Dr. Yiying Zhang have been studying neuropathogenesis, anesthesia neurotoxicity, anesthesia/surgery toxicity, postoperative neurocognitive disorder and postoperative delirium (POD) in Alzheimer’s disease (AD) since 2009. Specifically, Dr. Zhang have studied the effects of anesthetics on mitochondrial function in vitro and in vivo, as well as the potential association between neuroinflammation and mitochondrial function following the anesthesia and/or surgery. Recently, Dr. Zhang have focused on studying potential gut microbiota-neuroinflammation-mitochondria cascade in the pathogenesis of POD. Dr. Zhang’s investigation has independently built up the protocol/methods and demonstrated that there are age-dependent specific gut microbiota profile (microbiota dysbiosis), age-dependent mitochondrial dysfunction, and age-dependent POD-like behavior in the mice. Moreover, Dr. Zhang’s group found that the anesthesia/surgery was able to decrease gut lactobacillus and butyric acid in the aged mice, and the oral treatment of lactobacillus and probiotic was able to mitigate the POD-like behavior in the aged mice. Dr. Zhang’s research is funded by NIH. In addition, Dr. Zhang have applied and combined the nanobeam technology with protein purification methods to successfully measure fecal Amyloid beta (A) levels of the mice and in cells.