The composition of the Gut Microbiome(GM)is regulated by numerous factors,including geography,ethnicity,diet,and genetics.This review systematically synthesizes studies on the GM across different geographic regions and ethnic minority groups in China.It focuses on elucidating the impact of geographical factors and ethnic backgrounds on GM composition and structure and provides an in-depth discussion on the association between ethnicity-specific microbial taxa,their metabolic functions,and susceptibility to diseases.By systematically comparing microbial compositional differences in microbiota-related diseases among different populations,this review aims to uncover the underlying patterns.The findings are expected to provide a theoretical foundation for ethnicity-specific GM research,the elucidation of disease mechanisms,and the development of targeted prevention and control strategies.

BACKGROUND:Porous gradient hydroxyapatite/zirconia composite, which can adhere to a variety of cel s, such as osteoblasts, bone marrow mesenchymal stem cel s and chondrocytes, can induce and promote fracture healing or replace bone defects. OBJECTIVE:To review the development and application of porous gradient hydroxyapatite/zirconia composite in bone tissue engineering. METHODS:Articles related to porous gradient hydroxyapatite/zirconia composite in bone tissue engineering were retrieved in CNKI and PubMed databases (1971-01/2014-12). The key words were“porous bioceramic, bone tissue engineering, bone morphogenetic protein-2, induced pluripotent stem cel s”in Chinese and English, respectively. A total of 54 articles based on inclusion criteria and exclusion criteria were obtained for the review. RESULTS AND CONCLUSION:Porous gradient hydroxyapatite/zirconia composite can provide a scaffold to induce natural y forming bone growing to fil the three-dimensional pores, thus realizing the perfect integration of tissue-engineered bone material and host-bone tissue. As zirconia functions as an enhancer of hydroxyapatite, high-quality artificial bone materials, which have elastic modulus, fracture toughness and structure similar to human bone, can be prepared by adjusting the proportion and porosity of materials. Additional y, the new hydroxyapatite/zirconia foamed ceramics as tissue-engineered bone carrying bone morphogenetic protein-2/chitosan gel sustained release system and bone marrow mesenchymal stem cel s derived from induced pluripotent stem cel s wil be expected to increase bone formation and bone fusion rates significantly in the future.