To determine if the milk immune microenvironment exhibits stage-associated changes across different lactation phases.
Approach:
Study Design: Multi-modal profiling using single-cell RNA sequencing, high-dimensional flow cytometry, and soluble protein assays on paired maternal blood and milk samples collected during colostrum, transitional, and mature milk stages.
Key Findings:
Human milk contains transcriptionally distinct immune and epithelial cellular populations compared to maternal peripheral blood.
Colostrum showed greater neutrophil enrichment with antimicrobial-associated transcriptional programs, including degranulation- and NETosis-associated signatures.
Later lactation stages exhibited stronger effector-memory-associated T-cell transcriptional signatures.
Stage-associated differences in soluble immune mediator profiles were observed, with early recruitment-associated cytokines declining and IL-7 increasing in mature milk.
Interpretation:
Human milk undergoes substantial stage-associated remodeling of cellular and soluble immune components across lactation.
Limitations:
Limited longitudinal paired analyses of fresh human milk and matched maternal blood across lactation stages.
The study cohort consisted of a small number of donors.
Conclusion:
Further studies will be required to determine the functional significance of these stage-associated immune features.
by Jia Ming Low, Melissa Shu Feng Ng, Chen-Shi Lin, Jian-Zhou Cui, Meera K. Shenoy, Sheau Yng Lim, Lu-Yi Ng, Si Min Lang, Wai-Chung Ong, Tamanna Ferdous, Rashi Gupta, Tanusya Murali Murali, Isabelle Tan, Karishma Sachaphibulkij, Yung-Seng Lee, Paul A MacAry
