Dietary intervention rescues maternal obesity induced behavior deficits and neuroinflammation in offspring

Adipokines measured during pregnancy and at birth are associated with infant negative affect

BACKGROUND

Increased adiposity during pregnancy may be related to offspring risk for mental health disorders, although the biological mechanisms are poorly understood. One promising hypothesis is that factors secreted from adipocytes such as leptin and adiponectin may explain this association. The current study examined whether pregnancy or umbilical cord blood concentrations of leptin and/or adiponectin a) predict elevated infant negative affect at 6 months (an early life marker of risk for psychopathology); and b) help explain the association between pregnancy adiposity and increased infant negative affect.

METHODS

Data came from a prospective cohort (N = 305) of pregnant individuals and their offspring. Second trimester adiposity was assessed using air displacement plethysmography. Concentrations of leptin and adiponectin were measured in second trimester plasma and umbilical cord plasma. Infant negative affect was assessed by standardized observation at 6 months. Second trimester inflammation was assessed using a comprehensive panel of cytokines.

RESULTS

Lower second trimester adiponectin was associated with elevated infant negative affect, and mediated the effect of pregnancy adiposity on infant negative affect. This association was independent of the effect of second trimester inflammation. Umbilical cord leptin also predicted higher infant negative affect and mediated the association between pregnancy adiposity and infant negative affect.

CONCLUSIONS

This is the first study to link pregnancy adiponectin or cord blood leptin to infant markers of risk for psychopathology, and the first to demonstrate that these adipokines mediate the association between pregnancy adiposity and offspring behavioral outcomes, suggesting novel markers of risk and potential mechanisms of effect.

Maternal obesity alters fetal neuroinflammation in a murine model of preterm birth

BACKGROUND

Preterm birth from intrauterine infection is a leading cause of neonatal neurologic morbidity. Likewise, maternal obesity is associated with intra-amniotic infection and inflammation. Whether maternal obesity is a risk factor for fetal brain injury that occurs with premature birth remains unknown. This study hypothesized that maternal obesity intensifies fetal neuroinflammation in the setting of premature delivery.

OBJECTIVE

This study aimed to examine the influence of maternal obesity on perinatal neuroinflammatory responses that arise with preterm birth using a murine model.

STUDY DESIGN

Dams with obesity were generated via a high-fat diet that was maintained throughout pregnancy. In parallel, dams without obesity (normal) received a control diet. All dams were paired with males on normal diet. Pregnant dams were randomized to receive an intrauterine administration of bacterial endotoxin (lipopolysaccharide) or the vehicle (phosphate-buffered saline) on embryo day 15.5 of what is typically a 19- to 21-day gestation. Fetal brains were harvested 6 hours after intrauterine administrations, and the expressions of key inflammatory cytokines (Il1b, Il6, and Tnf) and panels of metabolic, immune, and inflammatory genes were analyzed.

RESULTS

With the phosphate-buffered saline, there was no difference in gene expression related to maternal obesity. There were substantial differences in Il6 and immune/inflammatory expression profiles in fetal brains from dams with obesity vs normal dams that received lipopolysaccharide. Few differences were observed among the metabolic genes examined under these conditions. The gene expression pattern associated with maternal obesity correlated with pathways related to white matter injury.

CONCLUSION

The expression of neuroinflammatory markers instigated by bacterial endotoxin via intrauterine lipopolysaccharide was greater in embryo brains obtained from dams with obesity. Expression profiles suggest that in combination with intrauterine inflammation, maternal obesity may increase the risk of fetal white matter injury. Further investigation is warranted to understand the relationship between maternal health and neurologic outcomes associated with prematurity.

Nutrition and the gut-brain axis in neonatal brain injury and development

Early nutritional exposures, including during embryogenesis and the immediate postnatal period, affect offspring outcomes in both the short- and long-term. Alterations of these modifiable exposures shape the developing gut microbiome, intestinal development, and even neurodevelopmental outcomes. A gut-brain axis exists, and it is intricately connected to early life feeding and nutritional exposures. Here, we seek to discuss the (1) origins of the gut-brain access and relationship with neurodevelopment, (2) components of human milk (HM) beyond nutrition and their role in the developing newborn, and (3) clinical application of nutritional practices, including fluid management and feeding on the development of the gut-brain axis, and long-term neurodevelopmental outcomes. We conclude with a discussion on future directions and unanswered questions that are critical to provide further understanding and insight into how clinicians and healthcare providers can optimize early nutritional practices to ensure children not only survive, but thrive, free of neurodevelopmental impairment.

Maternal high-fat diet-induced microbiota changes are associated with alterations in embryonic brain metabolites and adolescent behaviour

The developing central nervous system is highly sensitive to nutrient changes during the perinatal period, emphasising the potential impact of alterations of maternal diet on offspring brain development and behaviour. A growing body of research implicates the gut microbiota in neurodevelopment and behaviour. Maternal overweight and obesity during the perinatal period has been linked to changes in neurodevelopment, plasticity and affective disorders in the offspring, with implications for microbial signals from the maternal gut. Here we investigate the impact of maternal high-fat diet (mHFD)-induced changes in microbial signals on offspring brain development, and neuroimmune signals, and the enduring effects on behaviour into adolescence. We first demonstrate that maternal caecal microbiota composition at term pregnancy (embryonic day 18: E18) differs significantly in response to maternal diet. Moreover, mHFD resulted in the upregulation of microbial genes in the maternal intestinal tissue linked to alterations in quinolinic acid synthesis and elevated kynurenine levels in the maternal plasma, both neuronal plasticity mediators related to glutamate metabolism. Metabolomics of mHFD embryonic brains at E18 also detected molecules linked to glutamate-glutamine cycle, including glutamic acid, glutathione disulphide and kynurenine. During adolescence, the mHFD offspring exhibited increased locomotor activity and anxiety-like behaviour in a sex-dependent manner, along with upregulation of glutamate-related genes compared to controls. Overall, our results demonstrate that maternal exposure to high-fat diet results in microbiota changes, behavioural imprinting, altered brain metabolism and glutamate signalling during critical developmental windows during the perinatal period.

Cannabidiol improves maternal obesity-induced behavioral, neuroinflammatory and neurochemical dysfunctions in the juvenile offspring

Maternal obesity is associated with an increased risk of psychiatric disorders such as anxiety, depression, schizophrenia and autism spectrum disorder in the offspring. While numerous studies focus on preventive measures targeting the mothers, only a limited number provide practical approaches for addressing the damages once they are already established. We have recently demonstrated the interplay between maternal obesity and treatment with cannabidiol (CBD) on hypothalamic inflammation and metabolic disturbances, however, little is known about this relationship on behavioral manifestations and neurochemical imbalances in other brain regions. Therefore, here we tested whether CBD treatment could mitigate anxiety-like and social behavioral alterations, as well as neurochemical disruptions in both male and female offspring of obese dams. Female Wistar rats were fed a cafeteria diet for 12 weeks prior to mating, and during gestation and lactation. Offspring received CBD (50 mg/kg) from weaning for 3 weeks. Behavioral tests assessed anxiety-like manifestations and social behavior, while neuroinflammatory and neurochemical markers were evaluated in the prefrontal cortex (PFC) and hippocampus. CBD treatment attenuated maternal obesity-induced anxiety-like and social behavioral alterations, followed by rescuing effects on imbalanced neurotransmitter and endocannabinoid concentrations and altered expression of glial markers, CB1, oxytocin and dopamine receptors, with important differences between sexes. Overall, the findings of this study provide insight into the signaling pathways for the therapeutic benefits of CBD on neuroinflammation and neurochemical imbalances caused by perinatal maternal obesity in the PFC and the hippocampus, which translates into the behavioral manifestations, highlighting the sexual dimorphism encompassing both the transgenerational effect of obesity and the endocannabinoid system.

Advances in the etiology and neuroimaging of children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder in children, characterized by age-inappropriate inattention, hyperactivity, and impulsivity, which can cause extensive damage to children's academic, occupational, and social skills. This review will present current advancements in the field of attention deficit hyperactivity disorder, including genetics, environmental factors, epigenetics, and neuroimaging features. Simultaneously, we will discuss the highlights of promising directions for further study.

