The mother's immune system is a balanced threat to the foetus, turning to protection of the neonate

Socioeconomic circumstances, health-related behaviours and paediatric infections: a mediation analysis

OBJECTIVE

To examine how the effect of disadvantaged socioeconomic circumstances on the risk of paediatric infections is mediated by pregnancy smoking, excess weight during pregnancy and breast feeding in children under 5 years of age.

DESIGN

A population-level, retrospective cohort study. The Swedish Medical Birth Register was combined with the National Patient Register, the longitudinal integration database for health insurance and labour market studies, the Cause of Death Register and a local register held by the Child Health Care Unit in Uppsala Region.

SETTING

Uppsala Region, Sweden.

PATIENTS

63 216 term and post-term singletons born to women who resided in Uppsala Region, Sweden between 1997 and 2015.

MAIN OUTCOME MEASURES

Number of hospital admissions for infectious diseases. Secondary outcomes were the number of hospitalisations for respiratory and enteric infections, respectively.

RESULTS

The effect of disadvantaged socioeconomic circumstances, that is, low maternal education on the overall risk of paediatric infections was mediated to a considerable (33%-64%) proportion by pregnancy smoking, excess weight during pregnancy and breast feeding.

CONCLUSIONS

Pregnancy smoking, excess weight during pregnancy and breast feeding mediate a considerable proportion of the association between deprived socioeconomic circumstances and paediatric infectious diseases. Therefore, inequalities in paediatric infectious diseases may be reduced by public health policies addressing these health-related behaviours.

Breastfeeding practice, breastfeeding policy and hospitalisations for infectious diseases in early and later childhood: a register-based study in Uppsala County, Sweden

OBJECTIVE

To examine the association between breastfeeding practice and hospitalisations for infectious diseases in early and later childhood, in particular, to compare exclusive breast feeding 4-5 months with exclusive breastfeeding 6 months or more. Thereby, provide evidence to inform breastfeeding policy.

DESIGN

A register-based cohort study.

SETTING

A cohort was created by combining the Swedish Medical Birth Register, the National Inpatient Register, the Cause of Death Register, the Total Population Register, the Longitudinal integration database for health insurance and labour market studies, with the Uppsala Preventive Child Health Care database.

PATIENTS

37 825 term and post-term singletons born to women who resided in Uppsala County (Sweden) between 1998 and 2010.

MAIN OUTCOME MEASURES

Number of hospitalisations for infectious diseases in early (<2 years) and later childhood (2-4 years).

RESULTS

The risk of hospitalisations for infectious diseases decreased with duration of exclusive breastfeeding until 4 months of age. In early childhood, breast feeding was associated with a decreased risk of enteric and respiratory infections. In comparison with exclusive breast feeding 6 months or more, the strongest association was found between no breastfeeding and enteric infections (adjusted incidence rate ratios, aIRR 3.32 (95% CI 2.14 to 5.14)). In later childhood, breast feeding was associated with a lower risk of respiratory infections. In comparison with children exclusively breastfed 6 months or more, the highest risk was found in children who were not breastfed (aIRR 2.53 (95% CI 1.51 to 4.24)). The risk of hospitalisations for infectious diseases was comparable in children exclusively breastfed 4-5 months and children exclusively breastfed 6 months or more.

CONCLUSIONS

Our results support breastfeeding guidelines that recommend exclusive breastfeeding for at least 4 months.

Detection of respiratory syncytial virus (RSV) at birth in a newborn with respiratory distress

Respiratory syncytial virus (RSV) is the most common respiratory pathogen in infants and young children. From the nasopharyngeal or conjunctival mucosa of infected individuals, RSV spreads to the lower respiratory tract causing acute bronchiolitis and pneumonia after an incubation period of 4-6 days. In addition to its well-documented tropism for the airway epithelium, it has been shown previously that RSV can also spread hematogenously and efficiently infect extrapulmonary tissues of human hosts. Furthermore, it has been shown in animal models that RSV can spread transplacentally from the respiratory tract of a pregnant mother to the lungs of the fetus. This report describes a documented case of neonatal RSV infection strongly suggestive of prenatal transmission of this infection in humans from an infected mother to her offspring.

Leaky gut, microbiota, and cancer: an incoming hypothesis

Multigenic disease development is dependent on both missing and overactivated pathways, just as the homeostasis of our body systems is the product of many complex, redundant mechanisms. The goal of finding a common factor in the disease pathogenesis is difficult, as genetic and pathophysiological data are still incomplete, and the individual variability is enormous. Nevertheless, the examination of the role of human microbiota in illnesses using animal models of human diseases reared in defined (gnotobiotic) conditions could allow insight into the unusual complexity of the mechanisms involved in the initiation and maintenance of chronic diseases, including cancer. Although the most important findings in this fascinating field are still to come, a hypothesis, which is more than speculative, can be made, as it is clear that our bacterial companions affect our fates more than previously assumed.

