“After a few weeks of not eating them, I eat a huge bowl of them. Hilarity ensues. The next day, I have massive gas despite normally eating over 100g/day of fiber. Then it’s gone. I can eat as many beans as I like with no gas at all. Until the next time I go a long time not eating them. Some say it takes a long time for the gut to evolve, but others – and experience – suggest days.”
I agree about the timescale of adaptation.
Regarding transient gas. I have two main thoughts on this.
One would be that gas-degrading microbes must proliferate in proportion to the increase in gas production by other microbes (due to the addition of fermentable substrate). And this proliferation of gas-degraders is at a lag relative to the beginning of gas production and thus a transient period of bloating. Which diminishes when population of gas degraders ‘catch up with’ gas production.
The second thought (which I think is the correct one) is that when a new substrate is introduced it is metabolised by the incumbent microbiota (whatever that may be) and if there is a deficiency in beneficial species (which by my definition would NOT produce large amounts of gas) THAT CAN METABOLISE SPECIFICALLY THAT NEW SUBSTRATE THAT HAS JUST BEEN INTRODUCED, then the spill over of substrate would be metabolised by species which do not need to be particularly well adapted — because there is excess substrate (loss of specificity occurs) — and these less well adapted non-beneficial species produce gas… UNTIL the beneficial species (which can metabolise that specific substrate) have increased in population to the extent that they monopolise the entire supply of that new substrate.
According to evolutionary logic, the beneficial species should ultimately be better adapted to metabolize natural substrates and so they would win out. I should add that, because it’s a fundamental assumption.
What’s interesting about the bean gas observation is that I think it shows the gas-degrader-deficiency-theory is NOT the culprit for the initial gas when starting a new fiber source (in this case galactans).
If it were true, then adapting to initial gas on ANY fiber source (or let’s say 3-4 sources, to account for the fact that the gas could be H2 or CH4, etc.) would suffice to adapt you to ALL future additions to your fiber blend.
In other words: if you get over the gas hump with a blend of RPS, inulin, and psyllium (for example), then the addition of GOS (for example) should not cause a repeat of the intial gas adaptation period. And yet, for many this DOES occur.
So I do NOT think a deficiency of gas degraders is responsible.
I think my second thought is more likely…
But I always like to consider contradicting scenarios… A devil’s advocate point in this case could be perhaps species are much more segregated across the mucosal lining than we think (within biofilm communities) hence making possible a LOCALISED proliferation of gas-degraders within a specific biofilm community that contain microbes which metabolise substrate Y into gas: hence no gas from substrate Y.
Substrate X comes along and is metabolised in a DIFFERENT community (because it requires different microbial metabolic pathways to ferment, from microbes not present in the former community) where there does NOT (yet) exist sufficient quantities of gas-degraders localised to that community. So the gas-degraders from the other community do not have any interaction with the gas output from the latter community, hence the requirement to once again build up a gas-degrading population from the ground up.
This is why I’ll be making videos! It will be much clearer.