Xylitol is a sugar alcohol, a type of sweetener that stimulates the same taste receptors as sugar, but it isn’t sugar. Most sugar alcohols don’t get metabolized at all until they get to the gut, where the gut bacteria ferment them. As a result, while they don’t generally affect blood sugar, they do tend to cause gas and bloating at a certain threshold. That threshold is different for different people, depending upon their gut microbiomes.
All of these things are true of xylitol, to some degree, though it’s different in several important ways from other sugar alcohols. It also carries some distinctive health benefits not shared by other sugar alcohols.
How Xylitol Differs from Other Sugar Alcohols
Xylitol is made from xylose, from the bark of birch trees and other vegetable and hardwood sources. Birch wood, bark, gum, and juice, all containing xylose, have been traditionally used in various parts of the world for post-meal dental care, bad breath, and for teething.
Unlike other sugar alcohols, xylitol does have some calories, though not nearly as many as sugar. This is one reason why it correspondingly has fewer gut symptoms than some other sugar alcohols. The symmetrical structure of the molecule itself also makes it less of a trigger for gas, bloating, and diarrhea than other sugar alcohols, too.
Xylitol for Dental and Oral Health
Historically, xylitol has primarily been used for dental health. It’s probably best known as a means of inhibiting streptococcus mutans, the bacteria usually responsible for dental caries. It accomplishes this task via a “bait and switch”: the bacteria consume sugar for metabolism, and xylitol looks similar enough to sugar that the bacteria will absorb it instead, if it’s present. But xylitol is still structurally different enough from sugar that the bacteria cannot extract energy from it as they would from sugar. They keep trying, though–until they ultimately starve.
Xylitol also blocks formation of the biofilm produced by cavity-causing bacteria, better known as dental plaque.
Once the pathogenic bacterial population in the mouth shifts, the tooth has a chance to remineralize and reverse the cavity.
Indeed, studies show that consumption of large quantities of xylitol consistently for a year can dramatically shift the population of dental bacteria in the mouth for the better. It helps to keep oral candida populations in check too.
In addition to inhibiting pathogenic bacteria, xylitol also stimulates the flow of saliva into the mouth, which alkalinizes, and contains the healing minerals necessary for teeth to remineralize.
Xylitol for Bones
There’s a definite connection between acidity and osteoporosis. Perhaps because xylitol intake helps to alkaline the body, it’s also been shown to improve bone volume, mineral content, bone strength and elasticity.
Bones are made of collagen, and xylitol encourages collagen synthesis, too.
Xylitol for Ear Infections
The bacteria in the mouth can affect bacteria in the nose and ears also.
Xylitol nasal sprays are often used to keep sinus bacterial populations balanced, probably for similar reasons. And, just like xylitol inhibits the growth of strep mutans, it also inhibits pneumococci, a common cause of ear infections.
This study does show that xylitol seems to be effective at preventing acute ear infections, while this study shows that children predisposed to ear infections experience 42% fewer ear infections, when consuming xylitol regularly.
Xylitol Side Effects
Studies show consistent and long-term consumption of large amounts of xylitol, on the order of grams daily, suggesting that it is xylitol is safe long-term and at relatively high doses.
Those who are sensitive to sugar alcohols may not be able to tolerate this much, though. This is especially true of those sensitive to FODMAPS, usually secondary to active SIBO. Once successfully treated, FODMAPs should be well tolerated again, though– and in theory, so should xylitol.
That said, even those who cannot handle other sugar alcohols, such as erythritol, sorbitol, or maltitol, can often tolerate similar amounts of xylitol without a problem. For those who have an initial adverse reaction to it, this study suggests that tolerance to xylitol may be acquired over time in increasing increments, as the gut bacterial population shifts to accommodate it.
Even for those who can’t handle large amounts of it, xylitol mints or gum after meals for dental health is generally well tolerated.