Research: Mother's milk

20 March 2006

An unexpected benefit of breast milk has been discovered.

Mother's milk is well known to be good for young infants, transferring protective maternal antibodies as well as providing nutrition. Now Dr Mario Labeta and colleagues at Cardiff University College of Medicine have discovered another benefit: it stimulates an infant's own innate immune response.

The innate immune response is an evolutionarily ancient, non-specific form of defence – a first-line response that is mobilised rapidly, before the more specific acquired immune system (such as antibodies and T cells) kicks in. Much has recently been discovered about the innate response, and it is turning out to be more important than once thought.

The innate system is generally triggered by structures shared among microbial pathogens. They are recognised by a family of proteins known as the Toll-like receptors (TLRs).

Dr Labeta and colleagues tested the effect of early breast milk on the response of various cell lines and immune cells to microbial pathogens. Most notably, they found that breast milk enhanced responses triggered by one particular TLR (TLR4). This enhancement depended on a specific milk protein not found in infant formula.

As well as demonstrating a novel activity of human milk, the work has also identified a possible new target for modulating innate immune responses.

External links

• LeBouder E et al. Modulation of neonatal microbial recognition: TLRmediated innate immune responses are specifically and differentially modulated by human milk. J Immunol 2006;176(6):3742–52.