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We found that diet-induced obesity in female mice has tissue- and time-dependent effects on intestinal paracellular permeability as well as monocyte-derived and tissue-resident macrophage numbers, surface marker phenotype, and intracellular production of the cytokines IL-10 and TNF. These changes were not mediated by TNF.

Introduction: Frailty in older adults, characterized by a decline in multiple physiological systems and increasing vulnerability to loss of independence, disability, and death, is a public health priority in developed countries. Etiology of frailty extends across the lifespan and may begin in early life, but empirical evidence for this association is scarce. In this study, we examined whether adverse childhood experiences (ACEs) are associated with frailty in later life. Methods: We conducted a cross-sectional analysis of data for a population-based sample of 27,748 adults aged 45–85 years from the Canadian Longitudinal Study on Aging. The frailty index (FI) was computed with 76 health-related characteristics of physical and cognitive performance, self-rated health, chronic conditions, visual and hearing ability, activities of daily living, and well-being. Self-reported exposure to ACEs included physical, emotional, and sexual abuse, neglect, and witnessing intimate partner violence prior age of 16 and parental death, divorce, and living with a family member with mental illness prior age of 18. Generalized linear regression models with gamma error distribution and identity link function, adjusted for age and sex, were used to examine associations of each ACE type and the number of ACE types (0, 1, 2, or 3+) reported by an individual with FI. All models were adjusted for income, education, smoking, and alcohol consumption in sensitivity analysis. Results: Individuals exposed to ACEs had elevated levels of FI (mean = 0.13, SD = 0.09) than those unexposed, with the largest difference observed for neglect (B [95% CI]: 0.05 [0.04, 0.06]) and the smallest for parental death and divorce (0.015 [0.01,0.02]). The ACE count was associated with frailty in a graded manner, with the FI difference reaching 0.04 [0.037, 0.044] for participants exposed to 3+ ACE types. The association between ACEs and frailty tended to be stronger for women than men and for men aged 45–64 years than older men. Conclusions: Our study supports previous studies showing that exposure to ACEs is associated with frailty in adults. Our findings suggest that screening for ACEs involving childhood maltreatment may be useful for identifying individuals at risk of frailty and prevention of ACEs may have long-term benefits for healthy aging.

Macrophages are essential for homeostatic maintenance of the anti-inflammatory and tolerogenic intestinal environment, yet monocyte-derived macrophages can promote local inflammation. Pro-inflammatory macrophage accumulation within the intestines may contribute to the development of systemic chronic inflammation and immunometabolic dysfunction in obesity. Using a model of high fat diet-induced obesity in C57BL/6J female mice, we assessed intestinal permeability by in vitro and in vivo assays, and quantitated intestinal macrophages in ileum and colon tissues by multicolour flow cytometry after short (6 weeks), intermediate (12 weeks), and prolonged (18 weeks) diet allocation. We characterized monocyte-derived CD4−TIM4− and CD4+TIM4− macrophages, as well as tissue-resident CD4+TIM4+ macrophages. Diet-induced obesity had tissue and time-dependent effects on intestinal permeability, as well as monocyte and macrophage numbers, surface phenotype, and intracellular production of the cytokines IL-10 and TNF. We found that obese mice had increased paracellular permeability, in particular within the ileum, but this did not elicit recruitment of monocytes, nor a local pro-inflammatory response by monocyte-derived or tissue-resident macrophages, in either the ileum or colon. Proliferation of monocyte-derived and tissue-resident macrophages was also unchanged. Wildtype and TNF−/- littermate mice had similar intestinal permeability and macrophage population characteristics in response to diet-induced obesity. These data are unique from reported effects of diet-induced obesity on macrophages in metabolic tissues, as well as outcomes of acute inflammation within the intestines, and collectively indicate that TNF does not mediate effects of diet-induced obesity on intestinal monocyte-derived and tissue-resident intestinal macrophages in young female mice.Abstract Figure

Pregnancy requires maternal adaptations to support fetal growth: whether these adaptations include temporal shifts in the gut microbiome is still unclear. We investigated the maternal gut microbiome longitudinally over the course of pregnancy and the impact of pre-pregnancy BMI (pBMI) and GWG. We also determined whether parity modulated observed associations. We show that the gut microbiota of participants with higher pBMI changed less over the course of pregnancy in primiparous, but not multiparous participants. This suggests that previous pregnancies may have persistent impacts on maternal adaptations to pregnancy. This ecological memory appears to be passed to the next generation, as parity modulated the impact of maternal GWG on the infant gut microbiome. This work supports a role for the gut microbiome in maternal adaptations to pregnancy and highlights the need for longitudinal sampling and accounting for parity as key considerations for studies of the microbiome in pregnancy and infants.

SummaryPaternal obesity has been implicated in adult-onset metabolic disease in offspring. However, the molecular mechanisms driving these paternal effects and the developmental processes involved remain poorly understood. One underexplored possibility is the role of paternally driven gene expression in placenta function. To address this, we investigated paternal high-fat diet-induced obesity in relation to sperm epigenetic signatures, the placenta transcriptome and cellular composition. C57BL6/J males were fed either a control or high-fat diet for 10 weeks beginning at 6 weeks of age. Males were timed-mated with control-fed C57BL6/J females to generate pregnancies, followed by collection of sperm, and placentas at embryonic day (E)14.5. Chromatin immunoprecipitation targeting histone H3 lysine 4 tri-methylation (H3K4me3) followed by sequencing (ChIP-seq) was performed on sperm to define obesity-associated changes in enrichment. Paternal obesity corresponded with altered sperm H3K4me3 enrichment at imprinted genes, and at promoters of genes involved in metabolism and development. Notably, sperm altered H3K4me3 was localized at placental enhancers and genes implicated in placental development and function. Bulk RNA-sequencing on placentas detected paternal obesity-induced sex-specific changes in gene expression associated with hypoxic processes such as angiogenesis, nutrient transport and imprinted genes. Paternal obesity was also linked to placenta development; specifically, a deconvolution analysis revealed altered trophoblast cell lineage specification. These findings implicate paternal obesity-effects on placenta development and function as one mechanism underlying offspring metabolic disease.Summary sentencePaternal obesity impacts the sperm epigenome at genes implicated in placenta development and is associated with an altered placenta transcriptome and trophoblast cell lineage specification.