Influence of maternal high-fat diet on offspring's locomotor activity during anxiety-related behavioral tests: A systematic review

The aim of this review was to summarize and discuss the impact of a maternal high-fat diet on the locomotor activity of offspring during anxiety-related behavioral tests. A search was performed in the LILACS, Web of Science, SCOPUS and PUMBED databases, using the following inclusion criteria: studies in which rodent dams were submitted to a high-fat diet during gestation and/or lactation and in which the locomotor activity parameters of offspring were evaluated during an anxiety-related test. Twenty-three articles met these criteria and were included. Most studies, 14 out of 23, found that a maternal high-fat diet did not alter offspring locomotor activity. Six articles found that a maternal high-fat diet increased the locomotor activity of offspring, while three found decreased locomotion. This effect may be associated with the initial response to the test and the fact that it was the first day of exposure to the apparatus.

Neurodevelopmental Programming of Adiposity: Contributions to Obesity Risk

This review analyzes the published evidence regarding maternal factors that influence the developmental programming of long-term adiposity in humans and animals via the central nervous system (CNS). We describe the physiological outcomes of perinatal underfeeding and overfeeding and explore potential mechanisms that may mediate the impact of such exposures on the development of feeding circuits within the CNS-including the influences of metabolic hormones and epigenetic changes. The perinatal environment, reflective of maternal nutritional status, contributes to the programming of offspring adiposity. The in utero and early postnatal periods represent critically sensitive developmental windows during which the hormonal and metabolic milieu affects the maturation of the hypothalamus. Maternal hyperglycemia is associated with increased transfer of glucose to the fetus driving fetal hyperinsulinemia. Elevated fetal insulin causes increased adiposity and consequently higher fetal circulating leptin concentration. Mechanistic studies in animal models indicate important roles of leptin and insulin in central and peripheral programming of adiposity, and suggest that optimal concentrations of these hormones are critical during early life. Additionally, the environmental milieu during development may be conveyed to progeny through epigenetic marks and these can potentially be vertically transmitted to subsequent generations. Thus, nutritional and metabolic/endocrine signals during perinatal development can have lifelong (and possibly multigenerational) impacts on offspring body weight regulation.

Maternal pre-pregnancy weight status and gestational weight gain in association with child behavior: The mediating role of prenatal systemic inflammation

BACKGROUND AND AIMS

Maternal pre-pregnancy obesity and excessive gestational weight gain (EGWG) may predispose children to behavioral problems through increased prenatal inflammation. We investigated the association between maternal body mass index (BMI) and gestational weight gain (GWG), and child behavioral problems (primary aim), and the mediating role of prenatal inflammation (secondary aim).

METHODS

We used self-reported pre-pregnancy BMI and estimated-GWG data (N = 1137) from a longitudinal cohort study. Maternal serum C-reactive protein (CRP) was measured in the 3rd-trimester. Parent-reported Child Behavior Checklist (CBCL) was used to assess child internalizing and externalizing behaviors at 3-years-of-age. We used analysis of covariance (ANCOVA), multiple linear regression, and mediation analyses for data analysis.

RESULTS

Maternal obesity (F = 21.98, df 3836), EGWG (F = 6.53, df 2764), and their combination (F = 18.51, df 3764) were associated with the 3rd trimester CRP, but not child behavior in the whole sample. Maternal underweight was associated with withdrawal problems in all children (β = 0.56, 95%CI, 0.11,1.00) and aggressive behaviors in female children (β = 2.59, 95%CI, 0.28,4.91). Obesity had a significant association with externalizing behaviors in female children after controlling for maternal CRP (β = 3.72, 95%CI, 0.12,7.32). Both inadequate and EGWG were associated with somatic complaints in male children (β = 0.50, 95%CI, 0.05,0.95; β = 0.36, 95%CI, 0.01,0.71, respectively). Combined obesity/EGWG was associated with externalizing (β = 6.12, 95%CI, 0.53,11.70) and aggressive (β = 4.23, 95%CI, 0.90,7.56) behaviors in female children. We found no significant effects through CRP.

CONCLUSIONS

Maternal pre-pregnancy BMI and GWG showed sex-specific associations with child behavioral problems. Prenatal CRP, although increased in obesity and EGWG, did not mediate these associations.

Maternal Pregnancy and Pre-Pregnancy Weight and Behavioural Outcomes in Children

Reported associations of pre-pregnancy weight and/or gestational weight gain with offspring behavioural outcomes are inconsistent. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), this study aimed to examine these associations at five developmental stages between the ages of 3 and 16. Over 6800 mother-offspring pairs at age 3 and 3925 pairs at age 16 were included. Pre-pregnancy underweight was associated with a 22% increased risk of total behavioural difficulties (OR = 1.22, 95% CI 1.02-1.45). In separate analyses using the SDQ subscales, pre-pregnancy underweight was linked to a 37% (OR = 1.37, 95% CI 1.14-1.65) and 33% (OR = 1.33, 95% CI 1.01-1.76) increased risk of emotional symptoms and prosocial behaviour problems over time, respectively. While pre-pregnancy overweight was associated with an 11% (OR = 1.11, 95% CI 1.03-1.20) and 18% (OR = 1.18, 95% CI 1.03-1.36) increased risk of conduct and peer relationship problems, respectively, pregnancy obesity was associated with a 43% increased risk of emotional problems (OR = 1.43, 95% CI 1.16-1.77). We found no evidence of associations between gestational weight gain and child behaviour except for a reduced risk in prosocial behaviour problems (OR = 0.82, 95% CI 0.70-0.96). Our findings provide insights into the link between preconception BMI and child behaviour, underscoring the necessity for further research to validate these associations and elucidate underlying mechanisms.

Evaluating different models of maternal stress on stress-responsive systems in prepubertal mice

Introduction

Maternal adversity during pregnancy influences neurodevelopment in human and model animal offspring. Adversity can result from stressors coming from many different directions ranging from environmental to nutritional and physiological to immune (e.g., infection). Most stressors result in fetal overexposure to glucocorticoids that have been directly linked to long- and short-term negative impacts on neurological health of offspring. Neuropsychiatric diseases postulated to have fetal origins are diverse and include such things cardiovascular disease, obesity, affective disorders, and metabolic and immune disorders.

Methods

The experiments in the current study compare 3 stressors: prenatal exposure to dexamethasone (DEX), maternal high fat diet (HFD), and maternal caloric restriction (CR). Offspring of mothers with these treatments were examined prepubertally to evaluate stress responsiveness and stress-related behaviors in in male and female mice.

Results

Prenatal exposure to synthetic glucocorticoid, DEX, resulted in decreased neonatal body weights, reduced social interaction behavior, and hypoactive stress response offspring exposed to maternal DEX. Maternal CR resulted in decreased body weights and social interaction behavior in males and females and increased anxiety-like behavior and acute stress response only in males. HFD resulted in altered body weight gain in both sex offspring with decreased anxiety-like behavior in a female-biased manner.

Discussion

The idea that glucocorticoid responses to different stressors might serve as a common stimulus across stress paradigms is insufficient, given that different modes of prenatal stress produced differential effects. Opposite nutritional stressors produced similar outcomes for anxiety-like behavior in both sexes, social-like behavior in females, and a hyperactive adrenal stress response in males. One common theme among the three models of maternal stress (DEX, CR, and HFD) was consistent data showing their role in activating the maternal and fetal immune response. By tuning in on the more immediate immunological aspect on the developing fetus (e.g., hormones, cytokines), additional studies may tease out more direct outcomes of maternal stress in rodents and increase their translational value to human studies.

Supplementation of the maternal diet with Brazil nut (Bertholletia excelsa H.B.K.) prevents cognitive impairment in the offspring of obese mothers

Maternal obesity may trigger long-term neurodevelopmental disorders in offspring. Considering the benefits of the Brazil nut (Bertholletia excelsa H.B.K.), a rich source of nutrients such as selenium, this study aimed to evaluate its effect on the behavior of obese rat offspring and its relationship with oxidative stress. From 60 days of age until weaning, female Wistar rats were fed a high-fat diet (mHF) or an HF diet supplemented with 5% Brazil nut (mHF/BN), while control mothers (mCTL) were fed a standard diet or a standard diet supplemented with 5% Brazil nut (mBN). Male pups received a standard diet throughout life and, at 30 and 90 days old, were subjected to behavioral tasks to evaluate anxiety and cognition. Biochemical evaluations were performed at 90 days of age. No alterations were observed in the anxiety behavior of the offspring. However, the offspring of the mHF group (oHF) exhibited impaired short-term memory at 30 and 90 days of age and impaired long-term memory at 30 days. Short-term memory impairment was prevented by Brazil nuts in young rats (30 days). While the serum selenium concentration was reduced in the oHF group, the serum catalase concentration was reduced in all groups, without changes in lipid peroxidation or protein carbonylation. Brazil nut maternal diet supplementation prevented short- and long-term cognitive impairment in the offspring, which may be related to the selenium levels.

