Heart disease is closely related to fatty embolism in arterial blood vessels, but a new study suggests that fat molecules may come not only from food but also from a certain type of bacteria in the mouth. Researchers believe that oral diseases are often related to heart disease. Which of the following, if true, would best support the researcher's point of view? ['Heart disease is usually caused by atherosclerosis, during which arterial blood vessels are blocked by a substance called "lipids".', 'The lipid molecules produced by this bacterium are different from the composition of lipids in mammals and belong to a special bacterial family.', 'In general, these bacteria only remain active in the mouth, and they may cause periodontal disease in the right environment.', 'Cytokines caused by oral diseases can destroy islet glands, reduce the amount of necessary insulin secreted by the body, and easily cause diabetes.']