Study under review: Preventing Respiratory Tract Infections by Synbiotic Interventions: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
The human gastrointestinal tract is colonized by trillions of microbes from more than 1,000 bacterial species that are involved in several critical physiological functions. These include the modulation of intestinal barrier function, nutrient absorption and energy metabolism, regulation of the immune system, and protection against exogenous pathogenic bacteria. However, there is potential for these functions to be disrupted as a result of gut dysbiosis. Gut dysbiosis refers to the disturbance of the gut microbiota homeostasis due to (i) qualitative and quantitative changes in the gut microbiota itself, (ii) changes in the metabolic activities of the microbiota, or (iii) changes in the local distribution of the microbiota.
Since the gut microbiome is involved in physiological functions that relate to immunity and protection from pathogens, and considering that there is “crosstalk” between the gut microbiota and the lungs (termed the gut-lung axis), it’s no surprise that gut dysbiosis has been associated with respiratory tract infections (RTIs)—infectious diseases of the upper or lower respiratory tract, which include the common cold, laryngitis, pharyngitis/tonsillitis, bronchitis, and pneumonia.
One potential strategy to help prevent RTIs is the use of synbiotics, which are products that combine probiotics (live microorganisms that supposedly provide health benefits when used in adequate amounts) and prebiotics (compounds that provide nutrition for the growth of beneficial microorganisms). Since pro- and prebiotics may have independent beneficial effects on the immune system, it has been suggested that the appropriate combination of both may have synergistic effects. However, trials examining the use of synbiotics for RTI prevention have yielded conflicting results. The study under review is the first meta-analysis to have pooled the available trials together to examine the overall impact of synbiotic use on RTI prevention.
The human gastrointestinal tract is colonized by microorganisms that are involved in critical physiological functions, some of which relate to host immunity. Since probiotics (live microorganisms) and prebiotics (food for live microorganisms) may have independent beneficial effects for preventing respiratory tract infections (RTIs), combining both into synbiotics may have synergistic effects. However, trials examining the use of synbiotics for RTI prevention have provided mixed results. The meta-analysis under review pooled the available trials together to examine the overall impact of synbiotic use on RTI prevention.
Other Articles in Issue #65 (March 2020)
NERD News: Pharmaceutical peanut powder power!
In this first installment of NERD News, we cover a new drug that lowers the chance of severe allergic reaction to peanuts in children who already have peanut allergy.
Deep Dive: Thick fiber for slimming down
Consuming viscous, soluble fiber may help reduce bodyweight in the absence of calorie restriction… but not to a meaningful extent.
Investigating vitamin D for reducing arterial stiffness
Vitamin D deficiency is correlated with stiffness of the arteries, which is a predictor of cardiovascular disease. This meta-analysis looked at clinical trials to see if vitamin D supplementation can affect arterial stiffness.
Probiotics for stool solidity during cancer treatment
Probiotics seem to help with diarrhea caused by radiation treatment, but better quality evidence is needed to confirm how well it works, and what doses and strains work best.
Can supplementation help silence tinnitus?
This study found that a blend of lots vitamins and antioxidants had a significant impact on tinnitus, but it’s far from clear which ingredients played a role and which sat on the sidelines.
Safety Spotlight: Dairy, dietary supplement use, and breast cancer
In this first-ever installment of Safety Spotlight, we examine two observational studies that explored the association of breast cancer with dairy intake and breast cancer outcomes with supplement use.
Investigating inulin-type fructans for glycemic control
These prebiotics seem to make a decent dent in glycemic control problems, especially for people with prediabetes and type 2 diabetes.