Protective Effects of Human Milk-Derived Exosomes on Intestinal Stem Cells Damaged by Oxidative Stress.

Breastfeeding has been shown to have a protective effect on the occurrence of necrotizing enterocolitis (NEC), but the mechanism remains unclear. In the context of NEC pathogenesis, many of the protective properties of exosomes on the intestinal epithelial compartment make it an ideal therapeutic target. In the present study, our hypothesis was that intestinal stem cells (ISCs) would be protected from injury by human milk-derived exosomes (HMDEs). Human breast milk was collected, and exosomes were isolated using ExoQuick reagent. Magnetic-activated cell sorting isolation of prominin-1+ ISCs was performed from small intestines of neonatal rat. ISCs were treated with or without H2O2, and HMDEs, an equal volume of HMDE-free milk, or a control solution [phosphate-buffered solution (PBS)] was added, respectively. In the absence of HMDEs, exposure of ISCs to H2O2 led to decreased cell viability. However, addition of HMDEs to ISCs exposed to H2O2 led to significantly increased ISC viability. There was a significant upregulation of mRNA expression of Axin2, c-Myc, and Cyclin D1 genes of the Wnt/ß-catenin axis in ISCs treated with HMDEs (6.99 ± 2.34, 4.21 ± 1.68, 6.17 ± 2.22, respectively, P < 0.05 for all), as compared to control. In the presence of carnosic acid (a specific Wnt/ß-catenin signaling inhibitor), the cell viability was significantly decreased. Thus, HMDEs protect ISCs from oxidative stress injury in vitro, which were possibly mediated via the Wnt/ß-catenin signaling pathway. Our findings indicate that oral administration of HMDEs might be a promising measure in treating NEC or in preventing the development of NEC in high-risk infants when breast milk is not available.

Early-life gut microbiome and cow's milk allergy- a prospective case - control 6-month follow-up study.

Increasing evidence suggests that perturbations in the intestinal microbiota in early infancy are implicated in the pathogenesis of food allergy (FA); existing evidence on the structure and composition of the intestinal microbiota in human beings with FA is limited and conflicting. The main object of the study was to compare the faecal microbiota between healthy and cow's milk allergy (CMA) infants at the baseline immediately after the diagnosis, and to evaluate the changes in the faecal microbiota after 6 months of treatment of CMA infants with hypoallergenic formula (HF), compared with healthy children fed on standard milk formulae. Sixty infants younger than 4 months of age with challenge-proven CMA and 60 healthy age-matched children were investigated in this prospective case - control follow-up study. Faecal samples were collected at baseline and at 6 months of follow-up, microbial diversity and composition were characterized by high-throughput 16S rRNA sequencing. The average age (±SD) of the infants at inclusion was 2.9 ±â€¯1.0 months. Children with CMA have lower gut microbiota diversity and an elevated Enterobacteriaceae to Bacteroidaceae (E/B ratio) in early infancy compared with healthy children (115.8 vs. 0.8, P = 0.0002). After 6 months of treatment with HF, CMA infants had a higher Lactobacillaceae (6.3% vs. 0.5%, P = 0.04) and lower Bifidobacteriaceae (0.3% vs. 8.2%, P = 0.03) and Ruminococcaceae (1.5% vs. 10.5%, P = 0.03) abundance compared with control children. Conclusion: Low gut microbiota diversity and an elevated E/B ratio in early infancy may contribute to the development of FA, including CMA. A strict elimination diet may weaken FA by reducing E/B ratio and promoting a gut microbiota that would benefit the acquisition of oral tolerance.

Children with cow's milk allergy following an elimination diet had normal growth but relatively low plasma leptin at age two.

AIM: To assess nutrient intake, growth and nutritional status of infants with cow's milk allergy (CMA) who follow a therapeutic elimination diet since the first few months of life. METHODS: Sixty infants younger than four months of age with challenge-proven CMA and 60 healthy age-matched children were investigated. Anthropometric and body composition (BC) were assessed up to 24 months. Dietary intake was recorded by the parents for three consecutive days before visits at 6, 12, 18 and 24 months. Blood albumin, prealbumin, retinol binding protein and metabolic-related hormones were examined at 24 months. RESULTS: The average age at enrolment was 2.9 ± 1.0 months. At the end of the follow-up, there were no differences in daily milk consumption, nutrient intake, weight and height z scores or BC measures between the groups; however, the plasma leptin level was lower in infants with CMA (1.67 ± 1.03 vs 2.05 ± 1.48) (ng/mL) (p < 0.05) compared to healthy children. CONCLUSIONS: Children with CMA who followed an elimination diet could achieve a normal nutritional status, except for relatively lower plasma leptin levels, at the age of 2. Further studies with larger cohorts and research on the long-term consequences of these early differences are needed.