The Effects of Prebiotics, Synbiotics, and Short-Chain Fatty Acids on Respiratory Tract Infections and Immune Function: A Systematic Review and Meta-Analysis

Abstract

Prebiotics, synbiotics and short-chain fatty acids (SCFA) have been shown to decrease systemic inflammation and play a protective role in chronic respiratory conditions. However, the effect on infection and immune function are unclear. The objective of this systematic review was to summarise the current evidence for prebiotic, synbiotic and SCFA supplementation on respiratory tract infections (RTIs) and immune function. Relevant English language articles up to May 2021 were identified via online databases: MEDLINE, EMBASE, CINAHL, and Cochrane Library. Included studies (n = 58) examined the effect of prebiotics, synbiotics or SCFA, delivered orally, on the incidence, severity or duration of RTIs and/or markers of immune function (e.g. peripheral blood immunophenotyping, NK cell activity). The majority of studies were randomized controlled trials (RCTs) reporting on RTIs in infants and children. Meta-analysis indicated that the number of subjects with ≥1 RTI were reduced with prebiotic (OR 0.73, 95% CI [0.62, 0.86], P = 0.0002, n = 17) and synbiotic (OR 0.75, 95% CI [0.65, 0.87], P = 0.0001, n = 9) supplementation compared to placebo. Further, NK cell activity was increased with synbiotic (SMD 0.74, 95% CI [0.42, 1.06], P < 0.0001, n = 3) supplementation. This review provides evidence that prebiotic, specifically oligosaccharide, supplementation may play a protective role in RTIs in infants and children. There is less evidence for this effect in adults. Supplementation with pre- and synbiotic treatment may alter immune function by increasing NK cell activity, though effects on immunophenotype were less clear.

Managing children with frequent respiratory infections and associated wheezing: a preliminary randomized study with a new multicomponent nasal spray

“…Concerning the preventive effects provided by probiotics, three systematic reviews and meta-analyses examined this issue. [53][54][55] The first study evaluated the impact of prebiotics, synbiotics, and short-chain fatty acids on RRIs with 58 trials. 53 This analysis concluded that oligosaccharide supplementation was effective in infants and children.…”

“…[53][54][55] The first study evaluated the impact of prebiotics, synbiotics, and short-chain fatty acids on RRIs with 58 trials. 53 This analysis concluded that oligosaccharide supplementation was effective in infants and children. The second study analyzed probiotic-fermented dairy products, selecting 22 randomized controlled trials.…”

Probiotics, prebiotics, and postbiotics in health and disease

“…Quality control is vital for the effectiveness of probiotic products; however, inconsistencies in manufacturing processes and storage conditions can affect product quality, leading to variations in clinical outcomes 196 . In terms of the above challenges, prebiotics have more advantages than probiotics, but they still need the assistance of probiotics to exert their functions 197 . Regulatory concerns arise due to the varying classification of probiotics, prebiotics, postbiotics as dietary supplements, food additives, or medicines among countries, leading to differing regulatory standards and approval processes 198 .…”

“… 196 In terms of the above challenges, prebiotics have more advantages than probiotics, but they still need the assistance of probiotics to exert their functions. 197 Regulatory concerns arise due to the varying classification of probiotics, prebiotics, postbiotics as dietary supplements, food additives, or medicines among countries, leading to differing regulatory standards and approval processes. 198 The consumption of live bacteria in probiotics or certain types of prebiotics and postbiotics may conflict with some cultural or religious beliefs.…”

The Link between Different Types of Prebiotics in Infant Formula and Infection Rates: A Review

“…This review concluded that supplementation with prebiotics-especially Oss-may play a role in reducing the incidence and duration of respiratory tract infections in infants and children. There is insufficient evidence of this protective effect for the adult population [50]. Rashidi et al concluded in 2021 that supplementation with prebiotics, probiotics, and synbiotics in infant formula (PRO-formula) plays a protective role against respiratory tract infections.…”