I don't think that the ideas about "leaky gut" have been proved yet. However, there is much discussion about the stomach 'flora' being both the seat of many auto-immune conditions. They are using fecal transplants in an attempt to help certain conditions.
I don't know about those of you on here who have have IBS, but most of those I have come across (I been having the symptoms treated for at least 20 years) have other auto-immune conditions which researchers hope could be helped by such transplants. I have two others so find all the research very interesting.
Estranged Son and Future Granddaughter
To think that London, or anywhere else for that matter, does not belong to any one demographic