Abstract
BackgroundPrevious studies have suggested that the consumption of probiotic fermented dairy products (PFDP) may have a protective effect on respiratory tract infections (RTIs). However, the results of studies are inconclusive. We aimed to systematically investigate the effect of PFDP on RTIs by performing a meta-analysis of randomized controlled trials (RCTs).MethodsPubMed and Scopus databases were systematically searched up to October 2020 to identify eligible RCTs. Meta-analysis outcomes were risk of incidence of upper (URTIs ) and lower (LRTIs ) respiratory tract infections. A random-effects model was used to pool the relative risks (RR) and corresponding 95 % confidence intervals (CI) for outcomes following conception of PFDP.ResultsA total of 22 RCTs, with a total sample size of 10,190 participants, were included in this meta-analysis. Compared with placebo, consumption of PFDP had a significant protective effect against RTIs in the overall analysis (RR = 0.81, 95 %CI: 0.74 to 0.89) and in children (RR = 0.82, 95 %CI: 0.73 to 0.93), adults (RR = 0.81, 95 %CI: 0.66 to 1.00), and elderly population (RR = 0.78, 95 %CI: 0.61 to 0.98). The significant decreased risk of RTIs was also observed for URTIs (RR = 0.83, 95 %CI: 0.73 to 0.93), while, this effect was marginal for LRTIs (RR = 0.78, 95 %CI: 0.60 to 1.01, P = 0.06). The disease-specific analysis showed that PFDP have a protective effect on pneumonia (RR = 0.76, 95 %CI: 0.61 to 0.95) and common cold (RR = 0.68, 95 %CI: 0.49 to 0.96).ConclusionsConsumption of PFDP is a potential dietary approach for the prevention of RTIs.
Highlights
Search strategy We followed PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) in the design and reporting of the methods for this systematic review [1]
probiotic fermented dairy products (PFDP) had a protective effect on pneumonia and common cold
The protective effect of PFDP was modified by probiotic genus and type of dairy product used for intervention
Summary
Methods Search strategy We followed PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) in the design and reporting of the methods for this systematic review [1]. PubMed and Scopus online databases were searched from inception to October 2020 for RCTs examining the effect of probiotic fermented dairy products on incidence of respiratory tract infections. Previous studies have suggested that the consumption of probiotic fermented dairy products (PFDP) may have a protective effect on respiratory tract infections (RTIs). ARIs are a main public health problem worldwide and contribute to increased morbidity and mortality, as they result in a large number of outpatient visits, hospital admissions, and the widespread administration of antibiotics [2]. These diseases affect all age groups every year and put a heavy burden on the world’s health and economic systems. LRTIs-induced pneumonia can be predominantly fatal in children and the elderly or in immunocompromised individuals [4, 8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
