Allergic disease in the first year of life is associated with differences in subsequent neurodevelopment and behaviour

Childhood Physical Health and Attention Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis of Modifiable Factors

Although neurobiologic and genetic factors figure prominently in the development of attention deficit/hyperactivity disorder (ADHD), adverse physical health experiences and conditions encountered during childhood may also play a role. Poor health is known to impact the developing brain with potential lifelong implications for behavioral issues. In attempt to better understand the relationship between childhood physical health and the onset and presence of ADHD symptoms, we summarized international peer-reviewed articles documenting relationships between a select group of childhood diseases or health events (e.g., illnesses, injuries, syndromes) and subsequent ADHD outcomes among children ages 0-17 years. Drawing on a larger two-phase systematic review, 57 longitudinal or retrospective observational studies (1978-2021) of childhood allergies, asthma, eczema, head injury, infection, or sleep problems and later ADHD diagnosis or symptomatology were identified and subjected to meta-analysis. Significant associations were documented between childhood head injuries, infections, and sleep problems with both dichotomous and continuous measures of ADHD, and between allergies with dichotomous measures of ADHD. We did not observe significant associations between asthma or eczema with ADHD outcomes. Heterogeneity detected for multiple associations, primarily among continuously measured outcomes, underscores the potential value of future subgroup analyses and individual studies. Collectively, these findings shed light on the importance of physical health in understanding childhood ADHD. Possible etiologic links between physical health factors and ADHD are discussed, as are implications for prevention efforts by providers, systems, and communities.

Early childhood neurodevelopmental milestones in children with allergic diseases: the Japan Environment and Children's Study (JECS)

This study investigated the potential link between early childhood allergic diseases and neurodevelopmental milestone attainment during the first 3 years of life. Utilizing data from a large-scale prospective birth cohort study in Japan, encompassing 87,986 children, we examined physician-diagnosed and caregiver-reported allergic conditions, including atopic dermatitis (AD), asthma, and food allergy (FA). Neurodevelopmental milestones were assessed using the Ages and Stages Questionnaires at 1, 1.5, 2, 2.5, and 3 years of age. Stabilized inverse probability-weighted generalized estimating equation models were employed to estimate odds ratios (ORs). Our analysis revealed no significant association of AD and asthma with delay in communication, gross motor, fine motor, problem-solving, and personal-social skills during the initial 3 years of life. However, children with FA showed an increased likelihood of experiencing gross motor delay compared with that shown by those without FA (weighted adjusted OR: 1.14). Despite this, no significant association of FA with other developmental domains was observed. Early childhood allergies may not influence neurodevelopmental delays. However, there is a potential association between FA and delays, specifically in gross motor skills, that warrants routine developmental monitoring and additional investigations.

Evaluation of emotional, Behavioral, and clinical characteristics of children aged 1-5 with a history of food-related anaphylaxis

BACKGROUND

Our study aimed to investigate emotional, behavioral, and social characteristics assessed with internationally validated psychometric scales and their relationship with demographic, clinical, and laboratory data in children with a history of food-related anaphylaxis.

METHOD

The study included patients aged 1-5 who were followed up in the pediatric allergy outpatient clinic with a diagnosis of food-related anaphylaxis. All participants were evaluated during admission to the clinic using a study questionnaire, which was prepared by the authors, consisting of three parts: a sociodemographic information form, a clinical evaluation form, and the Aberrant Behavior Checklist (ABC) for psychiatric evaluation. Parents answered the questionnaires regarding the patients' emotional and behavioral health.

RESULTS

Thirty patients aged between 12 and 62 months were included in the study. The data were compared with 30 healthy controls with similar age and gender distribution. The total ABC score (p = 0.015), and the stereotypic behavior (p = 0.003) and hyperactivity (p = 0.002) subscale scores were significantly higher in patients with anaphylaxis history compared to the controls.

CONCLUSION

Emotional and behavioral status assessments and the clinical follow-up of food allergies of patients who experienced anaphylaxis in early childhood are useful for the holistic management and early recognition of possible pathologies.

