The emerging role of MicroRNAs in the regulation of gene expression by nutrients.

MicroRNAs (miRNAs) are a class of evolutionarily conserved, small non-coding RNAs of 19-24 nucleotides in length that regulate gene expression mostly at the posttranscriptional level. They are known to be involved in the control of different processes such as cell cycling, programmed cell death, cell differentiation, tumor development, metastasis, and sensing of nutrient stress. This review summarizes the evidence regarding the changes in miRNA expression that are caused by diets with a deficiency or augmented intake of nutrients such as amino acids, carbohydrates, fatty acids, vitamins, and phytochemicals. As diet is known to influence the expression of miRNAs, miRNA profiling has the potential to be useful in the assessment of nutritional status in dietary intervention studies. Additionally, as it can change miRNA expression, diet may be used as a therapeutic agent to treat many different diseases. Also, we explored here some ideas on therapeutics based on the manipulation of miRNA expression levels for dietary-derived diseases as well as the putative effect of food-derived miRNAs on host gene expression.