In the 1840s, Surgeon John Goodsir kicked off a debate on the presence and role of microorganisms in the gut with his observations of Sarcina Ventriculi in a patient's stomach fluid.
The Early 1900s
Scientists observed associations between human longevity and yoghurt consumption (containing lactobacilli strains of bacteria).
The Mid 1900s
In the 1950's research accelerated. From faecal microbiota transplantation to the transfer of bacterial cultures to germ-free mice, research was primarily focused on the gut.
The NIH launched the Human Microbiome Project and 16S rRNA sequencing allowing scientists to easily and reliably characterize complex bacterial communities.