Factors affecting lactoferrin concentration in human milk: how much do we know?

Area of Science:

• Biochemistry
• Immunology
• Neonatal Nutrition

Background:

• Lactoferrin (LF) is a key breast milk glycoprotein with known antimicrobial and anti-inflammatory properties.
• Its benefits for infants, particularly preterm infants, are under investigation in clinical trials.
• Factors influencing LF concentration in breast milk remain unclear, hindering optimal application.

Purpose of the Study:

• To systematically review and identify factors affecting lactoferrin concentration in human breast milk.
• To synthesize current evidence on maternal and infant-related variables influencing breast milk LF levels.
• To highlight research gaps and guide future studies on lactoferrin in lactation.

Main Methods:

• A systematic review methodology was employed, involving a two-step approach for study identification and selection.
• Inclusion criteria focused on studies examining factors associated with breast milk lactoferrin concentration.
• Seventy qualified articles published between 1976 and 2015 from 29 countries were included.

Main Results:

• Breast milk lactoferrin concentration is highest in colostrum and declines over the postpartum period.
• Lactation stage was the primary factor consistently associated with LF levels.
• No other maternal (e.g., race, parity) or infant (e.g., infection, prematurity) factors were consistently linked to LF concentration across studies.

Conclusions:

• Lactation stage significantly impacts breast milk lactoferrin levels, with a clear decline after colostrum.
• Limited consistent evidence exists for other maternal or infant factors influencing LF concentration.
• Standardized, large-scale, multicenter studies are crucial to identify clinically relevant factors affecting LF expression and promote its use, especially for preterm infants.