Probiotic capsules and xylitol chewing gum to manage symptoms of pharyngitis: a randomized controlled factorial trial

Probiotics for preventing acute upper respiratory tract infections

BACKGROUND

Probiotics are live micro-organisms that may give a beneficial physiological effect when administered in adequate amounts. Some trials show that probiotic strains can prevent respiratory infections. Even though our previously published review showed the benefits of probiotics for acute upper respiratory tract infections (URTIs), several new studies have been published. This is an update of a review first published in 2011 and updated in 2015.

OBJECTIVES

To assess the effectiveness and safety of probiotics (any specified strain or dose), compared with placebo or no treatment, in the prevention of acute URTIs in people of all ages, at risk of acute URTIs.

SEARCH METHODS

We searched CENTRAL (2022, Issue 6), MEDLINE (1950 to May week 2, 2022), Embase (1974 to 10 May 2022), Web of Science (1900 to 10 May 2022), the Chinese Biomedical Literature Database, which includes the China Biological Medicine Database (from 1978 to 10 May 2022), the Chinese Medicine Popular Science Literature Database (from 2000 to 10 May 2022), and the Master's Degree Dissertation of Beijing Union Medical College Database (from 1981 to 10 May 2022). We searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov for completed and ongoing trials on 10 May 2022.

SELECTION CRITERIA

We included individual randomised controlled trials (RCTs) and cluster-RCTs comparing probiotics with placebo or no treatment to prevent acute URTIs. The participants were children, adults, or the elderly in the community, care facilities, schools, or hospitals. Our main outcomes were the number of participants diagnosed with URTIs (at least one event and at least three events), the incidence rate (number of cases/person year) of acute URTIs, and the mean duration of an episode of URTIs. Our secondary outcomes were the number of participants who were absent from childcare centre, school, or work due to acute URTIs; the number of participants who used prescribed antibiotics for acute URTIs; and the number of participants who experienced at least one adverse event from probiotics. We excluded studies if they did not specify acute respiratory infections as 'upper'; studies with more than 50% of participants vaccinated against influenza or other acute URTIs within the last 12 months; and studies with significantly different proportions of vaccinated participants between the probiotics arm and the placebo or no treatment arm.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of trials and extracted data using standard Cochrane methodological procedures. We analysed both intention-to-treat and per-protocol data and used a random-effects model. We expressed results as risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, both with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 23 individual RCTs and one cluster-RCT. As one of the individual RCTs did not report outcomes in a usable way, we could only meta-analyse data from 23 trials, involving a total of 6950 participants including children (aged from one month to 11 years old), adults (mean age 37.3), and older people (mean age 84.6 years). One trial reported 22.5% flu-vaccine participants within the last 12 months, and 25.4% flu-vaccine participants during the intervention. Probiotics were more likely to be given with milk-based food in children; administered in powder form in adults; and given with milk-based food or in capsules in the elderly. Most of the studies used one or two strains (e.g. Lactobacillus plantarum HEAL9, Lactobacillus paracasei (8700:2 or N1115)) and 109 or 1011 colony-forming units (CFU)/day of probiotics for more than three months. We found that probiotics may reduce the number of participants diagnosed with URTIs (at least one event) (RR 0.76, 95% CI 0.67 to 0.87; P < 0.001; 16 studies, 4798 participants; low-certainty evidence); likely reduce the number of participants diagnosed with URTIs (at least three events) (RR 0.59, 95% CI 0.38 to 0.91; P = 0.02; 4 studies, 763 participants; moderate-certainty evidence); may reduce the incidence rate (number of cases/person year) of URTIs (rate ratio 0.82, 95% CI 0.73 to 0.92, P = 0.001; 12 studies, 4364 participants; low-certainty evidence); may reduce the mean duration of an episode of acute URTIs (MD -1.22 days, 95% CI -2.12 to -0.33; P = 0.007; 6 studies, 2406 participants; low-certainty evidence); likely reduce the number of participants who used prescribed antibiotics for acute URTIs (RR 0.58, 95% CI 0.42 to 0.81; P = 0.001; 6 studies, 1548 participants; moderate-certainty evidence); and may not increase the number of participants who experienced at least one adverse event (RR 1.02, 95% CI 0.90 to 1.15; P = 0.79; 8 studies, 2456 participants; low-certainty evidence). Evidence showing a decrease in the number of people absent from childcare centre, school, or work due to acute URTIs with probiotics is very uncertain (RR 0.14, 95% CI 0.03 to 0.59; 1 study, 80 participants; very low-certainty evidence). Adverse events from probiotics were minor, and most commonly gastrointestinal symptoms, such as vomiting, flatulence, diarrhoea, and bowel pain.  AUTHORS' CONCLUSIONS: Overall, we found that probiotics were better than placebo or no treatment in preventing acute URTIs.

