Feasibility of daily pain measurement using text messages in hidradenitis suppurativa clinical trials; data from the THESEUS study

Treatment of Hidradenitis Suppurativa Evaluation Study (THESEUS) was an observational study involving 10 centres in the UK and one of its objectives was to optimize the outcome measure instruments for use in future hidradenitis suppurativa trials. Part of the study included sending daily text messages to patients for 12 weeks once the intervention had been started. Our study showed that the response rates to the text messages were 70%, 60%, 55% and 20% after 2, 4, 8 and 12 weeks, respectively.

Treatment of Hidradenitis Suppurativa Evaluation Study (THESEUS): a prospective cohort study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, painful disease affecting flexures and other skin regions, producing nodules, abscesses and skin tunnels. Laser treatment targeting hair follicles and deroofing of skin tunnels are standard HS interventions in some countries but are rarely offered in the UK.

OBJECTIVES

To describe current UK HS management pathways and influencing factors to inform the design of future randomized controlled trials (RCTs).

METHODS

THESEUS was a nonrandomized 12-month prospective cohort study set in 10 UK hospitals offering five interventions: oral doxycycline 200 mg daily; oral clindamycin and rifampicin both 300 mg twice daily for 10 weeks, extended for longer in some cases; laser treatment targeting hair follicles; deroofing; and conventional surgery. The primary outcome was the combination of clinician-assessed eligibility and participant hypothetical willingness to receive each intervention. The secondary outcomes were the proportion of participants selecting each intervention as their final treatment option; the proportion who switch treatments; treatment fidelity; and attrition rates. THESEUS was prospectively registered on the ISRCTN registry: ISRCTN69985145.

RESULTS

The recruitment target of 150 participants was met after 18 months, in July 2021, with two pauses due to the COVID-19 pandemic. Baseline demographics reflected the HS secondary care population: average age 36 years, 81% female, 20% non-White, 64% current or ex-smokers, 86% body mass index ≥ 25, 68% with moderate disease, 19% with severe disease and 13% with mild disease. Laser was the intervention with the highest proportion (69%) of participants eligible and willing to receive treatment, then deroofing (58%), conventional surgery (54%), clindamycin and rifampicin (44%), and doxycycline (37%). Laser was ranked first choice by the greatest proportion of participants (41%). Attrition rates were 11% and 17% after 3 and 6 months, respectively. Concordance with doxycycline was 52% after 3 months due to lack of efficacy, participant choice and adverse effects. Delays with procedural interventions were common, with only 43% and 26% of participants starting laser and deroofing, respectively, after 3 months. Uptake of conventional surgery was too small to characterize the intervention. Switching treatment was uncommon and there were no serious adverse events.

CONCLUSIONS

THESEUS has established laser treatment and deroofing for HS in the UK and demonstrated their popularity with patients and clinicians for future RCTs.

Cord blood lipid correlation network profiles are associated with subsequent attention-deficit/hyperactivity disorder and autism spectrum disorder symptoms at 2 years: a prospective birth cohort study

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are neurodevelopmental conditions with early life origins. Alterations in blood lipids have been linked to ADHD and ASD; however, prospective early life data are limited. This study examined (i) associations between the cord blood lipidome and ADHD/ASD symptoms at 2 years of age, (ii) associations between prenatal and perinatal predictors of ADHD/ASD symptoms and cord blood lipidome, and (iii) mediation by the cord blood lipidome.

METHODS

From the Barwon Infant Study cohort (1074 mother-child pairs, 52.3% male children), child circulating lipid levels at birth were analysed using ultra-high-performance liquid chromatography-tandem mass spectrometry. These were clustered into lipid network modules via Weighted Gene Correlation Network Analysis. Associations between lipid modules and ADHD/ASD symptoms at 2 years, assessed with the Child Behavior Checklist, were explored via linear regression analyses. Mediation analysis identified indirect effects of prenatal and perinatal risk factors on ADHD/ASD symptoms through lipid modules.

FINDINGS

The acylcarnitine lipid module is associated with both ADHD and ASD symptoms at 2 years of age. Risk factors of these outcomes such as low income, Apgar score, and maternal inflammation were partly mediated by higher birth acylcarnitine levels. Other cord blood lipid profiles were also associated with ADHD and ASD symptoms.

INTERPRETATION

This study highlights that elevated cord blood birth acylcarnitine levels, either directly or as a possible marker of disrupted cell energy metabolism, are on the causal pathway of prenatal and perinatal risk factors for ADHD and ASD symptoms in early life.

FUNDING

The foundational work and infrastructure for the BIS was sponsored by the Murdoch Children's Research Institute, Deakin University, and Barwon Health. Subsequent funding was secured from the Minderoo Foundation, the European Union's Horizon 2020 research and innovation programme (ENDpoiNTs: No 825759), National Health and Medical Research Council of Australia (NHMRC) and Agency for Science, Technology and Research Singapore [APP1149047], The William and Vera Ellen Houston Memorial Trust Fund (via HOMER Hack), The Shepherd Foundation, The Jack Brockhoff Foundation, the Scobie & Claire McKinnon Trust, the Shane O'Brien Memorial Asthma Foundation, the Our Women Our Children's Fund Raising Committee Barwon Health, the Rotary Club of Geelong, the Ilhan Food Allergy Foundation, Geelong Medical and Hospital Benefits Association, Vanguard Investments Australia Ltd, the Percy Baxter Charitable Trust, and Perpetual Trustees.

Treatment of Hidradenitis Suppurativa Evaluation Study: the THESEUS prospective cohort study

Background

Hidradenitis suppurativa is a chronic inflammatory skin disease characterised by recurrent inflammatory lesions and skin tunnels in flexural sites such as the axilla. Deroofing of skin tunnels and laser treatment are standard hidradenitis suppurativa interventions in some countries but not yet introduced in the United Kingdom.

Objective

To understand current hidradenitis suppurativa management pathways and what influences treatment choices to inform the design of future randomised controlled trials.

Design

Prospective 12-month observational cohort study, including five treatment options, with nested qualitative interviews and an end-of-study consensus workshop.

Setting

Ten United Kingdom hospitals with recruitment led by dermatology and plastic surgery departments.

Participants

Adults with active hidradenitis suppurativa of any severity not adequately controlled by current treatment.

Interventions

Oral doxycycline 200 mg once daily; oral clindamycin and rifampicin, both 300 mg twice daily for 10 weeks initially; laser treatment targeting the hair follicle (neodymium-doped yttrium aluminium garnet or alexandrite); deroofing; and conventional surgery.

Main outcome measures

Primary outcome was the proportion of participants who are eligible, and hypothetically willing, to use the different treatment options. Secondary outcomes included proportion of participants choosing each of the study interventions, with reasons for their choices; proportion of participants who switched treatments; treatment fidelity; loss to follow-up rates over 12 months; and efficacy outcome estimates to inform outcome measure instrument responsiveness.

Results

Between February 2020 and July 2021, 151 participants were recruited, with two pauses due to the COVID-19 pandemic. Follow-up rates were 89% and 83% after 3 and 6 months, decreasing to 70% and 44% at 9 and 12 months, respectively, because pandemic recruitment delays prevented all participants reaching their final review. Baseline demographics included an average age of 36 years, 81% female, 20% black, Asian or Caribbean, 64% current or ex-smokers and 86% with a raised body mass index. Some 69% had moderate disease, 19% severe disease and 13% mild disease. Regarding the study's primary outcome, laser treatment was the intervention with the highest proportion (69%) of participants who were eligible and hypothetically willing to receive treatment, followed by deroofing (58%), conventional surgery (54%), the combination of oral clindamycin and rifampicin (44%) and doxycycline (37%). Considering participant willingness in isolation, laser was ranked first choice by the greatest proportion (41%) of participants. The cohort study and qualitative study demonstrated that participant willingness to receive treatment was strongly influenced by their clinician. Fidelity to oral doxycycline was only 52% after 3 months due to lack of effectiveness, participant preference and adverse effects. Delays receiving procedural interventions were common, with only 43% and 26% of participants commencing laser therapy and deroofing, respectively, after 3 months. Treatment switching was uncommon and there were no serious adverse events. Daily pain score text messages were initiated in 110 participants. Daily responses reduced over time with greatest concordance during the first 14 days.

Limitations

It was not possible to characterise conventional surgery due to a low number of participants.

Conclusion

The Treatment of Hidradenitis Suppurativa Evaluation Study established deroofing and laser treatment for hidradenitis suppurativa in the United Kingdom and developed a network of 10 sites for subsequent hidradenitis suppurativa randomised controlled trials.

Future work

The consensus workshop prioritised laser treatment and deroofing as interventions for future randomised controlled trials, in some cases combined with drug treatment.

Trial registration

This trial is registered as ISRCTN69985145.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/35/64) and is published in full in Health Technology Assessment; Vol. 27, No. 30. See the NIHR Funding and Awards website for further award information.

The distribution of dietary choline intake and serum choline levels in Australian women during pregnancy and associated early life factors

BACKGROUND

Maternal dietary choline has a central role in foetal brain development and may be associated with later cognitive function. However, many countries are reporting lower than recommended intake of choline during pregnancy.

METHODS

Dietary choline was estimated using food frequency questionnaires in pregnant women participating in population-derived birth cohort, the Barwon Infant Study (BIS). Dietary choline is reported as the sum of all choline-containing moieties. Serum total choline-containing compounds (choline-c), phosphatidylcholine and sphingomyelin were measured using nuclear magnetic resonance metabolomics in the third trimester. The main form of analysis was multivariable linear regression.

RESULTS

The mean daily dietary choline during pregnancy was 372 (standard deviation (SD) 104) mg/day. A total of 236 women (23%) had adequate choline intake (440 mg/day) based on the Australian and New Zealand guidelines, and 27 women (2.6%) took supplemental choline ([Formula: see text] 50 mg/dose) daily during pregnancy. The mean serum choline-c in pregnant women was 3.27 (SD 0.44) mmol/l. Ingested choline and serum choline-c were not correlated (R2) = - 0.005, p = 0.880. Maternal age, maternal weight gain in pregnancy, and a pregnancy with more than one infant were associated with higher serum choline-c, whereas gestational diabetes and environmental tobacco smoke during preconception and pregnancy were associated with lower serum choline-c. Nutrients or dietary patterns were not associated with variation in serum choline-c.