Pathways of atopic disease and neurodevelopmental impairment: assessing the evidence for infant antibiotics

INTRODUCTION

Epidemiologic studies are starting to report associations between antibiotic use in early life and neurodevelopmental disorders. Through mechanisms within the gut microbiota-brain axis, indeed, it is plausible that infant antibiotic treatment plays a role in the development of atopic disease and neurodevelopmental disorders.

AREAS COVERED

This narrative review summarizes and interprets published evidence on infant antibiotic use in future outcomes of atopic disease, and neurodevelopmental delay and disorders, including attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). To this end, we critically assess study bias from 2 main confounding factors, maternal/infant infection and infant feeding status. We also discuss common mechanisms that link atopy and neurodevelopment, and propose hypotheses related to immune activation and the gut microbiome.

EXPERT OPINION

Atopic disease and neurodevelopmental disorders share many risk factors and biological pathways. Infant antibiotic use has been linked to both disorders and is likely a marker for prenatal or infant infection. The mediating role of breastfeeding can also not be discounted. The exploration of causal pathways along the gut-brain axis leading towards neurodevelopmental impairment is evolving and of future interest.

Sex-specific associations among infant food and atopic sensitizations and infant neurodevelopment

INTRODUCTION

Food sensitization is a first and strong indicator of immune deviation in the progression to other allergic conditions. Sensitization to food or other allergens and related inflammation during critical windows of infant development may adversely affect neurodevelopmental milestones. However, additional research is needed to test this association further.

METHODS

Associations between atopic (any food or aeroallergen) or food sensitization (specific to egg, soybean, peanut, and milk) at age 1 year and neurodevelopment up to 2 years of age were evaluated in the national CHILD Cohort Study, with a secondary aim examining whether these associations were sex-specific. Food and atopic sensitization were assessed by skin prick tests (SPT) in 1-year-old infants, with neurodevelopment assessed using the cognitive, language, motor, and social-emotional subscales of the Bayley Scales of Infant Development (BSID-III) administered at 1 and 2 years of age.

RESULTS

Atopic sensitization was present among 16.4% of infants, while 13.4% had food sensitizations. Only socioemotional scores reached statistical significance among the four BSID-III domains. Both atopic and food sensitization at 1 year of age was associated with lower social-emotional scores, independent of the infant's ethnicity. These findings were sex-specific and only observed among boys, among whom social-emotional scores were lowered by 5 points if atopic sensitization was present (-5.22 [95% CI: -9.96, -0.47], p = 0.03) or if food sensitization was present (-4.85 [95% CI: -9.82,0.11], p = 0.06). Similar results were observed using the standard SPT cut-off of ≥3 mm - for atopic sensitization (-5.17 [95% CI: -11.14, -0.80], p = 0.09) and for food sensitization (-4.61 [95% CI: -10.96, 1.74], p = 0.15).

CONCLUSION

In our study of term infants, we found an inverse, cross-sectional association between atopic and food sensitization status and social-emotional development scores in male children but not female children.

Prenatal IgE as a Risk Factor for the Development of Childhood Neurodevelopmental Disorders

Background: Few studies have examined if maternal allergic disease is associated with an offspring's neurodevelopment. We hypothesized that Th-2 biased maternal immune function assessed as total serum immunoglobulin (Ig) E is associated with attention deficit hyperactivity disorder (ADHD). Methods: Data are from the Wayne County Health, Environment, Allergy, and Asthma Longitudinal Study (WHEALS), a racially and socioeconomically diverse birth cohort in metropolitan Detroit, Michigan. Maternal total IgE was measured prenatally and at 1-month postpartum. Child total IgE was assessed at birth, 6 months, and 2 years of age. ADHD diagnosis was based on the parental report at the 10-12-year study visits or medical chart abstraction. Total IgE was log2 transformed. Poisson regression models with robust error variance were used to calculate the risk ratios (RR). Inverse probability weighting was used to correct for potential bias due to a loss to follow-up and non-response. Results: Of the 636 maternal-child pairs in the analysis, 513 children were neurotypical and 123 had ADHD. Maternal prenatal total IgE was significantly associated with ADHD even after adjustment for potential confounders (RR = 1.08, 95% CI 1.03-1.13). Maternal and child IgE measures were positively and significantly correlated, but child total IgE was not associated with ADHD at any time point. Conclusions: Maternal prenatal IgE may influence neurodevelopment, but additional studies are needed to confirm and expand these findings.

