The researchers randomly assigned nearly 1,000 people with sore throats to one of four regimens: chewing gum containing xylitol; probiotic capsules; both treatments combined; or a control group that only got a different gum without xylitol.
They found that xylitol and probiotics didn’t work any better than the gum without any remedy at all, according to the report in the Canadian Medical Association Journal.
“We were hoping that one or the other would prove beneficial in sore throat but unfortunately not,” said senior study author Michael Moore of the University of Southampton in the UK.
“It was not clear before the trial whether they would be helpful or not, but it is a priority to find alternative approaches to treatment that don’t involve antibiotics so it was worth testing out these two potential treatments,” Moore said by email.
The study included 934 people, with complete data on the effect of the remedies available for 689 individuals.
All of the study participants came to the doctor complaining of a sore throat. At the initial exams, about two-thirds had inflammation in their throat and more than half had a cough.
Most had also experienced at least one previous sore throat in the previous three months, and more than 30 percent had at least three sore throat episodes.
They were randomly assigned to one of the four treatment groups, and then asked to record a diary of symptoms and the number of probiotic capsules or sticks of gum they had each day depending on what group they were in.
If gum was part of their regimen, participants were asked to chew five pieces daily. If their treatment included probiotics, they were asked to take one capsule daily with milk.
Participants were considered compliant with their assigned treatment if they followed these directions at least 75 percent of the time.
After three months, participants didn’t report any meaningful difference in the severity of sore throat symptoms or difficulty swallowing based on what group they were in.
One limitation of the study is that many participants dropped out before three months or didn’t provide complete data, the authors note. Another drawback is that the study wasn’t long enough to assess whether the tested remedies might help in the long run if people got recurring sore throats.
Still, the findings suggest there is no reason for doctors to prescribe probiotics or xylitol for sore throats, the researchers conclude.
For patients with strep throat, penicillin works and antibiotics are an effective and appropriate treatment, noted Dr. Jeffrey Linder, a researcher at Northwestern University Feinberg School of Medicine in Chicago.
“Most sore throats are not strep and should be treated symptomatically,” Linder, who wasn’t involved in the study, said by email.
This means getting plenty of rest, drinking plenty of fluids, and taking over the counter medications for inflammation and pain, Linder advised.