Human milk mycobiota composition: relationship with gestational age, delivery mode, and birth weight.

Intestinal and human milk microbiota studies during infancy have shown variations according to geographical location, delivery mode, gestational age, and mother-related factors during pregnancy. In this study, we performed metagenomic mycobiota analyses of 44 transient and mature human milk among five different groups: mothers of normal spontaneous delivery-term (NS-T), caesarean delivery-term (CS-T), premature (PT), small for gestational age (SGA), and large for gestational age (LGA) infants. Fungi were detected in 80 out of the 88 samples. Regarding the number of observed fungal species, the NS-T group was more homogeneous (less variable) comparing the other groups (P<0.05). In the transient human milk samples, the most abundant species were Saccharomyces cerevisiae (33.3%) and Aspergillus glaucus (27.4%). While A. glaucus (33.7%) was second most abundant species in mature milk, S. cerevisiae disappeared (P<0.01) and Penicillium rubens became the most abundant species (35.5%) (P<0.05). Among the NS-T group, the most abundant species was Malassezia globosa in both transient and mature milk. In contrast, S. cerevisiae was the most abundant species in transient human milk (45.0%) in the CS-T group, but it disappeared in mature milk (P<0.01). In transient milk, M. globosa was only represented 6.0-9.0% of taxa in the PT, SGA, and LGA groups (P<0.05). In transient and mature milk in the PT, SGA and LGA groups, the most abundant species were A. glaucus and P. rubens. In mature milk samples, P. rubens is more abundant in CS-T group, PT group and LGA group, than the NS-T groups (P<0.05 for all). Although fungi constitute only a very small part of the human milk microbiome, we observed some changes that the human milk mycobiota composition varies in caesarean delivery, premature, SGA and LGA groups, comparing the normal spontaneous delivery, as well as differences between transient and mature human milk.

Human milk antibiotic residue levels and their relationship with delivery mode, maternal antibiotic use and maternal dietary habits.

OBJECTIVE: It is important to identify undesirable toxins and metabolites present in human milk that may be passed on to nursing infants. Such residues may derive from the antibiotics that are widely used to treat infectious diseases in both humans and food-producing animals. To the best of our knowledge, there are no reports in the literature on human milk antibiotic residue levels. PATIENT AND METHODS: As a part of the Human Milk Artificial Pollutants (HUMAP) study, we aimed to evaluate human milk antibiotic residues among mothers with 7 to 90-day-old babies. Pregnant women who had received antibiotic treatment during pregnancy were excluded. The use of antibiotic prophylaxis with cefazoline sodium during labor was noted among the study subjects. Human milk antibiotic residues were evaluated with the InfiniPlex for Milk Array (Randox Laboratories, London, United Kingdom), a semi-automated system with a multi-array biochip designed to detect antibiotic residues and toxins. RESULTS: The HUMAP study included 83 mothers, ranging in age from 17 to 41 years (mean 29.7 ± 6.2 years). Of these, 59% received cefazoline sodium shortly after birth, while 41% did not receive any antibiotics during the pregnancy, delivery or lactational periods. Testing revealed that 71/83 (85.5%) human milk samples were positive for beta-lactams and 12 (14.5%) samples were positive for quinolones. There was no difference in maternal age, gestational week, delivery type, sampling time, maternal dietary habits between the mothers with quinolones or beta-lactam residues in their milk and those without (p > 0.05 for both). Beta-lactam and quinolone residues were detected in 85.7% and 23.5%, respectively, of the human milk samples of mothers who did not receive antibiotics at birth and/or during the first seven days after birth. CONCLUSIONS: We found that the majority of human milk samples included beta-lactams or quinolones, even though the mothers did not receive these antibiotics during pregnancy and lactation. Antibiotic residues in human milk may affect early maintenance of the intestinal microbiota. Previous studies have shown that antimicrobials in food might increase the risks of allergies and could lead to the development of antibiotic-resistant bacterial strains. Effective policies on food safety and appropriate antibiotic use during pregnancy and lactation are needed.

Demonstration of pulse controlled all-optical switch/modulator.

An all-optical pulse controlled switch/modulator based on evanescent coupling between a polymer slab waveguide and a single mode fiber is demonstrated. Very fast all-optical modulation/switching is achieved via Kerr effect of the nonlinear polymer placed in the evanescent region of the optical fiber. Local refractive index perturbation (Δn=-1.45612×10(-5)) on the thin film leads to 0.374 nW power modulation at the fiber output, which results in a switching efficiency of ≈1.5%.