CONCLUSION

In this cohort, approximately one-quarter of women met daily choline recommendations during pregnancy. Future studies are needed to understand the potential impact of low dietary choline intake during pregnancy on infant cognition and metabolic intermediaries.

Pre-pregnancy obesity is associated with greater systemic inflammation and increased risk of antenatal depression

BACKGROUND

Pre-pregnancy obesity is an emerging risk factor for perinatal depression. However, the underlying mechanisms remain unclear. We investigated the association between pre-pregnancy body mass index (BMI) and perinatal depressive symptoms in a large population-based pre-birth cohort, the Barwon Infant Study. We also assessed whether the levels of circulating inflammatory markers during pregnancy mediated this relationship.

METHODS

Depressive symptoms were assessed in 883 women using the Edinburgh Postnatal Depression Scale (EPDS) and psychological stress using the Perceived Stress Scale (PSS) at 28 weeks gestation and 4 weeks postpartum. Glycoprotein acetyls (GlycA), high-sensitivity C-reactive protein (hsCRP) and cytokines were assessed at 28 weeks gestation. We performed regression analyses, adjusted for potential confounders, and investigated mediation using nested counterfactual models.

RESULTS

The estimated effect of pre-pregnancy obesity (BMI ≥ 30 kg/m2) on antenatal EPDS scores was 1.05 points per kg/m2 increase in BMI (95% CI: 0.20, 1.90; p = 0.02). GlycA, hsCRP, interleukin (IL) -1ra and IL-6 were higher in women with obesity, compared to healthy weight women, while eotaxin and IL-4 were lower. Higher GlycA was associated with higher EPDS and PSS scores and partially mediated the association between pre-pregnancy obesity and EPDS/PSS scores in unadjusted models, but this association attenuated upon adjustment for socioeconomic adversity. IL-6 and eotaxin were negatively associated with EPDS/PSS scores, however there was no evidence for mediation.

CONCLUSIONS

Pre-pregnancy obesity increases the risk of antenatal depressive symptoms and is also associated with systemic inflammation during pregnancy. While discrete inflammatory markers are associated with antenatal depressive symptoms and perceived stress, their role in mediating the effects of pre-pregnancy obesity on antenatal depression requires further investigation.

Gut microbiota maturity mediates the protective effect of siblings on food allergy

BACKGROUND

The mechanisms underlying the protective effect of older siblings on allergic disease remain unclear but may relate to the infant gut microbiota.

OBJECTIVE

We sought to investigate whether having older siblings decreases the risk of IgE-mediated food allergy by accelerating the maturation of the infant gut microbiota.

METHODS

In a birth cohort assembled using an unselected antenatal sampling frame (n = 1074), fecal samples were collected at 1 month, 6 months, and 1 year, and food allergy status at 1 year was determined by skin prick test and in-hospital food challenge. We used 16S rRNA gene amplicon sequencing to derive amplicon sequence variants. Among a random subcohort (n = 323), microbiota-by-age z scores at each time point were calculated using fecal amplicon sequence variants to represent the gut microbiota maturation over the first year of life.

RESULTS

A greater number of siblings was associated with a higher microbiota-by-age z score at age 1 year (β  = 0.15 per an additional sibling; 95% CI, 0.05-0.24; P = .003), which was in turn associated with decreased odds of food allergy (odds ratio, 0.45; 95% CI, 0.33-0.61; P < .001). Microbiota-by-age z scores mediated 63% of the protective effect of siblings. Analogous associations were not observed at younger ages.

CONCLUSIONS

The protective effect of older siblings on the risk of developing IgE-mediated food allergy during infancy is substantially mediated by advanced maturation of the gut microbiota at age 1 year.

Research priorities in the management of hidradenitis suppurativa

There is a need for high-quality research to support the management of hidradenitis suppurativa. This letter offers suggestions for priority research topics derived from a stakeholder consensus meeting. Investigation of laser hair removal treatment, potentially in combination with medical treatment, was recognized as an important focus for future hidradenitis suppurativa research.

Mycobacterium ulcerans culture results according to duration of prior antibiotic treatment: A cohort study

Mycobacterium ulcerans disease is a necrotising disease of the skin and subcutaneous tissue and is effectively treated with eight-weeks antibiotic therapy. Significant toxicities, however, are experienced under this prolonged regimen. Here, we investigated the length of antibiotic duration required to achieve negative cultures of M. ulcerans disease lesions and evaluated the influence of patient characteristics on this outcome. M. ulcerans cases from an observational cohort that underwent antibiotic treatment prior to surgery and had post-excision culture assessment at Barwon Health, Victoria, from May 25 1998 to June 30 2019, were included. Antibiotic duration before surgery was grouped as <2 weeks, ≥2-<4 weeks, ≥4-<6 weeks, ≥6-<8 weeks, ≥8-<10 weeks and ≥10-20 weeks. Cox regression analyses were performed to assess the association between variables and culture positive results. Ninety-two patients fitted the inclusion criteria. The median age was 60 years (IQR 28-74.5) and 51 (55.4%) were male. Rifampicin-based regimens were predominantly used in combination with clarithromycin (47.8%) and ciprofloxacin (46.7%), and the median duration of antibiotic treatment before surgery was 23 days (IQR, 8.0-45.5). There were no culture positive results after 19 days of antibiotic treatment and there was a significant association between antibiotic duration before surgery and a culture positive outcome (p<0.001). The World Health Organisation category of the lesion and the antibiotic regimen used had no association with the culture outcome. Antibiotics appear to be effective at achieving negative cultures of M. ulcerans disease lesions in less than the currently recommended eight-week duration.

Cord blood immune profile: Associations with higher prenatal plastic chemical levels

Prenatal exposure to plastic chemicals has been associated with alterations to early-life immune function in children. However, previous studies have generally been small and focused on limited repertoires of immune indices. In a large population-based pre-birth cohort (n = 1074), third-trimester measurements of eight phthalate metabolites and three analogues of bisphenols were used to estimate prenatal exposure to phthalate and bisphenol compounds. In cord blood, immune cell populations were measured by flow cytometry and an extensive panel of cytokines and chemokines were measured by multiplex immunoassay. We used these cord blood analytes to estimate "early life" immune profiles. The full study sample comprises data from 774 infants with prenatal plastic metabolite measurements and any cord blood immune data. Multiple linear regression analysis was used to evaluate whether prenatal phthalate and bisphenol exposure was prospectively associated with cord blood immune cell populations and cytokine and chemokine levels. Generally, inverse associations were observed between prenatal phthalate exposure and cord blood immune indices. Higher exposure to di-n-butyl phthalate was associated with lower cord blood levels of platelet-derived growth factor (PDGF) and interferon gamma-induced protein 10 (IP-10); higher exposure to the sum of dibutyl phthalates was associated with lower cord blood levels of IP-10; and higher exposure to benzyl butyl phthalate was associated with lower cord blood levels of interleukin 1 beta (IL-1β). There was less evidence of associations between bisphenols and cord blood immune indices. These results extend previous work examining prenatal plastic chemical exposure and early-life immune development and highlight the importance of further examination of potential associations with health-related outcomes.

Maternal gut microbiota during pregnancy and the composition of immune cells in infancy

Background

Preclinical studies have shown that maternal gut microbiota during pregnancy play a key role in prenatal immune development but the relevance of these findings to humans is unknown. The aim of this prebirth cohort study was to investigate the association between the maternal gut microbiota in pregnancy and the composition of the infant’s cord and peripheral blood immune cells over the first year of life.

Methods

The Barwon Infant Study cohort (n=1074 infants) was recruited using an unselected sampling frame. Maternal fecal samples were collected at 36 weeks of pregnancy and flow cytometry was conducted on cord/peripheral blood collected at birth, 6 and 12 months of age. Among a randomly selected sub-cohort with available samples (n=293), maternal gut microbiota was characterized by sequencing the 16S rRNA V4 region. Operational taxonomic units (OTUs) were clustered based on their abundance. Associations between maternal fecal microbiota clusters and infant granulocyte, monocyte and lymphocyte subsets were explored using compositional data analysis. Partial least squares (PLS) and regression models were used to investigate the relationships/associations between environmental, maternal and infant factors, and OTU clusters.

Results

We identified six clusters of co-occurring OTUs. The first two components in the PLS regression explained 39% and 33% of the covariance between the maternal prenatal OTU clusters and immune cell populations in offspring at birth. A cluster in which Dialister, Escherichia, and Ruminococcus were predominant was associated with a lower proportion of granulocytes (p=0.002), and higher proportions of both central naïve CD4⁺ T cells (CD4⁺/CD45RA⁺/CD31⁻) (p<0.001) and naïve regulatory T cells (Treg) (CD4⁺/CD45RA⁺/FoxP3^low) (p=0.02) in cord blood. The association with central naïve CD4⁺ T cells persisted to 12 months of age.

Conclusion

This birth cohort study provides evidence consistent with past preclinical models that the maternal gut microbiota during pregnancy plays a role in shaping the composition of innate and adaptive elements of the infant’s immune system following birth.

Infant inflammation predicts childhood emotional and behavioral problems and partially mediates socioeconomic disadvantage

BACKGROUND

Emotional and behavioral problems (EBP) are common in children. Environmental factors like socioeconomic disadvantage influence EBP pathogenesis and can trigger inflammation. However, the link between early inflammation-EBP in children is unclear. We investigated the associations between i) infant inflammatory biomarkers and subsequent EBP and ii) early life environmental factors and EBP and assessed whether infant inflammation mediated these associations.

