Chewing gum is a massive $19 billion dollar industry–and for good reason. Wrigley reports the average person chews 300 pieces a year, amounting to 100,000 tons of gum total annually (that is 90,718,474 kg). At this moment I’m working on a stick of Stride ID peppermint, which is refreshing to say the least.
The gum I’m chewing and a large proportion of the chewing gum sold worldwide contains xylitol, a sugar alcohol naturally found in plums, strawberries, raspberries, and rowan berries. Though xylitol is comparable in sweetness to sucrose (i.e. table sugar), it has 33% fewer calories and little effect on blood sugar. Notably, xylitol can induce hypoglycemia in dogs, which can be life-threatening. In humans, xylitol is as nontoxic (and was ingested at 430 gram daily without side effects) though can have a laxative effect in children (if ingested at over 65 grams daily).
Uhari et al. from Oulu, Finland report from their double-blind randomized study with 11 nurseries in Finland with pre-screened, healthy children that chewing xylitol containing gum significantly reduces occurence of acute otitis media, inflammation of the middle ear due to infection. They attribute fewer infections due to the antimicrobial effect xylitol has on Streptococcus pneumoniae, which may cause ear infections.
Significantly fewer antimicrobials were prescribed among those receiving xylitol: 29/157 (18.5%) children had at least one period of treatment versus 43/149 (28.9%) (difference 10.4%; 0.9% to 19.9%; P = 0.032). The carriage rate of S pneumoniae varied from 17.4% to 28.2% with no difference between the groups.
Xylitol has previously been found to inhibit Streptococcus pneumoniae growth in vitro in a dose-dependent method. Bacteria collected from study subjects were identified using haemolysis on sheep blood agar, colony characterization, and optochine sensitivity. Researchers note that their study doesn’t indicate a minimal threshold for the antimicrobial effect though 8.4 grams of xylitol daily in chewing gum appears significantly better than control.