There Is No ‘Healthy’ Microbiome.

LONDON — In the late 17th century, the Dutch naturalist Anton van Leeuwenhoek looked at his own dental plaque through a microscope and saw a world of tiny cells “very prettily a-moving.”

He could not have predicted that a few centuries later, the trillions of microbes that share our lives — collectively known as the microbiome — would rank among the hottest areas of biology…

http://www.nytimes.com/2014/11/02/opinion/sunday/there-is-no-healthy-mic…