The Gut Microbiome as a Component of the Gut-Brain Axis in Cognitive Health.

INTRODUCTION: The human microbiome, the microorganisms living in and on the body, plays a vital role in brain physiology and pathophysiology. The gut microbiome (GMB) has been identified as a link in the gut-brain axis moderating cognitive development and health. OBJECTIVES: The objectives of this scoping review are to discuss mechanisms of the microbiome-gut-brain axis in cognition, review the existing literature on the GMB and cognition, and discuss implications for nursing research. METHODS: We searched Pubmed using the terms "gut microbiome," "brain," and "cognition" and the terms "gut brain axis," "microbiome," and "cognition"; removed duplicates, studies not published in English, and unrelated publications; and added additional articles identified through references. We retained the 85 most relevant publications for this review. RESULTS: Common themes in the current literature include GMB components; interactions on cognitive development; effects of GMB-gut-brain interactions on cognition, mild cognitive impairment and Alzheimer's disease; effects of GMB interactions with physiologic stress on cognition in critical care; and GMB modification for improved cognition. Review of the literature on each of these topics reveals multiple theoretical mechanisms of action for GMB-gut-brain interaction that modify cognitive development and function across the lifespan. DISCUSSION: GMB components and dysbiosis have been implicated in many cognitive states, and specific microbiota constituents contribute to cognitive development, stability, and impairment. The study of these interactions is relevant to nursing research as it addresses the holistic human experience and microbiome constituents are modifiable, facilitating translation into the clinical setting.

Maternal Interleukin Genotypes Are Associated With NICU Outcomes Among Low-Birth-Weight Infants.

BACKGROUND: Maternal interleukin (IL) single nucleotide polymorphisms (SNPs) are associated with obstetrical outcomes. Conversely, infant SNPs are associated with subsequent neonatal intensive care unit (NICU) outcomes. Little is known about relationships between maternal SNPs and neonatal outcomes. PURPOSE: To examine the relationships between maternal IL genotypes and neonatal outcomes. METHODS: An ancillary study was conducted among mothers ( N = 63) who delivered very low-birth-weight infants ( N = 74). Maternal DNA was extracted from breast milk and genotyped. Outcomes included fecal calprotectin, length of stay, scores for neonatal acute physiology with perinatal extension (SNAPPE-II), weight gain, oxygen needs, necrotizing enterocolitis, intraventricular hemorrhage, sepsis, retinopathy of prematurity, blood transfusions, and feeding intolerance. Multivariate analyses examined the relationships between maternal IL SNPs and outcomes, controlling for gestational age and the ratio of maternal milk to total milk. RESULTS: Absence of a minor allele in 2 IL6 SNPs was associated with fecal calprotectin ( p = .0222, p = .0429), length of stay ( p = .0158), SNAPPE-II ( p = .0497), weight gain ( p = .0272), and days on oxygen ( p = .0316). IL6 genotype GG (rs1800795) was associated with length of stay ( p = .0034) and calprotectin ( p = .0213). Minor-allele absence in 2 IL10 SNPs was associated with days on oxygen ( p = .0320). There were associations between IL10 genotype TT (rs1800871) and calprotectin ( p = .0270) and between IL10 genotypes AA (rs1800872 and rs1800896) and calprotectin ( p = .0158, p = .0045). CONCLUSION: Maternal IL SNPs are associated with NICU outcomes. A potential clinical application includes an antenatal risk profile to identify neonatal needs.

Effect of Promoter Polymorphisms on Cytokine Concentration in Preterm Breast Milk and Subsequent Infant Outcomes.

BACKGROUND: Breast milk concentrations of immune components are variable between women and interleukin (IL) differences may be associated with infant outcomes. Molecular mechanisms for milk variability remain unknown. OBJECTIVE: The aims were to (1) examine the relationship between maternal IL genotypes and milk concentrations of IL4, IL6, and IL10, (2) describe the trajectories of milk IL change, (3) examine whether maternal IL genotypes predict IL trajectories and/or average weekly IL concentration, and (4) examine if weekly IL levels and/or IL trajectories are associated with infant outcomes. METHODS: Milk aliquots were collected from each feeding of mother's own milk and pooled weekly. DNA was extracted from 1 sample of each mother's breast milk whey (n = 64), and single nucleotide polymorphisms (SNPs) of IL genes were genotyped. Milk IL concentrations were measured and trajectory analysis examined IL milk change over time. Multivariate breast milk IL concentration analyses controlled for gestational age and prepregnancy body mass index. Multivariate infant outcome (n = 73) analyses controlled for gestational age and the ratio of human milk to total milk. RESULTS: Trajectory analysis resulted in linear group shapes, with 2 distinct subgroups in IL6 and 3 subgroups in IL4 and IL10. Trajectory groups trended toward significance with calprotectin, intraventricular hemorrhage, and blood transfusions. Multivariate analyses resulted in trending associations between maternal SNPs and subsequent IL6 and IL10 milk levels. There was a trending relationship between IL milk levels and both fecal calprotectin and intraventricular hemorrhage. CONCLUSION: Maternal IL SNPs may affect IL breast milk levels and IL milk levels may be associated with infant outcomes.

