More and more evidences suggest that the gut-brain axis is comprehensively involved in the entire pathological courses of Alzheimer's disease (AD), and is a new source of its β-amyloid protein (Aβ) and tau pathologies and chronic inflammations in the brain. In this paper, the potential targets and application prospects in the prevention and treatment of AD are discussed from the aspects of gastrointestinal tract, intracerebral inflammation and intestinal flora.

Objective:To understand the breastfeeding situation in the neonatal intensive care units (NICUs) in Qianxinan Prefecture, Guizhou Province, and to assess the knowledge, attitudes, and practices of doctors and nurses regarding breastfeeding, aiming to provide foundational data for improving breastfeeding quality.Methods:A questionnaire was developed to survey the knowledge, attitudes, and practices related to breastfeeding in NICUs. The questionnaire was divided into three dimensions: knowledge (seven items, total score of 7), attitudes (nine items, total score of 45), and practices (seven items, total score of 35). Lower scores indicated weaker recognition of breastfeeding. Additionally, five items were included to identify the most influential factors affecting breastfeeding. From November 25 to November 30, 2023, a survey was conducted among doctors and nurses with professional qualifications who had worked in the neonatal departments of nine hospitals in Qianxinan Prefecture for at least one year. Independent sample t-tests and Chi-square tests were used to compare the scores of doctors and nurses from different levels of hospitals and within the same level of hospitals across the three dimensions. Results:(1) Among the nine hospitals, three were tertiary grade A hospitals (referred to as "tertiary hospitals"), with 95.6% (43/45) of the doctors and 96.5% (110/114) of the nurses participating in the survey. Six were secondary grade A hospitals (referred to as "secondary hospitals"), with 95.0% (38/40) of the doctors and 97.6% (83/85) of the nurses participating. (2) All nine hospitals were baby-friendly hospitals and all had breastfeeding promotional materials. Six hospitals had NICUs that promoted breastfeeding, with an average NICU breastfeeding rate of 25.8% across the prefecture between year 2021 to 2023. (3) The proportion of doctors who had received breastfeeding training was higher than that of nurses within the same level of hospitals [tertiary hospitals: 69.8% (30/43) vs. 40.0% (44/110), χ 2=10.97, P=0.001; secondary hospitals: 47.4% (18/38) vs. 24.1% (20/83), χ 2=6.55, P=0.010], although the overall training rates were low. (4) In tertiary hospitals, doctors scored higher than nurses in the attitude dimension [(35.35±4.75) vs. (33.18±5.60) scores, t=－2.03, P=0.044] and also in the practice dimension [(26.98±3.00) vs. (25.60±3.75) scores, t=－2.17, P=0.032]. In secondary hospitals, the total knowledge dimension score of doctors was higher than that of nurses [(4.92±1.44) vs. (4.20±1.45) scores, t=－2.52, P=0.013]. In tertiary hospitals, the total scores for attitude and practice dimensions of doctors were higher than those of doctors in secondary hospitals, and the total scores for knowledge, attitude, and practice dimensions of nurses were higher than those of nurses in secondary hospitals (all P<0.05). (5) In the knowledge dimension, the lowest scoring item of doctors in the tertiary hospitals was "Breastfeeding is possible for maternal hepatitis B newborns after receiving vaccines and immunoglobulin"; the lowest scoring item of nurses in the tertiary hospital, and doctors and nurses in the secondary hospitals was "The duration of breastfeeding has a greater impact on neonatal outcomes". In the attitude dimension, the lowest scoring item for doctors and nurses in both tertiary and secondary hospitals was "You think the breastfeeding process is more troublesome than feeding preterm formula". In the practice dimension, the lowest scoring item of the doctors and nurses in the tertiary hospitals was "Your hospital had enough breastfeeding knowledge training", while for the doctors and nurses in the secondary hospitals were "You have more opportunities to participate in various breastfeeding-related training" and "Breast feeding should be started as soon as possible when the infant is stable after active treatment", respectively. (6) The most influential factors affecting breastfeeding were: lack of cooperation from parents (50.0%, 137/274), relative insufficient human resources for doctors and nurses (21.9%, 60/274), and the absence or poor implementation of breastfeeding management policies (18.3%, 50/274), etc. Conclusions:The breastfeeding rate in NICU of county-level hospitals is relatively low, and medical staff, especially nurses, have insufficient knowledge about breastfeeding. It is necessary to strengthen various breastfeeding training for medical staff to enhance their understanding of NICU breastfeeding.