New lipids in enteral feeding.

PURPOSE OF REVIEW: Lipid sources for enteral nutrition continue to be an exciting area of investigation. It is timely to review recent developments which have largely contributed to thrust enteral feeding into a new era. RECENT FINDINGS: Although much more research needs to be done, there is a better understanding of the competitive relationships between n-6/n-3 fatty acids in conditions of metabolic and immune stress as well as in autoimmune and degenerative diseases. Although structured lipids are more completely absorbed and cleared, other more important clinical benefits need to be documented before they can be considered cost-effective. Immune enhancing formulas are the subject of controversy and some have been shown to be more effective than others. Enteral formulations with short-chain fatty acids are promising but more experimental work on the normal, and the sick colon is needed. Finally, there are a few isolated studies suggesting that enteral feeding with liposomes and with lipolytic products may have advantages when the digestive phase needs to be circumvented. The era of nutrigenomics, in which the effect of specific lipids on genes and proteins is being explored, is with us. We can look forward to nutrigenetics when the effect of genetic variation on the interaction between diet and disease will guide our practice. SUMMARY: Clinicians already have access to lipid sources and formulations which allow them to individualize enteral feeding programs. More clinical and technological research needs to be carried out, however, before products can be tailored to produce optimal effects in specific conditions.