scholarly journals Gut Reactions: How Far Are We from Understanding and Manipulating the Microbiota Complexity and the Interaction with Its Host? Lessons from Autism Spectrum Disorder Studies

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3492
Author(s):  
Martina Lombardi ◽  
Jacopo Troisi

Autism is a group of neurodevelopmental disorders, characterized by early onset difficulties in social communication and restricted, repetitive behaviors and interests. It is characterized by familial aggregation, suggesting that genetic factors play a role in disease development, in addition to developmentally early environmental factors. Here, we review the role of the gut microbiome in autism, as it has been characterized in case-control studies. We discuss how methodological differences may have led to inconclusive or contradictory results, even though a disproportion between harmful and beneficial bacteria is generally described in autism. Furthermore, we review the studies concerning the effects of gut microbial-based and dietary interventions on autism symptoms. Also, in this case, the results are not comparable due to the lack of standardized methods. Therefore, autism-specific microbiome signatures and, consequently, possible microbiome-oriented interventions are far from being recognized. We argue that a multi-omic longitudinal implementation may be useful to study metabolic changes connected to microbiome changes.

2020 ◽  
Vol 27 (31) ◽  
pp. 5119-5136 ◽  
Author(s):  
Barbara Carpita ◽  
Donatella Marazziti ◽  
Lionella Palego ◽  
Gino Giannaccini ◽  
Laura Betti ◽  
...  

Background: Autism Spectrum Disorder (ASD) is a condition strongly associated with genetic predisposition and familial aggregation. Among ASD patients, different levels of symptoms severity are detectable, while the presence of intermediate autism phenotypes in close relatives of ASD probands is also known in literature. Recently, increasing attention has been paid to environmental factors that might play a role in modulating the relationship between genomic risk and development and severity of ASD. Within this framework, an increasing body of evidence has stressed a possible role of both gut microbiota and inflammation in the pathophysiology of neurodevelopment. The aim of this paper is to review findings about the link between microbiota dysbiosis, inflammation and ASD. Methods: Articles ranging from 1990 to 2018 were identified on PUBMED and Google Scholar databases, with keyword combinations as: microbiota, immune system, inflammation, ASD, autism, broad autism phenotype, adult. Results: Recent evidence suggests that microbiota alterations, immune system and neurodevelopment may be deeply intertwined, shaping each other during early life. However, results from both animal models and human samples are still heterogeneous, while few studies focused on adult patients and ASD intermediate phenotypes. Conclusion: A better understanding of these pathways, within an integrative framework between central and peripheral systems, might not only shed more light on neural basis of ASD symptoms, clarifying brain pathophysiology, but it may also allow to develop new therapeutic strategies for these disorders, still poorly responsive to available treatments.


Author(s):  
Emily Neuhaus

Autism spectrum disorder (ASD) is defined by deficits in social communication and interaction, and restricted and repetitive behaviors and interests. Although current diagnostic conceptualizations of ASD do not include emotional difficulties as core deficits, the disorder is associated with emotion dysregulation across the lifespan, with considerable implications for long-term psychological, social, and educational outcomes. The overarching goal of this chapter is to integrate existing knowledge of emotion dysregulation in ASD and identify areas for further investigation. The chapter reviews the prevalence and expressions of emotion dysregulation in ASD, discusses emerging theoretical models that frame emotion dysregulation as an inherent (rather than associated) feature of ASD, presents neurobiological findings and mechanisms related to emotion dysregulation in ASD, and identifies continuing controversies and resulting research priorities.


Author(s):  
Viktor Román ◽  
Nika Adham ◽  
Andrew G. Foley ◽  
Lynsey Hanratty ◽  
Bence Farkas ◽  
...  