The microbiome-gut-brain axis in nutritional neuroscience

Emerging evidence is highlighting the microbiome as a key regulator of the effect of nutrition on gut-brain axis signaling. Nevertheless, it is not yet clear whether the impact of nutrition is moderating the microbiota-gut-brain interaction or if diet has a mediating role on microbiota composition and function to influence central nervous system function, brain phenotypes and behavior. Mechanistic evidence from cell-based in vitro studies, animal models and preclinical intervention studies are linking the gut microbiota to the effects of diet on brain function, but they have had limited translation to human intervention studies. While increasing evidence demonstrates the triangulating relationship between diet, microbiota, and brain function across the lifespan, future mechanistic and translational studies in the field of microbiota and nutritional neuroscience are warranted to inform potential strategies for prevention and management of several neurological, neurodevelopmental, neurodegenerative, and psychiatric disorders. This brief primer provides an overview of the most recent advances in the nutritional neuroscience - microbiome field, highlighting significant opportunities for future research.

A Maternal High-Fat Diet Causes Anxiety-Related Behaviors by Altering Neuropeptide Y1 Receptor and Hippocampal Volumes in Rat Offspring: the Potential Effect of N-Acetylcysteine

The children of obese mothers are known to have a high risk of obesity and metabolic disease and are prone to developing cognitive deficits, although the underlying mechanism is not yet fully understood. This study investigated the relationship between neuropeptide Y1 receptor (NPY1R) and anxiety-like behaviors in the hippocampi of male rat offspring exposed to maternal obesity and the potential neuroprotective effects of N-acetylcysteine (NAC). A maternal obesity model was created using a high-fat (60% k/cal) diet. NAC (150 mg/kg) was administered by intragastric gavage for 25 days in both the NAC and obesity + NAC (ObNAC) groups. All male rat offspring were subjected to behavioral testing on postnatal day 28, the end of the experiment. Stereological analysis was performed on hippocampal sections, while NPY1R expression was determined using immunohistochemical methods. Stereological data indicated significant decreases in the total volume of the hippocampus and CA1 and dentate gyrus (DG) regions in the obese (Ob) group (p < 0.01). Decreased NPY1R expression was observed in the Ob group hippocampus (p < 0.01). At behavioral assessments, the Ob group rats exhibited increased anxiety and less social interaction, although the ObNAC group rats exhibited stronger responses than the Ob group (p < 0.01). The study results show that NAC attenuated anxiety-like behaviors and NPY1R expression and also protected hippocampal volume against maternal obesity. The findings indicate that a decrease in NPY1R-positive neurons in the hippocampus of male rats due to maternal conditions may be associated with increased levels of anxiety and a lower hippocampal volume. Additionally, although there is no direct evidence, maintenance of NPY1R expression by NAC may be critical for regulating maternal obesity-induced anxiety-related behaviors and hippocampal structure.

A Potential Role for Neuroinflammation in ADHD

Attention deficit hyperactivity disorder (ADHD) is a neurobehavioural disorder in children and adolescents. Although increases in oxidative stress and disturbances of neurotransmitter system such as the dopaminergic and abnormalities in several brain regions have been demonstrated, the pathophysiology of ADHD is not fully understood. Nevertheless, ADHD involves several factors that have been associated with an increase in neuroinflammation. This chapter presents an overview of factors that may increase neuroinflammation and play a potential role in the development and pathophysiology of ADHD. The altered immune response, polymorphisms in inflammatory-related genes, ADHD comorbidity with autoimmune and inflammatory disorders and prenatal exposure to inflammation are associated with alterations in offspring brain development and are a risk factor; genetic and environmental risk factors that may increase the risk for ADHD and medications can increase neuroinflammation. Evidence of an association between these factors has been an invaluable tool for research on inflammation in ADHD. Therefore, evidence studies have made it possible to generate alternative therapeutic interventions using natural products as anti-inflammatories that could have great potential against neuroinflammation in ADHD.

Mapping trends and hotspot regarding gastrointestinal microbiome and neuroscience: A bibliometric analysis of global research (2002-2022)

BACKGROUND

Scholars have long understood that gastrointestinal microorganisms are intimately related to human disorders. The literature on research involving the gut microbiome and neuroscience is emerging. This study exposed the connections between gut microbiota and neuroscience methodically and intuitively using bibliometrics and visualization. This study's objectives were to summarize the knowledge structure and identify emerging trends and potential hotspots in this field.

MATERIALS AND METHODS

On October 18, 2022, a literature search was conducted utilizing the Web of Science Core Collection (WoSCC) database for studies on gut microbiota and neuroscience studies from 2002 to 2022 (August 20, 2022). VOSviewer and CiteSpace V software was used to conduct the bibliometrics and visualization analysis.

RESULTS

From 2002 to 2022 (August 20, 2022), 2,275 publications in the WoSCC database satisfied the criteria. The annual volume of publications has rapidly emerged in recent years (2016-2022). The most productive nation (n = 732, 32.18%) and the hub of inter-country cooperation (links: 38) were the United States. University College Cork had the most research papers published in this area, followed by McMaster University and Harvard Medical School. Cryan JF, Dinan TG, and Clarke G were key researchers with considerable academic influence. The journals with the most publications are "Neurogastroenterology and Motility" and "Brain Behavior and Immunity." The most cited article and co-cited reference was Cryan JF's 2012 article on the impact of gut microbiota on the brain and behavior. The current research hotspot includes gastrointestinal microbiome, inflammation, gut-brain axis, Parkinson's disease (PD), and Alzheimer's disease (AD). The research focus would be on the "gastrointestinal microbiome, inflammation: a link between obesity, insulin resistance, and cognition" and "the role of two important theories of the gut-brain axis and microbial-gut-brain axis in diseases." Burst detection analysis showed that schizophrenia, pathology, and psychiatric disorder may continue to be the research frontiers.

CONCLUSION

Research on "gastrointestinal microbiome, inflammation: a link between obesity, insulin resistance, and cognition" and "the role of two important theories of the gut-brain axis and microbial-gut-brain axis in diseases" will continue to be the hotspot. Schizophrenia and psychiatric disorder will be the key research diseases in the field of gut microbiota and neuroscience, and pathology is the key research content, which is worthy of scholars' attention.

Maternal gut microbiota mediate intergenerational effects of high-fat diet on descendant social behavior

Dysbiosis of the maternal gut microbiome during pregnancy is associated with adverse neurodevelopmental outcomes. We previously showed that maternal high-fat diet (MHFD) in mice induces gut dysbiosis, social dysfunction, and underlying synaptic plasticity deficits in male offspring (F₁). Here, we reason that, if HFD-mediated changes in maternal gut microbiota drive offspring social deficits, then MHFD-induced dysbiosis in F₁ female MHFD offspring would likewise impair F₂ social behavior. Metataxonomic sequencing reveals reduced microbial richness among female F₁ MHFD offspring. Despite recovery of microbial richness among MHFD-descendant F₂ mice, they display social dysfunction. Post-weaning Limosilactobacillus reuteri treatment increases the abundance of short-chain fatty acid-producing taxa and rescues MHFD-descendant F₂ social deficits. L. reuteri exerts a sexually dimorphic impact on gut microbiota configuration, increasing discriminant taxa between female cohorts. Collectively, these results show multigenerational impacts of HFD-induced dysbiosis in the maternal lineage and highlight the potential of maternal microbiome-targeted interventions for neurodevelopmental disorders.