It is clear that the gastrointestinal tract influences metabolism and immune function. Most studies to date have used male test subjects, with a focus on effects of obesity and dietary challenges. Despite significant physiological adaptations that occur across gestation, relatively few studies have examined pregnancy-related gut function. In this study, we investigated the impacts of pregnancy and adiposity on maternal intestinal epithelium morphology, in vivo intestinal permeability, and peripheral blood immunophenotype, using control (CTL) and high-fat (HF) fed non-pregnant female mice and pregnant mice at mid-(embryonic day (E)14.5) and late (E18.5) gestation. We found that small intestine length increased between non-pregnant mice and dams at late-gestation, but ileum villus length, and ileum and colon crypt depths and goblet cell numbers remained similar. Compared to CTL-fed mice, HF-fed mice had reduced small intestine length, ileum crypt depth and villus length. Goblet cell numbers were only consistently reduced in HF-fed non-pregnant mice. Pregnancy increased in vivo gut permeability, with a greater effect at mid-versus late-gestation. Non-pregnant HF-fed mice had greater gut permeability, and permeability was also increased in HF-fed pregnant dams at mid but not late-gestation. The impaired maternal gut barrier in HF-fed dams at mid-gestation coincided with changes in maternal blood and bone marrow immune cell composition, including an expansion of circulating inflammatory Ly6Chigh monocytes. In summary, pregnancy has temporal effects on maternal intestinal structure and barrier function, and on peripheral immunophenotype, which are further modified by HF diet-induced maternal adiposity.

Microbial colonization of the human intestine impacts host metabolism and immunity; however, exactly when colonization occurs is unclear. Although many studies have reported bacterial DNA in first-pass meconium samples, these samples are typically collected hours to days after birth. Here, we investigated whether bacteria could be detected in meconium before birth. Fetal meconium (n = 20) was collected by rectal swab during elective breech caesarean deliveries without labour and before antibiotics and compared to technical and procedural controls (n = 5), first-pass meconium (neonatal meconium; n = 14) and infant stool (n = 25). Unlike first-pass meconium, no microbial signal distinct from negative controls was detected in fetal meconium by 16S ribosomal RNA gene sequencing. Additionally, positive aerobic (n = 10 of 20) and anaerobic (n = 12 of 20) clinical cultures of fetal meconium (13 of 20 samples positive in at least one culture) were identified as likely skin contaminants, most frequently Staphylococcus epidermidis, and not detected by sequencing in most samples (same genera detected by culture and sequencing in 2 of 13 samples with positive culture). We conclude that fetal gut colonization of healthy term infants does not occur before birth and that microbial profiles of neonatal meconium reflect populations acquired during and after birth. Fetal meconium does not have a detectable microbiota, as shown using 16S rRNA sequencing and culture of rectal swabs collected during elective breech caesarean sections without labour and before antibiotics, indicating that colonization occurs during and after birth.

Key points The prevalence of obesity and non-alcoholic fatty liver disease in children is dramatically increasing at the same time as consumption of foods with a high sugar content. Intake of high fructose corn syrup (HFCS) is a possible etiology as it is thought to be more lipogenic than glucose. In a mouse model, HFCS intake during adolescence increased fat mass and hepatic lipid levels in male and female mice. However, only males showed impaired glucose tolerance. Multiple metabolites including lipids, bile acids, carbohydrates, and amino acids were altered in liver in a sex-specific manner at 6 weeks of age. Some of these changes were also present in adulthood even though HFCS exposure ended at 6 weeks. HFCS significantly altered the gut microbiome which was associated with changes in key microbial metabolites. These results suggest that HFCS intake during adolescence has profound metabolic changes that are linked to changes in the microbiome and these changes are sex-specific. Abstract The rapid increase in obesity, diabetes and fatty liver disease in children over the past 20 years has been linked to increased high fructose corn syrup (HFCS) consumption making it essential to determine the short and long-term effects of HFCS during this vulnerable developmental window. We hypothesized that HFCS exposure during adolescence significantly impairs hepatic metabolic signaling pathways and alters gut microbial composition contributing to changes in energy metabolism with sex-specific effects. C57bl/6J mice with free access to HFCS during adolescence (3-6 weeks of age) underwent glucose tolerance and body composition testing and hepatic metabolomics, gene expression and triglyceride content analysis at 6 and 30 weeks of age (n = 6-8 per sex). At 6 weeks HFCS-exposed mice had significant increases in fat mass, glucose intolerance, hepatic triglycerides (females) and de novo lipogenesis gene expression (ACC, DGAT, FAS, ChREBP, SCD, SREBP, CPT and PPARα) with sex-specific effects. At 30 weeks HFCS-exposed mice also had abnormalities in glucose tolerance (males) and fat mass (females). HFCS exposure enriched carbohydrate, amino acid, long chain fatty acid and secondary bile acid metabolism at 6 weeks with changes in secondary bile metabolism at 6 and 30 weeks. Microbiome studies performed immediately before and after HFCS exposure identified profound shifts of microbial species in male mice only. In summary, a short-term HFCS exposure during adolescence induces fatty liver, alters important metabolic pathways, some of which continue to be altered in adulthood, and changes the microbiome in a sex-specific manner. This article is protected by copyright. All rights reserved.

The placenta is a metabolically active interfacial organ that plays crucial roles in fetal nutrient delivery, gas exchange and waste removal reflecting dynamic maternal and fetal interactions during gestation. There is growing evidence that the sex of the placenta influences fetal responses to external stimuli in utero, such as changes in maternal nutrition and exposure to environmental stressors. However, the exact biochemical mechanisms associated with sex-specific metabolic adaptations during pregnancy and its link to placental function and fetal development remain poorly understood. Herein, multisegment injection-capillary electrophoresis-mass spectrometry is used as a high throughput metabolomics platform to characterize lyophilized placental tissue (~2 mg dried weight) from C57BL/6J mice fed a standardized diet. Over 130 authentic metabolites were consistently measured from placental extracts when using a nontargeted metabolomics workflow with stringent quality control and robust batch correction. Our work revealed distinct metabolic phenotype differences that exist between male (n = 14) and female (n = 14) placentae collected at embryonic day E18.5. Intracellular metabolites associated with fatty acid oxidation and purine degradation were found to be elevated in females as compared to male placentae (p 0.40), including uric acid, valerylcarnitine, hexanoylcarnitine, and 3-hydroxyhexanolycarnitine. This murine model sheds new insights into sex-specific differences in placental mitochondrial function and protective mechanisms against deleterious oxidative stress that may impact fetal growth and birth outcomes later in life.

