Purpose of ReviewDietary supplementation with nutrients such as glutamine and omega-3 fatty acids to modulate/boost host immunity in critical illness is a new concept. We review current evidence (animal and human studies) on the role of immunonutrition in acute respiratory distress syndrome (ARDS).Recent FindingsDietary supplementation during stress states (ARDS) with omega-3 fatty acids has been shown to attenuate inflammation and improve lung microvascular permeability in animals. In humans, omega-3 fatty acid supplementation has shown mixed results. While studies show improvement in oxygenation and lung mechanics, a recent study demonstrated increased mortality with omega-3 fatty acids. Similarly, animal studies suggest that lower glutamine levels are associated with worse outcomes in surgical and septic patients. But, a recent study in humans has shown an increased trend towards all-cause mortality.SummaryCurrent evidence is conflicting and does not support use of immune-modulating therapies (glutamine or omega-3 fatty acids) in ARDS.