Bioactive metabolites of OMEGA-6 and OMEGA-3 fatty acids are associated with inflammatory cytokine concentrations in maternal and infant plasma at the time of delivery.

BACKGROUND & AIMS: Inflammation is necessary for a healthy pregnancy. However, unregulated or excessive inflammation during pregnancy is associated with severe maternal and infant morbidities, such as pre-eclampsia, abnormal infant neurodevelopment, or preterm birth. Inflammation is regulated in part by the bioactive metabolites of omega-6 (n-6) and omega-3 (n-3) fatty acids (FAs). N-6 FAs have been shown to promote pro-inflammatory cytokine environments in adults, while n-3 FAs have been shown to contribute to the resolution of inflammation; however, how these metabolites affect maternal and infant inflammation is still uncertain. The objective of this study was to predict the influence of n-6 and n-3 FA metabolites on inflammatory biomarkers in maternal and umbilical cord plasma at the time of delivery. METHODS: Inflammatory biomarkers (IL-1ß, IL-2, IL-6, IL-8, IL-10, and TNFα) for maternal and umbilical cord plasma samples in 39 maternal-infant dyads were analyzed via multi-analyte bead array. Metabolites of n-6 FAs (arachidonic acid and linoleic acid) and n-3 FAs (eicosapentaenoic acid and docosahexaenoic acid) were assayed via liquid chromatography-mass spectrometry. Linear regression models assessed relationships between maternal and infant inflammatory markers and metabolite plasma concentrations. RESULTS: Increased plasma concentrations of maternal n-6 metabolites were predictive of elevated pro-inflammatory cytokine concentrations in mothers; similarly, higher plasma concentrations of umbilical cord n-6 FA metabolites were predictive of elevated pro-inflammatory cytokine concentrations in infants. Higher plasma concentrations of maternal n-6 FA metabolites were also predictive of elevated pro-inflammatory cytokines in infants, suggesting that maternal n-6 FA status has an intergenerational impact on the inflammatory status of the infant. In contrast, maternal and cord plasma concentrations of n-3 FA metabolites had a mixed effect on inflammatory status in mothers and infants, which may be due to the inadequate maternal dietary intake of n-3 FAs in our study population. CONCLUSIONS: Our results reveal that maternal FA status may have an intergenerational impact on the inflammatory status of the infant. Additional research is needed to identify how dietary interventions that modify maternal FA intake prior to or during pregnancy may impact maternal and infant inflammatory status and associated long-term health outcomes.

Clostridium difficile stool shedding in infants hospitalized in two neonatal intensive care units is lower than previous point prevalence estimates using molecular diagnostic methods.

BACKGROUND: The point prevalence of Clostridium difficile stool shedding in hospitalized infants from two neonatal intensive care units (NICUs) was examined utilizing standard clinical testing compared with duplex PCR to identify toxigenic and non-toxigenic C. difficile strains. METHODS: All infants from the two NICUs affiliated with a single academic medical center were eligible for inclusion. Stool collection was blinded to patient characteristics and occurred during a one week period at each NICU and repeated with a second weeklong collection 6 months later to increase sample size. Stools were tested for C. difficile using EIA (GDH/toxin A/B) with samples testing +/+ or +/- subsequently evaluated by Loop-Mediated Isothermal Amplification (LAMP) and by duplex PCR amplification of tcdB and tpi (housekeeping) genes. Cytotoxicity assays were performed on all samples positive for C. difficile by any modality. RESULTS: Eighty-four stools were collected from unique infants for evaluation. EIA results showed 6+/+ [7.1%], 7 +/- [8.3%], and 71 -/- [84.5%] samples. All 6 EIA +/+ were confirmed as toxigenic C. difficile by LAMP; 6/7 EIA +/- were negative by LAMP with one identified as invalid. Duplex PCR concurred with LAMP in all 6 stools positive for toxigenic C. difficile. PCR identified 2 EIA -/- stools positive for tpi, indicating shedding of non-toxigenic C. difficile. Cytotoxicity assay was positive in 4/6 duplex PCR positive samples and negative for all stools that were EIA +/- but negative by molecular testing. CONCLUSIONS: C. difficile blinded point prevalence in infants from two NICUs was 7.1% by molecular methods; and lower than expected based on historical incidence estimates. In house duplex PCR had excellent concordance with clinically available LAMP and EIA tests, and added detection of non-toxigenic C. difficile strain shedding. Evolving NICU care practices may be influencing the composition of infant gut microbiota and reducing the point prevalence of C. difficile shedding in NICU patient stools.

An overview of assessment methodology for obesity-related variables in infants at risk.

BACKGROUND: The first 2 years of a child's life are a particularly critical time period for obesity prevention. AIM: An increasing amount of research across the world is aimed at understanding factors that impact early childhood obesity and developing interventions that target these factors effectively. With this growing interest, new and interdisciplinary research teams are developing to meet this research need. Due to rapid growth velocity during this phase of the lifespan, typical assessments used in older populations may not be valid or applicable in infants, and investigators need to be aware of the pros and cons of specific methodological strategies. METHODS: This paper provides an overview of methodology available to assess obesity-related factors in the areas of anthropometry and body composition, nutrient intake, and energy expenditure in infants aged 0-2 years. RESULTS: Gold standard measures for body composition, such as dual-energy X-ray absorptiometry (DXA) or other imaging techniques, are costly, require highly trained personnel, and are limited for research application. Nutrient intake methodology primarily includes surveys and questionnaires completed via parent proxy report. In terms of energy expenditure, methods of calorimetry are expensive and may not differentiate between different activities. Questionnaires or physical activity sensors offer another way of energy expenditure assessment. However, questionnaires have a certain recall bias, while the sensors require further validation. CONCLUSIONS: Overall, in addition to understanding the pros and cons of each assessment tool, researchers should take into consideration the experience of the interdisciplinary team of investigators, as well as the cost and availability of measures at their institution.