Maternal undernutrition decreases sperm production in male offspring, possibly through insulin-like growth factor (IGF-I). To test this hypothesis, we fed pregnant Wistar rats ad libitum with a standard diet (CONTROL) or fed 50% of CONTROL intake, either throughout pregnancy (UNP), lactation (UNL, or both (UNPL). After weaning, male offspring (n = 10 per treatment) were fed a standard diet until postnatal day 160, when testes process for histological and molecular analyses. IGF-I immunostaining area and intensity in the testis were greater (P = 0.003) in the UNPL group compared to CONTROL, but lower in the UNP group (P < 0.0001). Levels of IGF-I receptor transcript were lower in the UNPL and UNL groups, compared to CONTROL. There were more Ki-67-positive germ and Sertoli cells, in all underfed groups than in CONTROL. Compared to CONTROL, frequency of spermatogenic cycle stage VII was lower in all underfed groups, and seminiferous tubule diameter was smaller in UNP and UNPL. Plasma FSH concentrations were greater in UNP male offspring compared to all groups (P = 0.05), whereas inhibin B concentrations were greater in UNP (P = 0.01) and UNL (P = 0.003) than in CONTROL or UNPL. Thus, prenatal undernutrition leads to a decrease in testicular IGF-I levels, whereas of pre- and postnatal undernutrition increased testicular IGF-I levels and decreased amounts of IGF-I receptor mRNA in adult offspring. We conclude that maternal undernutrition during pregnancy and lactation leads to long-lasting effects on adult male offspring testicular morphology, spermatogenesis, and IGF-I testicular system.

It is now well established that, beyond its role in nutrient processing and absorption, the intestine and its accompanying gut microbiome constitute a major site of immunological and endocrine regulation that mediates whole-body metabolism. Despite the growing field of host-microbe research, few studies explore what mechanisms govern this relationship in the context of pregnancy. During pregnancy, significant maternal metabolic adaptations are made to accommodate the additional energy demands of the developing fetus and to prevent adverse pregnancy outcomes. Recent data suggest that the maternal gut microbiota may play a role in these adaptations, but changes to maternal gut physiology and the underlying intestinal mechanisms remain unclear. In this review, we discuss selective aspects of intestinal physiology including the role of the incretin hormone, glucagon-like peptide 1 (GLP-1), and the role of the maternal gut microbiome in the maternal metabolic adaptations to pregnancy. Specifically, we discuss how bacterial components and metabolites could mediate the effects of the microbiota on host physiology, including nutrient absorption and GLP-1 secretion and action, and whether these mechanisms may change maternal insulin sensitivity and secretion during pregnancy. Finally, we discuss how these pathways could be altered in disease states during pregnancy including maternal obesity and diabetes.

Paternal obesity predisposes offspring to metabolic dysfunction, but the underlying mechanisms remain unclear. We investigated whether this metabolic dysfunction is associated with changes in placental vascular development and is fueled by endoplasmic reticulum (ER) stress-mediated changes in fetal hepatic development. We also determined whether paternal obesity indirectly affects the in utero environment by disrupting maternal metabolic adaptations to pregnancy. Male mice fed a standard chow or high fat diet (60%kcal fat) for 8–10 weeks were time-mated with female mice to generate pregnancies and offspring. Glucose tolerance was evaluated in dams at mid-gestation (embryonic day (E) 14.5) and late gestation (E18.5). Hypoxia, angiogenesis, endocrine function, macronutrient transport, and ER stress markers were evaluated in E14.5 and E18.5 placentae and/or fetal livers. Maternal glucose tolerance was assessed at E14.5 and E18.5. Metabolic parameters were assessed in offspring at ~60 days of age. Paternal obesity did not alter maternal glucose tolerance but induced placental hypoxia and altered placental angiogenic markers, with the most pronounced effects in female placentae. Paternal obesity increased ER stress-related protein levels (ATF6 and PERK) in the fetal liver and altered hepatic expression of gluconeogenic factors at E18.5. Offspring of obese fathers were glucose intolerant and had impaired whole-body energy metabolism, with more pronounced effects in female offspring. Metabolic deficits in offspring due to paternal obesity may be mediated by sex-specific changes in placental vessel structure and integrity that contribute to placental hypoxia and may lead to poor fetal oxygenation and impairments in fetal metabolic signaling pathways in the liver.

Obesity and diabetes increase circulating levels of microbial components derived from the gut microbiota. Individual bacterial factors (i.e., postbiotics) can have opposing effects on metabolic inflammation and blood glucose control. We tested the net effect of gut bacterial extracts on blood glucose using a microbiota-based vaccination strategy in mice. Male and female mice had improved insulin sensitivity and blood glucose control five weeks after a single subcutaneous injection of a specific dose of a bacterial extract obtained from the luminal contents of the proximal gut. Injection of mice with proximal gut extracts from germ-free mice revealed that bacteria were required for a microbiota-based vaccination to improve blood glucose control. Vaccination ofNod1−/−,Nod2−/−, andRipk2−/−mice showed that each of these innate immune proteins was required for bacterial extract injection to improve blood glucose control. A microbiota-based vaccination promoted a proximal gut immunoglobulin-G (IgG) response directed against bacterial extract antigens, where subcutaneous injection of mice with the luminal contents of the ileum elicited a bacterial extract-specific IgG response that is compartmentalized to the ileum of vaccinated mice. A microbiota-based vaccination was associated with an altered the microbiota composition in the ileum and colon of mice. Lean mice required a single injection of proximal gut bacterial extracts, but high fat diet (HFD)-fed, obese mice required prime-boost bacterial extract injections for improvements in blood glucose control. These data show that, upon subversion of the gut barrier, vaccination with proximal gut bacterial extracts engages innate immunity to promote long-lasting improvements in blood glucose control in a dose-dependent manner.

Objective:Maternal obesity is associated with obesity and metabolic disorders in offspring. However, there remains a paucity of data on strategies to reverse the effects of maternal obesity on maternal and offspring health. With maternal undernutrition, taurine supplementation improves outcomes in offspring mediated in part via improved glucose–insulin homeostasis. The efficacy of taurine supplementation in the setting of maternal obesity on health and well-being of offspring is unknown. We examined the effects of taurine supplementation on outcomes related to growth and metabolism in offspring in a rat model of maternal obesity.Design:Wistar rats were randomised to: 1) control diet during pregnancy and lactation (CON); 2) CON with 1.5% taurine in drinking water (CT); 3) maternal obesogenic diet (MO); or 4) MO with taurine (MOT). Offspring were weaned onto the control diet for the remainder of the study.Results:At day 150, offspring body weights and adipose tissue weights were increased in MO groups compared to CON. Adipose tissue weights were reduced in MOT versus MO males but not females. Plasma fasting leptin and insulin were increased in MO offspring groups but were not altered by maternal taurine supplementation. Plasma homocysteine concentrations were reduced in all maternal taurine-supplemented offspring groups. There were significant interactions across maternal diet, taurine supplementation and sex for response to an oral glucose tolerance test , a high-fat dietary preference test and pubertal onset in offspring.Conclusions:These results demonstrate that maternal taurine supplementation can partially ameliorate adverse developmental programming effects in offspring in a sex-specific manner.

