Human Milk Oligosaccharides in the Milk of Mothers Delivering Term versus Preterm Infants

Abstract

Human milk oligosaccharides (HMOs) are a major component of human milk, and play an important role in protecting the infant from infections. Preterm infants are particularly vulnerable, but have improved outcomes if fed with human milk. This study aimed to determine if the HMO composition of preterm milk differed from that of term milk at equivalent stage of lactation and equivalent postmenstrual age. In all, 22 HMOs were analyzed in 500 samples of milk from 25 mothers breastfeeding very preterm infants (< 32 weeks of gestational age, < 1500 g of birthweight) and 28 mothers breastfeeding term infants. The concentrations of most HMOs were comparable at equivalent postpartum age. However, HMOs containing α-1,2-linked fucose were reduced in concentration in preterm milk during the first month of lactation. The concentrations of a number of sialylated oligosaccharides were also different in preterm milk, in particular 3′-sialyllactose concentrations were elevated. At equivalent postmenstrual age, the concentrations of a number of HMOs were significantly different in preterm compared to term milk. The largest differences manifest around 40 weeks of postmenstrual age, when the milk of term infants contains the highest concentrations of HMOs. The observed differences warrant further investigation in view of their potential clinical impact.

Neutral Human Milk Oligosaccharides Are Associated with Multiple Fixed and Modifiable Maternal and Infant Characteristics

“…There are several studies reporting that Secretor-status and Lewis type can determine fucosylation patterns [15]. FUT2 encoded by the Secretor gene determines the presence of α1,2-fucosylated HMOs such as 2 -FL and LNFP-I, and FUT3 encoded by the Lewis gene synthesizes α1,4-fucosylated HMOs such as LNFP-II and Lacto-N-difucohexaose (LNDFH) [15][16][17]. Other FUTs determined the presence of α1,3-fucosylated HMOs such as 3 -FL and LNFP-IV, whose synthesis was not influenced by the Se or Le genes.…”

“…Beyond genetic factors, several studies reported that HMOs composition varied with lactation stage [11,15,17,[20][21][22][23][24][25][26]. However, most studies collected samples in a single time point or focused on first few weeks of lactation.…”

Modifications of Own Mothers’ Milk Fortification Protocol Affect Early Plasma IGF-I and Ghrelin Levels in Preterm Infants. A Randomized Clinical Trial

“…, and lipid (g•kg −1 •d −1 ) intake were calculated including milk content and the amount of HMF as well as the parenterally administered macronutrients. Lactose intake was calculated from the total carbohydrates measured in OMM assuming a 20% of total carbohydrates as non-metabolized oligosaccharides [29][30][31][32][33][34][35]. Energy intake was calculated from the macronutrient concentrations by using the Atwater factors: 9 kcal/g for fat and 4 kcal/g for protein and estimated lactose.…”

Human Milk and Lactation

“…Authors enhance the importance of passive immunisation through mothers' antibodies transfer from breast milk, which has a key role for infant immune protection in the first months [9]. Differences in oligosaccharides content between term and preterm milk have also been examined in view of the potential implications for preterm infants' clinical outcomes with special regard to their increased vulnerability to infections [10]. Given the widely known anti-inflammatory and antimicrobial properties of human milk, authors have also explored its implementation as a powerful therapeutic agent for skin issues, suggesting its potential use in settings with limited access to medicine [11].…”

“…Benefits of human milk feeding are indeed even more critical among specific populations at high risk of developing adverse outcomes, as preterm infants [22]. This value is highlighted not only by the positive effects that human milk has in modulating preterms' outcomes at every level but also by the results of studies in this issue demonstrating the higher levels of bioactive, micro and macronutrient contents in preterm milk, compared to full-term [10,[23][24][25][26]. Within this context, however, authors have underlined the potential lack of mineral content of preterm milk that should be taken into consideration in the approach to the fortification of milk for the preterm population [27].…”