there is a issue with the probiotic Vivomixx or with the prebiotics.
I am just thinking out loud, maybe taking one single strain at a time would be better...
Or, have you already tried Short Chain FOS? I don't think most of FOS are SC...
No I don't think there is any particular problem with the probiotic or prebiotics.
I have tried many other probiotics, single strains and a wide variety of prebiotics, albeit in very small doses. I am one of those who reacts adversely to even moderate doses of concentrated prebiotics.
I think there are two issues. The most important one is the gut. For reasons that are not clear, our gut flora has become unbalanced and is resistant to change. It is very difficult to perturb the system. Maybe some key species that cross-feed or otherwise facilitate others are absent.
Secondly, all available probiotics are very poor substitutes for what we really need. After all they almost invariably consist of Lactobacilli and Bifidobacteria. The latter are significant, but still only minor constituents of the gut. The former are very minor.
Apart from B. longum, the keystone species in our guts are simply not available as supplements.
It does seem that there is a beneficial effect from existing probiotic species just transiting through the gut and that is why I continue to take them. I certainly don't expect them to transform my gut - and they clearly don't.
I think the claims by Elixa that transformation will occur in 6 days are ridiculous - just hype.