We investigated whether diet-induced changes in the maternal intestinal microbiota were associated with changes in bacterial metabolites and their receptors, intestinal inflammation, and placental inflammation at mid-gestation (E14.5) in female mice fed a control (17% kcal fat, n = 7) or a high-fat diet (HFD 60% kcal fat, n = 9; ad libitum) before and during pregnancy. Maternal diet-induced obesity (mDIO) resulted in a reduction in maternal fecal short-chain fatty acid producing Lachnospiraceae, lower cecal butyrate, intestinal antimicrobial peptide levels, and intestinal SCFA receptor Ffar3, Ffar2 and Hcar2 transcript levels. mDIO increased maternal intestinal pro-inflammatory NFκB activity, colonic CD3+ T cell number, and placental inflammation. Maternal obesity was associated with placental hypoxia, increased angiogenesis, and increased transcript levels of glucose and amino acid transporters. Maternal and fetal markers of gluconeogenic capacity were decreased in pregnancies complicated by obesity. We show that mDIO impairs bacterial metabolite signaling pathways in the mother at mid-gestation, which was associated with significant structural changes in placental blood vessels, likely as a result of placental hypoxia. It is likely that maternal intestinal changes contribute to adverse maternal and placental adaptations that, via alterations in fetal hepatic glucose handling, may impart increased risk of metabolic dysfunction in offspring.

People exposed to adverse childhood experiences (ACEs) suffer from an increased risk of chronic disease and shorter lifespan. These individuals also tend to exhibit accelerated reproductive development and show signs of advanced cellular aging as early as childhood. These observations suggest that ACEs may accelerate biological processes of aging through direct or indirect mechanisms; however, few population-based studies have data to test this hypothesis. We analysed ACEs and biological aging data from the Canadian Longitudinal Study on Aging (CLSA; n = 23,354 adults aged 45-85) and used the BioAge R package to compute three indices of biological aging from blood-chemistry and organ-function data: Klemera-Doubal method (KDM) biological age, phenotypic age (PA), and homeostatic dysregulation (HD). Adults with ACEs tended to be biologically older than those with no ACEs, although the observed effect-sizes were small (Cohen's d0.15), with the exception of neglect (d=0.35 for KDM and PA). Associations were similar for men and women and tended to be smaller for older as compared to midlife participants. Subtypes of ACEs perceived as being more severe (e.g., being pushed or kicked, experiencing forced sexual activity, witnessing physical violence) and more frequent and diverse exposures were associated with relatively larger effect-sizes. These findings support the hypothesis that ACEs contribute to accelerated biological aging, although replication is needed in studies with access to prospective records of ACEs and cellular-level measurements of biological aging. Furthermore, future work to better understand the degree to which associations between ACEs and biological aging are moderated by specific life-course pathways, and mediated by lifestyle and socioeconomic factors is warranted.

Chronic low-grade systemic inflammation in obesity contributes to the development and progression of aspects of metabolic syndrome. In obese male mice, expanded adipose tissue releases proinflammatory cytokines, including TNF, which promotes an increase in immature, proinflammatory, peripheral blood Ly-6Chigh monocytes. The aim of this study was to characterize how TNF alters circulating cellular immunity in female mice with diet-induced obesity. We initially quantified peripheral blood immune cells by flow cytometry in female wild-type C57BL/6J mice after 3–30 wk of allocation to a high-fat (HF) or standard chow diet. We assessed effects of diet and time on neutrophil, monocyte, B cell, NK cell, CD4+ T cell, and CD8+ T cell populations. There was a significant interaction of the effects of diet type and time on the numbers and prevalence of circulating total monocytes and Ly-6Chigh, Ly-6Clow, and Ly-6C− subsets. Circulating monocytes, in particular Ly-6Chigh monocytes, were increased in HF-fed mice compared with chow-fed mice. Ly-6Chigh monocytes from HF-fed mice also had a more immature phenotype yet were highly responsive to the chemotactic ligand CCL2 and had greater intracellular production of TNF. Comparisons of the effects of HF diet feeding in littermate wild-type (TNF+/+) and TNF−/− female mice showed that genetic ablation of TNF did not protect from higher adiposity or an increase in circulating, immature, proinflammatory Ly-6Chigh monocytes during HF diet–induced obesity. These data emphasize the importance of considering biological sex when determining the mechanisms of TNF action in obesity-induced cellular inflammation and in other chronic inflammatory conditions.

Paternal obesity predisposes offspring to metabolic dysfunction, but the underlying mechanisms remain unclear. We investigated whether paternal obesity-induced offspring metabolic dysfunction is associated with placental endoplasmic reticulum (ER) stress and impaired vascular development. We determined whether offspring glucose intolerance is fueled by ER stress-mediated changes in fetal hepatic development. Furthermore, we also determined whether paternal obesity may indirectly affect in utero development by disrupting maternal metabolic adaptations to pregnancy. Male mice fed a standard chow diet (CON; 17% kcal fat) or high fat diet (PHF; 60% kcal fat) for 8-10 weeks were time-mated with control female mice to generate pregnancies and offspring. Glucose tolerance in pregnant females was evaluated at mid-gestation (embryonic day (E) 14.5) and term gestation (E18.5). At E14.5 and E18.5, fetal liver and placentae were collected, and markers of hypoxia, angiogenesis, endocrine function, and macronutrient transport, and unfolded protein response (UPR) regulators were evaluated to assess ER stress. Young adult offspring glucose tolerance and metabolic parameters were assessed at ∼60 days of age. Paternal obesity did not alter maternal glucose tolerance or placental lactogen in pregnancy but did induce placental hypoxia, ER stress, and altered placental angiogenesis. This effect was most pronounced in placentae associated with female fetuses. Consistent with this, paternal obesity also activated the ATF6 and PERK branches of the UPR in fetal liver and altered hepatic expression of gluconeogenic factors at E18.5. Adult offspring of obese fathers showed glucose intolerance and impaired whole-body energy metabolism, particularly in female offspring. Thus, paternal obesity programs sex-specific adverse placental structural and functional adaptations and alters fetal hepatic development via ER stress-induced pathways. These changes likely underpin metabolic deficits in adult offspring.Summary SentencePaternal obesity alters placental vascular structures and is associated with sex-specific compromises in glucose tolerance and metabolism in young offspring