Maternal Western-style diet reduces social engagement and increases idiosyncratic behavior in Japanese macaque offspring

Recent evidence in humans and animals indicates an association between maternal obesity and offspring behavioral outcomes. In humans, increased maternal body mass index has been linked to an increased risk of children receiving a diagnosis of early-emerging neurodevelopmental disorders such as Attention Deficit/Hyperactivity Disorder (ADHD) and/or Autism Spectrum Disorder (ASD). However, a limited number of preclinical studies have examined associations between maternal Western-Style Diet (mWSD) exposure and offspring social behavior. To our knowledge, this is the first study to investigate relationships between mWSD exposure and social behavior in non-human primates. Since aberrant social behavior is a diagnostic criterion for several neurodevelopmental disorders, the current study focuses on examining the influence of maternal nutrition and metabolic state on offspring social behavior in Japanese macaques (Macaca fuscata). We found that mWSD offspring initiated less affiliative social behaviors as well as proximity to a peer. Using path analysis, we found that the association between mWSD consumption and reduced offspring social engagement was statistically mediated by increased maternal interleukin (IL)-12 during the third trimester of pregnancy. Additionally, mWSD offspring displayed increased idiosyncratic behavior, which was related to alterations in maternal adiposity and leptin in the third trimester. Together, these results suggest that NHP offspring exposed to mWSD exhibit behavioral phenotypes similar to what is described in some early-emerging neurodevelopmental disorders. These results provide evidence that mWSD exposure during gestation may be linked to increased risk of neurodevelopmental disorders and provides targets for prevention and intervention efforts.

Maternal obesity and the impact of associated early-life inflammation on long-term health of offspring

The prevalence of obesity is increasingly common in the United States, with ~25% of women of reproductive age being overweight or obese. Metaflammation, a chronic low grade inflammatory state caused by altered metabolism, is often present in pregnancies complicated by obesity. As a result, the fetuses of mothers who are obese are exposed to an in-utero environment that has altered nutrients and cytokines. Notably, both human and preclinical studies have shown that children born to mothers with obesity have higher risks of developing chronic illnesses affecting various organ systems. In this review, the authors sought to present the role of cytokines and inflammation during healthy pregnancy and determine how maternal obesity changes the inflammatory landscape of the mother, leading to fetal reprogramming. Next, the negative long-term impact on offspring’s health in numerous disease contexts, including offspring’s risk of developing neuropsychiatric disorders (autism, attention deficit and hyperactive disorder), metabolic diseases (obesity, type 2 diabetes), atopy, and malignancies will be discussed along with the potential of altered immune/inflammatory status in offspring as a contributor of these diseases. Finally, the authors will list critical knowledge gaps in the field of developmental programming of health and diseases in the context of offspring of mothers with obesity, particularly the understudied role of hematopoietic stem and progenitor cells.

Pregnancy-induced maternal microchimerism shapes neurodevelopment and behavior in mice

Life-long brain function and mental health are critically determined by developmental processes occurring before birth. During mammalian pregnancy, maternal cells are transferred to the fetus. They are referred to as maternal microchimeric cells (MMc). Among other organs, MMc seed into the fetal brain, where their function is unknown. Here, we show that, in the offspring’s developing brain in mice, MMc express a unique signature of sensome markers, control microglia homeostasis and prevent excessive presynaptic elimination. Further, MMc facilitate the oscillatory entrainment of developing prefrontal-hippocampal circuits and support the maturation of behavioral abilities. Our findings highlight that MMc are not a mere placental leak out, but rather a functional mechanism that shapes optimal conditions for healthy brain function later in life.

During pregnancy, maternal cells are transferred to the fetus, where they can reach the developing brain. In this study, the authors demonstrate that these maternal cells play an important role in neurodevelopment.

Inflammatory Signatures of Maternal Obesity as Risk Factors for Neurodevelopmental Disorders: Role of Maternal Microbiota and Nutritional Intervention Strategies

Obesity is a main risk factor for the onset and the precipitation of many non-communicable diseases. This condition, which is associated with low-grade chronic systemic inflammation, is of main concern during pregnancy leading to very serious consequences for the new generations. In addition to the prominent role played by the adipose tissue, dysbiosis of the maternal gut may also sustain the obesity-related inflammatory milieu contributing to create an overall suboptimal intrauterine environment. Such a condition here generically defined as “inflamed womb” may hold long-term detrimental effects on fetal brain development, increasing the vulnerability to mental disorders. In this review, we will examine the hypothesis that maternal obesity-related gut dysbiosis and the associated inflammation might specifically target fetal brain microglia, the resident brain immune macrophages, altering neurodevelopmental trajectories in a sex-dependent fashion. We will also review some of the most promising nutritional strategies capable to prevent or counteract the effects of maternal obesity through the modulation of inflammation and oxidative stress or by targeting the maternal microbiota.

The impact of maternal high-fat diet on offspring neurodevelopment

A maternal high-fat diet affects offspring neurodevelopment with long-term consequences on their brain health and behavior. During the past three decades, obesity has rapidly increased in the whole human population worldwide, including women of reproductive age. It is known that maternal obesity caused by a high-fat diet may lead to neurodevelopmental disorders in their offspring, such as autism spectrum disorder, attention deficit hyperactivity disorder, anxiety, depression, and schizophrenia. A maternal high-fat diet can affect offspring neurodevelopment due to inflammatory activation of the maternal gut, adipose tissue, and placenta, mirrored by increased levels of pro-inflammatory cytokines in both maternal and fetal circulation. Furthermore, a maternal high fat diet causes gut microbial dysbiosis further contributing to increased inflammatory milieu during pregnancy and lactation, thus disturbing both prenatal and postnatal neurodevelopment of the offspring. In addition, global molecular and cellular changes in the offspring's brain may occur due to epigenetic modifications including the downregulation of brain-derived neurotrophic factor (BDNF) expression and the activation of the endocannabinoid system. These neurodevelopmental aberrations are reflected in behavioral deficits observed in animals, corresponding to behavioral phenotypes of certain neurodevelopmental disorders in humans. Here we reviewed recent findings from rodent models and from human studies to reveal potential mechanisms by which a maternal high-fat diet interferes with the neurodevelopment of the offspring.

Mediterranean Diet Reduces Social Isolation and Anxiety in Adult Female Nonhuman Primates

Dietary composition is associated with the differential prevalence of psychiatric disorders; the Western diet confers increased risk, while the Mediterranean diet appears to reduce risk. In nonhuman primates, anxiety-like behaviors and social isolation have been linked to both Western diet consumption and increased inflammatory disease risk, and recent evidence suggests that diet composition may affect immune system function in part through its effects on behavior. This is particularly important in the context of the global COVID-19 pandemic in which social isolation has been associated with disease. Here, we examined the effects of Western- and Mediterranean-like diets on social behavior in a randomized, 34-month preclinical trial in middle-aged female cynomolgus macaques (Macaca fascicularis). Diet induced rapid and persistent changes in a suite of behaviors. After just three months of experimental diet consumption, a composite measure of diet-altered behavior (DAB) significantly differed between the two diets (p = 0.014) and remained different throughout the 24-month experimental observation period (p = 2.2 × 10−8). Monkeys fed the Western diet spent more time alone (FDR = 4.4 × 10−5) and displayed more anxiety behavior (FDR = 0.048), whereas monkeys fed the Mediterranean diet spent more time resting (FDR = 0.0013), attentive (FDR = 0.017), and in body contact with groupmates (FDR = 4.1 × 10−8). These differences were largely due to changes in behavior of animals fed the Mediterranean diet, while Western-diet-fed-animals exhibited similar behaviors compared to the eight-month baseline period, during which all monkeys consumed a common laboratory diet. These observations provide experimental support in a nonhuman primate model, demonstrating a potential therapeutic benefit of the Mediterranean diet consumption to reduce social isolation and anxiety and thus mitigate social isolation-associated disorders that often accompany illness and disability.

Behavioral and Cognitive Consequences of Obesity in Parents and Offspring in Female and Male Rats: Implications of Neuroinflammation and Neuromodulation

Obesity is a rapidly growing public health concern that can create a family-wise burden. This study was aimed to investigate behavioral, cognitive, neuroinflammatory, and neuromodulatory consequences of the diet and parental obesity. Female and male Wistar albino rats were fed on either an obesogenic or standard diet for 12 weeks, beginning with weaning. Thereafter, the animals were matched and allowed to mate. Pups born to obese or normal parents received either the diet or standard chow to the same age. The obesogenic diet and/or parental obesity increased the locomotor activity in both females and males. The diet exhibited anxiolytic-like and antidepressant-like properties, and impaired short-term object memory as well as spatial memory. Interestingly, the obesogenic diet resulted in neuroinflammation only in naïve animals, but not in the ones with parental obesity. BDNF, SIRT1, and p53 expressions were decreased, whereas RelN expression was increased in the brain with the diet, regardless of parental obesity. Multi-factor analyses demonstrated that the obesogenic diet is the prominent influencer of cognitive, neuroinflammatory, and neuromodulatory results while parental obesity has an effect on spatial memory, neuroinflammation, and hippocampal RelN and p53 expressions. Here, we provided supporting evidence for detrimental cognitive and neuroinflammatory consequences of early life consumption of the obesogenic diet which accompanies alterations in neuromodulatory factors. Surprisingly, the diet was found beneficial against anxiety-like and depression-like behaviors, and additionally, parental obesity was demonstrated to impair some aspects of cognitive performance which appears unrelated to neuroinflammation.

