What are poisonous substances produced by microorganisms like bacteria and viruses called?

The term for poisonous substances produced by microorganisms such as bacteria and viruses is "toxins." Toxins are harmful substances that can provoke a range of effects on the body, often leading to illness or disease. These substances can vary widely in their impact and mechanism of action, but they typically interfere with biological processes at the cellular level, leading to tissue damage or disrupted bodily functions.

In contrast, pathogens refer to microorganisms capable of causing disease but do not specifically denote the harmful substances they produce. Antibodies are proteins produced by the immune system in response to pathogens, functioning to neutralize toxins and infections. Nutrients are substances required for growth and energy but do not entail any harmful effects like toxins. Thus, the only option that accurately identifies the harmful substances produced by microorganisms is "toxins."