METHODS

Inflammatory biomarkers glycoprotein acetyls (GlycA) and high-sensitivity C-reactive protein (hsCRP) were quantified at birth and 12 months in a population-derived birth cohort, the Barwon Infant Study. Early life factors including demographic, prenatal, and perinatal factors were collected from antenatal to the two-year period. Internalizing and externalizing problems at age two were measured by the Child Behavior Checklist. Prospective associations were examined by multivariable regression analyses adjusted for potential confounders. Indirect effects of early life factors on EBP through inflammation were identified using mediation analyses.

RESULTS

Elevated GlycA levels at birth (GlycAbirth) were associated with greater internalizing problems at age two (β = 1.32 per SD increase in GlycA; P = 0.001). Inflammation at birth had a stronger magnitude of effect with later EBP than at 12 months. GlycAbirth partially mediated the associations between lower household income (6%), multiparity (12%) and greater number of older siblings (13%) and EBP. Patterns were less evident for hsCRP or externalizing problems.

CONCLUSIONS

GlycAbirth was positively associated with EBP at age two and partially mediated the association between several indicators of socioeconomic disadvantage and EBP. Prenatal and perinatal inflammation may be relevant to early neurodevelopment and emotional health.

Population-based plasma lipidomics reveals developmental changes in metabolism and signatures of obesity risk: a mother-offspring cohort study

BACKGROUND

Lipids play a vital role in health and disease, but changes to their circulating levels and the link with obesity remain poorly characterized in expecting mothers and their offspring in early childhood.

METHODS

LC-MS/MS-based quantitation of 480 lipid species was performed on 2491 plasma samples collected at 4 time points in the mother-offspring Asian cohort GUSTO (Growing Up in Singapore Towards healthy Outcomes). These 4 time points constituted samples collected from mothers at 26-28 weeks of gestation (n=752) and 4-5 years postpartum (n=650), and their offspring at birth (n=751) and 6 years of age (n=338). Linear regression models were used to identify the pregnancy and developmental age-specific variations in the plasma lipidomic profiles, and their association with obesity risk. An independent birth cohort (n=1935), the Barwon Infant Study (BIS), comprising mother-offspring dyads of Caucasian origin was used for validation.

RESULTS

Levels of 36% of the profiled lipids were significantly higher (absolute fold change > 1.5 and P_adj < 0.05) in antenatal maternal circulation as compared to the postnatal phase, with phosphatidylethanolamine levels changing the most. Compared to antenatal maternal lipids, cord blood showed lower concentrations of most lipid species (79%) except lysophospholipids and acylcarnitines. Changes in lipid concentrations from birth to 6 years of age were much higher in magnitude (log₂FC=-2.10 to 6.25) than the changes observed between a 6-year-old child and an adult (postnatal mother) (log₂FC=-0.68 to 1.18). Associations of cord blood lipidomic profiles with birth weight displayed distinct trends compared to the lipidomic profiles associated with child BMI at 6 years. Comparison of the results between the child and adult BMI identified similarities in association with consistent trends (R²=0.75). However, large number of lipids were associated with BMI in adults (67%) compared to the children (29%). Pre-pregnancy BMI was specifically associated with decrease in the levels of phospholipids, sphingomyelin, and several triacylglycerol species in pregnancy.

CONCLUSIONS

In summary, our study provides a detailed landscape of the in utero lipid environment provided by the gestating mother to the growing fetus, and the magnitude of changes in plasma lipidomic profiles from birth to early childhood. We identified the effects of adiposity on the circulating lipid levels in pregnant and non-pregnant women as well as offspring at birth and at 6 years of age. Additionally, the pediatric vs maternal overlap of the circulating lipid phenotype of obesity risk provides intergenerational insights and early opportunities to track and intervene the onset of metabolic adversities.

CLINICAL TRIAL REGISTRATION

This birth cohort is a prospective observational study, which was registered on 1 July 2010 under the identifier NCT01174875 .

Household size, T regulatory cell development, and early allergic disease: a birth cohort study

BACKGROUND

Children born to larger households have less allergic disease. T regulatory cell (Treg) development may be a relevant mechanism, but this has not been studied longitudinally.

OBJECTIVE

We aim to (i) describe how prenatal and postnatal environmental factors are associated with Treg development and (ii) investigate whether serial Treg measures predict allergic outcomes at 1 year of age.

METHODS

A birth cohort (n = 1074) with information on prenatal and postnatal early life factors. Both naïve Treg (nTreg) and activated Treg (aTreg) cell populations (as a proportion of CD4⁺ T cells) were available in 463 infants at birth (cord blood), 600 at 6 months, and 675 at 12 months. 191 infants had serial measures. Measures of allergic status at 12 months were polysensitization (sensitization to 2 or more allergens), clinically proven food allergy, atopic eczema, and atopic wheeze.

RESULTS

Infants born to larger households (3 or more residents) had higher longitudinal nTreg proportions over the first postnatal year with a mean difference (MD) of 0.67 (95% CI 0.30-1.04)%. Higher nTreg proportions at birth were associated with a reduced risk of infant allergic outcomes. Childcare attendance and breastfeeding were associated with higher longitudinal nTreg proportions (MD 0.48 (95% CI 0.08-0.80)%.

CONCLUSION

Multiple prenatal and postnatal microbial factors are associated with nTreg and aTreg development. Larger household size was associated with higher nTreg at birth which in turn was associated with reduced allergic sensitization and disease at 12 months of age.

Early life infection and proinflammatory, atherogenic metabolomic and lipidomic profiles in infancy: a population-based cohort study

Background:

The risk of adult onset cardiovascular and metabolic (cardiometabolic) disease accrues from early life. Infection is ubiquitous in infancy and induces inflammation, a key cardiometabolic risk factor, but the relationship between infection, inflammation, and metabolic profiles in early childhood remains unexplored. We investigated relationships between infection and plasma metabolomic and lipidomic profiles at age 6 and 12 months, and mediation of these associations by inflammation.

Methods:

Matched infection, metabolomics, and lipidomics data were generated from 555 infants in a pre-birth longitudinal cohort. Infection data from birth to 12 months were parent-reported (total infections at age 1, 3, 6, 9, and 12 months), inflammation markers (high-sensitivity C-reactive protein [hsCRP]; glycoprotein acetyls [GlycA]) were quantified at 12 months. Metabolic profiles were 12-month plasma nuclear magnetic resonance metabolomics (228 metabolites) and liquid chromatography/mass spectrometry lipidomics (776 lipids). Associations were evaluated with multivariable linear regression models. In secondary analyses, corresponding inflammation and metabolic data from birth (serum) and 6-month (plasma) time points were used.

Results:

At 12 months, more frequent infant infections were associated with adverse metabolomic (elevated inflammation markers, triglycerides and phenylalanine, and lower high-density lipoprotein [HDL] cholesterol and apolipoprotein A1) and lipidomic profiles (elevated phosphatidylethanolamines and lower trihexosylceramides, dehydrocholesteryl esters, and plasmalogens). Similar, more marked, profiles were observed with higher GlycA, but not hsCRP. GlycA mediated a substantial proportion of the relationship between infection and metabolome/lipidome, with hsCRP generally mediating a lower proportion. Analogous relationships were observed between infection and 6-month inflammation, HDL cholesterol, and apolipoprotein A1.

Conclusions:

Infants with a greater infection burden in the first year of life had proinflammatory and proatherogenic plasma metabolomic/lipidomic profiles at 12 months of age that in adults are indicative of heightened risk of cardiovascular disease, obesity, and type 2 diabetes. These findings suggest potentially modifiable pathways linking early life infection and inflammation with subsequent cardiometabolic risk.

Funding:

The establishment work and infrastructure for the BIS was provided by the Murdoch Children’s Research Institute (MCRI), Deakin University, and Barwon Health. Subsequent funding was secured from National Health and Medical Research Council of Australia (NHMRC), The Shepherd Foundation, The Jack Brockhoff Foundation, the Scobie & Claire McKinnon Trust, the Shane O’Brien Memorial Asthma Foundation, the Our Women’s Our Children’s Fund Raising Committee Barwon Health, the Rotary Club of Geelong, the Minderoo Foundation, the Ilhan Food Allergy Foundation, GMHBA, Vanguard Investments Australia Ltd, and the Percy Baxter Charitable Trust, Perpetual Trustees. In-kind support was provided by the Cotton On Foundation and CreativeForce. The study sponsors were not involved in the collection, analysis, and interpretation of data; writing of the report; or the decision to submit the report for publication. Research at MCRI is supported by the Victorian Government’s Operational Infrastructure Support Program. This work was also supported by NHMRC Senior Research Fellowships to ALP (1008396); DB (1064629); and RS (1045161) , NHMRC Investigator Grants to ALP (1110200) and DB (1175744), NHMRC-A*STAR project grant (1149047). TM is supported by an MCRI ECR Fellowship. SB is supported by the Dutch Research Council (452173113).

Shortened Infant Telomere Length Is Associated with Attention Deficit/Hyperactivity Disorder Symptoms in Children at Age Two Years: A Birth Cohort Study

Environmental factors can accelerate telomere length (TL) attrition. Shortened TL is linked to attention deficit/hyperactivity disorder (ADHD) symptoms in school-aged children. The onset of ADHD occurs as early as preschool-age, but the TL-ADHD association in younger children is unknown. We investigated associations between infant TL and ADHD symptoms in children and assessed environmental factors as potential confounders and/or mediators of this association. Relative TL was measured by quantitative polymerase chain reaction in cord and 12-month blood in the birth cohort study, the Barwon Infant Study. Early life environmental factors collected antenatally to two years were used to measure confounding. ADHD symptoms at age two years were evaluated by the Child Behavior Checklist Attention Problems (AP) and the Attention Deficit/Hyperactivity Problems (ADHP). Associations between early life environmental factors on TL or ADHD symptoms were assessed using multivariable regression models adjusted for relevant factors. Telomere length at 12 months (TL12), but not at birth, was inversely associated with AP (β = −0.56; 95% CI (−1.13, 0.006); p = 0.05) and ADHP (β = −0.66; 95% CI (−1.11, −0.21); p = 0.004). Infant secondhand smoke exposure at one month was independently associated with shorter TL12 and also higher ADHD symptoms. Further work is needed to elucidate the mechanisms that influence TL attrition and early neurodevelopment.