Sleep Patterns and Development of Children with Atopic Dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic inflammatory disease that begins in early childhood. Sleep problems have increased in children with AD. The aim of this study was to evaluate sleep patterns and the development of children with AD at an early age.

METHODS

This is a cross-sectional study consisting of a total of 80 children aged 0-36 months with AD. Patients were evaluated by the Brief Infant Sleep Questionnaire and International Guide for Monitoring Child Development.

RESULTS

The median age (IQR) of the patients was 6 (4.25-9) months, 63.7% of them were male and 50% of them had sleep problems. Male sex (OR: 3.78, p = 0.024, 95% CI, 0.083-0.837), patients with AD who were in the first 3 months after diagnosis (OR: 3.56; 95% CI, 1.220-10.43, p = 0.020), and moderate-severe AD (OR: 5.09; 95% CI, 1.649-15.748, p = 0.005) were determined as risk factors for sleep problems. In all, 12.5% of the patients needed support for one or more developmental areas (gross motor skills, expressive language and communication, receptive language, fine motor skills, relationship, and play). Developmental delay was higher in patients with sleep problems (p = 0.037). Multiple siblings (OR: 14.381; 95% CI, 1.557-132.871, p = 0.019) and the presence of sleep problems (OR: 8.011; 95% CI, 1.764-36.387, p = 0.024) were found to be risk factors for developmental delay.

CONCLUSION

Boys with moderate-severe AD within the first 3 months of diagnosis were at increased risk for sleep problems. Children with AD who have multiple siblings and sleep problems should be evaluated for developmental delay and monitored closely.

Children with allergic rhinitis and a risk of epilepsy: A nationwide cohort study

PURPOSE

Little is known about whether allergic disease is associated with a subsequent increased risk of childhood-onset epilepsy. We used a large, population-based cohort study to examine whether children with antecedent allergic rhinitis (AR) were associated with a subsequent increased risk of epilepsy.

METHODS

This retrospective population-based cohort study was conducted by using data from the 2000-2012 Taiwan's National Health Insurance Research Database. We enrolled 67,537 children aged 0-18 years diagnosed with AR and 67,537 age- and gender-matched children without the diagnosis of AR. The incidence rate (per 10,000 person-years) of epilepsy was calculated. We used Cox proportional hazards regression analysis to estimate hazard ratios (HRs) and 95 % confident interval (CI).

RESULTS

Of the 135,074 children included in the analyses, those with AR had a higher incidence rate of epilepsy (6.84 versus 3.95 per 10,000 person-years, p < 0.001) and an earlier age at diagnosis of epilepsy than those without AR [8.54 (4.90) versus 9.33 (5.40) years, p = 0.03)]. The Kaplan-Meier survival analysis demonstrated that the children with AR had a higher likelihood of developing epilepsy than those without AR (p < 0.001). After adjusting for confounding factors in multivariate model, children with AR had a 76 % increased risk of epilepsy (HR 1.76, 95 % CI 1.51-2.04) than those without AR. Boys had a 21 % increased risk of epilepsy (HR 1.21, 95 % CI 1.05-1.40) than girls.

CONCLUSIONS

These results suggest that children with AR were associated with an increased subsequent risk of epilepsy.

Determinants of neurodevelopment in early childhood - results from the Copenhagen prospective studies on asthma in childhood (COPSAC2010 ) mother-child cohort

AIM

The objective of this study was to identify possible pre- and postnatal factors influencing neurodevelopment of the young child.