Objectives Gestational weight gain (GWG) is increasingly monitored in the United States and Canada. While promoting healthy GWG offers benefits, there may be costs with over-surveillance. We aimed to explore these costs/benefits. Methods Quantitative data from 350 pregnant survey respondents and qualitative focus group data from 43 pregnant/post-partum and care-provider participants were collected in the Mothers to Babies (M2B) study in Hamilton, Canada. We report descriptive statistics and discussion themes on GWG trajectories, advice, knowledge, perceptions, and pregnancy diet. Relationships between GWG monitoring/normalization and worry, knowledge, diet quality, and sociodemographics-namely low-income and racialization-were assessed using χ2 tests and a linear regression model and contextualized with focus group data. Results Most survey respondents reported GWG outside recommended ranges but rejected the mid-20th century cultural norm of "eating for two"; many worried about gaining excessively. Conversely, respondents living in very low-income households were more likely to be gaining less than recommended GWG and to worry about gaining too little. A majority had received advice about GWG, yet half were unable to identify the range recommended for their prepregnancy BMI. This proportion was even lower for racialized respondents. Pregnancy diet quality was associated with household income, but not with receipt or understanding of GWG guidance. Care-providers encouraged normalized GWG, while worrying about the consequences of pathologizing "abnormal" GWG. Conclusions Translation of GWG recommendations should be done with a critical understanding of GWG biological normalcy. Supportive GWG monitoring and counseling should consider clinical, socioeconomic, and community contexts.

Microbial colonization of the human intestine impacts host metabolism and immunity, however when colonization occurs is unclear. Although numerous studies have reported bacterial DNA in first-pass meconium samples, these samples are collected hours to days after birth. We investigated whether bacteria could be detected in meconium prior to birth. Fetal meconium (n = 20) was collected by rectal swab during elective breech Cesarean sections without labour prior to antibiotics and compared to technical and procedural controls (n = 5), first-pass meconium (neonatal meconium; n = 14), and infant stool (n = 25). Unlike first-pass meconium, no microbial signal distinct from negative controls was detected in fetal meconium by 16S rRNA gene sequencing. Additionally, positive aerobic (n = 10 of 20) and anaerobic (n = 12 of 20) clinical cultures of fetal meconium (13 of 20 samples positive in at least one culture) were identified as likely skin contaminants, most frequently Staphylococcus epidermidis, and not detected by sequencing in most samples (same genera detected by culture and sequencing in 2 of 13 samples with positive culture). We conclude that fetal gut colonization does not occur before birth, and that microbial profiles of neonatal meconium reflect populations acquired during and after birth.

Objective:To disrupt cycles of health inequity, traceable to dietary inequities in the earliest stages of life, public health interventions should target improving nutritional wellbeing in preconception/pregnancy environments. This requires a deep engagement with pregnant/postpartum people (PPP) and their communities (including their health and social care providers, HSCP). We sought to understand the factors that influence diet during pregnancy from the perspectives of PPP and HSCP, and to outline intervention priorities.Design:We carried out thematic network analyses of transcripts from ten focus group discussions (FGD) and one stakeholder engagement meeting with PPP and HSCP in a Canadian city. Identified themes were developed into conceptual maps, highlighting local priorities for pregnancy nutrition and intervention development.Setting:FGD and the stakeholder meeting were run in predominantly lower socioeconomic position (SEP) neighbourhoods in the sociodemographically diverse city of Hamilton, Canada.Participants:All local, comprising twenty-two lower SEP PPP and forty-three HSCP.Results:Salient themes were resilience, resources, relationships and the embodied experience of pregnancy. Both PPP and HSCP underscored that socioeconomic-political forces operating at multiple levels largely determined the availability of individual and relational resources constraining diet during pregnancy. Intervention proposals focused on cultivating individual and community resilience to improve early-life nutritional environments. Participants called for better-integrated services, greater income supports and strengthened support programmes.Conclusions:Hamilton stakeholders foregrounded social determinants of inequity as main factors influencing pregnancy diet. They further indicated a need to develop interventions that build resilience and redistribute resources at multiple levels, from the household to the state.

We tested whether changes in Sertoli cell transcription factors and germ cell heat shock proteins (HSPs) are linked to the effects of maternal undernutrition on male offspring fertility. Rats were fed ad libitum with a standard diet (CONTROL) throughout pregnancy and lactation or with 50% of CONTROL intake throughout pregnancy (UNP) or lactation (UNL) or both periods (UNPL). After postnatal Day 21, 10 male pups per group were fed a standard diet ad libitum until postnatal Day 160 when testes were processed for histological, mRNA and immunohistochemical analyses. Compared with CONTROL: caspase-3 was increased in UNP and UNPL (P = 0.001); Bax was increased in UNL (P = 0.002); Bcl-2 (P

Key points Traditionally the female sex, compared with the male sex, has been perceived as having greater variability in many physiological traits, including within the immune system. We investigated effects of biological sex and the female reproductive cycle on numbers of circulating leukocytes in C57BL/6J mice. We show that biological sex, but not female reproductive cyclicity, has a significant effect on peripheral blood immune cell prevalence and variability, and that sex differences were not consistent amongst common inbred laboratory mouse strains. We found that male C57BL/6J mice, compared with female mice, have greater variability in peripheral blood immunophenotype, and that this was influenced by body weight. We created summary tables for researchers to facilitate experiment planning and sample size calculations for peripheral immune cells that consider the effects of biological sex. Abstract Immunophenotyping (i.e. quantifying the number and types of circulating leukocytes) is used to characterize immune changes during health and disease, and in response to pharmacological and other interventions. Despite the importance of biological sex in immune function, there is considerable uncertainty amongst researchers as to the extent to which biological sex or the female reproductive cycle influence blood immunophenotype. We quantified circulating leukocytes by multicolour flow cytometry in young C57BL/6J mice and assessed the effects of the reproductive cycle, biological sex, and other experimental and biological factors on data variability. We found that there are no significant effects of the female reproductive cycle on the prevalence of peripheral blood B cells, NK cells, CD4+ T cells, CD8+ T cells, monocytes, or neutrophils. Immunophenotype composition and variability do not significantly change between stages of the female reproductive cycle. There are, however, sex-specific differences in immune cell prevalence, with fewer monocytes, neutrophils, and NK cells in female mice. Surprisingly, immunophenotype is more variable in male mice, and weight is a significant contributing factor. We provide tools for researchers to perform a priori sample size calculations for two-group and factorial analyses. We show that immunophenotype varies between inbred mouse strains, and that using equal sample sizes of male and female mice is not always appropriate for within-sex evaluations of immune cell populations in peripheral blood.

