I’ve done some reading and experiments with inulin, using meal shakes and straight inulin powder, under different conditions to figure out how to use it.
I read that gut microbiota gradually adjust to inulin levels over time, and may grow gassy on sudden changes. Recommendation is to start at 2g/day and increase gradually over 4 weeks up to 5g-10g/day - or at your desired shake intake or inulin tolerance limit.
If one skips the regularly scheduled inulin-containing shake, it helps to have a powdered inulin supplement in water, to keep the microbiota calm, as I found a sudden decrease in inulin also upsets them.
Inulin is a FODMAP, so bloating and gas is massively increased if inulin is mixed up in the gut with other high FODMAP foods: wheat, and most fruit and veg. The worst gas I found is from taking an inulin-containing shake to “top up” the calories intake after a FODMAP-containing meal…
The best way I found to use an inulin-containing shake is as a full meal replacement (so no other food an hour before or after). It also works well as “first thing in the morning” shake to be followed later by a low-FODMAP breakfast (e.g. oats, eggs & sausage), or last-thing-at-night at least 3-4 hours after eating dinner.