Relieving Sore Throat Formula Exerts a Therapeutic Effect on Pharyngitis through Immunoregulation and NF-κB Pathway

Relieving Sore Throat Formula (RSTF) is a formula approved by the China Food and Drug Administration and has been used for the treatment of pharyngitis in clinic for many years. However, the potential pharmacological mechanism still remains unknown. We combined multiple methods including bioinformatics data digging, network pharmacology analysis, and pathway analysis to predict the potential target of RSTF. We verified our in silico prediction results with an in vivo/vitro antibacterial effect test, mouse phagocytic index test, proliferation, transformation, and migration of mouse spleen lymphocytes. Alteration of NF-κB pathway was determined by Western blotting, immunofluorescence, and PCR. The in vivo experiments demonstrated that the RSTF could significantly relieve the symptoms of pharyngitis. A rat saliva secretion test showed that RSTF can effectively relieve the xerostomia symptom. A phenol red excretion test showed that RSTF has an eliminating phlegm effect. A hot plate method and granuloma experiment proved that RSTF also have analgesic and anti-inflammatory effects. In silico prediction demonstrates that 70 active compounds of RSTF were filtered out through ADME screening and 84 putative targets correlated with different diseases. Pathway enrichment analysis showed that the candidate targets were mostly related to the response to bacteria and immunity signalling pathways, which are known contributors to pharyngitis. Experimental results confirmed that RSTF exerted therapeutic effects on pharyngitis mainly by antibacterial effect and downregulation of NF-κB activities. It is demonstrated both in silico and in vivo/vitro that RSTF exerted therapeutic effects on pharyngitis mainly through an antibiotic effect and downregulation of NF-κB signalling pathway.

Clustering of continuous and binary outcomes at the general practice level in individually randomised studies in primary care - a review of 10 years of primary care trials

BACKGROUND

In randomised controlled trials, the assumption of independence of individual observations is fundamental to the design, analysis and interpretation of studies. However, in individually randomised trials in primary care, this assumption may be violated because patients are naturally clustered within primary care practices. Ignoring clustering may lead to a loss of power or, in some cases, type I error.

METHODS

Clustering can be quantified by intra-cluster correlation (ICC), a measure of the similarity between individuals within a cluster with respect to a particular outcome. We reviewed 17 trials undertaken by the Department of Primary Care at the University of Southampton over the last ten years. We calculated the ICC for the primary and secondary outcomes in each trial at the practice level and determined whether ignoring practice-level clustering still gave valid inferences. Where multiple studies collected the same outcome measure, the median ICC was calculated for that outcome.

RESULTS

The median intra-cluster correlation (ICC) for all outcomes was 0.016, with interquartile range 0.00-0.03. The median ICC for symptom severity was 0.02 (interquartile range (IQR) 0.01 to 0.07) and for reconsultation with new or worsening symptoms was 0.01 (IQR 0.00, 0.07). For HADS anxiety the ICC was 0.04 (IQR 0.02, 0.05) and for HADS depression was 0.02 (IQR 0.00, 0.05). The median ICC for EQ. 5D-3 L was 0.01 (IQR 0.01, 0.04).

CONCLUSIONS

There is evidence of clustering in individually randomised trials primary care. The non-zero ICC suggests that, depending on study design, clustering may not be ignorable. It is important that this is fully considered at the study design phase.

Probiotics in health and disease: fooling Mother Nature?

Probiotics are ubiquitous, consumption by the general public is common, and the dogma remains that they are beneficial for general and gut health. However, evolving evidence suggests a potentially "harmful" impact of many commercially available probiotics. There is also significant variability in formulations that leads to a lack of a universally acceptable definition of probiotics. In this perspective, we review the flaws with definition, relevant observational and randomized studies that showed both positive and negative impacts on health and disease, unbiased interpretation of key trials, emerging evidence from microbiome and immuno-oncological studies, and impact on systemic immunity. We propose that caution be exercised prior to endorsements of their illness-directed consumption and rampant general usage. As a deeper understanding of the human microbiome accrues and our ability to manipulate this complex ecosystem improves, the probiotic of tomorrow might be the precision tool that deals with diseases on a broad front. Gut microbiome, akin to fingerprints, is indigenous to an individual and 'one size fits all' prescription strategy should be discouraged until a more universally acceptable 'favorable taxa' or a 'personalized probiotic,' to complement an individual's native microbiota, gets fashioned.

Xylitol's Health Benefits beyond Dental Health: A Comprehensive Review

Xylitol has been widely documented to have dental health benefits, such as reducing the risk for dental caries. Here we report on other health benefits that have been investigated for xylitol. In skin, xylitol has been reported to improve barrier function and suppress the growth of potential skin pathogens. As a non-digestible carbohydrate, xylitol enters the colon where it is fermented by members of the colonic microbiota; species of the genus Anaerostipes have been reported to ferment xylitol and produce butyrate. The most common Lactobacillus and Bifidobacterium species do not appear to be able to grow on xylitol. The non-digestible but fermentable nature of xylitol also contributes to a constipation relieving effect and improved bone mineral density. Xylitol also modulates the immune system, which, together with its antimicrobial activity contribute to a reduced respiratory tract infection, sinusitis, and otitis media risk. As a low caloric sweetener, xylitol may contribute to weight management. It has been suggested that xylitol also increases satiety, but these results are not convincing yet. The benefit of xylitol on metabolic health, in addition to the benefit of the mere replacement of sucrose, remains to be determined in humans. Additional health benefits of xylitol have thus been reported and indicate further opportunities but need to be confirmed in human studies.