Dietary fat: a potent microglial influencer

Poor nutrition, lack of exercise, and genetic predisposition all contribute to the growing epidemic of obesity. Overweight/obesity create an environment of chronic inflammation that leads to negative physiological and neurological outcomes, such as diabetes, cardiovascular disease, and anxiety/depression. While the whole body contributes to metabolic homeostasis, the neuroimmune system has recently emerged as a key regulator of metabolism. Microglia, the resident immune cells of the brain, respond both directly and indirectly to dietary fat, and the environment in which microglia develop contributes to their responsiveness later in life. Thus, high maternal weight during pregnancy may have consequences for microglial function in offspring. Here, we discuss the most recent findings on microglia signaling in overweight/obesity with a focus on perinatal programming.

Does obesity put your brain at risk?

BACKGROUND AND AIMS

The negative impact of obesity on the brain is an issue of increasing clinical interest. Hence, this review summarized evidence linking obesity with brain morphology (gray and white matter volume), brain function (functional activation and connectivity), and cognitive function.

METHODS

A criticals review of the relevant published English articles between 2008 and 2022, using PubMed, Google Scholar and Science Direct. Studies were included if (1) an experimental/intervention study was conducted (2) the experiment/intervention included both high fat diet or body weight, whether it could counteract the negative effect brain morphological or functional change. Critical analysis for a supporting study was also carried out.

RESULTS

Brain dysfunction can be recognized as result from neuroinflammation, oxidative stress, change in gut-brain hormonal functionality decrease regional blood flow or diminished hippocampal size and change in gut-brain hormonal functionality; which collectively translate into a cycle of deranged metabolic control and cognitive deficits, often obesity referred as changes in brain biochemistry and brain function. Recently, a few changes in brain structure and functions could be traced back even to obese children or adult. Evidence here suggested that obesity elicits early neuroinflammation effects, which likely disrupt the normal metabolism in hypothalamus, and hippocampus result from brain insulin resistance. The mechanisms of these robust effects are discussed herein.

CONCLUSION

Brain disease is inseparable from obesity itself and requires a better recognition to allow future therapeutic targeting for treatment of obesity. Additional research is needed to identify the best treatment targets and to identify if these changes reversible.

β-Glucan-Rich Extract of Gray Oyster Mushroom, Pleurotus pulmonarius, Improves Object Recognition Memory and Hippocampus Morphology in Mice Fed a High-Fat Diet

Obesity may cause behavioral alterations, while maternal obesity can contribute to metabolic disorders in subsequent generations. The effect of β-glucan-rich Pleurotus pulmonarius (βgPp) was investigated on mouse neurobehavior and hippocampus and its offspring's hippocampus development. Female ICR mice were fed with normal diet (ND), ND with βgPp, high-fat diet (HFD), or HFD with βgPp for 3 months followed by behavioral test and mating. Immunohistochemistry for the expression of neuronal nuclear protein (NeuN) and ionized calcium binding adaptor molecule-1 (Iba-1) in the hippocampus was carried out. βgPp significantly enhanced short-term object recognition memory in HFD-fed mice. βgPp also ameliorated the histological alterations and neuronal loss and increased Iba-1-positive microglia in the hippocampus regions of HFD-fed mice and their male offspring. These findings demonstrated that βgPp supplementation attenuated the effects of HFD on object recognition memory and the alterations on the hippocampal regions of maternal mice and their male offspring.

Perinatal diet and offspring anxiety: A scoping review

Health behaviors during pregnancy have an impact on the developing offspring. Dietary factors play a role in the development of mental illness: however, less is known about the impact of diet factors during pre-conception, gestation, and lactation on anxiety levels in offspring. This scoping review sought to systematically map the available research involving human and animal subjects to identify nutritional interventions which may have a harmful or protective effect, as well as identify gaps. Studies investigating an association between any perinatal diet pattern or diet constituent and offspring anxiety were included. The number of studies reporting an association with increased or decreased levels of anxiety were counted and presented in figures. A total of 55,914 results were identified as part of a larger scoping review, and 120 articles met the criteria for inclusion. A greater intake of phytochemicals and vitamins were associated with decreased offspring anxiety whereas maternal caloric restriction, protein restriction, reduced omega-3 consumption, and exposure to a high fat diet were associated with higher levels of offspring anxiety. Results were limited by a very large proportion of animal studies. High quality intervention studies involving human subjects are warranted to elucidate the precise dietary factors or constituents that modulate the risk of anxiety in offspring.

Animal Foetal Models of Obesity and Diabetes - From Laboratory to Clinical Settings

The prenatal period, during which a fully formed newborn capable of surviving outside its mother's body is built from a single cell, is critical for human development. It is also the time when the foetus is particularly vulnerable to environmental factors, which may modulate the course of its development. Both epidemiological and animal studies have shown that foetal programming of physiological systems may alter the growth and function of organs and lead to pathology in adulthood. Nutrition is a particularly important environmental factor for the pregnant mother as it affects the condition of offspring. Numerous studies have shown that an unbalanced maternal metabolic status (under- or overnutrition) may cause long-lasting physiological and behavioural alterations, resulting in metabolic disorders, such as obesity and type 2 diabetes (T2DM). Various diets are used in laboratory settings in order to induce maternal obesity and metabolic disorders, and to alter the offspring development. The most popular models are: high-fat, high-sugar, high-fat-high-sugar, and cafeteria diets. Maternal undernutrition models are also used, which results in metabolic problems in offspring. Similarly to animal data, human studies have shown the influence of mothers' diets on the development of children. There is a strong link between the maternal diet and the birth weight, metabolic state, changes in the cardiovascular and central nervous system of the offspring. The mechanisms linking impaired foetal development and adult diseases remain under discussion. Epigenetic mechanisms are believed to play a major role in prenatal programming. Additionally, sexually dimorphic effects on offspring are observed. Therefore, further research on both sexes is necessary.

DHA Supplementation of Obese Rats throughout Pregnancy and Lactation Modifies Milk Composition and Anxiety Behavior of Offspring

We investigated if supplementing obese mothers (MO) with docosahexaenoic acid (DHA) improves milk long-chain polyunsaturated fatty acid (LCPUFA) composition and offspring anxiety behavior. From weaning throughout pregnancy and lactation, female Wistar rats ate chow (C) or a high-fat diet (MO). One month before mating and through lactation, half the mothers received 400 mg DHA kg⁻¹ d⁻¹ orally (C+DHA or MO+DHA). Offspring ate C after weaning. Maternal weight, total body fat, milk hormones, and milk nutrient composition were determined. Pups’ milk nutrient intake was evaluated, and behavioral anxiety tests were conducted. MO exhibited increased weight and total fat, and higher milk corticosterone, leptin, linoleic, and arachidonic acid (AA) concentrations, and less DHA content. MO male and female offspring had higher ω-6/ ω-3 milk consumption ratios. In the elevated plus maze, female but not male MO offspring exhibited more anxiety. MO+DHA mothers exhibited lower weight, total fat, milk leptin, and AA concentrations, and enhanced milk DHA. MO+DHA offspring had a lower ω-6/ω-3 milk intake ratio and reduced anxiety vs. MO. DHA content was greater in C+DHA milk vs. C. Supplementing MO mothers with DHA improves milk composition, especially LCPUFA content and ω-6/ω-3 ratio reducing offspring anxiety in a sex-dependent manner.

