Exploration of microRNAs in butter and their potential influence on human health

Milk is the richest body fluid in microRNAs (miRNAs), which are small non-coding RNAs, regulating many biological processes, influencing human health. With the objective of determining their bioavailability in processed dairy products, we established the miRNomes of butter using small-RNA-Seq, identifying 526 miRNAs, including 50 % in common with milk miRNomes. The top 30 most abundant miRNAs were not the exact mirror of the top 30 miRNAs already reported in Holstein milk and milk fat miRNomes, suggesting differences during the butter production process or storage. We identified predicted miRNAs whose sequences also aligned with those of bacteria used in dairy processing. The effects of the top 30 miRNAs on human health were estimated by in silico analyses, revealing potential consequences on cell life and regulation of gene expression that could affect consumer health. Our results highlight the importance of the bioavailability of food miRNAs, including in various processed dairy foods.