Probiotics, microorganisms known to benefit their host, appear in curious sites – from the projected $23 billion market involving upper-middle class white women searching for perfect intestinal balance to the international truggle to treat infant mortality in the ‘third world’. Lactobacillus reuteri is a strain that, according to its global distributer, “was isolated from the breast milk of a woman living in perfect harmony with nature in the Peruvian Andes.” In the same moment, world health efforts promote probiotics as a treatment for infant diarrhea and female sexual health issues in Sub-Saharan Africa. My senior thesis asks how early twentieth century narratives of racial impurity in United States food campaigns are reshaped today through clinical, corporate, and international discourses on probiotics. I will research histories of bacteriology and food nutrition, current probiotics advertising campaigns, and notions of intellectual property in relation to probiotics patenting. Finally, I will account for the role of racial coding in international aid efforts related to probiotics. My methodology will involve archival work as well as
interviews with local and international yogurt producers, microbiologists, and practitioners of patent law. In examining the way probiotics travel, I can begin to explore how (and for whom) these microorganisms co-constitute human bodies.