Effectiveness of the probiotic Streptococcus salivarius K12 for the treatment and/or prevention of sore throat: a systematic review

BACKGROUND

Sore throat resulting from pharyngotonsillitis is one of the commonest reasons for primary care consultation and inappropriate antibiotic prescription and finding effective alternative treatments is important.

OBJECTIVES

To review the evidence for using the probiotic Streptococcus salivarius K12 (SsK12) for the prevention or treatment of pharyngotonsillitis.

DATA SOURCES

PubMed, Embase, CINAHL and Cochrane Library.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials (RCTs).

PARTICIPANTS

Adults or children.

INTERVENTIONS

SsK12 as active treatment or prophylaxis, against pharyngotonsillitis.

METHODS

Literature search.

RESULTS

Four articles were identified (1846 participants). All were deemed to be of poor quality using the Cochrane risk-of-bias assessment. Two trials studied SsK12 prophylaxis for streptococcal pharyngitis (children without history of recurrence). One compared daily administration of SsK12 to no treatment over 6 months (n = 222, age 33-45 months), reporting significantly lower incidence in the SsK12 group (16.2% vs. 48.6%, p < 0.01), whereas another placebo-controlled RCT over four school terms (n = 1314, 5-14 years) found no significant difference (7.8% vs. 8.8%, p 0.34) with SsK12 (administered on school days). Another trial found daily SsK12 to significantly protect children (n = 250, 6-7 years) against chronic adenoiditis exacerbation over 3 months compared to no treatment (71.7% vs. 100%, p < 0.0001). The one placebo-controlled RCT in adults that studied the use of SsK12 for acute pharyngotonsillitis (concurrently with penicillin) showed no significant benefit. In all trials, SsK12 was safe and well tolerated.

CONCLUSIONS

SsK12 appears safe and well tolerated. However, further RCTs are required to establish its role as a prophylactic therapy, particularly among patients experiencing frequent exacerbations of pharyngitis. In the acute setting, SsK12 is unlikely to be effective if given concurrently with antibiotics; however, further RCTs should establish its role as an alternative to antibiotics in nonsevere cases or when prescribed after antibiotic therapy for the prevention of disease recurrence and/or secondary infection.

Lactobacillus rhamnosus GG versus Placebo for Acute Gastroenteritis in Children

BACKGROUND

Acute gastroenteritis develops in millions of children in the United States every year, and treatment with probiotics is common. However, data to support the use of probiotics in this population are limited.

METHODS

We conducted a prospective, randomized, double-blind trial involving children 3 months to 4 years of age with acute gastroenteritis who presented to one of 10 U.S. pediatric emergency departments. Participants received a 5-day course of Lactobacillus rhamnosus GG at a dose of 1×10¹⁰ colony-forming units twice daily or matching placebo. Follow-up surveys were conducted daily for 5 days and again 14 days after enrollment and 1 month after enrollment. The primary outcome was moderate-to-severe gastroenteritis, which was defined as an illness episode with a total score on the modified Vesikari scale of 9 or higher (scores range from 0 to 20, with higher scores indicating more severe disease), within 14 days after enrollment. Secondary outcomes included the duration and frequency of diarrhea and vomiting, the duration of day-care absenteeism, and the rate of household transmission (defined as the development of symptoms of gastroenteritis in previously asymptomatic household contacts).

RESULTS

Among the 971 participants, 943 (97.1%) completed the trial. The median age was 1.4 years (interquartile range, 0.9 to 2.3), and 513 participants (52.9%) were male. The modified Vesikari scale score for the 14-day period after enrollment was 9 or higher in 55 of 468 participants (11.8%) in the L. rhamnosus GG group and in 60 of 475 participants (12.6%) in the placebo group (relative risk, 0.96; 95% confidence interval, 0.68 to 1.35; P=0.83). There were no significant differences between the L. rhamnosus GG group and the placebo group in the duration of diarrhea (median, 49.7 hours in the L. rhamnosus GG group and 50.9 hours in the placebo group; P=0.26), duration of vomiting (median, 0 hours in both groups; P=0.17), or day-care absenteeism (median, 2 days in both groups; P=0.67) or in the rate of household transmission (10.6% and 14.1% in the two groups, respectively; P=0.16).

CONCLUSIONS

Among preschool children with acute gastroenteritis, those who received a 5-day course of L. rhamnosus GG did not have better outcomes than those who received placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT01773967 .).