Treatment of Hidradenitis Suppurativa Evaluation Study (THESEUS): protocol for a prospective cohort study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, painful, inflammatory skin disease with estimates of prevalence in the European population of 1%-2%. Despite being a relatively common condition, the evidence base for management of HS is limited. European and North American management guidelines rely on consensus for many aspects of treatment and within the UK variations in management of HS have been identified. The HS James Lind Alliance Priority Setting Partnership (PSP) published a top 10 list of future HS research priorities including both medical and surgical interventions. The aims of the THESEUS study are to inform the design of future HS randomised controlled trials (RCTs) and to understand how HS treatments are currently used. THESEUS incorporates several HS PSP research priorities, including investigation of oral and surgical treatments. Core outcome domains have been established by the HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC) and THESEUS is designed to validate instruments to measure the domains.

METHODS AND ANALYSIS

The THESEUS study is a prospective observational cohort study. Participants, adults with active HS of any severity, will be asked to select one of five HS treatment options that is appropriate for their HS care. Participants will be allocated to their chosen treatment intervention and followed for a period of up to 12 months. Outcomes will be assessed at 3-monthly intervals using HISTORIC core outcome instruments. Video recordings of the surgical and laser operations will provide informational and training videos for future trials. Nested mixed-methods studies will characterise the interventions in clinical practice, understand facilitators and barriers to recruitment into future HS RCTs and examine patients' and clinicians' perspectives on HS treatment choices.

TRIAL REGISTRATION NUMBER

ISRCTN69985145.

Innate Immune Activation and Circulating Inflammatory Markers in Preschool Children

Early childhood is characterised by repeated infectious exposures that result in inflammatory responses by the innate immune system. In addition, this inflammatory response to infection is thought to contribute to the epidemiological evidence linking childhood infection and adult non-communicable diseases. Consequently, the relationship between innate immune responses and inflammation during early life may inform prevention of NCDs later in life. In adults, non-genetic host factors such as age, sex, and obesity, strongly impact cytokine production and circulating mediators, but data in children are lacking. Here, we assessed cytokine responses and inflammatory markers in a population of healthy preschool children (mean age 4.2 years). We studied associations between cytokines, plasma inflammatory markers and non-genetic host factors, such as sex, age, adiposity, season, and immune cell composition. Similar to adults, boys had a higher inflammatory response than girls, with IL-12p70 and IL-10 upregulated following TLR stimulation. Adiposity and winter season were associated with increased circulating inflammatory markers but not cytokine production. The inflammatory markers GlycA and hsCRP were positively associated with production of a number of cytokines and may therefore reflect innate immune function and inflammatory potential. This dataset will be informative for future prospective studies relating immune parameters to preclinical childhood NCD phenotypes.

A Pathway-Based Genetic Score for Oxidative Stress: An Indicator of Host Vulnerability to Phthalate-Associated Adverse Neurodevelopment

The developing brain is highly sensitive to environmental disturbances, and adverse exposures can act through oxidative stress. Given that oxidative stress susceptibility is determined partly by genetics, multiple studies have employed genetic scores to explore the role of oxidative stress in human disease. However, traditional approaches to genetic score construction face a range of challenges, including a lack of interpretability, bias towards the disease outcome, and often overfitting to the study they were derived on. Here, we develop an alternative strategy by first generating a genetic pathway function score for oxidative stress (gPFSox) based on the transcriptional activity levels of the oxidative stress response pathway in brain and other tissue types. Then, in the Barwon Infant Study (BIS), a population-based birth cohort (n = 1074), we show that a high gPFSox, indicating reduced ability to counter oxidative stress, is linked to higher autism spectrum disorder risk and higher parent-reported autistic traits at age 4 years, with AOR values (per 2 additional pro-oxidant alleles) of 2.10 (95% CI (1.12, 4.11); p = 0.024) and 1.42 (95% CI (1.02, 2.01); p = 0.041), respectively. Past work in BIS has reported higher prenatal phthalate exposure at 36 weeks of gestation associated with offspring autism spectrum disorder. In this study, we examine combined effects and show a consistent pattern of increased neurodevelopmental problems for individuals with both a high gPFSox and high prenatal phthalate exposure across a range of outcomes, including high gPFSox and high DEHP levels against autism spectrum disorder (attributable proportion due to interaction 0.89; 95% CI (0.62, 1.16); p < 0.0001). The results highlight the utility of this novel functional genetic score and add to the growing evidence implicating gestational phthalate exposure in adverse neurodevelopment.

Ontogeny of circulating lipid metabolism in pregnancy and early childhood: a longitudinal population study

Background: There is mounting evidence that in utero and early life exposures may predispose an individual to metabolic disorders in later life; and dysregulation of lipid metabolism is critical in such outcomes. However, there is limited knowledge about lipid metabolism and factors causing lipid dysregulation in early life that could result in adverse health outcomes in later life. We studied the effect of antenatal factors such as gestational age, birth weight and mode of birth on lipid metabolism at birth; changes in the circulating lipidome in the first four years of life and the effect of breastfeeding in the first year of life. From this study, we aim to generate a framework for deeper understanding into factors effecting lipid metabolism in early life, to provide early interventions for those at risk of developing metabolic disorders including cardiovascular diseases.

Methods and findings: We performed comprehensive lipid profiling of 1074 mother-child dyads in the Barwon Infant Study (BIS), a population based pre-birth cohort and measured 776 distinct lipid species across 42 lipid classes using ultra high-performance liquid chromatography (UHPLC). We measured lipids in 1032 maternal serum samples at 28 weeks' gestation, 893 cord serum samples at birth, 793, 735, and 511 plasma samples at six, twelve months, and four years, respectively. The lipidome differed between mother and newborn and changed markedly with increasing child's age. Cord serum was enriched with long chain poly-unsaturated fatty acids (LC-PUFAs), and corresponding cholesteryl esters relative to the maternal serum. Alkenylphosphatidylethanolamine species containing LC-PUFAs increased with child's age, whereas the corresponding lysophospholipids and triglycerides decreased. We performed regression analyses to investigate the associations of cord serum lipid species with antenatal factors: gestational age, birth weight, mode of birth and duration of labor. Majority of the cord serum lipids were strongly associated with gestational age and birth weight, with most lipids showing opposing associations. Each mode of birth showed an independent association with cord serum lipids. Breastfeeding had a significant impact on the plasma lipidome in the first year of life, with upto 17-fold increases in a few species of alkyldiaclylglycerols at 6 months of age.

Conclusions: This study sheds light on lipid metabolism in infancy and early childhood and provide a framework to define the relationship between lipid metabolism and health outcomes in early childhood.

Funding Statement: This work was supported by the A*STAR-NHMRC joint call funding (1711624031).

Maternal inflammatory and omega-3 fatty acid pathways mediate the association between socioeconomic disadvantage and childhood cognition

Poor cognitive outcomes in early childhood predict poor educational outcomes and diminished health over the life course. We sought to investigate (i) whether maternal metabolites predict child cognition, and (ii) if maternal metabolomic profile mediates the relationship between environmental exposures and child cognition. Metabolites were measured using nuclear magnetic resonance-based metabolomics in pregnant women from a population-derived birth cohort. Child cognition was measured at age 2 years. In 662 mother-child pairs, elevated inflammatory markers (β = -2.62; 95% CI -4.10, -1.15; P = 0.0005) and lower omega-3 fatty acid-related metabolites (β = 0.49; 95% CI 0.09, 0.88; P = 0.02) in the mother were associated with lower child cognition and partially mediated the association between lower child cognition and multiple risk factors common to socioeconomic disadvantage. Modifying maternal prenatal metabolic pathways related to inflammation and omega-3 fatty acids may offset the adverse associations between prenatal risk factors related to socioeconomic disadvantage and low child cognition.

A systematic review of gut microbiota composition in observational studies of major depressive disorder, bipolar disorder and schizophrenia

The emerging understanding of gut microbiota as 'metabolic machinery' influencing many aspects of physiology has gained substantial attention in the field of psychiatry. This is largely due to the many overlapping pathophysiological mechanisms associated with both the potential functionality of the gut microbiota and the biological mechanisms thought to be underpinning mental disorders. In this systematic review, we synthesised the current literature investigating differences in gut microbiota composition in people with the major psychiatric disorders, major depressive disorder (MDD), bipolar disorder (BD) and schizophrenia (SZ), compared to 'healthy' controls. We also explored gut microbiota composition across disorders in an attempt to elucidate potential commonalities in the microbial signatures associated with these mental disorders. Following the PRISMA guidelines, databases were searched from inception through to December 2021. We identified 44 studies (including a total of 2510 psychiatric cases and 2407 controls) that met inclusion criteria, of which 24 investigated gut microbiota composition in MDD, seven investigated gut microbiota composition in BD, and 15 investigated gut microbiota composition in SZ. Our syntheses provide no strong evidence for a difference in the number or distribution (α-diversity) of bacteria in those with a mental disorder compared to controls. However, studies were relatively consistent in reporting differences in overall community composition (β-diversity) in people with and without mental disorders. Our syntheses also identified specific bacterial taxa commonly associated with mental disorders, including lower levels of bacterial genera that produce short-chain fatty acids (e.g. butyrate), higher levels of lactic acid-producing bacteria, and higher levels of bacteria associated with glutamate and GABA metabolism. We also observed substantial heterogeneity across studies with regards to methodologies and reporting. Further prospective and experimental research using new tools and robust guidelines hold promise for improving our understanding of the role of the gut microbiota in mental and brain health and the development of interventions based on modification of gut microbiota.

Gut Microbiome Diversity and Composition Are Associated with Habitual Dairy Intakes: A Cross-Sectional Study in Men

BACKGROUND

At a population level, the relation between dairy consumption and gut microbiome composition is poorly understood.

OBJECTIVES

We sought to study the cross-sectional associations between individual dairy foods (i.e., milk, yogurt, and cheese), as well as total dairy intake, and the gut microbiome composition in a large, representative sample of men living in south-eastern Australia.

