Described herein are cholix-IL-10 fusion proteins, and methods of use thereof, which can be characterized by a distinct response in an individual when administered. This distinct response can comprise changes in levels of one or more markers in the individual and/or co-localization of IL-10 in the Lamina propria of the individual. Further described herein, in some embodiments, are oral formulations of the cholix-IL-10 fusion proteins. Described herein are methods for the purification of an IL-10 delivery construct, including methods for refolding and enrichment, which can result in maintenance of a high percentage of the IL-10 delivery constructs in the biologically active dimer form. Described herein are oral formulations configured for site-specific release of a therapeutic protein in the small intestines or colon. In some cases, the therapeutic protein is in the form of a dimer, such as an IL-10 delivery construct capable of crossing the gut epithelium.