Probiotics for prevention and treatment of respiratory tract infections in children: A systematic review and meta-analysis of randomized controlled trials.
Plain language summary
Respiratory tract infections (RTIs) are a leading cause of morbidity and mortality among children worldwide. Probiotics are thought to be able to balance the gut microbiota and interact with the immune system, which may promote resistance against pathogens. There are conflicting results from studies investigating the effect of probiotics on RTI infection. The aim of this systematic review and meta-analysis was to provide the latest and convincing evidence of the effect of probiotic consumption on RTIs in children. 32 studies were included in the qualitative analysis, and 23 in the quantitative meta-analysis. All trials were randomised, double-blinded, and placebo-controlled. Probiotic supplementation had a significant effect on the reduction of number of subjects having at least 1 respiratory symptom episode, on the number of days the children were ill and the number of days absent from day care/school. There was no significant statistical difference of illness episode duration. There was statistical heterogeneity among the trials, and subgroup analysis did not highlight the source of this. It was noted, however, that the probiotic strain, the duration of regimens, administration forms, doses, and follow-up times differed across the included studies, as did the age of children. The authors conclude that probiotic consumption may decrease the incidence and illness duration of RTIs, and that further research is needed to establish optimal probiotic strains, dosing, administration form, time of intervention, and long-time follow-up.
BACKGROUND Respiratory tract infections (RTIs) represent one of the main health problems in children. Probiotics are viable bacteria that colonize the intestine and affect the host intestinal microbial balance. Accumulating evidence suggests that probiotic consumption may decrease the incidence of or modify RTIs. The authors systematically reviewed data from randomized controlled trials (RCTs) to investigate the effect of probiotic consumption on RTIs in children. METHODS MEDLINE/PubMed, Embase, Cochrane Library, and Web of Science were systematically searched for RCTs regarding the effect of probiotics on RTIs in children. The outcomes included number of children experienced with at least 1 RTI episode, duration of illness episodes, days of illness per subject, and school/day care absenteeism due to infection. A random-effects model was used to calculate pooled relative risks, or mean difference (MD) with the corresponding 95% confidence interval (CI). RESULTS A total of 23 trials involving 6269 children were eligible for inclusion in the systematic review. None of the trials showed a high risk of bias. The quality of the evidence of outcomes was moderate. The age range of subjects was from newborn to 18 years. The results of meta-analysis showed that probiotic consumption significantly decreased the number of subjects having at least 1 RTI episode (17 RCTs, 4513 children, relative risk 0.89, 95% CI 0.82-0.96, P = 0.004). Children supplemented with probiotics had fewer numbers of days of RTIs per person compared with children who had taken a placebo (6 RCTs, 2067 children, MD -0.16, 95% CI -0.29 to 0.02, P = 0.03), and had fewer numbers of days absent from day care/school (8 RCTs, 1499 children, MD -0.94, 95% CI -1.72 to -0.15, P = 0.02). However, there was no statistically significant difference of illness episode duration between probiotic intervention group and placebo group (9 RCTs, 2817 children, MD -0.60, 95% CI -1.49 to 0.30, P = 0.19). CONCLUSION Based on the available data and taking into account the safety profile of RCTs, probiotic consumption appears to be a feasible way to decrease the incidence of RTIs in children.
Single-component versus multicomponent dietary goals for the metabolic syndrome: a randomized trial.
Annals of internal medicine. 2015;(4):248-57
BACKGROUND Few studies have compared diets to determine whether a program focused on 1 dietary change results in collateral effects on other untargeted healthy diet components. OBJECTIVE To evaluate a diet focused on increased fiber consumption versus the multicomponent American Heart Association (AHA) dietary guidelines. DESIGN Randomized, controlled trial from June 2009 to January 2014. (ClinicalTrials.gov: NCT00911885). SETTING Worcester, Massachusetts. PARTICIPANTS 240 adults with the metabolic syndrome. INTERVENTION Participants engaged in individual and group sessions. MEASUREMENTS Primary outcome was weight change at 12 months. RESULTS At 12 months, mean change in weight was -2.1 kg (95% CI, -2.9 to -1.3 kg) in the high-fiber diet group versus -2.7 kg (CI, -3.5 to -2.0 kg) in the AHA diet group. The mean between-group difference was 0.6 kg (CI, -0.5 to 1.7 kg). During the trial, 12 (9.9%) and 15 (12.6%) participants dropped out of the high-fiber and AHA diet groups, respectively (P = 0.55). Eight participants developed diabetes (hemoglobin A1c level ≥6.5%) during the trial: 7 in the high-fiber diet group and 1 in the AHA diet group (P = 0.066). LIMITATIONS Generalizability is unknown. Maintenance of weight loss after cessation of group sessions at 12 months was not assessed. Definitive conclusions cannot be made about dietary equivalence because the study was powered for superiority. CONCLUSION The more complex AHA diet may result in up to 1.7 kg more weight loss; however, a simplified approach to weight reduction emphasizing only increased fiber intake may be a reasonable alternative for persons with difficulty adhering to more complicated diet regimens. PRIMARY FUNDING SOURCE National Heart, Lung, and Blood Institute.
Effects of task-specific locomotor and strength training in adults who were ambulatory after stroke: results of the STEPS randomized clinical trial.
Physical therapy. 2007;(12):1580-602
BACKGROUND AND PURPOSE A phase II, single-blinded, randomized clinical trial was conducted to determine the effects of combined task-specific and lower-extremity (LE) strength training to improve walking ability after stroke. SUBJECTS The participants were 80 adults who were ambulatory 4 months to 5 years after a unilateral stroke. METHOD The exercise interventions consisted of body-weight-supported treadmill training (BWSTT), limb-loaded resistive leg cycling (CYCLE), LE muscle-specific progressive-resistive exercise (LE-EX), and upper-extremity ergometry (UE-EX). After baseline assessments, participants were randomly assigned to a combined exercise program that included an exercise pair. The exercise pairs were: BWSTT/UE-EX, CYCLE/UE-EX, BWSTT/CYCLE, and BWSTT/LE-EX. Exercise sessions were 4 times per week for 6 weeks (total of 24 sessions), with exercise type completed on alternate days. OUTCOMES were self-selected walking speed, fast walking speed, and 6-minute walk distance measured before and after intervention and at a 6-month follow-up. RESULTS The BWSTT/UE-EX group had significantly greater walking speed increases compared with the CYCLE/UE-EX group; both groups improved in distance walked. All BWSTT groups increased walking speed and distance whether BWSTT was combined with LE strength training or not. DISCUSSION AND CONCLUSION After chronic stroke, task-specific training during treadmill walking with body-weight support is more effective in improving walking speed and maintaining these gains at 6 months than resisted leg cycling alone. Consistent with the overtraining literature, LE strength training alternated daily with BWSTT walking did not provide an added benefit to walking outcomes.