Gene

Human gastrointestinal tract

Bacteria

Biology

Archaea

Environmental health

Human Microbiome Project

Genetics

Microbiome

Methanogen

Human disease

Bioinformatics

Human microbiome

Microbiology

Internal medicine

Gastrointestinal tract

Medicine

Disease

Human health

Metagenomics

Pathology

Nature Reviews Gastroenterology & Hepatology

The human microbiome is strongly interwoven with human health and disease. Besides bacteria, viruses and eukaryotes, numerous archaea are located in the human gastrointestinal tract and are responsible for methane production, which can be measured in clinical methane breath analyses. Methane is an important readout for various diseases, including intestinal methanogen overgrowth. Notably, the archaea responsible for methane production are largely overlooked in human microbiome studies due to their non-bacterial biology and resulting detection issues. As such, their importance for health and disease remains largely unclear to date, in particular as not a single archaeal representative has been deemed to be pathogenic. In this Perspective, we discuss the current knowledge on the clinical relevance of methanogenic archaea. We explain the archaeal unique response to antibiotics and their negative and positive effects on human physiology, and present the current understanding of the use of methane as a diagnostic marker. Archaea are an overlooked member of the human gut microbiota. This Perspective discusses key characteristics of archaea, their role in human health and physiology, and the clinical relevance of methanogenic archaea in the human gastrointestinal tract.

Methanogenic archaea in the human gastrointestinal tract