From royal wet nurses to Facebook: The evolution of breastmilk sharing.

Wet-nursing was an essential practice that allowed for infant survival after many mothers died in childbirth. The story of wet-nursing is complicated by both religious pressures and cultural expectations of women. It is likely that these historical practices have shaped our current social, political and legislative environments regarding breastfeeding. The aim of this article is to provide a historical perspective on the practice of wet-nursing, with a focus on: 1) social views of wet nurses, 2) breastmilk evaluation and 3) the ideal wet nurse. Historical perspectives from Ancient Egypt, Ancient Greece and Rome, 19th and 20th century America and current practices are examined. An appreciation for the evolution of breastmilk sharing provides clinicians and lactation advocates with the historical origins which provided the template for current practice as it relates to donor milk, breastfeeding culture and relevant legislation.

WIC (The Special Supplemental Nutrition Program for Women, Infants, and Children): policy versus practice regarding breastfeeding.

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides foods, education, and referrals to participants who are considered to be at nutritional risk. The outreach of the program is impressive, and nearly 9.17 million people participated in the program in 2010. WIC participation is associated with many positive outcomes, including improved birthweights and childhood dietary practices. Despite these benefits, WIC mothers experience lower breastfeeding rates when compared with demographically similar women who do not participate in the WIC program. According to WIC, "A breastfeeding mother and her infant shall be placed in the highest priority level." Despite this statement and others that support breastfeeding, WIC allocates only 0.6% of its budget toward breastfeeding initiatives. Formula expenses accounted for 11.6% ($850 million) of WIC's 2009 expenses. The inconsistency between WIC's policies that encourage breastfeeding vs. practices that favor formula begs further examination. Research shows consistent success with peer counseling programs among WIC participants; however, little money is budgeted for these programs. Rebates included, WIC spends 25 times more on formula than on breastfeeding initiatives. The American Academy of Nursing Expert Panel on Breastfeeding is calling for a re-evaluation of how these taxpayer dollars are spent. Additionally, the American Academy of Nursing recommends a shift from formula bargaining to an investment in structured peer counseling programs. All WIC programs should offer peer counseling support services that encourage breastfeeding and meet the needs of the families they serve.

The utility of breastmilk for genetic or genomic studies: a systematic review.

This study synthesized scientific literature that applies genetic or genomic approaches to breastmilk. A literature search of PubMed was conducted in March 2012 using the key words "breast milk," "lactation," "genetic," "gene expression," and "epigenetic." Additional articles were identified/selected for evaluation with MeSH term searches, and a review of article reference lists was obtained from the search. The initial 657 abstracts retrieved from the literature search were reviewed, and 16 studies were selected for evaluation. Studies that examined the transmission of viruses/bacteria into breastmilk and/or measured concentration of specific proteins without examination of genetic material from milk were excluded. Data related to subjects, tissue, purpose, setting, gene/protein, approach (candidate versus genome-wide), platform, statistical analysis, and results were extracted. Gene expression and epigenetic/epigenomic study designs have been successfully implemented using breastmilk. A major weakness of both gene expression studies and epigenetic studies that examine breastmilk is the omission of maternal information known to influence milk composition. This review article is the first to synthesize evidence related to the application of breastmilk to evaluate RNA and epigenetic modifications. Additional research is needed that applies epigenetic analyses to human breastmilk samples. Findings from this review can be used for future research designs that use breastmilk for genetic analyses.

Psychometric evaluation of the Epworth sleepiness scale in an obstetric population.

BACKGROUND: The Epworth Sleepiness Scale (ESS) was initially developed to measure daytime sleep propensity in patients affected by a variety of sleep disorders. Obstetrical research has measured sleepiness in pregnant women with the ESS, although psychometric analyses and dimensionality evaluations have never been conducted with this population. OBJECTIVE: The objective was to perform a psychometric evaluation of the ESS in an obstetric population. The design was a secondary data analysis of the subjects enrolled in the Prenatal Exposures and Preeclampsia Prevention III (PEPP) study. The setting for the subjects who received prenatal care was at Magee-Women's Hospital UPMC in Pittsburgh, Pennsylvania and included 337 pregnant women in their first trimester that completed the ESS. METHODS: Principal components analysis and confirmatory factor analysis were performed using SPSS and M-Plus. Additionally, reliability was assessed and construct validity was measured using the Life Orientation Test (LOT). Lastly, a relationship between daytime sleepiness and snoring was investigated using item 5e from the Pittsburgh Sleep Quality Index (PSQI). RESULTS: PCA with varimax rotation yielded two factors that explained approximately 50% of the variance and CFA results verified this two-factor solution. An overall Cronbach's alpha (0.751) revealed moderate reliability (Factor 1α=.754; Factor 2α=.524). Both convergent and discriminant validity were established. CONCLUSION: The ESS is appropriate for use in an obstetric population to measure daytime sleepiness. Future work should include additional evaluations of the ESS in a diverse group of pregnant women.