The archaea reference was in a quote that this article made of a Science Daily report
"The microbes in the human gut belong to three broad domains, defined by their molecular phylogeny: Eukarya, Bacteria, and Achaea."Wow - this surprised me. An article at some place called Food Consumer that was mentioning archaea.
But that was pretty much the only decent part. Things went downhill fast with a link to some total BS on a way to cure every disorder on the planet by focusing on gut microbial health.
The article then pulls a classic trick - referencing some of the new human micro biome work in Nature to make the discussion here seem scientific. But alas it is not. Consider this doozy of a line
"The ideal balance of beneficial to pathogenic bacteria in your gut is about 85 percent good bacteria and 15 percent bad. Maintaining this ideal ratio is what it's all about when we're talking about optimizing your gut health. "Yes that is right everyone - you want to maintain a ratio where 15% of the bacteria in your gut are pathogenic. Aaarrggh.
Not surprisingly, when I searched around the web for detail on the person behind this article - some Dr. Mercola - who I have never heard of - I discovered that he is considered by many to be a quack. No disagreement from me.