How the placenta-brain lipid axis impacts the nutritional origin of child neurodevelopmental disorders: Focus on attention deficit hyperactivity disorder and autism spectrum disorder

Dietary fish is a rich source of omega-3 (n-3) fatty acids, and as such, is believed to have played an important role in the evolution of the human brain and its advanced cognitive function. The long chain polyunsaturated fatty acids, particularly the n-3 docosahexanoic acid (DHA), are critical for proper neurological development and function. Both low plasma DHA and obesity in pregnancy are associated with neurodevelopmental disorders such as attention deficit and hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in childhood, and n-3 supplementation has been shown to improve symptoms, as reviewed herein. The mechanisms underlying the connection between maternal obesity, n-3 fatty acid levels and offspring's neurological outcomes are poorly understood, but we review the evidence for a mediating role of the placenta in this relationship. Despite promising data that n-3 fatty acid supplementation mitigates the effect of maternal obesity on placental lipid metabolism, few clinical trials or animal studies have considered the neurological outcomes of offspring of mothers with obesity supplemented with n-3 FA in pregnancy.

Improving translational relevance: The need for combined exposure models for studying prenatal adversity

Prenatal environmental adversity is a risk factor for neurodevelopmental disorders (NDDs), with the neuroimmune environment proposed to play a role in this risk. Adverse maternal exposures are associated with cognitive consequences in the offspring that are characteristics of NDDs and simultaneous neuroimmune changes that may underlie NDD risk. In both animal models and human studies the association between prenatal environmental exposure and NDD risk has been shown to be complex. Maternal overnutrition/obesity and opioid use are two different examples of complex exposure epidemics, each with their own unique comorbidities. This review will examine maternal obesity and maternal opioid use separately, illustrating the pervasive comorbidities with each exposure to argue a need for animal models of compound prenatal exposures. Many of these comorbidities can impact neuroimmune function, warranting systematic investigation of combined exposures to begin to understand this complexity. While traditional approaches in animal models have focused on modeling a single prenatal exposure or second exposure later in life, a translational approach would begin to incorporate the most prevalent co-occurring prenatal exposures. Long term follow-up in humans is extremely challenging, so animal models can provide timely insight into neurodevelopmental consequences of complex prenatal exposures. Animal models that represent this translational context of comorbid exposures behind maternal obesity or comorbid exposures behind maternal opioid use may reveal potential synergistic neuroimmune interactions that contribute to cognitive consequences and NDD risk. Finally, translational co-exposure models can identify concerning exposure combinations to guide treatment in complex cases, and identify high risk children starting in the prenatal period where early interventions improve prognosis.

Alteration of the Early Development Environment by Maternal Diet and the Occurrence of Autistic-like Phenotypes in Rat Offspring

Epidemiological and preclinical studies suggest that maternal obesity increases the risk of autism spectrum disorder (ASD) in offspring. Here, we assessed the effects of exposure to modified maternal diets limited to pregnancy and lactation on brain development and behavior in rat offspring of both sexes. Among the studied diets, a maternal high-fat diet (HFD) disturbed the expression of ASD-related genes (Cacna1d, Nlgn3, and Shank1) and proteins (SHANK1 and TAOK2) in the prefrontal cortex of male offspring during adolescence. In addition, a maternal high-fat diet induced epigenetic changes by increasing cortical global DNA methylation and the expression of miR-423 and miR-494. As well as the molecular changes, behavioral studies have shown male-specific disturbances in social interaction and an increase in repetitive behavior during adolescence. Most of the observed changes disappeared in adulthood. In conclusion, we demonstrated the contribution of a maternal HFD to the predisposition to an ASD-like phenotype in male adolescent offspring, while a protective effect occurred in females.

Sphingolipid and Endocannabinoid Profiles in Adult Attention Deficit Hyperactivity Disorder

Genes encoding endocannabinoid and sphingolipid metabolism pathways were suggested to contribute to the genetic risk towards attention deficit hyperactivity disorder (ADHD). The present pilot study assessed plasma concentrations of candidate endocannabinoids, sphingolipids and ceramides in individuals with adult ADHD in comparison with healthy controls and patients with affective disorders. Targeted lipid analyses of 23 different lipid species were performed in 71 mental disorder patients and 98 healthy controls (HC). The patients were diagnosed with adult ADHD (n = 12), affective disorder (major depression, MD n = 16 or bipolar disorder, BD n = 6) or adult ADHD with comorbid affective disorders (n = 37). Canonical discriminant analysis and CHAID analyses were used to identify major components that predicted the diagnostic group. ADHD patients had increased plasma concentrations of sphingosine-1-phosphate (S1P d18:1) and sphinganine-1-phosphate (S1P d18:0). In addition, the endocannabinoids, anandamide (AEA) and arachidonoylglycerol were increased. MD/BD patients had increased long chain ceramides, most prominently Cer22:0, but low endocannabinoids in contrast to ADHD patients. Patients with ADHD and comorbid affective disorders displayed increased S1P d18:1 and increased Cer22:0, but the individual lipid levels were lower than in the non-comorbid disorders. Sphingolipid profiles differ between patients suffering from ADHD and affective disorders, with overlapping patterns in comorbid patients. The S1P d18:1 to Cer22:0 ratio may constitute a diagnostic or prognostic tool.

Western diet as a trigger of Alzheimer's disease: From metabolic syndrome and systemic inflammation to neuroinflammation and neurodegeneration

An excess of saturated fatty acids and simple sugars in the diet is a known environmental risk factor of Alzheimer's disease (AD) but the holistic view of the interacting processes through which such diet may contribute to AD pathogenesis is missing. We addressed this need through extensive analysis of published studies investigating the effects of western diet (WD) on AD development in humans and laboratory animals. We reviewed WD-induced systemic alterations comprising metabolic changes, induction of obesity and adipose tissue inflammation, gut microbiota dysbiosis and acceleration of systemic low-grade inflammation. Next we provide an overview of the evidence demonstrating that WD-associated systemic alterations drive impairment of the blood-brain barrier (BBB) and development of neuroinflammation paralleled by accumulation of toxic amyloid. Later these changes are followed by dysfunction of synaptic transmission, neurodegeneration and finally memory and cognitive impairment. We conclude that WD can trigger AD by acceleration of inflammaging, and that BBB impairment induced by metabolic and systemic inflammation play the central role in this process. Moreover, the concurrence of neuroinflammation and Aβ dyshomeostasis, which by reciprocal interactions drive the vicious cycle of neurodegeneration, contradicts Aβ as the primary trigger of AD. Given that in 2019 the World Health Organization recommended focusing on modifiable risk factors in AD prevention, this overview of the sequential, complex pathomechanisms initiated by WD, which can lead from peripheral disturbances to neurodegeneration, can support future prevention strategies.

Identification of the Ghrelin and Cannabinoid CB2 Receptor Heteromer Functionality and Marked Upregulation in Striatal Neurons from Offspring of Mice under a High-Fat Diet

Cannabinoids have been reported as orexigenic, i.e., as promoting food intake that, among others, is controlled by the so-called “hunger” hormone, ghrelin. The aim of this paper was to look for functional and/or molecular interactions between ghrelin GHSR1a and cannabinoid CB₂ receptors at the central nervous system (CNS) level. In a heterologous system we identified CB₂-GHSR1a receptor complexes with a particular heteromer print consisting of impairment of CB₂ receptor/G_i-mediated signaling. The blockade was due to allosteric interactions within the heteromeric complex as it was reverted by antagonists of the GHSR1a receptor. Cannabinoids acting on the CB₂ receptor did not affect cytosolic increases of calcium ions induced by ghrelin acting on the GHSR1a receptor. In situ proximity ligation imaging assays confirmed the expression of CB₂-GHSR1a receptor complexes in both heterologous cells and primary striatal neurons. We tested heteromer expression in neurons from offspring of high-fat-diet mouse mothers as they have more risk to be obese. Interestingly, there was a marked upregulation of those complexes in striatal neurons from siblings of pregnant female mice under a high-fat diet.

