-
Frontiers in Neuroscience 2024Critical phases of neurodevelopment and gut microbiota diversification occur in early life and both processes are impacted by genetic and environmental factors. Recent...
Functional contribution of the intestinal microbiome in autism spectrum disorder, attention deficit hyperactivity disorder, and Rett syndrome: a systematic review of pediatric and adult studies.
INTRODUCTION
Critical phases of neurodevelopment and gut microbiota diversification occur in early life and both processes are impacted by genetic and environmental factors. Recent studies have shown the presence of gut microbiota alterations in neurodevelopmental disorders. Here we performed a systematic review of alterations of the intestinal microbiota composition and function in pediatric and adult patients affected by autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and Rett syndrome (RETT).
METHODS
We searched selected keywords in the online databases of PubMed, Cochrane, and OVID (January 1980 to December 2021) with secondary review of references of eligible articles. Two reviewers independently performed critical appraisals on the included articles using the Critical Appraisal Skills Program for each study design.
RESULTS
Our systematic review identified 18, 7, and 3 original articles describing intestinal microbiota profiles in ASD, ADHD, and RETT, respectively. Decreased Firmicutes and increased Bacteroidetes were observed in the gut microbiota of individuals affected by ASD and ADHD. Proinflammatory cytokines, short-chain fatty acids and neurotransmitter levels were altered in ASD and RETT. Constipation and visceral pain were related to changes in the gut microbiota in patients affected by ASD and RETT. Hyperactivity and impulsivity were negatively correlated with (phylum Firmicutes) and positively correlated with sp. (phylum Bacteroidetes) in ADHD subjects. Five studies explored microbiota-or diet-targeted interventions in ASD and ADHD. Probiotic treatments with sp. and fecal microbiota transplantation from healthy donors reduced constipation and ameliorated ASD symptoms in affected children. Perinatal administration of sp. prevented the onset of Asperger and ADHD symptoms in adolescence. Micronutrient supplementation improved disease symptomatology in ADHD without causing significant changes in microbiota communities' composition.
DISCUSSION
Several discrepancies were found among the included studies, primarily due to sample size, variations in dietary practices, and a high prevalence of functional gastrointestinal symptoms. Further studies employing longitudinal study designs, larger sample sizes and multi-omics technologies are warranted to identify the functional contribution of the intestinal microbiota in developmental trajectories of the human brain and neurobehavior.
SYSTEMATIC REVIEW REGISTRATION
https://clinicaltrials.gov/, CRD42020158734.
PubMed: 38516317
DOI: 10.3389/fnins.2024.1341656 -
Cureus Sep 2023Autism spectrum disorder is made up of several disorders, which include autism, Asperger syndrome, and pervasive developmental disorder. Boys are four times more likely... (Review)
Review
Autism spectrum disorder is made up of several disorders, which include autism, Asperger syndrome, and pervasive developmental disorder. Boys are four times more likely to be diagnosed than girls with autism spectrum disorder, and symptoms usually become apparent by the age of three. Autism spectrum disorders' core characteristic features are abnormal interaction, impairment in communication, and stereotyped behaviors with restricted activities and interests. There are also non-core features associated with autism spectrum disorder, and these are aggression, self-injurious behavior, and tantrums. To date, there is no one drug approved to treat the core symptoms of autism spectrum disorder, but antipsychotic drugs such as risperidone have been shown to be effective at treating both core and non-core symptoms in controlled trials using multiple behavioral rating scales such as the Aberrant Behavioral Checklist subscale, the Clinical Global Impression Improvement Scale, the Ritvo-Freeman Real Life Scale, the Children's Yale-Brown Obsessive Compulsive Scale, the Vineland Adaptive Behavior Scale, and the Social Withdrawal Subscale. The safety, efficacy, acceptability, and tolerability of risperidone were assessed in these studies, and weight gain was a common side effect observed, but the outcome was usually mild and self-limiting. The effect of risperidone on cognition was explored in this article. The studies selected for this article were of small sample size and short duration, which presented limitations for treatment with risperidone and an area that needs to be explored further for its contribution to clinical practice.
PubMed: 37731686
DOI: 10.7759/cureus.45524