METHODS

We used data from the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC₂₀₁₀ ) mother-child cohort, but excluded those with a neurological diagnosis, born <37 weeks of gestation and birthweights <2500 g, resulting in 650 children analysed. Neurodevelopment was assessed as age of achievement of early milestones, language scores at 1 and 2 years and cognitive score at 2 ½ years of age.

RESULTS

Neurodevelopmental scores were not associated with breastfeeding, persistent wheeze, eczema and number of sick days (p > 0.05 in all tests). Early age at milestone achievement was associated with male sex (p = 0.05), lower maternal age (p = 0.02), higher gestational age (p < 0.001) and paternity leave (p = 0.01). A higher 1-year language score was associated with female sex (p = 0.02) and maternal smoking during pregnancy (p = 0.01) and a higher 2-year language score with female sex (p < 0.001) and being first born (p = 0.01). A higher cognitive score was associated with female sex (p = 0.02).

CONCLUSION

Neurodevelopmental scores were unrelated to breastfeeding, persistent wheeze, eczema and number of sick days. Neurodevelopment in early childhood was mostly associated with gender.

Environmental Exposures and Neuropsychiatric Disorders: What Role Does the Gut-Immune-Brain Axis Play?

PURPOSE OF REVIEW

Evidence is growing that environmental exposures-including xenobiotics as well as microbes-play a role in the pathogenesis of many neuropsychiatric disorders. Underlying mechanisms are likely to be complex, involving the developmentally sensitive interplay of genetic/epigenetic, detoxification, and immune factors. Here, we review evidence supporting a role for environmental factors and disrupted gut-immune-brain axis function in some neuropsychiatric conditions.

RECENT FINDINGS

Studies suggesting the involvement of an altered microbiome in triggering CNS-directed autoimmunity and neuropsychiatric disturbances are presented as an intriguing example of the varied mechanisms by which environmentally induced gut-immune-brain axis dysfunction may contribute to adverse brain outcomes. The gut-immune-brain axis is a burgeoning frontier for investigation of neuropsychiatric illness. Future translational research to define individual responses to exogenous exposures in terms of microbiome-dependent skew of the metabolome, immunity, and brain function may serve as a lens for illumination of pathways involved in the development of CNS disease and fuel discovery of novel interventions.

Bidirectional relationships between psychological health and dermatological conditions in children

Dermatological conditions are common among children. They are a frequent cause of presentation to health care services and a leading contributor to burden of disease. Evidence supports the notion that bidirectional relationships exist between children’s physical and psychological health, whereby the child’s dermatological condition can impact their psychological health and well-being, while, in the reverse direction, psychological factors (eg, stress) can impact the severity and course of the child’s skin disease. The psychological impact of dermatological conditions in childhood needs to be taken into account during the assessment, planning, and treatment phases of management. Likewise, the potential effect of children’s emotional and behavioral difficulties on management, particularly in terms of the impact on parents’ ability to implement their child’s treatment plan, should be considered. This literature review summarizes the current evidence for the relationships between three common chronic dermatological conditions of childhood – atopic dermatitis, psoriasis, and urticaria – and psychological adjustment and quality of life in childhood. Overall, a general paucity of research in the pediatric context – combined with limitations in terms of study design, variability in operationalization of constructs, and heterogeneity in measurement of outcomes – makes it difficult to draw firm conclusions in this area. Based on the available research, implications for successful long-term management of these conditions are discussed in terms of integrating psychological and parenting support with medical management to improve adherence, reduce disease severity, and improve quality of life for children and their families.

Oral sensitization to whey proteins induces age- and sex-dependent behavioral abnormality and neuroinflammatory responses in a mouse model of food allergy: a potential role of mast cells

BACKGROUND

Growing evidence has strengthened the association of food allergy with neuropsychiatric symptoms such as depression, anxiety, and autism. However, underlying mechanisms by which peripheral allergic responses lead to behavioral dysfunction are yet to be determined. Allergen-activated mast cells may serve as mediators by releasing histamine and other inflammatory factors that could adversely affect brain function. We hypothesized that eliciting food allergy in experimental animals would result in behavioral changes accompanied by mast cell accumulation in the brain. Our hypothesis was tested in a mouse model of milk allergy using bovine milk whey proteins (WP) as the allergen.

