Fiber in the ICU: Should it Be a Regular Part of Feeding?

To highlight the controversy of fiber use in the current critical care nutrition guidelines; review the effect of fiber on the gut microbiota in the critically ill; and examine the data on fiber and outcomes in the intensive care setting.

Fiber is increasingly recognized as a necessary component of colonic health and nutrition support. In critical illness there is a shift toward gut dysbiosis and immune dysregulation. Through fermentation and the generation of short-chain fatty acids, fiber has a role in maintaining intestinal homeostasis, immune function, and supporting commensal bacteria. In contrast to fermentable fiber, recent animal models suggest that non-fermentable fiber can also favorably alter intestinal homeostasis in a mechanism distinct from short chain fatty acids. In the critically ill, RCTs and meta-analyses suggest that soluble and mixed fiber supplemented enteral nutrition can reduce diarrhea and is well tolerated. Based on limited data, there may be benefits in reducing length of hospital stay, certain infections, and glucose metabolism. Nonetheless, the role of fiber enriched nutrition in critically ill patients is controversial as evident in the conflicting guidelines.

Despite shortcomings in the literature, soluble and mixed fiber supplemented enteral nutrition is safe and beneficial in most hemodynamically stable intensive care patients. More research is necessary to determine optimal fiber composition.