Systematic reviews and meta-analyses suggest that behaviour change interventions have modest effect sizes, struggle to demonstrate effect in the long term and that there is high heterogeneity between studies. Such interventions take huge effort to design and run for relatively small returns in terms of changes to behaviour.So why do behaviour change interventions not work and how can we make them more effective? This article offers some ideas about what may underpin the failure of behaviour change interventions. We propose three main reasons that may explain why our current methods of conducting behaviour change interventions struggle to achieve the changes we expect: 1) our current model for testing the efficacy or effectiveness of interventions tends to a mean effect size. This ignores individual differences in response to interventions; 2) our interventions tend to assume that everyone values health in the way we do as health professionals; and 3) the great majority of our interventions focus on addressing cognitions as mechanisms of change. We appeal to people’s logic and rationality rather than recognising that much of what we do and how we behave, including our health behaviours, is governed as much by how we feel and how engaged we are emotionally as it is with what we plan and intend to do.Drawing on our team’s experience of developing multiple interventions to promote and support health behaviour change with a variety of populations in different global contexts, this article explores strategies with potential to address these issues.

Objective Obesity and diabetes increase circulating levels of microbial components derived from the gut microbiota. Individual bacterial factors (i.e., postbiotics) can have opposing effects on blood glucose. Methods We tested the net effect of gut bacterial extracts on blood glucose in mice using a microbiota-based vaccination strategy. Results Male and female mice had improved glucose and insulin tolerance five weeks after a single subcutaneous injection of a specific dose of a bacterial extract obtained from the luminal contents of the upper small intestine (SI), lower SI, or cecum. Injection of mice with intestinal extracts from germ-free mice revealed that bacteria were required for a microbiota-based vaccination to improve blood glucose control. Vaccination of Nod1−/−, Nod2−/−, and Ripk2−/− mice showed that each of these innate immune proteins was required for bacterial extract injection to improve blood glucose control. A microbiota-based vaccination promoted an immunoglobulin-G (IgG) response directed against bacterial extract antigens, where subcutaneous injection of mice with the luminal contents of the lower SI elicited a bacterial extract-specific IgG response that is compartmentalized to the lower SI of vaccinated mice. A microbiota-based vaccination was associated with an altered microbiota composition in the lower SI and colon of mice. Lean mice only required a single injection of small intestinal-derived bacterial extract, but high fat diet (HFD)-fed, obese mice required prime-boost bacterial extract injections for improvements in blood glucose control. Conclusions Subversion of the gut barrier by vaccination with a microbiota-based extract engages innate immunity to promote long-lasting improvements in blood glucose control in a dose-dependent manner., Graphical abstract Image 1, Highlights • Subcutaneous injection of gut bacterial extracts improved blood glucose control in mice. • Microbiota-based vaccination engaged NOD1-NOD2-RIPK2 to alter blood glucose. • Microbiota-based vaccination promoted a proximal gut IgG response. • Microbiota-based vaccination altered the composition of the gut microbiome. • Obese mice required prime-boost injections to improve blood glucose control.

Histological examination of the rat placenta and fetus is uncommon. Toxicological studies mainly rely on gross examination of the fetus and on fetal and placental weights. These are often insufficient to assess the fetal and placental toxicity of xenobiotics. The small size of the fetus makes its dissection labor-intensive. Thus, our objective was to develop a simple and accurate technique to evaluate the rat fetus and placenta. Sprague-Dawley rat fetuses at gestational day 19.5 ( n = 18) and their placentas ( n = 32) were fixed in formalin. Placentas were cut transversally in the center. Fetuses were cut following a freehand whole-body serial sectioning diagram adapted from Wilson’s method. Sections were stained with hematoxylin–eosin–phloxine–saffron, and histomorphometry was used to measure the area of the fetal placental region (27.2 ± 1.7 mm2), including the labyrinth (22.2 ± 1.0 mm2) and the basal zone (4.8 ± 0.8 mm2). Our whole-fetus serial sectioning technique resulted in 12 precise cutting planes that fit on 3 histological slides, enabling the examination of most organs without labor-intensive dissection. Quantitative analysis of placental areas improves the understanding of the pathogenesis of treatment-related changes. This technique provides a standardized method for future research in pertinent fields such as developmental biology and toxicology.

Environmental factors affecting development through embryogenesis, pregnancy, and infancy impact health through all subsequent stages of life. Known as the Developmental Origins of Health and Disease (DOHaD) hypothesis, this concept is widely accepted among health and social scientists. However, it is unclear whether DOHaD-based ideas are reaching the general public and/or influencing behaviour. This study thus investigated whether and under what circumstances pregnant people in Canada are familiar with DOHaD, and if DOHaD familiarity relates to eating behaviour. Survey responses from pregnant people from Hamilton, Canada, were used to assess respondents' knowledge of DOHaD (hereafter, DOHaDKNOWLEDGE) compared with their knowledge of more general pregnancy health recommendations (Pregnancy GuidelineKNOWLEDGE). The survey also characterized respondents' pregnancy diet quality and sociodemographic profiles. We fit two multiple, linear, mixed regression models to the data, one with DOHaDKNOWLEDGE score as the dependent variable and the other with diet quality score as the dependent. In both models, responses were clustered by respondents' neighbourhoods. Complete, internally consistent responses were available for 330 study-eligible respondents. Relative to Pregnancy GuidelineKNOWLEDGE, respondents had lower, more variable DOHaDKNOWLEDGE scores. Additionally, higher DOHaDKNOWLEDGE was associated with higher socio-economic position, older age, and lower parity, independent of Pregnancy GuidelineKNOWLEDGE. Diet quality during pregnancy was positively associated with DOHaDKNOWLEDGE, adjusting for sociodemographic factors. A subset of relatively high socio-economic position respondents was familiar with DOHaD. Greater familiarity with DOHaD was associated with better pregnancy diet quality, hinting that translating DOHaD knowledge to pregnant people may motivate improved pregnancy nutrition and thus later-life health for developing babies.

Evidence supporting the Developmental Origins of Health and Disease (DOHaD) hypothesis indicates that improving early life environments can reduce non-communicable disease risks and improve health over the lifecourse. A widespread understanding of this evidence may help to reshape structures, guidelines and individual behaviors to better the developmental conditions for the next generations. Yet, few efforts have yet been made to translate the DOHaD concept beyond the research community. To understand why, and to identify priorities for DOHaD Knowledge Translation (KT) programs, we review here a portion of published descriptions of DOHaD KT efforts and critiques thereof. We focus on KT targeting people equipped to apply DOHaD knowledge to their everyday home or work lives. We identified 17 reports of direct-to-public DOHaD KT that met our inclusion criteria. Relevant KT programs have been or are being initiated in nine countries, most focusing on secondary school students or care-workers-in-training; few target parents-to-be. Early indicators suggest that such programs can empower participants. Main critiques of DOHaD KT suggest it may overburden mothers with responsibility for children’s health and health environments, minimizing the roles of other people and institutions. Simultaneously, though, many mothers-to-be seek reliable guidance on prenatal health and nutrition, and would likely benefit from engagement with DOHaD KT. We thus recommend emphasizing solidarity, and bringing together people likely to one day become parents (youth), people planning pregnancies, expecting couples, care workers and policymakers into empowering conversation about DOHaD and about the importance and complexity of early life environments.

