Methane emission of humans is explained by dietary habits, host genetics, local formate availability and a uniform archaeome

Archaea are responsible for methane production in the human gastrointestinal tract. Twenty percent of the Western populations exhale substantial amounts of this gas. The underlying principle determining high or low methane emission and its effect on human health was still not sufficiently understood. In this study, we analysed the gastrointestinal microbiome, archaeome, metagenome, metabolome, and eating behaviour of 100 healthy young adults. We correlated high levels of human methane emission (5-75 ppm) with a 1000-fold increase in Methanobrevibacter smithii. This archaeon co-occurred with a bacterial community specialised on dietary fibre degradation, which included members of the Ruminococcaceae and Christensenellaceae. Methane production was negatively affected by high vitamin B12 and fat intake of the subjects, and was positively associated with increased formate concentrations in the gut. Overall, methane emission is explained by dietary habits, host genetics, local metabolite availability and microbiome/archaeome composition, emphasizing the unique biology of high methane-emitters which has potentially positive impact on human health. O_FIG O_LINKSMALLFIG WIDTH=171 HEIGHT=200 SRC="FIGDIR/small/423794v1_ufig1.gif" ALT="Figure 1"> View larger version (79K): org.highwire.dtl.DTLVardef@16eb91org.highwire.dtl.DTLVardef@c3b928org.highwire.dtl.DTLVardef@1b11fa5org.highwire.dtl.DTLVardef@194bed2_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstract:C_FLOATNO C_FIG