Probiotic capsules and xylitol chewing gum were ineffective in managing pharyngitis symptoms, according to results from a randomized controlled trial in England.
The results show that clinicians have no reason to treat patients seeking relief from sore throat with either remedy, researchers said.
“This is one of the few studies to address the effectiveness of two promising over-the-counter remedies for acute pharyngitis,” researcher Paul Little, MD, a professor of primary care research with Primary Care Group at the University of Southampton, England, and colleagues wrote in the Canadian Medical Association Journal. “The results show that neither probiotics nor xylitol is likely to have a meaningful effect.”
The researchers evaluated the probiotics and gum as alternatives to the continued use of antibiotics, which has been a significant driver of antimicrobial resistance. They conducted a parallel group controlled trial that included 689 patients aged 3 years and older at clinics around the University of Southampton. The patients had acute illness with a sore throat and abnormal conditions noted in throat examinations.
Patients were randomly assigned to one of three groups. In one group, patients were given chewing gum with 15% xylitol. According to previous studies, xylitol interferes with “bacterial growth and adherence to the pharyngeal wall,” Little and colleagues noted. Patients in the second group were given sorbitol gum without xylitol. Both groups were advised to chew five sticks of gum per day for 3 months. To eliminate the act of chewing — and not the presence of xylitol — as a potential effect on symptoms, patients in the third group did not chew gum.
Half of the patients in each group were further randomized to receive either probiotic capsules containing a mix of lactobacilli and bifidobacterial species or placebo capsules. All capsules were taken daily with milk for 3 months.
The patients kept a diary in which they scored the severity of sore throat, difficulty swallowing, feeling unwell, fever and sleep disturbance, each on a scale of 0 to 6. The study’s primary outcome was sore throat severity and difficulty swallowing during days 2 to 5.
The researchers found no significant differences in symptom severity scores among the groups. The mean severity score among patients taking placebo capsules was 2.75, compared with 2.78 among those taking probiotics. The mean severity score among those who did not chew gum was 2.73, compared with 2.72 with sorbitol gum and 2.73 with xylitol gum.
Likewise, there were no significant differences in HRs for symptom resolution in patients taking probiotics compared with placebo (adjusted HR = 1.08), those chewing sorbitol gum compared with no gum (aHR = 0.85), those chewing xylitol gum compared with no gum (aHR = 0.95) or those chewing xylitol gum compared with sorbitol gum (aHR = 1.03). – by Joe Green
Disclosures: The authors report no relevant financial disclosures.