Certain toxins, such as arsenic and thallium, can inhibit enzymes involved in the formation of acetyl CoA, such as the pyruvate dehydrogenase complex. This inhibition can lead to a decrease in acetyl CoA levels, resulting in impaired energy production and increased reliance on anaerobic pathways like glycolysis. Additionally, some toxins can cause an accumulation of metabolic intermediates upstream of acetyl CoA, leading to lactic acidosis and other metabolic disorders.