Enteral support is the preferred feeding route for stressed patients due in part to the provision of gut-specific fuels. In those patients who must be maintained parenterally, small amounts of enteral stimulation might blunt gut atrophy and lead to improvement in host defense mechanisms decreasing macromolecular and/or bacterial translocation (BT). Forty-eight rats were infused with TPN for 9 days, and were randomized to receive 0%, 6%, 12%, or 25% of their calories as partial enteral nutrition (PEN) in an isocaloric, isonitrogenous fashion. Twenty-four hours before harvest animals were gavaged with lactulose and urinary excretion quantified. At harvest, mesenteric lymph nodes were cultured to assess BT and intestinal histology determined. Provision of as little as 25% of total calories PEN improved nitrogen balance and reduced BT, in a dose dependent fashion. It did not alter TPN-associated increased macromolecular lactulose permeability (4.4% +/- 1.0%). Concurrent small amounts of PEN, aimed to support the gut's metabolic needs, are beneficial during periods of prolonged TPN.