits in food poisoning cases. These bacteria can produce toxins either while in the food or after ingestion, leading to symptoms like nausea, vomiting, diarrhea, and abdominal pain.

The other options, while related to food safety, do not directly cause food poisoning in the same way. Insufficient cooking temperatures can lead to undercooked food which may harbor pathogens, but it is the pathogens themselves that ultimately cause the illness. Similarly, consuming raw vegetables may pose a risk if they are contaminated, but again, it is the presence of harmful bacteria that results in food poisoning. Allergic reactions are a different issue altogether, as they involve the immune system's response to specific food proteins rather than pathogen-induced illness.