Pasteurization of mother's own milk for preterm infants does not reduce the incidence of late-onset sepsis

BACKGROUND

Feeding preterm infants human milk has a beneficial effect on the risk of late-onset sepsis (LOS). Due to lack of microbiological standards, practices such as pasteurization of mother's own milk differ widely among neonatal intensive care units worldwide.

OBJECTIVES

To investigate whether pasteurization of mother's own milk for very-low-birth-weight (VLBW) infants influences the incidence and severity of infection-related outcomes.

METHODS

In this randomized controlled trial, preterm infants (gestational age <32 weeks and/or birth weight <1,500 g) received either raw or pasteurized mother's own milk during the first 8 weeks of life. The primary outcome was the incidence of proven LOS. A dose-response relation was verified, i.e. the dependence of the risk of sepsis on the actual and cumulative quantities of mother's own milk.

RESULTS

This study included 303 VLBW infants (mean birth weight: 1,276 g; mean gestational age: 29 weeks) whose baseline and nutritional characteristics were similar. The incidence of laboratory-confirmed sepsis was not statistically different in infants fed raw milk compared to infants who received pasteurized milk: 22/151 (0.15, CI: 0.08-0.20) and 31/152 (0.20, CI: 0.14-0.27), respectively (RR: 0.71; 95% CI: 0.43-1.17). A significant dose-response relation was observed between the adjusted quantity of enteral feeding and the risk of LOS, regardless of the type of feeding.

CONCLUSION

For preterm infants, pasteurization of mother's own milk shows a trend towards an increase in infectious morbidity, although no statistical significance was reached. Practices should focus on collection, storage and labeling procedures to ensure the safety and quality of expressed milk.

Ethical considerations on methods used in abortions

There is a fundamental inconsistency in Western society's treatment of non-human animals on the one hand, and of human foetuses on the other. While most Western countries allow the butchering of animals and their use in experimentation, this must occur under carefully controlled conditions that are intended to minimize their pain and suffering as much as possible. At the same time, most Western countries permit various abortion methods without similar concerns for the developing fetus. The only criteria for deciding which abortion method is used centre in the stage of the pregnancy, the size of the fetus, the health of the pregnant woman and the physician's preference. This is out of step with the underlying ethos of animal cruelty legislation, cannot be justified ethically and should be rectified by adjusting abortion methods to the capacity of the fetus to experience nociception and/or pain.

The importance of antioxidant micronutrients in pregnancy

Pregnancy places increased demands on the mother to provide adequate nutrition to the growing conceptus. A number of micronutrients function as essential cofactors for or themselves acting as antioxidants. Oxidative stress is generated during normal placental development; however, when supply of antioxidant micronutrients is limited, exaggerated oxidative stress within both the placenta and maternal circulation occurs, resulting in adverse pregnancy outcomes. The present paper summarises the current understanding of selected micronutrient antioxidants selenium, copper, zinc, manganese, and vitamins C and E in pregnancy. To summarise antioxidant activity of selenium is via its incorporation into the glutathione peroxidase enzymes, levels of which have been shown to be reduced in miscarriage and preeclampsia. Copper, zinc, and manganese are all essential cofactors for superoxide dismutases, which has reduced activity in pathological pregnancy. Larger intervention trials are required to reinforce or refute a beneficial role of micronutrient supplementation in disorders of pregnancies.

The role of gut microbiota (commensal bacteria) and the mucosal barrier in the pathogenesis of inflammatory and autoimmune diseases and cancer: contribution of germ-free and gnotobiotic animal models of human diseases

Metagenomic approaches are currently being used to decipher the genome of the microbiota (microbiome), and, in parallel, functional studies are being performed to analyze the effects of the microbiota on the host. Gnotobiological methods are an indispensable tool for studying the consequences of bacterial colonization. Animals used as models of human diseases can be maintained in sterile conditions (isolators used for germ-free rearing) and specifically colonized with defined microbes (including non-cultivable commensal bacteria). The effects of the germ-free state or the effects of colonization on disease initiation and maintenance can be observed in these models. Using this approach we demonstrated direct involvement of components of the microbiota in chronic intestinal inflammation and development of colonic neoplasia (i.e., using models of human inflammatory bowel disease and colorectal carcinoma). In contrast, a protective effect of microbiota colonization was demonstrated for the development of autoimmune diabetes in non-obese diabetic (NOD) mice. Interestingly, the development of atherosclerosis in germ-free apolipoprotein E (ApoE)-deficient mice fed by a standard low-cholesterol diet is accelerated compared with conventionally reared animals. Mucosal induction of tolerance to allergen Bet v1 was not influenced by the presence or absence of microbiota. Identification of components of the microbiota and elucidation of the molecular mechanisms of their action in inducing pathological changes or exerting beneficial, disease-protective activities could aid in our ability to influence the composition of the microbiota and to find bacterial strains and components (e.g., probiotics and prebiotics) whose administration may aid in disease prevention and treatment.

