[Principles of microbiome research].

Microbiome research in the ear nose and throat (ENT) field has substantially gained in importance in recent decades. Modern sequencing methods have largely replaced traditional cultivation. Standardized protocols are essential to ensure reliable and comparable data. The article explains key terms, such as microbiome (the entire microbial community and its environment) and microbiota (only living microorganisms), along with the microbial taxonomy. Important measures for microbiome assessment include the alpha-diversity (species richness and distribution within a sample) and beta-diversity (differences between samples). A differentiation is made between two main approaches to microbiome sequencing: 1) 16S rRNA gene amplicon sequencing (identifies microbial community composition by sequencing the PCR product of a specific gene), 2) metagenomic sequencing (sequences the entire genomic material of a sample, allowing deeper insights). As nasal microbiome biomass is low, careful study design and controls are crucial. Microbiome research is a rapidly growing field with great potential but it requires meticulous planning and bioinformatics expertise for meaningful results.