FIGURE 4.

Forest plot of randomized controlled trials investigating the effect of lactoferrin supplementation on NK cell cytotoxicity in adults, subgrouped by outcome variable type (change from baseline or postintervention values). Individual trial effect estimates (boxes) and pooled effect estimate (diamond) for NK cell cytotoxicity are shown. Values are mean differences with 95% CIs determined with the use of generic IV random-effects models. Heterogeneity was quantified by I² at a significance of P < 0.10. IV, inverse variance.