Alpha-lactalbumin in human milk alters the proteolytic degradation of soluble CD14 by forming a complex

Mother's milk represents a foundational step in the proper development of newborn immunity. This is achieved, in part, through the action of numerous regulatory proteins such as soluble cluster of differentiation 14 (sCD14) found in significant quantities in human milk (~25-50 μg/mL). In adults, CD14 stimulates cytokine production in response to lipopolysaccharide (LPS), the major lipid component found in the outer membrane of Gram-negative bacteria. However, the fate and function of sCD14 in the neonatal gastrointestinal (GI) tract are unknown and may function differently from adults. Therefore, we administered human sCD14 to experimental animals and observed that it persisted in the upper GI tract after feeding. In our search for potential proteolytic protectants, immunoprecipitation of sCD14 from human milk revealed a 15-kD novel protein that copurified with sCD14. Mass spectrometry analysis of the protein identified alpha-lactalbumin. CD14 was also identified by immunoblot after immunoprecipitation of alpha-lactalbumin from milk. In vitro digestion assays revealed that purified alpha-lactalbumin decreases the proteolytic degradation of human milk derived sCD14 in vitro, suggesting a mechanism by which this key LPS receptor may remain functional in the neonate gut.

In vitro immunomodulatory activity of Lactobacillus fermentum CECT5716 and Lactobacillus salivarius CECT5713: two probiotic strains isolated from human breast milk

Commensal bacteria, including some species of lactobacilli commonly present in human breast milk, appear to colonize the neonatal gut and contribute to protection against infant infections, suggesting that lactobacilli could potentially modulate immunity. In this study, we evaluated the potential of two Lactobacillus strains isolated from human milk to modulate the activation and cytokine profile of peripheral blood mononuclear cell (PBMC) subsets in vitro. Moreover, these effects were compared to the same probiotic species of non-milk origin. Lactobacillus salivarius CECT5713 and Lactobacillus fermentum CECT5716 at 10⁵, 10⁶ and 10⁷ bacteria/mL were co-cultured with PBMC (10⁶/mL) from 8 healthy donors for 24 h. Activation status (CD69 and CD25 expressions) of natural killer (NK) cells (CD56+), total T cells (CD3+), cytotoxic T cells (CD8+) and CD4+ T cells was determined by flow cytometry. Regulatory T cells (Treg) were also quantified by intracellular Foxp3 evaluation. Regarding innate immunity, NK cells were activated by addition of both Lactobacillus strains, and in particular, the CD8+ NK subset was preferentially induced to highly express CD69 (~90%, p<0.05). With respect to acquired immunity, approximately 9% of CD8+ T cells became activated after co-cultivation with L. fermentum or L salivarius. Although CD4+ T cells demonstrated a weaker response, there was a preferential activation of Treg cells (CD4+CD25+Foxp3+) after exposure to both milk probiotic bacteria (p<0.05). Both strains significantly induced the production of a number of cytokines and chemokines, including TNFα, IL-1β, IL-8, MIP-1α, MIP-1β, and GM-CSF, but some strain-specific effects were apparent. This work demonstrates that L salivarius CECT5713 and L. fermentum CECT5716 enhanced both natural and acquired immune responses, as evidenced by the activation of NK and T cell subsets and the expansion of Treg cells, as well as the induction of a broad array of cytokines.

Influence of breast milk polyamines on suckling rat immune system maturation

The aim of this study was to ascertain whether the supplementation of polyamines present in breast milk, i.e. spermine (SPM) and spermidine (SPD), influenced the post-natal maturation of the systemic and intestinal immune system in rats. From birth, pups daily received SPM or SPD. At 5, 11 and 18 days old, small intestine intraepithelial lymphocytes (IEL), lamina propria lymphocytes (LPL) and splenocytes were phenotypically characterized. SPM and, less evidently, SPD accelerated the maturation of CD8+ IEL, and enhanced the presence of intraepithelial NK cells and IEL related with specific immune responses on the proximal and distal small intestine, respectively. Polyamines increased the percentage of more mature CD4+ LPL and enhanced the early presence of splenic B cells and, later, that of NK cells. However, no effect on Ig-secretory function was detected. These results suggest that breast milk polyamines improve the maturation of the rat intestinal and systemic immune system.