From parent to progeny.

How infants acquire their gut microbial communities and the various factors influencing these dynamics remain unclear. In this issue of Cell Host & Microbe, Selma-Royo et al. and Dubois et al.

Development of a human milk protein concentrate from donor milk: Impact of the pasteurization method on static in vitro digestion in a preterm newborn model.

The impact of high temperature short time (HTST, 72 °C, 15 s), Holder pasteurization- (63 °C, 30 min) and high hydrostatic pressure (HHP, 600 MPa-10 min) was evaluated on the digestibility of human milk protein concentrate (HMPC) by using a static in vitro gastrointestinal digestion system. The results showed that the processing steps used to produce the HMPC induced a decrease in readily available nitrogen (non-protein nitrogen and peptides). Overall, digestibility was similar between pasteurized and raw HMPC (degree of hydrolysis ranged from 26 to 34 %).

Human milk nutrient fortifiers alter the developing gastrointestinal microbiota of very-low-birth-weight infants.

Nutrient fortifiers are added to human milk to support the development of very-low-birth-weight infants. Currently, bovine-milk-based fortifiers (BMBFs) are predominantly administered, with increasing interest in adopting human-milk-based fortifiers (HMBFs). Although beneficial for growth, their effects on the gastrointestinal microbiota are unclear.

Impact of holder, high temperature short time and high hydrostatic pressure pasteurization methods on protein structure and aggregation in a human milk protein concentrate.

This work evaluated the impact of high temperature short time (HTST, 72 °C, 15 s), high hydrostatic pressure (HHP, 400-600 MPa at 5 and 10 min) and Holder pasteurization (HoP, 62.5 °C, 30 min) on protein profile and aggregation in a human milk protein concentrate (HMPC). The structural changes induced in milk proteins were investigated in HMPC as well as in sedimentable and non-sedimentable fractions recovered after ultracentrifugation.

Determinants of fatty acid content and composition of human milk fed to infants born weighing <1250 g.

Background: Infants born at very low birth weight (VLBW) are vulnerable to deficits in fatty acids (FAs) but little is known of factors that influence the intakes or composition of their human milk feeds.

Objectives: We aimed to identify sources of variability in the fat composition of human milk fed to VLBW infants and examine the impact of milk source (mother's own or donor) on fat and FA intakes.

Methods: Serial samples of mother's milk (n = 476) and donor milk (n = 53) fed to infants born weighing <1250 g (n = 114 infants from 100 mothers) were collected [Optimizing Mothers' Milk for Preterm Infants (OptiMoM) randomized clinical trial].

A Human Milk-Based Protein Concentrate Developed for Preterm Infants Retains Bioactive Proteins and Supports Growth of Weanling Rats.

Background: Bovine milk-based protein modulars are currently available to nutrient-enrich enteral feedings; however, they have limitations for use in very-low-birth-weight infants.

Objectives: Our objectives were to develop a human milk-based protein (HMP) concentrate and to conduct a preclinical assessment of the HMP concentrate in weanling rats.

Methods: An HMP concentrate was produced from donor milk using pressure-driven membrane filtration processes and high hydrostatic pressure processing.

Maternal BMI is positively associated with human milk fat: a systematic review and meta-regression analysis.

Background: Lack of robust estimates of human-milk nutrient composition and influential maternal factors, such as body composition, are barriers to informing nutrition policies and programs.

Objective: The objective was to understand the relation between maternal BMI and human-milk energy, fat, and/or total protein.

Methods: Four electronic databases (MEDLINE, Embase, CINAHL, and Web of Science) were searched.

The ultrafiltration molecular weight cut-off has a limited effect on the concentration and protein profile during preparation of human milk protein concentrates.

Optimizing protein intake for very low birth weight (<1,500 g) infants is fundamental to prevent faltering postnatal growth with the potential association of impaired neurodevelopment. The protein content of human milk is not sufficient to support the growth of very low birth weight infants. To meet their elevated protein requirements, human milk is currently fortified using typically bovine milk-based protein isolates (>85% on a dry basis).

Registered Dietitians' Knowledge, Attitudes, and Behaviour Related to Physical Activity and Sedentariness.

To explore knowledge, attitudes, and behaviour related to physical activity (PA) and sedentariness among registered dietitians (RDs) in family health teams in Ontario. This cross-sectional, descriptive study utilized a semi-structured interview guide to conduct qualitative interviews with 20 RDs. Self-administered questionnaires were used to assess personal PA (short version of the International Physical Activity Questionnaire) and sedentary behaviour (Sedentary Behavior Questionnaire).

Registered dietitians' beliefs and behaviours related to counselling patients on physical activity and sedentary behaviour from a theory of planned behaviour perspective.

Background: Registered dietitians working in team-based primary care settings (e.g., family health teams [FHTs]) are positioned to counsel on physical activity and sedentary behaviour when providing nutrition-related services to promote health and prevent disease.

Energy and Fat Intake for Preterm Infants Fed Donor Milk Is Significantly Impacted by Enteral Feeding Method.

Background: Pasteurized donor milk is the recommended supplement for preterm infants when mother's milk volumes are insufficient. Compared with mother's milk, the macronutrient content of donor milk is thought to be lower due to pasteurization and additional container changes during processing. Given that poor growth is concerning for preterm infants, it is important to understand how processing and feeding methods influence the nutrition composition of donor milk feeds.