The role of gastrointestinal microbiota in childhood health and disease: A narrative review

ABSTRACT The human microbiota is a complex community of microorganisms living predominantly in the gastrointestinal tract. It plays a critical role in shaping childhood health and disease, affecting metabolic function, immune development, and neurological outcomes from infancy through adolescence. This review examines the current evidence on the formation and development of the gastrointestinal microbiota in children, as well as its impact on various health outcomes, through a comprehensive literature search of major databases, including clinical trials, original studies, systematic reviews, and meta-analyses. Studies reviewed showed that factors such as mode of delivery, breastfeeding, antibiotic exposure, diet, and environmental conditions significantly impact microbial composition and diversity. Disruptions in microbiota composition, termed dysbiosis, have been increasingly linked to a spectrum of pediatric disorders, including neurodevelopmental conditions (autism spectrum disorder and attention deficit hyperactivity disorder), type 1 diabetes, allergies, asthma, and obesity. Understanding the association between gut microbiota and host physiology is crucial for developing strategies that promote lifelong health, starting in early childhood, and could uncover opportunities for early interventions that enhance long-term health outcomes. Therapeutic approaches, such as fecal microbiota transplantation and targeted diets like the Mediterranean and low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diets, show promise for restoring microbial balance and improving health outcomes. This review is limited by study variability, including differences in assessment methods, age groups, and geographic populations. Much of the data is observational, restricting causal conclusions. Ongoing research, including structured longitudinal and interventional randomized controlled trials, is crucial for effectively applying microbiome science in pediatric care.