The Breast Milk Immunoglobulinome

Karla Rio-Aige,Marta Selma-Royo,María J Rodríguez-Lagunas,Francisco J Pérez-Cano,Margarida Castell,María Carmen Collado,Ignasi Azagra-Boronat

doi:10.3390/nu13061810

Abstract

Breast milk components contribute to the infant’s immune development and protection, and among other immune factors, immunoglobulins (Igs) are the most studied. The presence of IgA in milk has been known for a long time; however, less information is available about the presence of other Igs such as IgM, IgG, and their subtypes (IgG1, IgG2, IgG3, and IgG4) or even IgE or IgD. The total Ig concentration and profile will change during the course of lactation; however, there is a great variability among studies due to several variables that limit establishing a clear pattern. In this context, the aim of this review was firstly to shed light on the Ig concentration in breast milk based on scientific evidence and secondly to study the main factors contributing to such variability. A search strategy provided only 75 studies with the prespecified eligibility criteria. The concentrations and proportions found have been established based on the intrinsic factors of the study—such as the sampling time and quantification technique—as well as participant-dependent factors, such as lifestyle and environment. All these factors contribute to the variability of the immunoglobulinome described in the literature and should be carefully addressed for further well-designed studies and data interpretation.

Highlights

Since the first studies describing the presence of IgA in breast milk tooktook place in the
When we study the complete set of metabolites in a cell, tissue, organ, or organism, we weasstudy the complete metabolites in a cell, tissue, organ, or organism, referWhen to them metabolome; whenset theofattention is focused on the set of expressed proteins, we refer to them as metabolome; when the attention is focused on the set of transcripts, expressed we call it proteome; and if we concentrate our attention on the set of all RNA
The variability of the results found for IgA and IgM is present here, being more dramatic in colostrum than in mature milk

Summary

Introduction

Breast Milk: A Source of Immunomodulatory Components. Breast milk has been tailored during human evolution to meet the demands of the infant. The composition of human milk is dynamic and changes throughout lactation. The first form of milk produced by the mammary glands during the first 2–4 days after delivery is colostrum, which is produced in low volumes (300–400 mL/day) and has higher levels of protein and lower levels of carbohydrates and fat content than mature breast milk. Colostrum is richer in immunological components, such as immunoglobulins (Igs), lactoferrin, leucocytes, and oligosaccharides, suggesting that its primary functions are immunological rather than nutritional [3,7]. From days 4–5 after delivery, colostrum changes to transition milk, which is characterized by a higher yield (500–800 mL/day) and by lower protein and Ig

Objectives

Methods

Results

Conclusion