LPS tolerance prevents anxiety-like behavior and amygdala inflammation of high-fat-fed dams' adolescent offspring

Maternal high-fat diets (HFD) can generate inflammation in the offspring's amygdala, which can lead to anxiety-like behaviors. Conversely, lipopolysaccharide (LPS) tolerance can reduce neuroinflammation in the offspring caused by maternal high-fat diets. This study evaluated the combination of LPS tolerance and high-fat maternal diet on amygdala's inflammatory parameters and the anxiety-like behavior in adolescent offspring. Female pregnant Wistar rats received randomly a standard diet or a high-fat diet during gestation and lactation. On gestation days 8, 10, and 12, half of the females in each group were intraperitonially injected with LPS (0.1 mg.kg-1). After weaning, the male offspring (n = 96) were placed in individual boxes in standard conditions, and when 6 weeks-old, the animals underwent: Open-Field, Light/Dark Box, Elevated Plus-Maze, and Rotarod tests. When 50 days-old the offspring were euthanized and the amygdala removed for cytokine and redox status analysis. The offspring in the HFD group showed lower amygdala IL-10 levels, high IL-6/IL-10 ratio, and anxiety-like behaviors. These effects were attenuated in the HFD offspring submitted to LPS tolerance, which showed an anti-inflammatory compensatory response in the amygdala. Also, this group showed a higher activity of the enzyme catalase in the amygdala. In addition, receiving the combination of LPS tolerance and maternal HFD did not lead to anxiety-like behavior in the offspring. The results suggest that LPS tolerance attenuated amygdala inflammation through an anti-inflammatory compensatory response besides preventing anxiety-like behavior caused by the high-fat maternal diet.

Mismatch between obesogenic intrauterine environment and low-fat postnatal diet may confer offspring metabolic advantage

OBJECTIVE

Mismatch between a depleted intrauterine environment and a substrate-rich postnatal environment confers an increased risk of offspring obesity and metabolic syndrome. Maternal diet-induced obesity (MATOB) is associated with the same outcomes. These experiments tested the hypothesis that a mismatch between a nutrient-rich intrauterine environment and a low-fat postnatal environment would ameliorate offspring metabolic morbidity.

METHODS

C57BL6/J female mice were fed either a 60% high-fat diet (HFD) or a 10% fat control diet (CD) for 14-week pre-breeding and during pregnancy/lactation. Offspring were weaned to CD. Weight was evaluated weekly; body composition was determined using EchoMRI. Serum fasting lipids and glucose and insulin tolerance tests were performed. Metabolic rate, locomotor, and sleep behavior were evaluated with indirect calorimetry.

RESULTS

MATOB-exposed/CD-weaned offspring of both sexes had improved glucose tolerance and insulin sensitivity compared to controls. Males had improved fasting lipids. Females had significantly increased weight and body fat percentage in adulthood compared to sex-matched controls. Females also had significantly increased sleep duration and reduced locomotor activity compared to males.

CONCLUSIONS

Reduced-fat dietary switch following intrauterine and lactational exposure to MATOB was associated with improved glucose handling and lipid profiles in adult offspring, more pronounced in males. A mismatch between a high-fat prenatal and low-fat postnatal environment may confer a metabolic advantage. The amelioration of deleterious metabolic programming by strict offspring adherence to a low-fat diet may have translational potential.

Neurobiological approaches of high-fat diet intake in early development and their impact on mood disorders in adulthood: A systematic review

The early stage of development is a vulnerable period for progeny neurodevelopment, altering cytogenetic and correct cerebral functionality. The exposure High-Fat Diet (HFD) is a factor that impacts the future mental health of individuals. This review analyzes possible mechanisms involved in the development of mood disorders in adulthood because of maternal HFD intake during gestation and lactation, considering previously reported findings in the last five years, both in humans and animal models. Maternal HFD could induce alterations in mood regulation, reported as increased stress response, anxiety-like behavior, and depressive-like behavior. These changes were mostly related to HPA axis dysregulations and neuroinflammatory responses. In conclusion, there could be a relationship between HFD consumption during the early stages of life and the development of psychopathologies during adulthood. These findings provide guidelines for the understanding of possible mechanisms involved in mood disorders, however, there is still a need for more human clinical studies that provide evidence to improve the understanding of maternal nutrition and future mental health outcomes in the offspring.

Diet-induced dysbiosis of the maternal gut microbiome in early life programming of neurodevelopmental disorders

The maternal gut microbiome plays a critical role in fetal and early postnatal development, shaping fundamental processes including immune maturation and brain development, among others. Consequently, it also contributes to fetal programming of health and disease. Over the last decade, epidemiological studies and work in preclinical animal models have begun to uncover a link between dysbiosis of the maternal gut microbiome and neurodevelopmental disorders in offspring. Neurodevelopmental disorders are caused by both genetic and environmental factors, and their interactions; however, clinical heterogeneity, phenotypic variability, and comorbidities make identification of underlying mechanisms difficult. Among environmental factors, exposure to maternal obesity in utero confers a significant increase in risk for neurodevelopmental disorders. Obesogenic diets in humans, non-human primates, and rodents induce functional modifications in maternal gut microbiome composition, which animal studies suggest are causally related to adverse mental health outcomes in offspring. Here, we review evidence linking maternal diet-induced gut dysbiosis to neurodevelopmental disorders and discuss how it could affect pre- and early postnatal brain development. We are hopeful that this burgeoning field of research will revolutionize antenatal care by leading to accessible prophylactic strategies, such as prenatal probiotics, to improve mental health outcomes in children affected by maternal diet-induced obesity.

High-fiber diet mitigates maternal obesity-induced cognitive and social dysfunction in the offspring via gut-brain axis

Maternal obesity has been reported to be related to neurodevelopmental disorders in the offspring. However, the underlying mechanisms and effective interventions remain unclear. This cross-sectional study with 778 children aged 7-14 years in China indicated that maternal obesity is strongly associated with children's lower cognition and sociality. Moreover, it has been demonstrated that maternal obesity in mice disrupted the behavior and gut microbiome in offspring, both of which were restored by a high-fiber diet in either dams or offspring via alleviating synaptic impairments and microglial maturation defects. Co-housing and feces microbiota transplantation experiments revealed a causal relationship between microbiota and behavioral changes. Moreover, treatment with the microbiota-derived short-chain fatty acids also alleviated the behavioral deficits in the offspring of obese dams. Together, our study indicated that the microbiota-metabolites-brain axis may underlie maternal obesity-induced cognitive and social dysfunctions and that high dietary fiber intake could be a promising intervention.

Maternal obesity and developmental programming of neuropsychiatric disorders: An inflammatory hypothesis

Maternal obesity is associated with the development of a variety of neuropsychiatric disorders; however, the mechanisms behind this association are not fully understood. Comparison between maternal immune activation and maternal obesity reveals similarities in associated impairments and maternal cytokine profile. Here, we present a summary of recent evidence describing how inflammatory processes contribute towards the development of neuropsychiatric disorders in the offspring of obese mothers. This includes discussion on how maternal cytokine levels, fatty acids and placental inflammation may interact with foetal neurodevelopment through changes to microglial behaviour and epigenetic modification. We also propose an exosome-mediated mechanism for the disruption of brain development under maternal obesity and discuss potential intervention strategies.

Exposure to maternal high-fat diet induces extensive changes in the brain of adult offspring

Maternal environmental exposures, such as high-fat diets, diabetes and obesity, can induce long-term effects in offspring. These effects include increased risk of neurodevelopmental disorders (NDDs) including autism spectrum disorder (ASD), depression and anxiety. The mechanisms underlying these late-life neurologic effects are unknown. In this article, we measured changes in the offspring brain and determined which brain regions are sensitive to maternal metabolic milieu and therefore may mediate NDD risk. We showed that mice exposed to a maternal high-fat diet display extensive brain changes in adulthood despite being switched to a low-fat diet at weaning. Brain regions impacted by early-life diet include the extended amygdalar system, which plays an important role in reward-seeking behaviour. Genes preferentially expressed in these regions have functions related to feeding behaviour, while also being implicated in human NDDs, such as autism. Our data demonstrated that exposure to maternal high-fat diet in early-life leads to brain alterations that persist into adulthood, even after dietary modifications.

Understanding the Link Between Maternal Overnutrition, Cardio-Metabolic Dysfunction and Cognitive Aging

Obesity has long been identified as a global epidemic with major health implications such as diabetes and cardiovascular disease. Maternal overnutrition leads to significant health issues in industrial countries and is one of the risk factors for the development of obesity and related disorders in the progeny. The wide accessibility of junk food in recent years is one of the major causes of obesity, as it is low in nutrient content and usually high in salt, sugar, fat, and calories. An excess of nutrients during fetal life not only has immediate effects on the fetus, including increased growth and fat deposition in utero, but also has long-term health consequences. Based on human studies, it is difficult to discern between genetic and environmental contributions to the risk of disease in future generations. Consequently, animal models are essential for studying the impact of maternal overnutrition on the developing offspring. Recently, animal models provided some insight into the physiological mechanisms that underlie developmental programming. Most of the studies employed thus far have focused only on obesity and metabolic dysfunctions in the offspring. These studies have advanced our understanding of how maternal overnutrition in the form of high-fat diet exposure can lead to an increased risk of obesity in the offspring, but many questions remain open. How maternal overnutrition may increase the risk of developing brain pathology such as cognitive disabilities in the offspring and increase the risk to develop metabolic disorders later in life? Further, does maternal overnutrition exacerbate cognitive- and cardio-metabolic aging in the offspring?