It is well established that early life environmental signals, including nutrition, set the stage for long-term health and disease risk – effects that span multiple generations. This relationship begins early, in the periconceptional period and extends into embryonic, fetal and early infant phases of life. Now known as the Developmental Origins of Health and Disease (DOHaD), this concept describes the adaptations that a developing organism makes in response to early life cues, resulting in adjustments in homeostatic systems that may prove maladaptive in postnatal life, leading to an increased risk of chronic disease and/or the inheritance of risk factors across generations. Reproductive maturation and function is similarly influenced by early life events. This should not be surprising, since primordial germ cells are established early in life and thus vulnerable to early life adversity. A multitude of ‘modifying’ cues inducing developmental adaptations have been identified that result in changes in reproductive development and impairments in reproductive function. Many types of nutritional challenges including caloric restriction, macronutrient excess and micronutrient insufficiencies have been shown to induce early life adaptations that produce long-term reproductive dysfunction. Many pathways have been suggested to underpin these associations, including epigenetic reprogramming of germ cells. While the mechanisms still remain to be fully investigated, it is clear that a lifecourse approach to understanding lifetime reproductive function is necessary. Furthermore, investigations of the impacts of early life adversity must be extended to include the paternal environment, especially in epidemiological and clinical studies of offspring reproductive function.

Background: The mechanisms mediating the impacts of fetal growth restriction (FGR) on follicular development are commonly studied in mouse/rat models, where ovarian development occurs largely during the early postnatal period. These models have shown that FGR is associated with premature follicle loss, early pubertal onset, and accelerated ovarian aging. Whether the same occurs in precocious species is unknown. Objective: Since guinea pig follicle development occurs in utero in a manner consistent with human ovarian development, we sought to determine whether FGR had similar impacts on guinea pig ovarian development. Methods: Dunkin-Hartley guinea pig dams were randomized to receive a control (CON) or a nutrient-restricted diet (FGR) prior to conception until weaning. Offspring ovaries were collected at prepubertal (postnatal day [P] 25) and young adult (P110) time points. Results: Prepubertal offspring exposed to FGR showed little differences in ovarian transcript levels and follicle counts. Young adult FGR offspring, however, showed reductions in the number of transitioning, primary, and antral follicles, as well as corpora lutea. This loss in follicles was associated with reduced insulin-like growth factor receptor and growth differentiation factor-9 messenger RNA levels in FGR P110 offspring compared to CON. Conclusion: We demonstrate that FGR in guinea pigs is accompanied by perturbations in signaling pathways essential for proper follicle growth and manifests as reductions in growing follicles in offspring, but these changes do not manifest until postpuberty. These data support the fact that accelerated reproductive maturation/aging is a conserved phenotype that is associated with in utero nutritional adversity.

Acephate has been used extensively as an insecticide in agriculture. Its downstream sequelae are associated with hyperglycemia, lipid metabolism dysfunction, DNA damage, and cancer, which are rapidly growing epidemics and which lead to increased morbidity and mortality rates and soaring health-care costs. Developing interventions will require a comprehensive understanding of which excess insecticides during perinatal life can cause insulin resistance and type 2 diabetes. A Wistar rat animal model suggests that acephate exposure during pregnancy and lactation causes alterations in maternal glucose metabolism and programs the offspring to be susceptible to type 2 diabetes at adulthood. Therapeutic approaches based on preventive actions to food contaminated with insecticides during pregnancy and lactation could prevent new cases of type 2 diabetes.

To investigate effects of betamethasone on fetal growth and neonatal outcomes in twins.A retrospective cohort study was conducted of twins delivered at one center in Berlin, Germany, between 1993 and 2011. The betamethasone group included twin pregnancies with preterm labor, cervical shortening, preterm premature rupture of membranes, or vaginal bleeding, and exposure to betamethasone between 23(+5) and 33(+6) weeks. The control group included twin pregnancies with no betamethasone exposure matched for length at delivery. Fetal growth and neonatal anthropometric data were analyzed by twin-pair structure, dose, and gestational age (linear mixed model).Overall, 1922 live-born twin pairs (653 betamethasone group, 1269 controls) were included. Compared with controls, late-preterm twins exposed to betamethasone were lighter (mean difference -126g), had a smaller head circumference (-0.4cm), and a shorter body length (-0.8cm) after adjustment for confounders (P0.05). Female neonates from mixed or same-sex twin pairs had a lower birth weight than controls (betamethasone ≤16mg: -114g; betamethasone 24mg: -124g; betamethasone24mg: -187g), with no detectable improvement in neonatal morbidity (hyperbilirubinemia, respiratory distress, asphyxia) or mortality.Betamethasone reduced birth weight, head circumference, and length of female preterm neonates in twin pairs in a dose-dependent manner. The neonatal mortality and morbidity were not improved by betamethasone.

Background and Aims: Non-alcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS) share risk associations of adiposity and insulin resistance. We examined the impact of a PCOS diagnosis on the metabolic phenotype of adolescent girls with NAFLD and compared this to girls without PCOS or NAFLD and to age-matched boys. Methods: Community-based adolescents from the Raine Cohort participated in assessments for NAFLD (572 girls and 592 boys) and PCOS (244 girls). One hundred and ninety-nine girls attended both assessments. Results: Amongst the 199 girls, PCOS was diagnosed in 16.1% and NAFLD in 18.6%. NAFLD was diagnosed in 10.1% of the boys. NAFLD was more prevalent in girls with PCOS than girls without PCOS (37.5% vs 15.1%, P = 0.003). Girls with NAFLD plus PCOS had greater adiposity (waist circumference, body mass index, suprailiac skinfold thickness [SST], serum androgens, high-sensitivity C-reactive protein, ferritin, homeostasis model assessment for insulin resistance (HOMA-IR), and lower serum sex hormone binding globulin levels than girls with NAFLD without a PCOS diagnosis (all P

Prenatal glucocorticoids, commonly used in women at risk of preterm delivery, can predispose the newborn to disease in later life. Since male reproductive function is likely to reflect testis development during fetal life, we studied the effects of prenatal glucocorticoids on two key intra-testicular factors that play roles in cellular proliferation and differentiation, 3β-hydroxysteroid dehydrogenase (3β-HSD) and inhibin-α. Pregnant sheep (n=42) were treated with betamethasone (0.5 mg/kg) or saline (control) at 104, 111 and 118 days of gestation (DG). Testicular tissue was sampled from fetuses at 121 and 132DG, and from lambs at 45 and 90 postnatal days (PD). Within the betamethasone treated group, 3β-HSD immunostaining area was greater at 121DG than at 90PD (P=0.04), but the intensity of immunostaining was higher at 90PD than at 121DG (P=0.04), 132DG (P=0.04) and 45PD (P=0.03). Control animals showed no changes in 3β-HSD area or intensity of immunostaining. No significant differences were observed between treated and control animals in immunostaining area, but immunostaining was more intense in the treated group than in the control group at 90PD (P=0.03). For inhibin-α, the proportion of immunostaining area declined in treated offspring from 121DG to 45PD, in contrast to control values, but recovered fully by 90PD, concomitantly with the onset of spermatogenesis. In conclusion, prenatal betamethasone increased the postnatal testicular expression of inhibin-α but reduced the expression of 3β-HSD. These effects could compromise androgen-mediated testicular development and therefore adult capacity for spermatogenesis.

