慢性萎缩性胃炎（CAG）是消化系统常见病，气味改变是其特征。课题组前期研究表明：阵列式气体传感器电子鼻可以灵敏地判断慢性胃炎常见证候的气味差异。本项目在此基础上，以360例CAG患者为对象，60例健康者为对照，采用证素辨证方法，将CAG患者分为气滞、湿热、气虚、阳虚、阴虚、血瘀6组，开展以下研究：①运用电子鼻采集口腔呼气和粪便气味图谱，基于深度特征学习提取CAG不同病性的气味图谱特征；②采用13C尿素呼气试验（13C-UBT）和16S rDNA测序，检测胃肠道菌群；③分析CAG不同病性的气味图谱特征与胃肠道菌群变化的关联，建立基于深度学习的CAG嗅诊辨识模型，构建CAG嗅诊辨识方法，阐释CAG嗅诊信息及机理。本项目以CAG不同病性为起点，观察相应的气味图谱特征和胃肠道菌群变化，建立CAG嗅诊辨识模型，从而丰富中医嗅诊理论与方法，有利于CAG癌前病变的筛查，也为本病的中医辨证和防治提供依据。

Chronic atrophic gastritis (CAG) is a common disease of the digestive system. Odor change is its characteristic. The previous result of the research group shows that the electronic nose based on the array gas sensor can be used to judge the odor difference of common syndromes of chronic gastritis. Based on the previous research, 360 patients with CAG were included in the study and 60 healthy persons were included in the control group. The syndrome elements differentiation method is used to divide CAG patients into 6 groups: Qi stagnation, damp-heat, Qi deficiency, Yang deficiency, Yin deficiency and blood stasis. The following research will be carried out: 1.using the electronic nose to collect oral exhalation and fecal odor response patterns, based on deep feature learning to extract the characteristics of odor response patterns of different disease natures of CAG; 2.detecting gastrointestinal flora changes by using 13C urea breath test (13C-UBT) and 16S rDNA sequencing; 3.analyzing the relationship between the odor response pattern characteristics of different disease natures of CAG and the changes of gastrointestinal flora, establishing a smelling examination identification model and method of CAG based on deep-learning, and researching the information and its mechanism of the smelling examination of CAG. Starting from the different disease natures of CAG, this project observes the corresponding characteristics of odor response patterns and changes of gastrointestinal flora, and establishes a smelling examination identification model of CAG, which enriches the theory and method of TCM smelling examination, and is conducive to the screening of CAG precancerous lesions. It also provides a basis for TCM syndrome differentiation and prevention of this disease.