"Surely many of the people who have overcome IBS/C with this fiber probably had SIBO and didn't even know they had it, yet were helped. However, as most of us know, acacia is a prebiotic and not recommended for use with SIBO. What are your thoughts on this? "
Hello - we actually have GI docs send folks to us for the Tummy Fiber for SIBO, because they want their patients on that prebiotic. (Whereas they normally want people to wait on probiotics until they are done with the course of antibiotics, because the antibiotics just kill off the probiotics as well.)
But, prebiotics work regardless of antibiotics, by creating an environment of short chain fatty acids in the bowel, an environment in which the healthy (and only the healthy) bacteria of the gut thrive. Those good guys then help keep the bad guys in check.
What is critical with the tummy fiber is that it is a SLOWLY fermenting prebiotic, so it has a very good gastrointestinal tolerance. What you don't want are RAPIDLY fermenting prebiotics, like inulin, FOS, and GOS (these are also FODMAPS). Those are a nightmare for not just SIBO but IBS in general.
The dosage and directions for the fiber are the same for IBS and SIBO, start with a low dose twice daily and gradually increase. For constipation you'll likely end up towards the higher end of the dose range, so just go slow and steady.
It's worth noting that it can take a month or two for a prebiotic effect to kick in and really show benefits, whereas the bowel motility regulation (for diarrhea or constipation) will likely happen much sooner.
We've heard from people whose docs put them on the tummy fiber right with the SIBO antibiotics, from people whose docs had them wait till they finished the antibiotics to start the fiber, and even from some whose docs substituted the fiber for the antibiotic entirely. I honestly do not know which approach is best or if this is something that could/should vary from person to person, it mostly seems to depends on the GI doc.