Objective: Autoimmune diseases are chronic, incurable, and affect approximately 50 million Americans. This is a strong need for better ways to treat autoimmune diseases. Parasites and parasite proteins have been observed to protect mice from symptoms of induced colitis in mice treated with dextran sodium sulfate (DSS), a model for inflammatory bowel disease (IBD). I hypothesize that non-living echinostomatid parasites, given during DSS treatment, can decrease intestinal inflammation and weight loss, providing a possible novel treatment for IBD.

Methods: A range of DSS concentrations (0.5%-3%) were delivered to female C57BL/6 mice in their drinking water in order to determine the concentration that induced colitis but not severe morbidity; 1% DSS was determined to be optimal. Next, two groups of mice were administered 1% DSS in their drinking water for the first six days of the nine-day experiment, while two groups received regular water throughout. The mice in one of the DSS treatment groups and one of the water control groups were orally administered heat-killed metacercariae in PBS on the third day of the experiment, while the remaining mice were administered just PBS as a control treatment. Weight of the mice and intestinal distress were monitored, as was water and food consumption. At the end of the experiment, colon lengths were measured and splenic cytokines (IL-4, IFN-γ, IL-10, and IL-2) were assessed by ELISA.

Results: Mice with DSS induced colitis that received the parasite treatment demonstrated more weight loss (p=0.01) and poorer intestinal distress (p=0.02) on the ninth day when compared to mice with DSS induced colitis that did not receive parasite treatment. The spleens from mice receiving DSS and parasite treatment showed lower levels of regulatory cytokine IL-2 than mice receiving DSS but not parasite treatment (p=0.013). Additionally, mice treated with DSS consumed less food on average than untreated mice (p<0.0001).

Conclusion: In contrast to my hypothesis, I found that feeding mice heat-killed echinostomatid parasites during DSS treatment did not improve symptoms of colitis. Future studies could be performed to determine if non living parasites can counteract symptoms of colitis, a possible novel treatment for patients with IBD.


Allison M Land

Committee Member

David S Sharlin

Committee Member

Robert E Sorensen

Date of Degree




Document Type



Master of Science (MS)


Biological Sciences


Science, Engineering and Technology



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