Juehua Yu

Abstract The gut microbiota plays a pivotal role in human health by modulating physiological homeostasis and influencing the pathogenesis of various diseases. Recent studies have underscored the close relationship between neurotransmitters, which act as communication mediators between the gut and brain, and the development and treatment of multiple brain disorders.

1. Introduction Neurodevelopmental disorders (NDDs) are a group of diseases that affect brain development and function. Such disorders include autism spectrum disorder (ASD), developmental delay (DD), intellectual disability (ID), and attention deficit hyperactivity disorder (ADHD) (1, 2). NDDs represent a significant public health concern in society, affecting roughly 1–2.5% of children worldwide (3, 4).

1. Introduction The COVID-19 pandemic has become a global health crisis. Apart from the significant challenges to public health, the pandemic has serious impacts on individual’s mental health worldwide (1). The prevalence of psychological distress, depression, anxiety, and post-traumatic stress symptoms has significantly increased during the pandemic (2–5).