METHODS

Male and female C57BL/6 mice at 4 weeks (young) and 10 months (old) of age underwent 5-week WP sensitization with weekly intragastric administration of 20 mg WP and 10 μg cholera toxin as an adjuvant. Age-matched sham animals were given the vehicle containing only the adjuvant. All animals were orally challenged with 50 mg WP in week 6 and their intrinsic digging behavior was assessed the next day. Animals were sacrificed 3 days after the challenge, and WP-specific serum IgE, intestinal and brain mast cells, glial activation, and epigenetic DNA modification in the brain were examined.

RESULTS

WP-sensitized males showed significantly less digging activity than the sham males in both age groups while no apparent difference was observed in females. Mast cells and their activities were evident in the intestines in an age- and sex-dependent manner. Brain mast cells were predominantly located in the region between the lateral midbrain and medial hippocampus, and their number increased in the WP-sensitized young, but not old, male brains. Noticeable differences in for 5-hydroxymethylcytosine immunoreactivity were observed in WP mice of both age groups in the amygdala, suggesting epigenetic regulation. Increased microglial Iba1 immunoreactivity and perivascular astrocytes hypertrophy were also observed in the WP-sensitized old male mice.

CONCLUSIONS

Our results demonstrated that food allergy induced behavioral abnormality, increases in the number of mast cells, epigenetic DNA modification in the brain, microgliosis, and astrocyte hypertrophy in a sex- and age-dependent manner, providing a potential mechanism by which peripheral allergic responses evoke behavioral dysfunction.

Anxiety and Atopic Disease: Comorbidity in a Youth Mental Health Setting

Anxiety frequently co-occurs with atopic diseases (e.g., allergies) in community samples, although data are limited to community and pediatric medical samples. Little work has examined atopy rates among mental health treatment seeking youth or whether youth with comorbid anxiety and atopy present similarly to non-comorbid youth. Using initial intake data from a University-based specialty youth clinic for anxiety and depressive disorders (n = 189), rates of atopic comorbidity were benchmarked against lifetime prevalence estimates in epidemiological samples. Anxiety severity and parental stress were compared between youth with and without atopy. Results indicated high rates of atopy in the clinical sample (51.3 %) relative to population atopy estimates (34.5 %). Anxious youth with atopy exhibited more overall and generalized anxiety symptoms relative to non-atopic youth (ps < .05); parental stress was comparable between atopic and non-atopic anxious youth. This suggests potentially heightened clinical severity for youth with co-occurring anxiety and atopy.

Peri-adolescent asthma symptoms cause adult anxiety-related behavior and neurobiological processes in mice

Human and animal studies have shown that physical challenges and stressors during adolescence can have significant influences on behavioral and neurobiological development associated with internalizing disorders such as anxiety and depression. Given the prevalence of asthma during adolescence and increased rates of internalizing disorders in humans with asthma, we used a mouse model to test if and which symptoms of adolescent allergic asthma (airway inflammation or labored breathing) cause adult anxiety- and depression-related behavior and brain function. To mimic symptoms of allergic asthma in young BALB/cJ mice (postnatal days [P] 7-57; N=98), we induced lung inflammation with repeated intranasal administration of house dust mite extract (most common aeroallergen for humans) and bronchoconstriction with aerosolized methacholine (non-selective muscarinic receptor agonist). Three experimental groups, in addition to a control group, included: (1) "Airway inflammation only", allergen exposure 3 times/week, (2) "Labored breathing only", methacholine exposure once/week, and (3) "Airway inflammation+Labored breathing", allergen and methacholine exposure. Compared to controls, mice that experienced methacholine-induced labored breathing during adolescence displayed a ∼20% decrease in time on open arms of the elevated plus maze in early adulthood (P60), a ∼30% decrease in brainstem serotonin transporter (SERT) mRNA expression and a ∼50% increase in hippocampal serotonin receptor 1a (5Htr1a) and corticotropin releasing hormone receptor 1 (Crhr1) expression in adulthood (P75). This is the first evidence that experimentally-induced clinical symptoms of adolescent asthma alter adult anxiety-related behavior and brain function several weeks after completion of asthma manipulations.

