Effect of a Fish Oil Structured Lipid-Based Diet on Prostaglandin Release From Mononuclear Cells in Cancer Patients After Surgery

Abstract

Background: The authors compared the effect on eicosanoid production (prostaglandin E₂ [PGE₂], 6-keto PGF_1α, and thromboxane B₂) from peripheral blood mononuclear cells (PBMC) of feeding an enteral diet containing a fish oil/mediumchain triglyceride structured lipid (FOSL-HN) vs an isonitrogenous, isocaloric formula (O-HN) in patients undergoing major abdominal surgery for upper gastrointestinal malignancies. A previous study, which used the same formulas and experimental design, suggested improved renal and liver function as well as a reduced number of gastrointestinal and infectious complications with the use of fish oil structured lipids. This study sought to investigate the potential mechanism for these effects by assessing eicosanoid production from PBMC with the two diets. Methods: This prospective, blinded, randomized trial was conducted in 20 patients who were jejunally fed either FOSL-HN or O-HN for 7 days. Serum chemistries, hematology, urinalysis, gastrointestinal complications, liver and renal function, and eicosanoid production from isolated PBMC, either unstimulated or stimulated with endotoxin, were measured at endotoxin baseline and on day 7. Comparisons were made in 10 and 8 evaluable patients based a priori on the ability to reach a tube feeding rate of >40 mL/h. Results: Patients receiving FOSL-HN experienced no untoward side effects compared with patients given O-HN and demonstrated the same general trend toward improved hepatic, renal and immune function found in the previous study. There was a significant reduction in PGE₂ (p < .03) and 6-keto PGF_1α (p < .01) production from PBMC with endotoxin stimulation in patients receiving FOSL-HN. Conclusions: The results of early enteral feeding with FOSL-HN after surgery in this follow-up study provide further support to claims of safety, tolerance, and improved physiologic function. There was an associated reduction in eicosanoid production from PBMCs, which is presumed to be the principal mechanism for these effects. (journal of Parenteral and Enteral Nutrition 21:266-274, 1997)