Immune cell-mediated protection of the mammary gland and the infant during breastfeeding.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing biological mechanisms and literature without systematic search methodology.
PubMed 25979492 · doi:10.3945/an.114.007377
What was done
The authors conducted a narrative review summarizing existing research on human milk leukocytes and the factors influencing them. The review examines the biological mechanisms of active and passive immune transfer from mother to infant through breastfeeding, the dynamic response of maternal leukocytes to maternal and infant infections, and their potential utility as diagnostic markers.
What was found
The abstract reports no numerical data, sample sizes, or statistical effect estimates. Qualitatively, it reports that breast milk contains maternal leukocytes that provide active immunity to the infant and protect the mammary gland via phagocytosis, antimicrobial factor secretion, and antigen presentation. It notes that milk leukocyte levels dynamically respond to infections in both mother and infant and are lower in nonexclusively breastfeeding dyads compared with exclusively breastfeeding dyads.
Why it matters
This paper frames breast milk leukocytes as a dynamic, responsive cellular immune defense rather than just passive nutrition, highlighting their potential role as diagnostic markers for maternal and infant infections.
Limits
As a narrative review, there is no systematic literature search, risk-of-bias assessment, or meta-analysis. The abstract provides no quantitative data or specific population metrics, and many discussed systemic actions in infant tissues rely on mechanistic reasoning rather than direct clinical trial evidence.
Cited by
- supports Breastfeeding provides an infant with probiotics and half of the mother's immune system.