Objective: Parenteral nutrition and elemental diets both cause bacterial translocation, immune dysfunction, and increased infection in laboratory animals, whereas elemental diets, with or without fiber, ameliorate some, but not all gut barrier failure. The purpose of this study is to investigate, in an Ussing chamber system, whether elemental vs. parenteral diets induce gut barrier failure in specific anatomical sites in the intestine and whether fiber can ameliorate this phenomenon.

Design: Controlled study in laboratory animals.

Setting: University laboratory.

Subjects: Male Sprague-Dawley rats.

Interventions: Nutritional support was provided to rats for 7 days by oral total parenteral nutrition (TPN; elemental diet) 307 kcal/kg/day, intravenous TPN (parenteral diet) 307 kcal/kg/day via jugular venous catheters, or rodent chow (controls).

Measurements and main results: Permeability to bacteria in intestinal segments of ileum, jejunum, and colon was evaluated in an Ussing chamber. Results were correlated with bacterial translocation to the mesenteric lymph nodes. Intravenous TPN caused greater bacterial translocation in all small intestinal segments and the cecum when compared with chow (p <.05). Oral TPN caused gut barrier failure only in the ileal segment, but not in the remainder of the small intestine (p <.001). Addition of cellulose provided a greater protection of the ileum to permeability than did pectin (p <.01).

Conclusions: TPN causes global intestinal barrier failure, but elemental diet prevents barrier failure in parts of the small intestine other than the ileum. The addition of cellulose fiber to elemental diet can ameliorate further barrier failure in the ileum.