Contributions of a Child's Built, Natural, and Social Environments to Their General Cognitive Ability: A Systematic Scoping Review

The etiology of a child’s cognitive ability is complex, with research suggesting that it is not attributed to a single determinant or even a defined period of exposure. Rather, cognitive development is the product of cumulative interactions with the environment, both negative and positive, over the life course. The aim of this systematic scoping review was to collate evidence associated with children’s cognitive health, including inherent factors as well as chemical and non-chemical stressors from the built, natural, and social environments. Three databases were used to identify recent epidemiological studies (2003–2013) that examined exposure factors associated with general cognitive ability in children. Over 100 factors were evaluated from 258 eligible studies. We found that recent literature mainly assessed the hypothesized negative effects of either inherent factors or chemical exposures present in the physical environment. Prenatal growth, sleep health, lead and water pollutants showed consistent negative effects. Of the few studies that examined social stressors, results consistently showed cognitive development to be influenced by both positive and negative social interactions at home, in school or the community. Among behavioral factors related to diet and lifestyle choices of the mother, breastfeeding was the most studied, showing consistent positive associations with cognitive ability. There were mostly inconsistent results for both chemical and non-chemical stressors. The majority of studies utilized traditional exposure assessments, evaluating chemical and non-chemical stressors separately. Collective evidence from a limited number of studies revealed that cumulative exposure assessment that incorporates multiple chemical and non-chemical stressors over the life course may unravel the variability in effect on cognitive development and help explain the inconsistencies across studies. Future research examining the interactions of multiple stressors within a child’s total environment, depicting a more real-world exposure, will aid in understanding the cumulative effects associated with a child’s ability to learn.

Allergic Diseases and Internalizing Behaviors in Early Childhood

BACKGROUND AND OBJECTIVES

The relationship between allergic diseases and internalizing disorders has not been well characterized with regard to multiple allergic diseases or longitudinal study. The objective of this study was to examine the association between multiple allergic diseases in early childhood with validated measures of internalizing disorders in the school-age years.

METHODS

Children enrolled in the Cincinnati Childhood Allergy and Air Pollution Study underwent skin testing and examinations at ages 1, 2, 3, 4, and 7 years. At age 7, parents completed the Behavior Assessment System for Children, Second Edition (BASC-2), a validated measure of childhood behavior and emotion. The association between allergic diseases at age 4, including allergic rhinitis, allergic persistent wheezing, atopic dermatitis, and allergic sensitization, and BASC-2 internalizing, anxiety, and depression T scores at age 7 was examined by logistic and linear regression, adjusting for covariates.

RESULTS

The cohort included 546 children with complete information on allergic disease and BASC-2 outcomes. Allergic rhinitis at age 4 was significantly associated with elevated internalizing (adjusted odds ratio [aOR]: 3.2; 95% confidence interval [CI]: 1.8-5.8), anxiety (aOR: 2.0; 95% CI: 1.2-3.6), and depressive scores (aOR: 3.2; 95% CI: 1.7-6.5) at age 7. Allergic persistent wheezing was significantly associated with elevated internalizing scores (aOR: 2.7; 95% CI: 1.2-6.3). The presence of >1 allergic disease (aOR: 3.6; 95% CI: 1.7-7.6) and allergic rhinitis with comorbid allergic disease(s) (aOR: 4.3; 95% CI: 2.0-9.2) at age 4 had dose-dependent associations with internalizing scores.

CONCLUSIONS

Children with allergic rhinitis and allergic persistent wheezing at age 4 are at increased risk of internalizing behaviors at age 7. Furthermore, multiple allergic diseases had a dose-dependent association with elevated internalizing scores.

A possible link between early probiotic intervention and the risk of neuropsychiatric disorders later in childhood: a randomized trial

BACKGROUND

Recent experimental evidence suggests that gut microbiota may alter function within the nervous system providing new insight on the mechanism of neuropsychiatric disorders.

