Gut methanogens
They keep hydrogen low so fermenting bacteria can keep working on fibre. Breath methane tests are research tools, not self-diagnosis.
Archaea — A prokaryotic domain that is not bacteria — methanogens, extremophiles and no known human pathogens.
Darker cells mean a higher score for this topic on that metric.
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Read Identity → How they live → Body & health, then use compare rails.
Public-health education — not a care plan, prescription, or outbreak briefing.
It names everyday desks for Tree of microbes before English norms look universal.
No — editorial 0–100 browsing aids inside this atlas only.
Use related cards and best-of / quiz rails after the first three chapters.
How they live and Body & health carry mechanisms; skim Identity first.
Methanobrevibacter smithii is a common human-gut archaeon that consumes hydrogen and makes methane. That chemistry can shift how bacteria ferment fibre — ecology, not an infection label.
Detecting archaeal DNA on skin or in hospitals usually means environmental cells or reagents, not an outbreak of 'archaeal plague'.
They keep hydrogen low so fermenting bacteria can keep working on fibre. Breath methane tests are research tools, not self-diagnosis.
Cows and other ruminants host dense methanogens. That alliance feeds people and also emits methane — a climate trade.
Unlike bacteria, viruses and protozoa, archaea have no established infectious-disease chapter in textbooks.
Heat-stable polymerases from Thermococcus and relatives powered PCR after bacterial Taq. Concept only — not a protocol.
Archaea in a clinical swab may be contaminants. Over-interpreting 16S hits wastes fear.
Inhibiting rumen methanogens is a climate research topic. Diet and animal welfare sit in the same conversation.
Human relevance is methane, microbiome ecology and industrial enzymes from extremophiles — not a germ-theory villain.
Single-celled prokaryotes with cell walls — the oldest widespread life form, and both partners and pathogens.
Familiarity 95Packets of DNA or RNA that are not cells — they replicate only inside living hosts.
Familiarity 96A eukaryotic kingdom of yeasts, moulds and mushrooms — chitin walls, external digestion, partners of plants.
Familiarity 80Viruses that infect bacteria — Earth's most abundant biological entities, and a concept-level idea in medicine.
Familiarity 42Motile unicellular eukaryotes — a teaching grade that includes pond ciliates and a minority of serious parasites.
Familiarity 58