Early-Life Microbiome and Neurodevelopmental Disorders: A Systematic Review and Meta-Analysis.

This research looked at how gut bacteria in early childhood might affect autism and ADHD development. Scientists reviewed 19 studies and found that children with autism had different gut bacteria patterns - more harmful Clostridium bacteria and less helpful Bifidobacterium bacteria. Children with ADHD also showed different bacterial patterns. While this suggests gut health might influence brain development, more long-term studies are needed to better understand these connections.

This systematic review and meta-analysis examined the relationship between early childhood gut microbiome and neurodevelopmental disorders, specifically autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). Analyzing 19 studies from 2,744 screened publications, researchers found consistent associations between gut microbiome dysbiosis and these conditions. Children with ASD showed increased Clostridium species and decreased Bifidobacterium species. ADHD cases were associated with decreased E. coli and increased Clostridia class, Firmicute phylum, Bifidobacterium genus, Akkermansia, and specific pathogenic species including Listeria monocytogenes and Toxoplasma gondii.

Study quality varied significantly according to Newcastle-Ottawa Scale assessment. The findings suggest gut microbial imbalances may contribute to neurodevelopmental disorder onset, though larger longitudinal studies are needed to strengthen evidence quality.

Findings suggest gut microbiome assessment and targeted interventions may have therapeutic potential for neurodevelopmental disorders. However, clinical applications should be cautious given methodological limitations. The research supports further investigation into probiotic therapies and dietary interventions targeting specific bacterial populations, particularly Bifidobacterium supplementation for ASD and microbiome modulation approaches for ADHD management.

Study quality varied significantly with some having serious methodological flaws according to Newcastle-Ottawa Scale assessment. Sample sizes and longitudinal follow-up periods were not clearly reported. The review acknowledges need for larger-scale longitudinal studies to improve evidence quality and establish causation.

This systematic review intends to find out how neurodevelopmental disorders, including Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD), are influenced by the gut microbiota throughout early childhood. The study looks at the variety and types of microbes that a child is exposed to, the particular microbiome profiles associated with neurodevelopmental outcomes, and the molecular processes that underlie these relationships. We performed a thorough search of PubMed, Scopus, the WHO Global Health Library (GHL), and ISI Web of Science. After screening 2,744 original studies based on predetermined eligibility criteria, 19 studies were included.

Microbial groupings, presence (high/low), and related neurodevelopmental disorders were among the primary areas of data extraction. The methodological quality of the studies was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). The investigated literature repeatedly showed a strong correlation between dysbiosis of the gut microbiota and neurodevelopmental disorders. Cases of ASD were associated with both a high number of Clostridium species and a low number of Bifidobacterium species.

On the other hand, a Low number of E. coli and a high number of the class Clostridia, phylum Firmicute, genus Bifidobacterium, and Akkermansia, as well as the species Listeria monocytogenes, Toxoplasma gondii, Streptococcus mutans, and Mycobacterium tuberculosis have been linked to ADHD. The NOS evaluation showed variation in the quality of the methodology; some studies had high scores, suggesting sound technique, while other studies had lower scores, indicating serious methodological flaws. The results highlight the potential impact of the gut microbiome throughout early life on neurodevelopmental outcomes, indicating that microbial imbalances may play a role in the onset of disorders like ASD and ADHD. However, to improve the quality of data, larger-scale longitudinal studies would be required.