The aim of this study was to analyze the risk factors for the development of type 2 diabetes mellitus (T2DM) with mild cognitive impairment (MCI) and its pathogenesis associated with gut microbiota. A prospective cohort study was conducted to recruit 3820 participants aged 45 years and above who attended health checkups at the checkup center of Linyi City People's Hospital, Shandong Province. A follow-up survey was conducted identifying whether the participant had T2DM as an exposure factor group. Socio-demographic characteristics, blood, urine, and stool samples, lifestyle surveys, dietary status, and neuropsychological tests were collected at baseline and follow-up, exploring the association between clinical characteristics and gut microbiota and the risk for the development of T2DM with MCI.

The aim of this study was to analyze the risk factors for the development of type 2 diabetes mellitus (T2DM) with mild cognitive impairment (MCI) and its pathogenesis associated with gut microbiota. A prospective cohort study was conducted to recruit 3820 participants aged 45 years and above who attended health checkups at the checkup center of Linyi City People's Hospital, Shandong Province. A follow-up survey was conducted identifying whether the participant had T2DM as an exposure factor group. Socio-demographic characteristics, blood, urine, and stool samples, lifestyle surveys, dietary status, and neuropsychological tests were collected at baseline and follow-up, exploring the association between clinical characteristics and gut microbiota and the risk for the development of T2DM with MCI. Therefore, it is important to explore the factors affecting T2DM with MCI and screen for intervening factors, further elucidate its pathogenesis, and search for specific biological markers of early cognitive impairment in T2DM. This is socially and economically important for screening individuals susceptible to T2DM with MCI so that measures can be taken for early intervention and early treatment to improve the quality of life of patients while reducing medical costs.

Inclusion Criteria:

• ≥ 45 years old;
• no impairments in vision, hearing, language, etc., and can cooperate to complete the questionnaire;
• agree to follow-up.

Exclusion Criteria:

• have major systemic diseases, such as malignant tumors;
• have serious mental illnesses.

The participants aged 45 years and above who attended health checkups at the checkup center of Linyi City People's Hospital, Shandong Province, were recruited in this study.