Changes in the metabolites involved in the BCAA pathway are known to influence the regulation of mTOR (Jewell and Guan, 2013; Zhenyukh et al., 2017), which plays a vital role in epidermal barrier formation and the signaling axis for the control of filaggrin as the fundamental pathophysiology of AD (Xda et al., 2020; Yang et al., 2014). This evidence concerns the gene FLG and Alzheimer disease.