A review of microRNA in cheese: From processing to putative biological implications

Dairy products hold high esteem in the area of food microRNAs (miRNAs) as a result of human breast milk being the first documented source of extrageneous miRNAs which is food-related. Thus, this makes milk from other species commercially available for consumption to be a subject of intense scrutiny. The observation of the possible evolutionary role of miRNAs, which are small single-stranded RNAs of about 22 nucleotides long capable of post-transcriptional gene expression control, borne out of the conservation of these molecules and their targets across species has to an extent prompted the comprehensive detailing of milk's miRNA profile. However, the same has not been replicated for other dairy products, including cheese, a widely consumed product from the dairy industry. This review provides an overview of the fate of miRNAs as they go down the processing flow from milk pasteurisation to cheese ripening, highlighting the whey drainage phase as a potential step with huge losses of the miRNA load. Though there is a dearth of studies inquiring into the biological effects of the cheese's miRNA portion, the survival of certain immune modulatory miRNAs in cheese, coupled with its ability to sustain branched-chain amino acids (BCAAs) following consumption, suggests an interesting view for future in vitro and in vivo studies in inflammatory and cell progression models. Yet, there is a need for a well-rounded view of the cheese miRNA composition prior to this.