• The subject is at least 18 years of age.

• The subject has a history of gastrointestinal alpha-gal allergy defined by elevated test for α-gal allergy (α-gal IgE \>0.1 U/L) due to complaints of either abdominal pain or discomfort, diarrhea, nausea with or without vomiting, or a combination of those complaints, within the last 5 years. The subjects must have experienced one or more of the four symptoms at least once monthly for at least two months. The subjects will fill out a symptom questionnaire of the presence of these four symptoms (abdominal pain or discomfort, diarrhea, nausea, vomiting), frequency and severity (mild, moderate, or severe) for the 3 months prior to diagnosis.

• The subject has experienced symptomatic improvement on a mammalian meat-free diet over at least a month's time, defined by saying yes to the following question: On the alpha-gal avoidant diet, have you had adequate relief of gastrointestinal symptoms?

• The subject has elevated α-gal IgE titer on screening for the trial if they do not have a positive titer within 6 months of enrollment.

• The subject is willing to not take nonsteroidal anti-inflammatory medications, leukotriene modifiers or steroids 14 days prior to challenge.

• The subject is willing to sign the informed consent form.