In situations of catabolic stress, the gut becomes atrophic and may have diminished barrier function as evidenced by an increase in bacterial translocation. The aim of this study was to examine the effect of minimum luminal nutrition during parenteral nutrition on the extent of jejunal atrophy and rate of bacterial translocation. Central venous lines were inserted into 30 rats before they underwent randomization to receive nutritional support with: (a) conventional parenteral nutrition; (b) conventional parenteral nutrition with 3 g/day of rat food (i.e., minimum luminal nutrition); or (c) rat food ad libitum. The rats were assessed after 10 days for nutritional status, extent of jejunal atrophy, caecal flora, as well as the extent of bacterial translocation to the mesenteric lymph nodes, liver and spleen. Rats in the rat food ad libitum group lost the smallest amount of weight and had the least amount of jejunal atrophy, yet had a similar rate of bacterial translocation as the parenterally nourished groups. When compared with the conventional parenteral nutrition group, the minimum luminal nutrition group had better preservation of the weight of the small bowel and its isolated mucosa (P < 0.01), but had a similar rate of bacterial translocation. Minimum luminal nutrition reduced the extent of atrophy of the gut but did not affect the incidence of bacterial translocation. It is inferred that there is no direct relationship between the extent of mucosal atrophy and incidence of bacterial translocation.