METHODS

Seventy-five infants who were randomized to receive Lactobacillus rhamnosus GG (ATCC 53103) or placebo during the first 6 mo of life were followed-up for 13 y. Gut microbiota was assessed at the age of 3 wk, 3, 6, 12, 18, 24 mo, and 13 y using fluorescein in situ hybridization (FISH) and qPCR, and indirectly by determining the blood group secretor type at the age of 13 y. The diagnoses of attention deficit hyperactivity disorder (ADHD) and Asperger syndrome (AS) by a child neurologist or psychiatrist were based on ICD-10 diagnostic criteria.

RESULTS

At the age of 13 y, ADHD or AS was diagnosed in 6/35 (17.1%) children in the placebo and none in the probiotic group (P = 0.008). The mean (SD) numbers of Bifidobacterium species bacteria in feces during the first 6 mo of life was lower in affected children 8.26 (1.24) log cells/g than in healthy children 9.12 (0.64) log cells/g; P = 0.03.

CONCLUSION

Probiotic supplementation early in life may reduce the risk of neuropsychiatric disorder development later in childhood possible by mechanisms not limited to gut microbiota composition.

mTOR plays an important role in cow's milk allergy-associated behavioral and immunological deficits

Autism spectrum disorder (ASD) is multifactorial, with both genetic as well as environmental factors working in concert to develop the autistic phenotype. Immunological disturbances in autistic individuals have been reported and a role for food allergy has been suggested in ASD. Single gene mutations in mammalian target of rapamycin (mTOR) signaling pathway are associated with the development of ASD and enhanced mTOR signaling plays a central role in directing immune responses towards allergy as well. Therefore, the mTOR pathway may be a pivotal link between the immune disturbances and behavioral deficits observed in ASD. In this study it was investigated whether the mTOR pathway plays a role in food allergy-induced behavioral and immunological deficits. Mice were orally sensitized and challenged with whey protein. Meanwhile, cow's milk allergic (CMA) mice received daily treatment of rapamycin. The validity of the CMA model was confirmed by showing increased allergic immune responses. CMA mice showed reduced social interaction and increased repetitive self-grooming behavior. Enhanced mTORC1 activity was found in the brain and ileum of CMA mice. Inhibition of mTORC1 activity by rapamycin improved the behavioral and immunological deficits of CMA mice. This effect was associated with increase of Treg associated transcription factors in the ileum of CMA mice. These findings indicate that mTOR activation may be central to both the intestinal, immunological, and psychiatric ASD-like symptoms seen in CMA mice. It remains to be investigated whether mTOR can be seen as a therapeutic target in cow's milk allergic children suffering from ASD-like symptoms.

Dietary long chain n-3 polyunsaturated fatty acids prevent impaired social behaviour and normalize brain dopamine levels in food allergic mice

Allergy is suggested to exacerbate impaired behaviour in children with neurodevelopmental disorders. We have previously shown that food allergy impaired social behaviour in mice. Dietary fatty acid composition may affect both the immune and nervous system. The aim of this study was to assess the effect of n-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) on food allergy-induced impaired social behaviour and associated deficits in prefrontal dopamine (DA) in mice. Mice were fed either control or n-3 LCPUFA-enriched diet before and during sensitization with whey. Social behaviour, acute allergic skin response and serum immunoglobulins were assessed. Monoamine levels were measured in brain and intestine and fatty acid content in brain. N-3 LCPUFA prevented impaired social behaviour of allergic mice. Moreover, n-3 LCPUFA supplementation increased docosahexaenoic acid (DHA) incorporation into the brain and restored reduced levels of prefrontal DA and its metabolites 3,4-dihydroxyphenylacetic acid, 3-methoxytyramine and homovanillic acid in allergic mice. In addition to these brain effects, n-3 LCPUFA supplementation reduced the allergic skin response and restored decreased intestinal levels of serotonin metabolite 5-hydroxyindoleacetic acid in allergic mice. N-3 LCPUFA may have beneficial effects on food allergy-induced deficits in social behaviour, either indirectly by reducing the allergic response and restoring intestinal 5-HT signalling, or directly by DHA incorporation into neuronal membranes, affecting the DA system. Therefore, it is of interest to further investigate the relevance of food allergy-enhanced impairments in social behaviour in humans and the potential benefits of dietary n-3 LCPUFA supplementation.

