In my last post I mentioned Mannitol which is also used in food and supplements. It has a number of positive medical benefits — however, what is good for one condition can be bad for another condition. This “naive alternative medicine belief” that if it is good for one condition it is good for all conditions is something to be very wary of. It is simplistic logic being applied to very complex situations.
- “Clostridium difficile.. can exploit specific metabolites that become more abundant in the mouse gut after antibiotics, including … carbon sources such as mannitol, fructose, sorbitol, raffinose and stachyose for growth.” 
- Increase in serum potassium resulting from the administration of hypertonic mannitol and other solutions. 
- “Xylitol at 10 and 20 per cent disturbed gastro-intestinal function but was tolerated better than sorbitol or mannitol” 
- “the severity of such gastro-intestinal disturbances, induced by large doses of polyols, decrease in the following order: mannitol, sorbitol, xylitol…The available clinical data generally suggest that moderate consumption of the above polyols is not harmful to human metabolism.” 
- Based on people without gut dysfunction
- “all three polyols[ galactitol, mannitol or xylitol] retarded the growth rate of the animals, the polyols were well tolerated.” 
- “Airway hyperresponsiveness (AHR) to inhaled mannitol is associated with indirect markers of mast cell activation and eosinophilic airway inflammation” 
I was unable to find any studies specific to how it impacts the microbiome apart from disturbing normal health guts.