Objective: Loss of intestinal epithelial barrier function is a major problem associated with total parenteral nutrition (TPN) administration. We have previously identified intestinal intraepithelial lymphocyte (IEL)-derived interferon gamma (IFN-) as a contributing factor to this barrier loss. The objective was to determine whether other IEL-derived cytokines may also contribute to intestinal epithelial barrier breakdown. Methods: C57BL/6J male mice received TPN or enteral nutrition (control) for 7 days. IEL-derived IL-10 was then measured. A significant decline in IEL-derived interleukin-10 (IL-10) expression was seen with TPN administration, a cytokine that has been shown in vitro to maintain tight junction integrity. We hypothesized that this change in IEL derived IL-10 expression could contribute to TPN-associated barrier loss. An additional group of mice was given exogenous recombinant IL-10 Results: Ussing chamber experiments showed that epithelial barrier function markedly declined in the TPN group. TPN resulted in a significant decrease of IEL-derived IL-10 expression. The expression of several tight junction molecules also decreased with TPN administration. Exogenous IL-10 administration in TPN mice significantly attenuated the TPN-associated the decline in ZO-1, E-cadherin, and Occludin expression, as well as a loss of intestinal barrier function. Conclusions: TPN administration led to a marked decline in IEL-derived IL-10 expression. This decline was coincident with a loss of intestinal epithelial barrier function. As the decline was partially attenuated with the administration of exogenous IL-10, out findings suggest that loss of IL-10 may be a contributing mechanism to TPN-associated epithelial barrier loss.