METHODS

Data on 474 men (mean ± SD: 64.5 ± 13.5 y old) from the Geelong Osteoporosis Study were used to assess the cross-sectional association between dairy consumption and gut microbiome. Information on dairy intake was self-reported. Men were categorized as consumers and nonconsumers of milk, yogurt, cheese, and high- and low-fat milk. Milk, yogurt, and cheese intakes were summed to calculate the total dairy consumed per day and categorized into either low (<2.5 servings/d) or high (≥2.5 servings/d) total dairy groups. Fecal samples were analyzed using bacterial 16S ribosomal RNA (rRNA) gene sequencing. After assessment of α and β diversity, differential abundance analysis was performed to identify bacterial taxa associated with each of milk, yogurt, and cheese consumption compared with nonconsumption, low compared with high total dairy, and low- compared with high-fat milk consumption. All analyses were adjusted for potential confounders.

RESULTS

α Diversity was not associated with consumption of any of the dairy groups. Differences in β diversity were observed between milk and yogurt consumption compared with nonconsumption. Taxa belonging to the genera Ruminococcaceae UCG-010 and Bifidobacterium showed negative and weak positive associations with milk consumption, respectively. A taxon from the genus Streptococcus was positively associated with yogurt consumption, whereas a taxon from the genus Eisenbergiella was negatively associated with cheese consumption. No specific taxa were associated with low- compared with high-fat milk nor low compared with high total dairy consumption.

CONCLUSIONS

In men, community-level microbiome differences were observed between consumers and nonconsumers of milk and yogurt. Bacterial taxon-level associations were detected with milk, yogurt, and cheese consumption. Total dairy consumption was not associated with any microbiome measures, suggesting that individual dairy foods may have differential roles in shaping the gut microbiome in men.

The role of diet quality and dietary patterns in predicting muscle mass and function in men over a 15-year period

A growing body of evidence suggests that diet quality may predict muscle health. This study found that a "Traditional" dietary pattern predicted greater muscle mass, and an anti-inflammatory diet predicted greater muscle mass and better muscle function over 15 years. These findings reinforce the importance of optimising dietary behaviours for healthy ageing.

INTRODUCTION

Research investigating the roles of individual nutrients in muscle health fails to account for the synergistic relationships between foods and nutrients. This study aimed to investigate the predictive value of diet quality and dietary patterns for muscle mass and function in men over a 15-year period.

METHODS

This longitudinal study was conducted in 522 men from the Geelong Osteoporosis Study with complete dietary and muscle mass or muscle function data at both baseline and 15-year follow-up assessments. Dietary exposures were extracted from food frequency questionnaires and included the Australian Recommended Food Score, the Dietary Inflammatory Index (DII®), and three a posteriori dietary patterns: Plant-focused, Western, and Traditional (Anglo-Australian). Outcome variables included dual-energy X-ray absorptiometry-derived skeletal muscle index (SMI) and muscle function measured with the timed up-and-go (TUG) test.

RESULTS

An anti-inflammatory diet and higher scores on a Traditional dietary pattern both predicted greater SMI ((B: -0.04 (95%CI -0.08, -0.00) kg/m²) and (B: 0.12 (95%CI 0.04, 0.20) kg/m²), respectively), while a pro-inflammatory diet predicted slower TUG (B: 0.11 (95%CI 0.001, 0.21) sec) over the 15-year follow-up period. These associations remained significant following adjustment for confounding variables. There were no associations observed for other dietary exposures.

CONCLUSION

A Traditional dietary pattern higher in vegetables, wholegrain cereals, and animal protein was associated with greater skeletal muscle mass, and an anti-inflammatory diet, also rich in vegetables, fruit, and wholegrain cereals, was associated with greater skeletal muscle mass and better muscle function over 15 years.

Diverse Bacterial Resistance Genes Detected in Fecal Samples From Clinically Healthy Women and Infants in Australia-A Descriptive Pilot Study

The gut microbiota is an immense reservoir of antimicrobial resistance genes (ARGs), the so-called “resistome.” In Australia, where antibiotic use is high and resistance rates in some common pathogens are increasing, very little is known about the human resistome. To assess the presence and diversity of ARGs in the gut of Australians from south-eastern Victoria, we investigated fecal samples from clinically healthy infants and pregnant women using non-targeted (shotgun metagenomics sequencing or SMS) and targeted sequencing (two Ion Ampliseq^TM panels). All methods detected ARGs in all samples, with the detection overall of 64 unique genes conferring resistance to 12 classes of antibiotics. Predominant ARGs belonged to three classes of antibiotics that are the most frequently prescribed in Australia: tetracycline, β-lactams and MLS_B (macrolide, lincosamide, streptogramin B). The three bacterial Orders commonly identified as carrying ARGs were Clostridiales, Bacteroidales, and Enterobacteriales. Our preliminary results indicate that ARGs are ubiquitously present and diverse among the gut microbiota of clinically healthy humans from south-eastern Victoria, Australia. The observed resistance pattern partly overlaps with antimicrobial usage in human medicine in Australia, but ARGs to tetracycline are more common than could be expected. Our current sample is small and limited to south-eastern Victoria, and more data on healthy individuals will be needed to better depict resistance patterns at the population level, which could guide population and/or environmental monitoring and surveillance of antibiotic resistance on various spatio-temporal scales in Australia. For future studies, we recommend using the Ion Ampliseq^TM Antimicrobial Resistance Research panel, which is sensitive and user-friendly, or combining several methods to increase the detected diversity.

The surgical management of hidradenitis suppurativa in the United Kingdom: a national survey of care pathways informing the THESEUS study

BACKGROUND

The evidence-base underpinning treatment efficacy and effectiveness for hidradenitis suppurativa (HS) is limited, as has been highlighted in the wide-ranging research priorities established by a James Lind Alliance priority-setting partnership (PSP). Understanding the landscape of surgical practice is a key step towards tackling undesired variation in care and resolving treatment uncertainties. This survey of current surgical practice aimed to describe care pathways involving surgeons for the management of HS and surgical approaches to management.

METHODS

In the development of the prospective cohort Treatment of Hidradenitis Suppurativa Evaluation Study (THESEUS), a bespoke electronic surgeon survey was conducted to describe variation in care pathways and surgical preferences in the management of HS. This was disseminated to a pre-defined denominator list of surgeons using local collaborators through the reconstructive surgery trials network (RSTN).

RESULTS

Key results were small numbers of surgeons working in formal multidisciplinary teams (MDTs) (8/198, 4%), heterogeneity of first-line intervention, low rates of guideline endorsed treatments (laser and deroofing in particular), variation in wound closure methods and follow-up length, and that over half of respondents do not use well-validated outcome instruments to determine treatment success/failure (110/198, 56%).

CONCLUSIONS

This survey demonstrated variation in care, which is likely to be undesirable. Surgeons treating HS patients might consider developing MDTs or referring patients to those with an interest in HS and considering routine outcome measurement. Such steps might reduce variation, increase standardisation of care and improve access to specific treatments.

1305Early chronic inflammation and behavioural problems in children at age two: a longitudinal study

Background

Inflammation has been suggested to contribute to the pathogenesis of adult mental illness and been implicated mechanistically in childhood behavioural problems like internalising and externalising symptoms. High-sensitive C-reactive protein (hsCRP) and glycoprotein acetyls (GlycA) are biomarkers of chronic low-grade inflammation. We aimed to investigate whether hsCRP and GlycA, and environmental factors that influence these inflammatory biomarkers, were associated with internalising and externalising behaviours in early childhood.

Methods

The Barwon Infant Study is a population-derived birth cohort recruited using an unselected antenatal sampling frame in Victoria, Australia. Infant bloods collected at birth and 12-month were analysed for hsCRP by ELISA and GlycA by NMR. Environmental factors were derived from questionnaires undertaken antenatally to four years postnatally. Internalising and externalising behaviours at age two were measured by the Child Behaviour Checklist. Associations between inflammatory biomarkers and behavioural outcomes were assessed by multivariable regression analyses adjusted for relevant factors.

Results

Increased GlycA levels at birth (GlycAbirth)(β = 5.22 T-score units; 95% confidence interval (CI)(1.22, 9.21; P=0.01) and decreased GlycA levels at 12 months (GlycA12months)(β=-6.47 T-score units; 95% CI(-11.44, -1.50); P=0.01) were associated with increased internalising behaviours at age two. Association persisted for GlycAbirth, but not for GlycA12months when adjusted for GlycA at both time points within the same model. Weak associations were observed for hsCRP at both time points and externalising behaviours at age two.

Conclusions

Our findings document an association between increased GlycAbirth and greater internalising behaviours in children aged two years. Elevated early chronic inflammation may be an important pathway in adverse behavioural development in children.

Key messages

Increased GlycA levels at birth is associated with greater internalising behaviours in children at age two years.

943Impact of maternal factors, pregnancy complications, and birth outcomes on the neonate metabolome

Background

Metabolic health in early life is critical for healthy development and can have long-lasting ramifications of risk of disease into adulthood. While many exposures during pregnancy are linked to altered fetal development and/or risk of disease in adult offspring, the molecular mechanisms underpinning these associations are poorly characterised. We aimed to describe the association between pregnancy/birth exposures and neonate metabolomics profile.

Methods

Metabolomics in cord blood plasma from 912 neonates in the Barwon Infant Study was quantified using the Nightingale Health NMR platform. Questionnaire and clinical data collected included maternal anthropometry, pregnancy complications, mode of delivery and infant anthropometry at birth. Linear regression models were used to investigate the relationship between these factors and 70 neonate metabolomics measures.

Results

Infant sex, gestational age, birth weight, and exposure to labour during birth were associated with differences across a wide range of metabolites. Exposure to gestational diabetes was associated with increased ketone bodies (acetoacetate and 3-hydroxybutyrate), and this relationship persisted after adjustment for other maternal and pregnancy exposures including maternal BMI. Maternal BMI was modestly associated with increased neonate triglycerides and inflammation.

