In developed countries, an enormous change has occurred within the human body over the past century—the loss of parasitic worms. Due to improvements in sanitation, roundworms that have inhabited human intestines (such as the hookworm above) and challenged our immune system for millions of years are no longer a threat. Does the end of this long-term relationship come at a cost? The roundworm Heligmosomoides polygyrus is a natural intestinal parasite of mice, and it offers an excellent model of the immunology of worm infections in humans. Scientists evaluated the impact of parasitic roundworms on immune disorders using mice prone to developing type 1 diabetes mellitus. Five-week-old mice were infected with H. polygyrus (Hp). Two weeks later, half of the mice were cured of the infection (Rx). When the mice were 40 weeks old, scientists calculated the percentage of mice that developed diabetes in both groups: those exposed to roundworms and those in uninfected control groups (** means P<0.01). What two conclusions are supported by the results shown below?

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1. Examine the graphs to understand the experimental setup and the results. The top graph shows the percentage of diabetic mice over time for the control group and the group with a long-term H. polygyrus infection. The bottom graph shows the same for the control group and the group with a short-term H. polygyrus infection.
2. Identify the key differences between the control group and the infected groups in both graphs. Notice that the control group (blue line) has a higher percentage of diabetic mice compared to the infected groups (red lines).
3. Observe the timing of the infection and treatment. In the top graph, mice were infected at 5 weeks and remained infected. In the bottom graph, mice were infected at 5 weeks and treated at 7 weeks to cure the infection.
4. Compare the progression of diabetes in the control and infected groups. In both graphs, the control group shows a steady increase in the percentage of diabetic mice, while the infected groups show a significantly lower percentage of diabetic mice.
5. Conclude that the presence of H. polygyrus infection, whether long-term or short-term, appears to reduce the incidence of diabetes in mice. This suggests that parasitic infections may have a protective effect against the development of immune disorders like type 1 diabetes.