Western Diet Consumption During Development: Setting the Stage for Neurocognitive Dysfunction

The dietary pattern in industrialized countries has changed substantially over the past century due to technological advances in agriculture, food processing, storage, marketing, and distribution practices. The availability of highly palatable, calorically dense foods that are shelf-stable has facilitated a food environment where overconsumption of foods that have a high percentage of calories derived from fat (particularly saturated fat) and sugar is extremely common in modern Westernized societies. In addition to being a predictor of obesity and metabolic dysfunction, consumption of a Western diet (WD) is related to poorer cognitive performance across the lifespan. In particular, WD consumption during critical early life stages of development has negative consequences on various cognitive abilities later in adulthood. This review highlights rodent model research identifying dietary, metabolic, and neurobiological mechanisms linking consumption of a WD during early life periods of development (gestation, lactation, juvenile and adolescence) with behavioral impairments in multiple cognitive domains, including anxiety-like behavior, learning and memory function, reward-motivated behavior, and social behavior. The literature supports a model in which early life WD consumption leads to long-lasting neurocognitive impairments that are largely dissociable from WD effects on obesity and metabolic dysfunction.

High-caloric or isocaloric maternal high-fat diets differently affect young-adult offspring behavior in anxiety-related tests and offspring sensitivity to acute fluoxetine

OBJECTIVE

to evaluate the influence of two maternal high-fat diets with different caloric contents on anxiety-like behavior in young-adult offspring and their sensitivity to acute fluoxetine.

METHODS

females Wistar rats were used and divided according to diet received during gestation and lactation: Control (CTR), high-fat/isocaloric (HI) and high-fat/high-caloric (HH). Offspring were subsequently divided into three subgroups according to acute administration of vehicle or fluoxetine (1 or 10 mg/kg). To assess animals' anxiety-like behaviors, three tests were used: open field (OF), elevated plus-maze (EPM) and free-exploratory paradigm (FEP).

RESULTS

In OF, HI and HH showed increased hyperactivity- and anxiety-related behaviors, HI being more hyperactive than HH. In response to fluoxetine, HI offspring decreased number of quadrants entered, decreased number of central entries and spent less time in rearing in peripheral areas, while HH offspring showed less time spent in rearing in the OF peripheral area. In EPM test, HI pups spent more time in closed arms than the HH pups. Fluoxetine decreased number of open arms entries for HI offspring and increased percentage of time spent in central area for HH animals. Maternal diet did not influence FEP test, neither HI nor HH presented a response after fluoxetine acute administration.

CONCLUSION

Maternal high-fat diets influence offspring anxiety-like behavior in state-anxiety tests but not in trait-anxiety test. Responsiveness to acute fluoxetine depended on maternal diet, dose and which behavioral tests were being evaluated.

Mechanisms Underlying the Cognitive and Behavioural Effects of Maternal Obesity

The widespread consumption of 'western'-style diets along with sedentary lifestyles has led to a global epidemic of obesity. Epidemiological, clinical and preclinical evidence suggests that maternal obesity, overnutrition and unhealthy dietary patterns programs have lasting adverse effects on the physical and mental health of offspring. We review currently available preclinical and clinical evidence and summarise possible underlying neurobiological mechanisms by which maternal overnutrition may perturb offspring cognitive function, affective state and psychosocial behaviour, with a focus on (1) neuroinflammation; (2) disrupted neuronal circuities and connectivity; and (3) dysregulated brain hormones. We briefly summarise research implicating the gut microbiota in maternal obesity-induced changes to offspring behaviour. In animal models, maternal obesogenic diet consumption disrupts CNS homeostasis in offspring, which is critical for healthy neurodevelopment, by altering hypothalamic and hippocampal development and recruitment of glial cells, which subsequently dysregulates dopaminergic and serotonergic systems. The adverse effects of maternal obesogenic diets are also conferred through changes to hormones including leptin, insulin and oxytocin which interact with these brain regions and neuronal circuits. Furthermore, accumulating evidence suggests that the gut microbiome may directly and indirectly contribute to these maternal diet effects in both human and animal studies. As the specific pathways shaping abnormal behaviour in offspring in the context of maternal obesogenic diet exposure remain unknown, further investigations are needed to address this knowledge gap. Use of animal models permits investigation of changes in neuroinflammation, neurotransmitter activity and hormones across global brain network and sex differences, which could be directly and indirectly modulated by the gut microbiome.

Maternal cafeteria diet exposure primes depression-like behavior in the offspring evoking lower brain volume related to changes in synaptic terminals and gliosis

Maternal nutritional programming by caloric exposure during pregnancy and lactation results in long-term behavioral modification in the offspring. Here, we characterized the effect of maternal caloric exposure on synaptic and brain morphological organization and its effects on depression-like behavior susceptibility in rats' offspring. Female Wistar rats were exposed to chow or cafeteria (CAF) diet for 9 weeks (pre-pregnancy, pregnancy, and lactation) and then switched to chow diet after weaning. By postnatal day 60, the male Wistar rat offspring were tested for depressive-like behavior using operational conditioning, novelty suppressed feeding, sucrose preference, and open-field test. Brain macro and microstructural morphology were analyzed using magnetic resonance imaging deformation-based morphometry (DBM) and western blot, immunohistochemistry for NMDA and AMPA receptor, synaptophysin and myelin, respectively. We found that the offspring of mothers exposed to CAF diet displayed deficient motivation showing decrease in the operant conditioning, sucrose preference, and suppressed feeding test. Macrostructural DBM analysis showed reduction in the frontomesocorticolimbic circuit volume including the nucleus accumbens (NAc), hippocampus, and prefrontal cortex. Microstructural analysis revealed reduced synaptic terminals in hippocampus and NAc, whereas increased glial fibrillary acidic protein in hippocampus and lateral hypothalamus, as well as a decrease in the hippocampal cell number and myelin reduction in the dentate gyrus and hilus, respectively. Also, offspring exhibited increase of the GluR1 and GLUR2 subunits of AMPA receptor, whereas a decrease in the mGluR2 expression in hippocampus. Our findings reveal that maternal programming might prime depression-like behavior in the offspring by modulating macro and micro brain organization of the frontomesocorticolimbic circuit.

Atypical Neocortical Development in the Cited2 Conditional Knockout Leads to Behavioral Deficits Associated with Neurodevelopmental Disorders

The mammalian neocortex develops from a single layer of neuroepithelial cells to form a six-layer heterogeneous mosaic of differentiated neurons and glial cells. This process requires a complex choreography of temporally and spatially restricted transcription factors and epigenetic regulators. Even subtle disruptions in this regulation can alter the way the neocortex forms and functions, leading to a neurodevelopmental disorder. One epigenetic regulator that is essential for the precise development of the neocortex is CITED2 (CBP/p300 Interacting Transactivator with ED-rich termini). Cited2 is highly expressed by intermediate progenitor cells in the subventricular zone during the generation of the superficial layers of the neocortex. A forebrain-specific conditional knockout of Cited2 (cKO) exhibits reduced proliferation of intermediate progenitor cells embryonically, leading to reduced thickness of the superficial layers and reduced corpus callosum (CC) volume postnatally. Further, the Cited2 cKO display disruptions in balanced neocortical arealization, with a specific reduction in the somatosensory neocortical length, and dysregulation of precise, area-specific neuronal connectivity. Here, we explore the behavioral consequences resulting from this aberrant neocortical development. We demonstrate that Cited2 cKO mice display decreased maternal separation-induced ultrasonic vocalizations (USVs) as neonates, and an increase in rearing behavior and lack of habituation following repeated acoustic startle as adults. They do not display alterations in anxiety-like behavior, overall locomotor activity, or social interactions. Together with the morphological, molecular, and connectivity disruptions, these results identify the Cited2 cKO neocortex as an ideal system to study mechanisms underlying neurodevelopmental and neuroanatomical disruptions with relevance to human neurodevelopmental disorders.