Levels of palmitic acid ester of hydroxystearic acid (PAHSA) are reduced in the breast milk of obese mothers.

To achieve optimal development of a newborn, breastfeeding is extensively recommended, but little is known about the role of non-nutritive bioactive milk components. We aimed to characterize the fatty acid esters of hydroxy fatty acids (FAHFAs), namely palmitic acid hydroxystearic acids (PAHSAs)-endogenous lipids with anti-inflammatory and anti-diabetic properties, in human breast milk. Breast milk samples from 30 lean (BMI=19-23) and 23 obese (BMI>30) women were collected 72h postpartum. Adipose tissue and milk samples were harvested from C57BL/6J mice. FAHFA lipid profiles were measured using reverse phase and chiral liquid chromatography-mass spectrometry method. PAHSA regioisomers as well as other FAHFAs were present in both human and murine milk. Unexpectedly, the levels of 5-PAHSA were higher relative to other regioisomers. The separation of both regioisomers and enantiomers of PAHSAs revealed that both R- and S-enantiomers were present in the biological samples, and that the majority of the 5-PAHSA signal is of R configuration. Total PAHSA levels were positively associated with weight gain during pregnancy, and 5-PAHSA as well as total PAHSA levels were significantly lower in the milk of the obese compared to the lean mothers. Our results document for the first time the presence of lipid mediators from the FAHFA family in breast milk, while giving an insight into the stereochemistry of PAHSAs. They also indicate the negative effect of obesity on 5-PAHSA levels. Future studies will be needed to explore the role and mechanism of action of FAHFAs in breast milk.

The Biological Effects of Bilirubin Photoisomers.

Although phototherapy was introduced as early as 1950's, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells.

Limited Amount of Formula May Facilitate Breastfeeding: Randomized, Controlled Trial to Compare Standard Clinical Practice versus Limited Supplemental Feeding.

OBJECTIVES: Breastfeeding is known to reduce infant morbidity and improve well-being. Nevertheless, breastfeeding rates remain low despite public health efforts. Our study aims to investigate the effect of controlled limited formula usage during birth hospitalisation on breastfeeding, using the primary hypothesis that early limited formula feeds in infants with early weight loss will not adversely affect the rate of exclusive or any breastfeeding as measured at discharge, 3 and 6 months of age. MATERIAL AND METHODS: We randomly assigned 104 healthy term infants, 24 to 48 hours old, with ≥ 5% loss of birth weight to controlled limited formula (CLF) intervention (10 ml formula by syringe after each breastfeeding, discontinued at onset of lactation) or control group (standard approach, SA). Groups were compared for demographic data and breastfeeding rates at discharge, 3 months and 6 months of age (p-values adjusted for multiple testing). RESULTS: Fifty newborns were analysed in CLF and 50 in SA group. There were no differences in demographic data or clinical characteristics between groups. We found no evidence of difference between treatment groups in the rates of exclusive as well as any breastfeeding at discharge (p-value 0.2 and >0.99 respectively), 3 months (p-value 0.12 and 0.10) and 6 months of infants' age (p-value 0.45 and 0.34 respectively). The percentage weight loss during hospitalisation was significantly higher in the SA group (7.3% in CLF group, 8.4% in SA group, p = 0.002). CONCLUSION: The study shows that controlled limited formula use does not have an adverse effect on rates of breastfeeding in the short and long term. Larger studies are needed to confirm a possible potential in controlled limited formula use to support establishing breastfeeding and to help to improve the rates of breastfeeding overall. TRIAL REGISTRATION: ISRCTN registry ISRCTN61915183.