Various fields have been identified in the “omics” era, such as genomics, proteomics, transcriptomics, metabolomics, phenomics, and metagenomics. Among these, metagenomics has enabled a significant increase in discoveries related to the microbial world. Newly discovered microbiomes in different ecologies provide meaningful information on the diversity and functions of microorganisms on the Earth. Therefore, the results of metagenomic studies have enabled new microbe-based applications in human health, agriculture, and the food industry, among others. This review summarizes the fundamental procedures on recent advances in bioinformatic tools. It also explores up-to-date applications of metagenomics in human health, food study, plant research, environmental sciences, and other fields. Finally, metagenomics is a powerful tool for studying the microbial world, and it still has numerous applications that are currently hidden and awaiting discovery. Therefore, this review also discusses the future perspectives of metagenomics.

Given the enormous increase in the risks of bone and cartilage defects with the rise in the aging population, the current treatments available are insufficient for handling this burden, and the supply of donor organs for transplantation is limited. Therefore, tissue engineering is a promising approach for treating such defects. Advances in materials research and high-tech optimized fabrication of scaffolds have increased the efficiency of tissue engineering. Electrospun nanofibrous scaffolds and hydrogel scaffolds mimic the native extracellular matrix of bone, providing a support for bone and cartilage tissue engineering by increasing cell viability, adhesion, propagation, and homing, and osteogenic isolation and differentiation, vascularization, host integration, and load bearing. The use of these scaffolds with advanced three- and four-dimensional printing technologies has enabled customized bone grafting. In this review, we discuss the different approaches used for cartilage and bone tissue engineering.