Abstract Rationale Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficits in social communication and interaction and restricted, repetitive behaviors. The unmet medical need in ASD is considerable since there is no approved pharmacotherapy for the treatment of these deficits in social communication, interaction, and behavior. Cariprazine, a dopamine D3-preferring D3/D2 receptor partial agonist, is already approved for the treatment of schizophrenia and bipolar I disorder in adults; investigation in patients with ASD is warranted. Objectives The aim of this study was to investigate the effects of cariprazine, compared with risperidone and aripiprazole, in the rat prenatal valporic acid (VPA) exposure model on behavioral endpoints representing the core and associated symptoms of ASD. Methods To induce the ASD model, time-mated Wistar rat dams were treated with VPA during pregnancy. Male offspring were assigned to groups and studied in a behavioral test battery at different ages, employing social play, open field, social approach-avoidance, and social recognition memory tests. Animals were dosed orally, once a day for 8 days, with test compounds (cariprazine, risperidone, aripiprazole) or vehicle before behavioral assessment. Results Cariprazine showed dose-dependent efficacy on all behavioral endpoints. In the social play paradigm, only cariprazine was effective. On the remaining behavioral endpoints, including the reversal of hyperactivity, risperidone and aripiprazole displayed similar efficacy to cariprazine. Conclusions In the present study, cariprazine effectively reversed core behavioral deficits and hyperactivity present in juvenile and young adult autistic-like rats. These findings indicate that cariprazine may be useful in the treatment of ASD symptoms.


Author(s):  
OJS Admin

Sensory issues and Repetitive Behaviors are the key features of Autism Disorder Syndrome (ASD). This is a neurodevelopmental condition marked by social communication impairments and the occurrence ofrestricted and repeated behavioral habits and desires, including irregular responses to sensory stimuli.


2018 ◽  
Author(s):  
Annelies van’t Westeinde ◽  
Élodie Cauvet ◽  
Roberto Toro ◽  
Ralf Kuja-Halkola ◽  
Janina Neufeld ◽  
...  

AbstractFemales with autism spectrum disorder have been reported to exhibit fewer and less severe restricted and repetitive behaviors and interests compared to males. This difference might indicate sex specific alterations of brain networks involved in autism symptom domains, especially within cortico-striatal and sensory integration networks. This study used a well-controlled twin design to examine sex differences in brain anatomy in relation to repetitive behaviors. In 75 twin pairs (n=150, 62 females, 88 males) enriched for autism spectrum disorder (n=32), and other neurodevelopmental disorders (n =32), we explored the association of restricted and repetitive behaviors and interests – operationalized by the Autism Diagnostic Interview-Revised (C domain) and the Social Responsiveness Scale-2 (Restricted Interests and Repetitive Behavior subscale), with cortical volume, surface area and thickness of neocortical, sub-cortical and cerebellar networks. Cotwin control analyses revealed within-pair associations between RRBI symptoms and the right intraparietal sulcus and right orbital gyrus in females only. These findings endorse the importance of investigating sex differences in the neurobiology of autism symptoms, and indicate different etiological pathways underlying restricted and repetitive behaviors and interests in females and males.


2016 ◽  
Vol 50 (3) ◽  
pp. 543-554 ◽  
Author(s):  
Filip Rybakowski ◽  
Izabela Chojnicka ◽  
Piotr Dziechciarz ◽  
Andrea Horvath ◽  
Małgorzata Janas-Kozik ◽  
...  

Author(s):  
Anna Kolesnik-Taylor ◽  
Emily Jones

Autism spectrum disorder (ASD) is characterized by difficulties in social communication and interaction, restrictive, and repetitive behaviors. The exact etiology of the condition is unknown, and the heterogeneity and the late emergence of characteristic symptoms of ASD limits our ability to identify infants and children who may require early intervention. One way to address the complexity of this condition is to examine early cognitive and brain development prior to the consolidation of behavioral symptoms at around 2–3 years. This chapter overviews early brain and cognitive development in ASD-relevant domains, and putative underlying brain mechanisms. Isolating critical features of early development may be used to reduce the diagnostic window and establish effective intervention options.


