ABSTRACT: Human milk is highly recommended for infant during the first six month of life by World Healthy Organisation (WHO). Human milk is not only rich in macro-nutritional components, but also rich in cells and molecules. MicroRNAs are small non-coding RNAs, which enriched in human milk. These molecules are vital in enormous biological and cellular functions including immune system and in response to infections. By using deep sequencing method, 770,374,554 raw reads were generated from all samples (n=26). Then, filter analysis was done to remove 81,091,772 (10.5%), and 689,282,782 clean reads (89.5%) were considered as clean reads, which was retained for the subsequent bioinformatics analysis. Annotation and matching reads to miRBase revealed1780 mature known microRNAs identified in human milk cells and lipids derived from healthy, cold and other infection types mothers. In particular, 1680 known microRNAs were determined in infected mothers (n=14), while 1,606 known microRNAs in healthy mothers (n=12). Of these known microRNAs, 453 microRNAs were differentially expressed (p<0.05) between healthy and infected samples. The majority of the highly expressed miRNAs in all samples, in particular top 20 microRNAs, were also differentially expressed between healthy and infections. Further, 592 novel mature microRNA sequences were predicted, with only 65,878 total reads. Amongst the total reads of the novel microRNAs, top 20 novel miRNAs were found to contributed in 73.3% (total reads 48,295) of the total reads (65,878).
