Embryonic Exposure to Tryptophan Yields Bullying Victimization via Reprogramming the Microbiota-Gut-Brain Axis in a Chicken Model

Abstract

Maternal metabolic disorder during early pregnancy may give rise to emotional and behavioral disorders in the child, vulnerable to bullying. Placental tryptophan fluctuation consequently disrupts offspring gut microbiome and brain neurogenesis with long-lasting physiological and social behavioral impacts. The aim of this study was to examine the hypothesis that the excess gestational tryptophan may affect children’s mental and physical development via modifying the microbiota-gut-brain axis, which lays the foundation of their mental status. Chicken embryo was employed due to its robust microbiota and independence of maternal influences during embryogenesis. The results indicated that embryonic tryptophan exposure reduced body weight and aggressiveness in the male offspring before and during adolescence. Additionally, the relative gut length and crypt depth were increased, while the villus/crypt ratio was decreased in tryptophan treated roosters, which was corresponding to the changes in the cecal microbiota composition. Furthermore, the catecholamine concentrations were increased in tryptophan group, which may be associated with the alterations in the gut microbiome and the gut-brain axis’s function. These changes may underlie the sociometric status of bullying; clarify how gestational tryptophan fluctuation compromises bullying and provide a strategy to prevent bullying by controlling dietary tryptophan and medication therapy during pregnancy.

Melatonin, a natural antioxidant therapy in spinal cord injury

“…For example, the damaged autonomic nervous system loses gastrointestinal sympathetic control, leading to insufficient intestinal motility and deficient mucosal secretions (Zhang C. et al, 2018). The gut microbiota works as a virtual endocrine organ, regulating mood and behaviors via the microbiota-gut-brain axis and immunity via the intestinal neuro-immune axis (Jacobson et al, 2021;Huang et al, 2022). Hence, SCI affects the behavior of the gastrointestinal system, alters the constitution of gut microbial community, and causes systemic disorders.…”

Effect of Pre- and Perinatal Factors and Infant Nutrition on the Intestinal Microbiota

“…One of the factors influencing gut microbiota disorders in children and brain development is placental tryptophan fluctuations, which can lead to adverse physiological and socio-behavioural consequences. Huang et al [ 21 ] investigated the hypothesis that the administration of tryptophan during pregnancy could affect children’s mental and physical development by modifying the microbiota–gut–brain axis (MGB), which underlies their mental state. Chicken embryos, whose microbiota are robust and independent from maternal influence, were used for this experiment.…”