Food allergy and food-based therapies in neurodevelopmental disorders

Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are neurodevelopmental disorders which occur in childhood and may persist into adulthood. Although the etiology of these disorders is largely unknown, genetic and environmental factors are thought to play a role in the development of ASD and ADHD. Allergic immune reactions, in prenatal and postnatal phases, are examples of these environmental factors, and adverse reactions to foods are reported in these children. In this review, we address the clinical and preclinical findings of (food) allergy in ASD and ADHD and suggest possible underlying mechanisms. Furthermore, opportunities for nutritional interventions in neurodevelopmental disorders are provided.

How mothers interact with children with suspected cow's milk allergy symptoms

AIM

To characterize mother-child interaction in children with suspected gastrointestinally manifested cow's milk allergy (GI-CMA) and to explore factors associated with the parentally perceived symptoms.

METHODS

We invited a randomly selected group of children with suspected GI-CMA and their mothers to take part in a video recording of them playing together. The mother-child interaction was rated using the Emotional Availability Scales (EAS, 4th edition) and compared with national normative data.

RESULTS

Video recordings were conducted with 24 patients (15 girls and nine boys) with a median age of 10.1 months (range 2.1-20.5 months) undergoing a double-blind, placebo-controlled food challenge for cow's milk allergy. The EAS profile in the challenge negative group (17/24) was significantly different from the normative data. The scores for maternal sensitivity (p = 0.0049) and nonintrusiveness (p = 0.0192), together with child responsiveness (p = 0.0053) and involvement of mother (p = 0.0085), were all significantly lower when compared to the normative data. The dimensions of maternal nonhostility and structuring, as well as the scores of the challenge positive group, did not differ from the normative data.

CONCLUSION

Dysfunctional mother-child emotional interaction was frequent in young children with suspected GI-CMA ruled out by the cow's milk challenge. Appropriate psychological support should be considered.

The neuro-immune axis: prospect for novel treatments for mental disorders

Disturbed bidirectional pathways between the (central) nervous system and immune system have been implicated in various mental disorders, including depressive and neurodevelopmental disorders. In this minireview, the role of the neuro-immune axis and its targetability in relation to major depression and autism spectrum disorder will be discussed. All together, the management of these and possibly other multi-factorial mental disorders needs a new and integrated therapeutic approach. Pharmacologically bioactive molecules as well as medical nutrition targeting the (gut)-immune-brain axis could be such an approach.

A neurobiological model for cry-fuss problems in the first three to four months of life

Although problem crying in the first three to four months of life is usually self-limiting, it is not a trivial condition. Early intervention is important, yet families receive conflicting advice from health professionals. The past decade has seen significant advances in neuroscience, lactation science, and developmental psychology, including new insights into the significance of developmentally sensitive windows. We propose a neurobiological model to explain the mechanisms of cry-fuss problems in the first months of life, and the mechanisms which underlie effective intervention, with a view to facilitating research collaboration and consistency of advice across health disciplines. We hypothesise that crying in the first three to four neurodevelopmentally sensitive months signals activation of the hypothalamic-pituitary-adrenal axis and adrenergic neuronal circuitry in response to perceptions of discomfort or threat. Susceptible infants may be conditioned by early stress, for example, by unidentified feeding difficulties, into a sensitised stress response, which usually settles at three to four months of age with neurodevelopmental maturity. Bouts of prolonged and unsoothable crying result from positive feedback loops in the hypothalamic-pituitary-adrenal and adrenergic systems. Importantly, epigenetic modulation of the infant's limbic neuronal circuitry may explain correlations between regulatory problems in the first months of life, and behavioural problems including feeding problems in later childhood.