Metabolome and microbiome analysis of human milk from women with lactational mastitis during remission

Lactational mastitis is a disease that brings pain to mothers and interrupts breastfeeding. After remission, mothers and doctors care about whether the milk is suitable to continue breastfeeding or not. However, relevant research, particularly multi-omics studies focusing on the remission phase of lactational mastitis, remains scarce. 16S rRNA sequencing was used to acquire the microbiome. LC–MS/MS was used to acquire the untargeted metabolome and lipidome of the milk samples from lactational mastitis patients in remission period (LMR) and control mothers. The results revealed that there were no significant differences between the milk from the LMR and control mothers in alpha and beta diversity, and the reported lactational mastitis related genera like Staphylococcus and Streptococcus . Significant differences were found in metabolomic and lipidomic profiles, differentially abundant metabolites especially enriched in some important lipid species like ceramides, triglyceride, O-acyl-hydroxy fatty acids, phosphatidylcholine and lysophosphatidylcholine. In addition, KEGG analysis showed arachidonic acid metabolism and α-linolenic acid metabolism were primarily associated with the aforementioned lipid changes. This study demonstrates that despite being in the remission period of lactational mastitis, the produced milk exhibits lipid dysregulation.