Paul - I've been researching / experimenting with this stuff for the last 5 years.

Have hunt around on my research website here 50k-Gi-insight, and you might find some insights or information that you can use.  The stuff on gut brain axis fascinating::

• gut - brain axis (19)
• gut - second brain (5)
• microbiome - neuroendocrine (1)
• y - grain brain (2)
• gluten - nuerotoxin (2)

More about "pre-biotics" here:

• Prebiotics vs Probiotics - Body + Soul

• 7 Reasons to Get Prebiotics in Your Diet, Plus Best Sources - Dr. Axe

Also take a look at the  programs on the ABC Catalyst programs:

Catalyst: Gut Reaction Pt 2 - ABC TV Science

www.abc.net.au/catalyst/stories/4070977.htm

Aug 21, 2014 - In the second episode of this two-part special Dr Graham Phillips reveals ... In a nutshell, if you eat a bad diet, you end up with bad gut bacteria, ...

Catalyst - Gut Reaction (Part 2) : ABC iview

iview.abc.net.au/programs/catalyst/SC1502H025S00

Jan 9, 2017 - Catalyst - Gut Reaction (Part 2) : The final part of a Catalyst investigation into whether food could actually be our medicine. A healthy diet could ...

Cheers

JB