Conclusions

Birth outcomes show compelling evidence for wide-spread differences in neonate metabolites in cord blood serum, and exposure to gestational diabetes is associated with increased ketone bodies. Further work is required to understand the biological processes underpinning these relationships and to determine if differences in metabolites persist later into childhood.

Key messages

Sex, gestational age, birthweight and exposure to labour are linked to metabolomics differences in cord blood plasma. Gestational diabetes is associated with increased neonate ketone bodies.

The maternal gut microbiome during pregnancy and offspring allergy and asthma

Environmental exposures during pregnancy that alter both the maternal gut microbiome and the infant's risk of allergic disease and asthma include a traditional farm environment and consumption of unpasteurized cow's milk, antibiotic use, dietary fiber and psychosocial stress. Multiple mechanisms acting in concert may underpin these associations and prime the infant to acquire immune competence and homeostasis following exposure to the extrauterine environment. Cellular and metabolic products of the maternal gut microbiome can promote the expression of microbial pattern recognition receptors, as well as thymic and bone marrow hematopoiesis relevant to regulatory immunity. At birth, transmission of maternally derived bacteria likely leverages this in utero programming to accelerate postnatal transition from a Th2 to Th1 and Th17 dominant immune phenotypes and maturation of regulatory immune mechanisms, which in turn reduce the child's risk of allergic disease and asthma. Although our understanding of these phenomena is rapidly evolving, the field is relatively nascent, and we are yet to translate existing knowledge into interventions that substantially reduce disease risk in humans. Here we review evidence that the maternal gut microbiome impacts the offspring's risk of allergic disease and asthma, discuss challenges and future directions for the field, and propose the hypothesis that maternal carriage of Prevotella copri during pregnancy decreases the offspring's risk of allergic disease via production of succinate which in turn promotes bone marrow myelopoiesis of dendritic cell precursors in the fetus.

Maternal prenatal gut microbiota composition predicts child behaviour

BACKGROUND

Murine studies demonstrate that maternal prenatal gut microbiota influences brain development and behaviour of offspring. No human study has related maternal gut microbiota to behavioural outcomes during early life. This study aimed to evaluate relationships between the prenatal faecal microbiota, prenatal diet and childhood behaviour.

METHODS

A sub-cohort of 213 mothers and 215 children were selected from a longitudinal pre-birth cohort. Maternal prenatal exposure measures collected during the third trimester included the faecal microbiota (generated using 16S rRNA amplicon sequencing), and dietary intake. The behavioural outcome used the Childhood Behaviour Checklist at age two. Models were adjusted for prenatal diet, smoking, perceived stress, maternal age and sample batch.

FINDINGS

We found evidence that the alpha diversity of the maternal faecal microbiota during the third trimester of pregnancy predicts child internalising behaviour at two years of age (-2·74, (-4·71, -0·78), p = 0·01 (Wald test), R2=0·07). Taxa from butyrate-producing families, Lachnospiraceae and Ruminococcaceae, were more abundant in mothers of children with normative behaviour. A healthy prenatal diet indirectly related to decreased child internalising behaviours via higher alpha diversity of maternal faecal microbiota.

INTERPRETATION

These findings support animal studies showing that the composition of maternal prenatal gut microbiota is related to offspring brain development and behaviour. Our findings highlight the need to evaluate potential impacts of the prenatal gut microbiota on early life brain development.

FUNDING

This study was funded by the National Health and Medical Research Council of Australia (1082307, 1147980), Murdoch Children's Research Institute, Barwon Health and Deakin University.

Associations between dairy consumption and constipation in adults: A cross-sectional study

OBJECTIVE

The current study aimed to assess the association between dairy consumption and constipation in the general adult population.

DESIGN

Data from the Geelong Osteoporosis Study were used to assess the association between dairy consumption and constipation in women (n=632) and men (n=609). Information on milk, yogurt and cheese, and constipation were self-reported. Total dairy was calculated by summing the intake of milk, yogurt and cheese and expressed as servings per day. Multivariable logistic regression models adjusted for irritable bowel syndrome, major depressive disorders, mobility, body mass index, age and fibre intake were used to examine the odds ratio (OR) and 95% confidence interval (CI) between the consumption of categories of total dairy, milk, yogurt, cheese, and constipation.

RESULTS

In women, consumption of 1-2 servings/d of total dairy was associated with reduced odds for constipation (OR: 0.49; 95% CI: 0.26-0.90; P=0.021) compared to consuming <1 serving/d of total dairy after adjusting for covariates. Also, consumption of 1-4 servings/d of milk was associated with marginally reduced odds for constipation (OR: 0.63; 95% CI: 0.39-1.02; P=0.058) compared to women who consumed <1 serving/d of milk after adjusting for covariates. There were no significant associations detected between other types of dairy consumption and constipation in women, and none in men.

CONCLUSION

In women, consumption of moderate amounts of dairy is associated with reduced odds for constipation whereas in men no associations were detected between dairy consumption and constipation. Further studies are warranted to confirm results.

Diet quality and a traditional dietary pattern predict lean mass in Australian women: Longitudinal data from the Geelong Osteoporosis Study

Low muscle mass is associated with reduced independence and increased risk for falls and fractures. Identification of modifiable risk factors for low muscle mass is thus imperative. This study aimed to examine the longitudinal relationship between both diet quality and patterns and lean mass in Australian women. Data from n = 494 participants of the Geelong Osteoporosis Study's 10- and 15-year women's follow-ups were used (conducted in 2004-08 and 2011-14, respectively), and participants were aged 21-89 years. Self-reported lifestyle and demographics were collected, and food frequency questionnaire data informed the dietary exposure variables: the Australian Recommended Food Score (ARFS); the Dietary Inflammatory Index (DII); and a posteriori dietary patterns. The outcome, Skeletal Muscle Index (SMI), was calculated from DXA-derived appendicular lean mass (ALM) relative to height (ALM kg/m2). Analyses employed Generalised Estimating Equations. A higher ARFS score positively predicted SMI over 5-years, and adjustments for age and physical activity did not attenuate this relationship (B:0.044, (95%CI 0.004, 0.084) kg/m2). Following adjustment, both an anti-inflammatory diet (B:-0.034, (95%CI -0.070, -0.002) kg/m2) and a 'traditional' dietary pattern predicted higher SMI (B:0.081, (95%CI 0.004, 0.158) kg/m2). No other associations were observed. Our study reinforces the importance of diet quality for healthy, aging muscle mass. Furthermore, a less inflammatory diet and a diet comprising a wide variety of plant and animal foods may be conducive to maintenance of muscle mass in women. Further studies investigating diet quality's impact on various muscle health measures over longer time periods are warranted.

Maternal and Cord Blood 25-Hydroxyvitamin D3 Are Associated with Increased Cord Blood and Naive and Activated Regulatory T Cells: The Barwon Infant Study

Vitamin D has shown immune-modulatory effects but mostly in in vitro and animal studies. Regulatory T cells (Treg) are important for a balanced immune system. The relationship between vitamin D on the number of circulating neonatal Treg is unclear. We sought to investigate the association between maternal and neonatal vitamin D metabolites and cord blood (CB) Treg subsets. In a cohort of Australian infants (n = 1074), recruited using an unselected antenatal sampling frame, 158 mother-infant pairs had data on the following: 1) 25-hydroxyvitamin D₃ (25(OH)D₃) measures in both maternal peripheral blood (28- to 32-wk gestation) and infant CB; 2) proportions (percentage of CD4⁺ T cells) of CB Treg subsets (CD4⁺CD45RA⁺ FOXP3^low naive Treg, and CD4⁺CD45RA^- FOXP3^high activated Treg [aTreg]); and 3) possible confounders, including maternal personal UV radiation. Multiple regression analyses were used. The median 25(OH)D₃ was 85.4 and 50.7 nmol/l for maternal and CB samples, respectively. Higher maternal 25(OH)D₃ levels were associated with increased CB naive Treg (relative adjusted mean difference [AMD] per 25 nmol/l increase: 5%; 95% confidence interval [CI]: 1-9%), and aTreg (AMD per 25 nmol/l increase: 17%; 95% CI: 6-28%). Furthermore, a positive association between CB 25(OH)D₃ levels and CB aTreg (AMD per 25 nmol/l increase: 29%; 95% CI: 13-48%) was also evident. These results persisted after adjustment for other factors such as maternal personal UV radiation and season of birth. 25(OH)D_3, may play a role in the adaptive neonatal immune system via induction of FOXP3⁺ Tregs. Further studies of immune priming actions of antenatal 25(OH)D₃ are warranted.

Exposure to adversity and inflammatory outcomes in mid and late childhood

BACKGROUND

We aimed to estimate the association between exposure to adversity and inflammatory markers in mid (4 years) and late (11-12 years) childhood, and whether effects differ by type and timing of exposure.

METHODS

Data sources: Barwon Infant Study (BIS; N = 510 analyzed) and Longitudinal Study of Australian Children (LSAC; N = 1156 analyzed). Exposures: Adversity indicators assessed from 0 to 4 (BIS) and 0-11 years (LSAC): parent legal problems, mental illness and substance abuse, anger in parenting responses, separation/divorce, unsafe neighborhood, and family member death; a count of adversities; and, in LSAC only, early (0-3), middle (4-7), or later (10-11) initial exposure. Outcomes: Inflammation quantified by high sensitivity C-reactive protein (hsCRP, Log (ug/ml)) and glycoprotein acetyls (GlycA, Log (umol/L)). Analyses: Linear regression was used to estimate relative change in inflammatory markers, adjusted for sociodemographic characteristics, with exposure to adversity. Outcomes were log-transformed.

RESULTS

Evidence of an association between adversity and hsCRP was weak and inconsistent (e.g., 3+ versus no adversity: BIS: 12% higher, 95%CI -49.4, 147.8; LSAC 4.6% lower, 95%CI: -36.6, 48.3). A small positive association between adversity and GlycA levels was observed at both 4 years (e.g., 3+ versus no adversity: 3.3% higher, 95%CI -3.0, 9.9) and 11-12 years (3.2% higher, 95%CI 0.8, 5.8). In LSAC, we did not find evidence that inflammatory outcomes differed by initial timing of adversity exposure.

