BCL2 and Cognitive impairment: Gas treatment improved cognitive deficits and Aβ deposition in APP/PS1 mice by inhibiting neuronal apoptosis via increasing the level of Bcl-2 and decreasing the level of Bax, increasing the expression levels of insulin-like growth factor-1(IGF-1) and cAMP response element-binding protein (CREB) in APP/PS1 mice, as well as rectifying the abnormal composition and structure of gut microbiota (Zhang Y. et al., 2023).