T lymphocyte numbers in human gut associated lymphoid tissue are reduced without enteral nutrition

Background Clinically, in the absence of enteral nutrition, the morbidity of infectious complication is high. Although experiments using mice have shown alterations in gut-associated lymphoid tissue (GALT) to be an important mechanism underlying impaired host defense, there are no clinical studies on the effects of nutritional routes on GALT. Methods: A total of 27 colon cancer cases who underwent right colectomy or hemicolectomy were reviewed. Six patients did not receive enteral nutrition for 4 to 28 days before surgery because of bowel obstruction (parenteral nutrition [PN] group). Twenty-one patients were enterally fed before surgery (enteral nutrition [EN] group). The terminal ileum from resected specimens was examined microscopically. T-cell numbers in intraepithelial spaces (IE) and the lamina propria (LP) were determined immunohistochemically in blinded fashion. Results: There were no significant differences in baseline characteristics between the 2 groups. T-cell number in the LP was significantly lower in the PN group than in the EN group, with no difference in IE cell numbers. Conclusions: Lack of enteral delivery of nutrients reduces GALT cell number in patients with colon cancer, as is the case in mice.