In this regard, Szklany et al. showed that supplementation of prebiotics, e.g., short-chain galacto-oligosaccharides (scGOS) and long-chain fructo-oligosaccharide (lcFOS), decreased the mRNA expression of Htr1A gene in the prefrontal cortex and also reduced anxiety-like and repetitive behaviors in mice57. Here, HTR1A is linked to Anxiety.