CONCLUSIONS

Small positive associations between adversity and inflammation were consistently observed for GlycA, across two cohorts with differing ages. Further work is needed to understand mechanisms, clinical relevance, and to identify opportunities for early intervention.

Obesity, Akkermansia muciniphila, and Proton Pump Inhibitors: Is there a Link?

OBJECTIVE

The gut bacterium Akkermansia muciniphila (A. muciniphila), has been linked to body composition and metabolism. However, the role of lifestyle factors and medication use in these relationships has not been considered. This study aimed to assess the relative abundance of A. muciniphila in participants and investigate its association with obesity, with consideration of potential confounding factors.

METHODS

Participants included 158 men of the Geelong Osteoporosis Study with dual-energy X-ray absorptiometry data, 16S rRNA gene bacterial profiling of stool samples, and lifestyle data. The relative abundance of A. muciniphila was estimated from total sequence reads, while obesity status was quantified by fat mass index (FMI, kg/m²).

RESULTS

In this cohort (66 ± 12 yr, mean ± SD), the most common medications were proton pump inhibitors (PPIs) (28%), and these were associated with both high FMI and decreased abundance of A. muciniphila. Before and after adjustments for PPIs, participants with substantial A. muciniphila (abundance ≥0.1%, n = 94) compared to very low (abundance <0.1%, n = 64), had lower FMI (adjusted -1.33 (95%CI -2.30, -0.36) kg/m², p = 0.007).

CONCLUSIONS

In this sample, relative abundance of A. muciniphila was inversely associated with high FMI, independent of PPI use. The relationship between obesity, reflux medication, and the gut microbiome warrants further investigation.

Transcriptomic analysis of adhesive capsulitis of the shoulder

Adhesive capsulitis (AC) is a disabling condition of the shoulder joint affecting 2 to 5% of the general population. Our understanding of the molecular mechanisms is limited. The present study aimed to determine potential biomarkers of AC through transcriptomic analysis. This multi-centre study investigated patients undergoing arthroscopic capsulotomy surgery for resistant AC compared to those undergoing arthroscopic stabilization surgery for glenohumeral instability (control). Tissue samples were harvested from the anterior capsule during surgery. Total RNA was extracted and RNA-sequencing-based transcriptomics were performed. A number of genes deemed differentially expressed in RNA-sequencing analysis were validated using real-time reverse transcription polymerase chain reaction (RT-PCR). Baseline characteristics of the AC group (n = 22) were; mean age 52.7 years (SD: 10.2), 73% female, and Oxford Shoulder Score 19.6 (SD: 8.0), compared with the control group (n = 26), average age 23.9 years (SD: 5.2), 15% female, and Oxford Shoulder Score 39.0 (SD: 7.4). Transcriptomic analysis with false discovery rate correction and log₂ fold change cut-off of ±1.5 revealed 545 differentially expressed genes in AC relative to control. Bioinformatic analyses were carried out to identify biological processes and pathways enriched in this dataset. Real-time RT-PCR using two different normalization processes confirmed increased expression of matrix metallopeptidase 13 (MMP13) and platelet-derived growth factor subunit B (PDGFB), in patients with AC, while tumor necrosis factor α (TNFA) expression was reduced. These findings provide a comprehensive assessment of transcriptional changes associated with AC that give insights into the aetiology of the disease and provides a resource for molecular targets to better diagnose and treat this condition.

Plasma metabolomic profiles associated with infant food allergy with further consideration of other early life factors

BACKGROUND

Fatty acids have been implicated in early life immune development. Food allergy provides a clear phenotype of early allergic disease. Fish oil and vitamin D have immune-modulating properties. We aimed to identify the metabolomic profile of (i) infant food allergy and (ii) factors linked to food allergy in past studies such as fish oil supplementation and serum 25OHD3 levels in early life.

METHODS

NMR was used to quantify 73 metabolites in plasma of 1 year old infants from the Barwon Infant Study (n=485). Logistic regression models were used to examine associations between infant metabolome and food allergy in infants. Linear regression models were used to describe associations between maternal fish oil supplementation and 25OHD3 levels with infant metabolites.

RESULTS

A higher linoleic acid: total fatty acid (FA) ratio and phenylalanine level were associated with higher odds of food allergy. Antenatal fish oil supplementation was positively associated with docosahexaenoic acid (DHA) and omega-3 related metabolite levels. Postnatal 25OHD3 levels at 1 year of age were positively associated with several FA measures and creatinine and inversely with the saturated FA: total FA ratio. Only the postnatal 25OHD3 patterns persisted after adjustment for multiple comparisons.

CONCLUSIONS

Infants with food allergy had altered fatty acid profiles at one year. Fish oil supplementation in pregnancy was associated with higher DHA and omega-3 related metabolites at 1 year of age. Associations were modest and the most robustly altered metabolomic profiles were with postnatal 25OHD3 levels.

HIF3A cord blood methylation and systolic blood pressure at 4 years - a population-based cohort study

Methylation levels at the hypoxia-inducible factor 3α gene (HIF3A) in blood have been linked to body mass index (BMI) in adults. Despite evidence implicating HIF3A in angiogenesis and metabolism, no studies have examined links between HIF3A methylation in early life and cardiovascular health. Here, we investigated the relationship between HIF3A methylation in blood at birth and 12 months of age with cardiovascular measures at 4 years. We also examined influences of prenatal exposures, birth outcomes, and genetic variation. Methylation of two HIF3A promoter regions in cord blood was measured using Sequenom EpiTYPER mass-spectrometry. The first promoter region was also measured in 12-month blood. Four-year cardiovascular measures included blood pressure, pulse wave velocity, and aortic and carotid intima-media thickness. Associations were tested using partial correlation tests and linear regression modelling. Methylation of the first HIF3A promoter in cord and 12-month blood was not associated with four-year measures. There was modest evidence of an association between DNA methylation at the second HIF3A promoter in cord blood and four-year systolic blood pressure (n = 353, r = 0.12, p = 0.03). In sex-stratified analysis, methylation of the second promoter was modestly associated with systolic and diastolic blood pressure (r = 0.16, p = 0.03 for both) in males only. In conclusion, HIF3A methylation at birth shows some evidence of an association with later blood pressure in childhood. Further work should determine whether this relationship persists into later childhood, and should assess potential functional links between HIF3A methylation and cardiovascular health more generally.

Deserters on the atopic march: Risk factors, immune profile and clinical outcomes of food sensitized-tolerant infants

BACKGROUND

A few studies have investigated the antecedents and outcomes of infants who demonstrate IgE sensitization to foods that they clinically tolerate. Improved understanding of this sensitized-tolerant phenotype may inform strategies for the prevention of food allergy.

METHODS

In an Australian birth cohort (n = 1074), assembled using an unselected antenatal sampling frame, participants were categorized as nonsensitized (NS), sensitizedtolerant (ST), or food allergic (FA) based on skin prick testing and food challenge at 12 months of age. Environmental exposures were recorded throughout. Cord blood regulatory T-cell populations were measured at birth. Subsequent childhood allergic disease was assessed by parent report, clinical examination, and repeat skin prick testing.

RESULTS

The covariates of interest varied between NS (n = 698), ST (n = 27), and FA (n = 61) groups as follows, suggesting that across these measures, the ST group was more similar to the NS than the FA group: family history of eczema NS 44.6%, ST. 44.6%, FA 65.6%; pet ownership at 12 months: NS 71.5%, ST 81.5%, FA 45.8%; eczema during the first 12 months: NS 19%, ST 32%, FA 64%; and aeroallergen sensitization at 4 years: NS 19.1%, ST 28.6%, FA 44.4%. At birth, a higher proportion of activated regulatory T cells was associated with ST (OR = 2.89, 95% CI 1.03-8.16, P = .045).

CONCLUSION

Food-sensitized-tolerance in infancy appears to be associated with a similar pattern of exposures, immunity, and outcomes to nonsensitized infants. In addition, we found some evidence that an elevated proportion of activated regulatory T cells at birth was specific to the sensitized-tolerant infants, which may be relevant to suppression of clinical disease.

Prenatal phthalate exposure, oxidative stress-related genetic vulnerability and early life neurodevelopment: A birth cohort study

Prenatal phthalate chemicals may have adverse effects on brain development by various mechanisms including oxidant damage. However, birth cohort findings have been conflicting. This study aimed to (i) investigate the interplay between maternal prenatal phthalate levels, infant genetic vulnerability to oxidative stress, and child neurodevelopment and (ii) examine combined putative oxidant exposures. In a population-based birth cohort of 1064 women with prenatal recruitment in Victoria, Australia, maternal urine was collected at 36 weeks of pregnancy and phthalate metabolite concentrations measured. An unweighted genetic score for oxidative stress was made using a candidate gene approach. Cognition was assessed using the BAYLEY-III at two years (n = 678). Parents completed questionnaires for doctor diagnosed autism spectrum disorder (ASD) (1.4 %), ASD traits (4.9 %) and child inattention/hyperactivity (n = 791). Analyses included multiple linear and logistic regression. Higher prenatal phthalate levels and a higher oxidative stress genetic score were each associated with subsequent ASD. Several oxidative stress-related SNPs modified the association between prenatal phthalates and ASD and other outcomes. Consistent patterns were evident across gene score-phthalate combinations for cognition, ASD, ASD traits and inattention/hyperactivity. Other putative oxidant factors such as prenatal smoking further increased risk. Prenatal phthalate levels and infant oxidative stress-related genetic vulnerability are associated with adverse neurodevelopment. Combined exposures are important. Current recommendations and regulation on maternal phthalate exposure during pregnancy require re-evaluation.

Gut microbiota composition during infancy and subsequent behavioural outcomes

Background

Despite intense interest in the relationship between gut microbiota and brain development, longitudinal data from human studies are lacking. This study aimed to investigate the relationship between the composition of gut microbiota during infancy and subsequent behavioural outcomes.