2019 ◽  
Vol 26 (35) ◽  
pp. 6341-6348 ◽  
Author(s):  
Brittany Pequegnat ◽  
Mario A. Monteiro

A large number of children in the autism spectrum disorder suffer from gastrointestinal (GI) conditions, such as constipation and diarrhea. Clostridium bolteae is a part of a set of pathogens being regularly detected in the stool samples of hosts affected by GI and autism symptoms. Accompanying studies have pointed out the possibility that such microbes affect behaviour through the production of neurotoxic metabolites in a so-called, gut-brain connection. As an extension of our Clostridium difficile polysaccharide (PS)-based vaccine research, we engaged in the discovery of C. bolteae surface carbohydrates. So far, studies revealed that C. bolteae produces a specific immunogenic PS capsule comprised of disaccharide repeating blocks of mannose (Manp) and rhamnose (Rhap) units: α-D-Manp-(1→[-4)-β-D-Rhap- (1→3)-α-D-Manp-(1→]n. For vaccinology and further immunogenic experiments, a method to produce C. bolteae PS conjugates has been developed, along with the chemical syntheses of the PS non-reducing end linkage, with D-Rha or L-Rha, α-D-Manp-(1→4)-α-D-Rhap- (1→O(CH2)5NH2 and α-D-Manp-(1→4)-α-L-Rhap-(1→O(CH2)5NH2, equipped with an aminopentyl linker at the reducing end for conjugation purposes. The discovery of C. bolteae PS immunogen opens the door to the creation of non-evasive diagnostic tools to evaluate the frequency and role of this microbe in autistic subjects and to a vaccine to reduce colonization levels in the GI tract, thus impeding the concentration of neurotoxins.


2011 ◽  
Vol 7 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Izumi Maezawa ◽  
Marco Calafiore ◽  
Heike Wulff ◽  
Lee-Way Jin

Autism spectrum disorders (ASDs) including classic autism is a group of complex developmental disabilities with core deficits of impaired social interactions, communication difficulties and repetitive behaviors. Although the neurobiology of ASDs has attracted much attention in the last two decades, the role of microglia has been ignored. Existing data are focused on their recognized role in neuroinflammation, which only covers a small part of the pathological repertoire of microglia. This review highlights recent findings on the broader roles of microglia, including their active surveillance of brain microenvironments and regulation of synaptic connectivity, maturation of brain circuitry and neurogenesis. Emerging evidence suggests that microglia respond to pre- and postnatal environmental stimuli through epigenetic interface to change gene expression, thus acting as effectors of experience-dependent synaptic plasticity. Impairments of these microglial functions could substantially contribute to several major etiological factors of autism, such as environmental toxins and cortical underconnectivity. Our recent study on Rett syndrome, a syndromic autistic disorder, provides an example that intrinsic microglial dysfunction due to genetic and epigenetic aberrations could detrimentally affect the developmental trajectory without evoking neuroinflammation. We propose that ASDs provide excellent opportunities to study the influence of microglia on neurodevelopment, and this knowledge could lead to novel therapies.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Edecio Cunha-Neto ◽  
Christophe Chevillard

Chagas disease, caused by the protozoanTrypanosoma cruzi, is endemic in Latin America and affects ca. 10 million people worldwide. About 30% of Chagas disease patients develop chronic Chagas disease cardiomyopathy (CCC), a particularly lethal inflammatory cardiomyopathy that occurs decades after the initial infection, while most patients remain asymptomatic. Mortality rate is higher than that of noninflammatory cardiomyopathy. CCC heart lesions present a Th1 T-cell-rich myocarditis, with cardiomyocyte hypertrophy and prominent fibrosis. Data suggest that the myocarditis plays a major pathogenetic role in disease progression. Major unmet goals include the thorough understanding of disease pathogenesis and therapeutic targets and identification of prognostic genetic factors. Chagas disease thus remains a neglected disease, with no vaccines or antiparasitic drugs proven efficient in chronically infected adults, when most patients are diagnosed. Both familial aggregation of CCC cases and the fact that only 30% of infected patients develop CCC suggest there might be a genetic component to disease susceptibility. Moreover, previous case-control studies have identified some genes associated to human susceptibility to CCC. In this paper, we will review the immunopathogenesis and genetics of Chagas disease, highlighting studies that shed light on the differential progression of Chagas disease patients to CCC.


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