Dietary microRNA-A Novel Functional Component of Food

MicroRNAs are a class of small RNAs that play essential roles in various biological processes by silencing genes. Evidence emerging in recent years suggests that microRNAs in food can be absorbed into the circulatory system and organs of humans and other animals, where they regulate gene expression and biological processes. These food-derived dietary microRNAs may serve as a novel functional component of food, a role that has been neglected to date. However, a significant amount of evidence challenges this new concept. The absorption, stability, and physiological effects of dietary microRNA in recipients, especially in mammals, are currently under heavy debate. In this review, we summarize our current understanding of the unique characteristics of dietary microRNAs and concerns about both the mechanistic and methodological basis for studying the biological significance of dietary microRNAs. Such efforts will benefit continuing investigations and offer new perspectives for the interpretation of the roles of dietary microRNA with respect to the health and disease of humans and animals.