Methods

A subcohort of 201 children with behavioural outcome measures was identified within a longitudinal, Australian birth-cohort study. The faecal microbiota were analysed at 1, 6, and 12 months of age. Behavioural outcomes were measured at 2 years of age.

Findings

In an unselected birth cohort, we found a clear association between decreased normalised abundance of Prevotella in faecal samples collected at 12 months of age and increased behavioural problems at 2 years, in particular Internalizing Problem scores. This association appeared independent of multiple potentially confounding variables, including maternal mental health. Recent exposure to antibiotics was the best predictor of decreased Prevotella.

Interpretation

Our findings demonstrate a strong association between the composition of the gut microbiota in infancy and subsequent behavioural outcomes; and support the importance of responsible use of antibiotics during early life.

Funding

This study was funded by the National Health and Medical Research Council of Australia (1082307, 1147980, 1129813), The Murdoch Children's Research Institute, Barwon Health, Deakin University, Perpetual Trustees, and The Shepherd Foundation. The funders had no involvement in the data collection, analysis or interpretation, trial design, recruitment or any other aspect pertinent to the study.

Folate levels in pregnancy and offspring food allergy and eczema

BACKGROUND

High folate status in pregnancy has been implicated in the increased prevalence of allergic disease, but there are no published data relating directly measured folate status in pregnancy to challenge-proven food allergy among offspring. The study aim was to examine the association between red blood cell (RBC) folate status in trimester three of pregnancy and allergic disease among offspring.

METHODS

Red blood cell folate levels were measured at 28-32 weeks' gestation in a prospective birth cohort (n = 1074). Food allergy outcomes were assessed in 1-year-old infants by skin prick testing and subsequent food challenge. Eczema was assessed by questionnaire and clinical review. High trimester three RBC folate was defined as greater than (>) 1360 nmol/L. Binomial regression was used to examine associations between trimester three RBC folate and allergic outcomes, adjusting for potential confounders.

RESULTS

Red blood cell folate levels were measured in 88% (894/1064) of pregnant women. The mean concentration was 1695.6 nmol/L (standard deviation 415.4) with 82% (731/894) >1360 nmol/L. There was no evidence of either linear or non-linear relationships between trimester three RBC folate and allergic outcomes, nor evidence of associations between high RBC folate and food allergy (adjusted risk ratio (aRR) 2.89, 95% CI 0.90-9.35), food sensitization (aRR 1.72, 95% CI 0.85-3.49), or eczema (aRR 0.97, 95% CI 0.67-1.38).

CONCLUSION

The majority of pregnant women in this study had high RBC folate levels. There was no evidence of associations between trimester three RBC folate and food allergy, food sensitization, or eczema among the offspring, although larger studies are required.

High incidence of respiratory disease in Australian infants despite low rate of maternal cigarette smoking

AIM

The burden of wheezing illnesses in Australian infants has not been documented since the success of initiatives to reduce maternal cigarette smoking. We aimed to determine the incidence of wheeze and related health-care utilisation during the first year of life among a contemporary Australian birth cohort.

METHODS

A birth cohort of 1074 infants was assembled between 2010 and 2013. Parents completed questionnaires periodically. Several non-exclusive infant respiratory disease phenotypes were defined, including any wheeze, wheeze with shortness of breath and recurrent wheeze. Skin prick testing was performed to determine atopic wheeze. Health-care utilisation for respiratory disease was determined from questionnaires and hospital medical records.

RESULTS

Retention to 1 year was 840/1074 (83%). The incidence of any wheeze was 51.8% (95% confidence interval (CI) 48.3-55.2%), wheeze with shortness of breath 20.6% (95% CI 17.9-23.5), recurrent wheeze 19.4% (95% CI 16.8-22.2) and atopic wheeze 6% (95% CI 4.6-7.8). Respiratory illness resulted in primary health-care utilisation in 82.2% (95% CI 79.3-84.8) of participants and hospital presentation in 8.8% (95% CI 7.2-10.6). Maternal smoking during pregnancy was uncommon (15.7%) and was not associated with wheeze or health resource utilisation. Male gender, familial atopy and asthma and smaller household size were associated with a higher incidence of wheeze.

CONCLUSIONS

The incidence of wheezing illness among Australian infants remains high despite relatively low rates of maternal smoking during pregnancy. The majority of the health-care burden is borne by primary health-care services. Further research is required to inform novel prevention strategies.

Pre-school child blood lead levels in a population-derived Australian birth cohort: the Barwon Infant Study

OBJECTIVES

To investigate blood lead levels in an Australian birth cohort of children; to identify factors associated with higher lead levels.

DESIGN, SETTING

Cross-sectional study within the Barwon Infant Study, a population birth cohort study in the Barwon region of Victoria (1074 infants, recruited June 2010 - June 2013). Data were adjusted for non-participation and attrition by propensity weighting.

PARTICIPANTS

Blood lead was measured in 523 of 708 children appraised in the Barwon Infant Study pre-school review (mean age, 4.2 years; SD, 0.3 years).

MAIN OUTCOME MEASURE

Blood lead concentration in whole blood (μg/dL).

RESULTS

The median blood lead level was 0.8 μg/dL (range, 0.2-3.7 μg/dL); the geometric mean blood lead level after propensity weighting was 0.97 μg/dL (95% CI, 0.92-1.02 μg/dL). Children in houses 50 or more years old had higher blood lead levels (adjusted mean difference [AMD], 0.13 natural log units; 95% CI, 0.02-0.24 natural log units; P = 0.020), as did children of families with lower household income (per $10 000, AMD, -0.035 natural log units; 95% CI, -0.056 to -0.013 natural log units; P = 0.002) and those living closer to Point Henry (inverse square distance relationship; P = 0.002). Associations between hygiene factors and lead levels were evident only for children living in older homes.

CONCLUSION

Blood lead levels in our pre-school children were lower than in previous Australian surveys and recent surveys in areas at risk of higher exposure, and no children had levels above 5 μg/dL. Our findings support advice to manage risks related to exposure to historical lead, especially in older houses.

Naïve regulatory T cells in infancy: Associations with perinatal factors and development of food allergy

BACKGROUND

In previous studies, deficits in regulatory T-cell (Treg) number and function at birth have been linked with subsequent allergic disease. However, longitudinal studies that account for relevant perinatal factors are required. The aim of this study was to investigate the relationship between perinatal factors, naïve Treg (nTreg) over the first postnatal year and development of food allergy.

METHODS

In a birth cohort (n = 1074), the proportion of nTreg in the CD4⁺ T-cell compartment was measured by flow cytometry at birth (n = 463), 6 (n = 600) and 12 (n = 675) months. IgE-mediated food allergy was determined by food challenge at 1 year. Associations between perinatal factors (gestation, labour, sex, birth size), nTreg at each time point and food allergy at 1 year were examined by linear regression.

RESULTS

A higher proportion of nTreg at birth, larger birth size and male sex was each associated with higher nTreg in infancy. Exposure to labour, as compared to delivery by prelabour Caesarean section, was associated with a transient decrease nTreg. Infants that developed food allergy had decreased nTreg at birth, and the labour-associated decrease in nTreg at birth was more evident among infants with subsequent food allergy. Mode of birth was not associated with risk of food allergy, and there was no evidence that nTreg at either 6 or 12 months were related to food allergy.

CONCLUSION

The proportion of nTreg at birth is a major determinant of the proportion present throughout infancy, highlighting the importance of prenatal immune development. Exposure to the inflammatory stimulus of labour appears to reveal differences in immune function among infants at risk of food allergy.

Decreased maternal serum acetate and impaired fetal thymic and regulatory T cell development in preeclampsia

Maternal immune dysregulation seems to affect fetal or postnatal immune development. Preeclampsia is a pregnancy-associated disorder with an immune basis and is linked to atopic disorders in offspring. Here we show reduction of fetal thymic size, altered thymic architecture and reduced fetal thymic regulatory T (Treg) cell output in preeclamptic pregnancies, which persists up to 4 years of age in human offspring. In germ-free mice, fetal thymic CD4+ T cell and Treg cell development are compromised, but rescued by maternal supplementation with the intestinal bacterial metabolite short chain fatty acid (SCFA) acetate, which induces upregulation of the autoimmune regulator (AIRE), known to contribute to Treg cell generation. In our human cohorts, low maternal serum acetate is associated with subsequent preeclampsia, and correlates with serum acetate in the fetus. These findings suggest a potential role of acetate in the pathogenesis of preeclampsia and immune development in offspring.

Early-life determinants of hypoxia-inducible factor 3A gene (HIF3A) methylation: a birth cohort study

Background

Methylation of the hypoxia-inducible factor 3α gene (HIF3A) has been linked to pregnancy exposures, infant adiposity and later BMI. Genetic variation influences HIF3A methylation levels and may modify these relationships. However, data in very early life are limited, particularly in association with adverse pregnancy outcomes. We investigated the relationship between maternal and gestational factors, infant anthropometry, genetic variation and HIF3A DNA methylation in the Barwon Infant Study, a population-based birth cohort. Methylation of two previously studied regions of HIF3A were tested in the cord blood mononuclear cells of 938 infants.

Results

No compelling evidence was found of an association between birth weight, adiposity or maternal gestational diabetes with methylation at the most widely studied HIF3A region. Male sex (− 4.3%, p < 0.001) and pre-eclampsia (− 5.4%, p = 0.02) negatively associated with methylation at a second region of HIF3A; while positive associations were identified for gestational diabetes (4.8%, p = 0.01) and gestational age (1.2% increase per week, p < 0.001). HIF3A genetic variation also associated strongly with methylation at this region (p < 0.001).

Conclusions

Pre- and perinatal factors impact HIF3A methylation, including pre-eclampsia. This provides evidence that specific pregnancy complications, previously linked to adverse outcomes for both mother and child, impact the infant epigenome in a molecular pathway critical to several vascular and metabolic conditions. Further work is required to understand the mechanisms and clinical relevance, particularly the differing effects of in utero exposure to gestational diabetes or pre-eclampsia.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0687-0) contains supplementary material, which is available to authorized users.