Very Interesting.
I remember reading articles by Kelly Del Tredici & Heiko Braak discussing gut to brain links. A friend was a techinal writer for Cell Magazine, and would edit papers for publication. I was hooked as it was fascinating. It was not a popular idea in the 1980's, but they kept publishing their research and findings.
Current article in Nature Magazine:
Pathogenesis of Parkinson disease—the gut–brain axis and environmental factors
http://www.nature.com/nrneurol/journ....2015.197.html
Oddly enough I would have never claimed to have lost my smell, but looking back for over 20 years I would "smell" things that I could visualize. Oddly enough I also would have the sense of something like roses, despite being February and none in the house.