Plasma and urinary inositol isomer profiles measured by UHPLC-MS/MS reveal differences in scyllo-inositol levels between non-pregnant and pregnant women.

Previous studies support that myo- and D-chiro-inositol isomers are promising bioactives for the treatment of women with polycystic ovary syndrome and for lowering the risk of gestational diabetes mellitus in pregnant women, whereas scyllo-inositol may have some benefits for neurological disorders (e.g., Alzheimer's disease). Though potentially useful to better understand inositol isomer metabolism and study their role in health and disease, routine analysis of inositol isomers in plasma and urine with a single analytical method is not yet feasible due to the lack of a suitable analytical assay. To address this, we developed and validated a robust ultra-high-performance-liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the quantification of inositol isomers in plasma and urine. This method resolves seven inositol isomers with accurate quantification of total chiro- (D and L enantiomers), myo-, and scyllo-inositols and is semi-quantitative for neo-inositol. For urine and plasma myo-inositol, the method repeatability and intermediate reproducibility were below 6% and 8%, respectively. Then, for both chiro- and scyllo-inositols, repeatability and intermediate reproducibility were below 10% and 14%, respectively. A pilot study was carried out to quantify and compare the pattern of inositol isomers in urine and plasma of non-pregnant and pregnant women and showed for the first time that urinary myo- and scyllo-inositol concentrations were significantly higher for women in the third trimester of pregnancy compared with non-pregnant women. These findings warrant further research to understand the biological significance of the observed differences in inositol profiles and suggest a potential role of scyllo-inositol.Graphical abstract Plasma and urinary inositol isomer profiles measured by UHPLC-MS/MS reveal differences in scyllo-inositol levels between non-pregnant and pregnant women.

Temporal changes of major protein concentrations in preterm and term human milk. A prospective cohort study.

BACKGROUND: Proteins are major contributors to the beneficial effects of human milk (HM) on preterm infant health and development. Alpha-lactalbumin, lactoferrin, serum albumin and caseins represent approximately 85% of the total HM protein. The temporal changes of these proteins in preterm (PT) HM and its comparison with term (T) HM is poorly characterized. AIMS: To quantify and compare the temporal changes of the major proteins in PT HM and T HM. METHODS: HM was collected for 4 months postpartum at 12 time points for PT HM (gestational age 28 0/7-32 6/7 weeks; 280 samples) and for 2 months postpartum at 8 time points for T HM (gestational age 37 0/7-41 6/7 weeks; 220 samples). Proteins were measured with a micro-fluidic LabChip system. RESULTS: Casein, alpha-lactalbumin and lactoferrin decreased with advancing stages of lactation in PT and T HM, whereas serum albumin remained stable. Only marginal differences between PT and T HM were observed for alpha-lactalbumin during postpartum weeks 3-5 and for serum albumin at the first week. However, a comparison of HM provided to preterm and term infants at the same postmenstrual ages revealed that alpha-lactalbumin contents were significantly lower in PT HM than in T HM during the 39-48 postmenstrual weeks. CONCLUSIONS: This study provides comprehensive information of the longitudinal changes of major proteins in PT and T HM, and suggests limited availability of alpha-lactalbumin, a nutritionally important protein, in breastfed PT infants after reaching the term corrected age. This information may be important to optimize HM protein fortification, although its biological relevance needs to be confirmed by intervention studies. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov (NCT02052245), https://clinicaltrials.gov/ct2/show/NCT02052245.

Temporal Changes of Protein Composition in Breast Milk of Chinese Urban Mothers and Impact of Caesarean Section Delivery.

Human breast milk (BM) protein composition may be impacted by lactation stage or factors related to geographical location. The present study aimed at assessing the temporal changes of BM major proteins over lactation stages and the impact of mode of delivery on immune factors, in a large cohort of urban mothers in China. 450 BM samples, collected in three Chinese cities, covering 8 months of lactation were analyzed for α-lactalbumin, lactoferrin, serum albumin, total caseins, immunoglobulins (IgA, IgM and IgG) and transforming growth factor (TGF) ß1 and ß2 content by microfluidic chip- or ELISA-based quantitative methods. Concentrations and changes over lactation were aligned with previous reports. α-lactalbumin, lactoferrin, IgA, IgM and TGF-ß1 contents followed similar variations characterized by highest concentrations in early lactation that rapidly decreased before remaining stable up to end of lactation. TGF-ß2 content displayed same early dynamics before increasing again. Total caseins followed a different pattern, showing initial increase before decreasing back to starting values. Serum albumin and IgG levels appeared stable throughout lactation. In conclusion, BM content in major proteins of urban mothers in China was comparable with previous studies carried out in other parts of the world and C-section delivery had only very limited impact on BM immune factors.