Inflammation contributes to obesity‐related hyperinsulinemia and insulin resistance, which often precede type 2 diabetes. Inflammation is one way that obesity can promote insulin resistance. It is not clear if the extent of obesity, hyperinsulinemia, or hyperglycemia, underpins changes in cellular immunity during diet‐induced obesity. In particular, the requirement for obesity or directionality in the relationship between insulin resistance and monocyte characteristics is poorly defined. Inflammatory cytokines such as tumor necrosis factor (TNF) can contribute to insulin resistance. It is unclear if TNF alters monocytosis or specific markers of cellular immunity in the context of obesity. We measured bone marrow and blood monocyte characteristics in WT and TNF −/− mice that were fed obesogenic, high fat (HF) diets. We also used hyperglycemic Akita mice and mice implanted with insulin pellets in order to determine if glucose or insulin were sufficient to alter monocyte characteristics. We found that diet‐induced obesity in male mice increased the total number of monocytes in blood, but not in bone marrow. Immature, inflammatory (Ly6Chigh) monocytes decreased within the bone marrow and increased within peripheral blood of HF‐fed mice. We found that neither hyperinsulinemia nor hyperglycemia was sufficient to induce the observed changes in circulating monocytes in the absence of diet‐induced obesity. In obese HF‐fed mice, antibiotic treatment lowered insulin and insulin resistance, but did not alter circulating monocyte characteristics. Fewer Ly6Chigh monocytes were present within the blood of HF‐fed TNF −/− mice in comparison to HF‐fed wild‐type (WT) mice. The prevalence of immature Ly6Chigh monocytes in the blood correlated with serum insulin and insulin resistance irrespective of the magnitude of adipocyte or adipose tissue hypertrophy in obese mice. These data suggest that diet‐induced obesity instigates a TNF‐dependent increase in circulating inflammatory monocytes, which predicts increased blood insulin and insulin resistance independently from markers of adiposity or adipose tissue expansion.

Key points Maternal obesity has been associated with shifts in intestinal microbiota, which may contribute to impaired barrier function Impaired barrier function may expose the placenta and fetus to pro-inflammatory mediators We investigated the impacts of diet-induced obesity in mice on maternal and fetal intestinal structure and placental vascularization Diet-induced obesity decreased maternal intestinal short chain fatty acids and their receptors, impaired gut barrier integrity and was associated with fetal intestinal inflammation. Placenta from obese mothers showed blood vessel immaturity, hypoxia, increased transcript levels of inflammation, autophagy and altered levels of endoplasmic reticulum stress markers. These data suggest that maternal intestinal changes probably contribute to adverse placental adaptations and also impart an increased risk of obesity in the offspring via alterations in fetal gut development. Abstract Shifts in maternal intestinal microbiota have been implicated in metabolic adaptations to pregnancy. In the present study, we generated cohorts of female C57BL/6J mice fed a control (17% kcal fat, n = 10-14) or a high-fat diet (HFD 60% kcal from fat, n = 10-14; ad libitum) aiming to investigate the impact on the maternal gut microbiota, intestinal inflammation and gut barrier integrity, placental inflammation and fetal intestinal development at embryonic day 18.5. HFD was associated with decreased relative abundances of short-chain fatty acid (SCFA) producing genera during pregnancy. These diet-induced shifts paralleled decreased maternal intestinal mRNA levels of SCFA receptor Gpr41, modestly decreased cecal butyrate, and altered mRNA levels of inflammatory cytokines and immune cell markers in the maternal intestine. Maternal HFD resulted in impaired gut barrier integrity, with corresponding increases in circulating maternal levels of lipopolysaccharide (LPS) and tumour necrosis factor. Placentas from HFD dams demonstrated blood vessel immaturity and hypoxia; decreased free carnitine, acylcarnitine derivatives and trimethylamine-N-oxide; and altered mRNA levels of inflammation, autophagy, and ER stress markers. HFD exposed fetuses had increased activation of nuclear factor-kappa B and inhibition of the unfolded protein response in the developing intestine. Taken together, these data suggest that HFD intake prior to and during pregnancy shifts the composition of the maternal gut microbiota and impairs gut barrier integrity, resulting in increased maternal circulating LPS, which may ultimate contribute to changes in placental vascularization and fetal gut development.

Shifts in maternal intestinal microbiota have been implicated in metabolic adaptations to pregnancy. In this study we investigated how high-fat diet intake impacts the maternal gut microbiota, intestinal inflammation and gut barrier integrity, placental inflammation, and fetal intestinal development at E18.5. High-fat diet (HFD) was associated with decreased relative abundancesof SCFA producing genera during pregnancy. These diet-induced shifts paralleled decreased maternal intestinal mRNA levels of SCFA receptor Gpr41, modestly decreased cecal butyrate, and altered mRNA levels of inflammatory cytokines and immune cell markers in the maternal intestine. Maternal HFD resulted inimpaired gut barrier integrity, with corresponding increases in circulating maternal levels of LPS and TNF.Placentafromhigh-fat fed damsdemonstrated blood vessel immatu-rityand hypoxia, decreased freecarnitine, acylcarnitine derivatives, TMAO, as well as altered mRNA levels of inflammation, autophagy and ER stress markers. HFD exposed fetuses had increased activation of NF-κB and inhibition of the unfolded protein response in the developing intestine. Together, these data suggest that high-fat diet intake prior to and during pregnancy shifts the composition of the maternal gut microbiota and impairs gut barrier integrity, resulting in increased maternal circulating LPS, which may ultimate contribute to changes in placental vasculariza-tion and fetal gut development.Funding informationFarncombe Family Digestive Health Research Institute (KMK); Canadian Institute of Health Research (CJB); Canada Research Chairs Program (MGS, DMS); Natural Sciences and Engineering Research Council of Canada, Genome Canada (PBM).