Pharmacological Efficacy of Probiotics in Respiratory Viral Infections: A Comprehensive Review

Alsayegh A, Ahmad FA, Akhtar MS, Alavudeen SS, Bantun F, Wahab S, Ahmed A, Ali M, Elbendary EY, Raposo A, Kambal N, H. Abdelrahman M. Ganoderma lucidum: Insight into antimicrobial and antioxidant properties with development of secondary metabolites

Ganoderma lucidum is a versatile mushroom. Polysaccharides and triterpenoids are the major bioactive compounds and have been used as traditional medicinal mushrooms since ancient times. They are currently used as nutraceuticals and functional foods. G. lucidum extracts and their bioactive compounds have been used as an alternative to antioxidants and antimicrobial agents. Secondary metabolites with many medicinal properties make it a possible substitute that could be applied as immunomodulatory, anticancer, antimicrobial, anti-oxidant, anti-inflammatory, and anti-diabetic. The miraculous properties of secondary metabolites fascinate researchers for their development and production. Recent studies have paid close attention to the different physical, genetic, biochemical, and nutritional parameters that potentiate the production of secondary metabolites. This review is an effort to collect biologically active constituents from G. lucidum that reveal potential actions against diseases with the latest improvement in a novel technique to get maximum production of secondary metabolites. Studies are going ahead to determine the efficacy of numerous compounds and assess the valuable properties achieved by G. lucidum in favor of antimicrobial and antioxidant outcomes.

A systematic review and meta-analysis on nutritional and dietary interventions for the treatment of acute respiratory infection in pediatric patients: An EAACI taskforce

Acute respiratory infections are a major cause of morbidity and mortality in children worldwide. Dietary and nutritional interventions, including minerals and vitamin supplementation, have been explored as potential treatments for these infections. However, the evidence on their efficacy is limited and inconclusive. This systematic review and meta-analysis aim to provide a comprehensive summary of the available evidence on the effectiveness of dietary and nutritional interventions for treating acute respiratory tract infections in children. A systematic review was conducted according to the PRISMA 2020 guidelines in April 2022 and updated in April 2023. Clinical trials focusing on dietary or nutritional interventions, including supplementations, in children with acute respiratory tract infections were included. The selection of interventions and outcomes was based on biological plausibility. Data were extracted using a standardized form, and the risk of bias was assessed using the Cochrane Risk of Bias Tool. Meta-analysis was performed using random-effect models. A total of 50 studies were included in the review. Four trials were conducted in low, 32 in lower-middle, 12 in upper-middle, and only two in high-income countries. The studies evaluated various dietary interventions, including zinc, vitamin A, vitamin E, vitamin D, and probiotics. The results of individual studies on the efficacy of these interventions were mixed, with some showing positive effects on clinical outcomes such as duration of symptoms, while others showed no significant impact. Meta-analysis was conducted for zinc supplementation in children with pneumonia, and the pooled results suggested a potential limited benefit in terms of reduced hospital length of stay but not time to recovery. Meta-analyses on vitamin D did not show any effect in children with pneumonia. This systematic review fills a critical gap in the literature by synthesizing the available evidence on the efficacy and safety of nutritional or dietary interventions for acute respiratory tract infections in children. The findings indicate no dietary or nutritional intervention can currently be recommended for the routine treatment of respiratory tract infections in children based on single supplement studies. The metanalysis suggests that zinc supplementation might have a beneficial effect on length of hospitalization in children with pneumonia. New studies are needed to establish more conclusive evidence for pediatric acute respiratory diseases especially for children living in a context of high-income countries.

Lactobacillus Probiotic Strains Differ in Their Ability to Adhere to Human Lung Epithelial Cells and to Prevent Adhesion of Clinical Isolates of Pseudomonas aeruginosa from Cystic Fibrosis Lung

The field of probiotic applications is rapidly expanding, including their use for the control of respiratory tract infections. Nevertheless, probiotics ability to colonize the lung environment and to compete with pulmonary pathogens is still a poorly investigated research area. In this study, we aimed to evaluate the adhesion ability of a number of commercial probiotic strains to the human lung epithelial cell line A549. Furthermore, we assessed probiotic ability to prevent host cell adhesion of one of the major lung pathogens in cystic fibrosis, Pseudomonas aeruginosa, and to reduce the pathogen-induced inflammatory response of human peripheral blood mononuclear cells (PBMCs) in terms of cytokine release. Lactobacillus acidophilus displayed the highest adhesion ability to A549 cells evaluated as percent of adhered bacteria compared to the inoculum. In agreement with such an observation, L. acidophilus was the most efficient in preventing adhesion to A549 cells of a P. aeruginosa isolate from CF sputum. Three-color fluorescence labeling of A549 cells, P. aeruginosa, and L. acidophilus, and confocal microcopy image analyses revealed a likely exclusion effect played by both live and UV-killed L. acidophilus towards P. aeruginosa. Such results were confirmed by CFU count. When co-cultured with PBMCs, both live and UV-killed L. acidophilus reduced the amount of IL-1β and IL-6 in culture supernatants in a statistically significant manner. Overall, the results obtained point to L. acidophilus as an interesting candidate for further studies for a potential aerogenous administration to control P. aeruginosa infections.

Clinical efficacy of probiotics in the treatment of patients with COVID-19: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

This study was conducted to assess the clinical efficacy of probiotics in the treatment of patients with COVID19.

METHODS

PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for studies from their inception to 8 February 2022. Randomized controlled trials (RCTs) that compared the clinical efficacy of probiotics with usual care or standard care for patients with COVID19 were included. The primary outcome was all-cause mortality. Random-effects model using MantelHaenszel and inverse variance methods were performed to analyze the data.

RESULTS

Eight RCTs with 900 patients were included. The study group receiving probiotics had a non-significantly lower rate of mortality than the control group had, but this difference was not significant (risk ratio [RR], 0.51; 95% CI, 0.22 to 1.16). However, the study group had significantly lower rates of dyspnea (RR, 0.11; 95% CI, 0.02 to 0.60), fever (RR, 0.37; 95% CI, 0.16 to 0.85) and headache (RR, 0.19; 95% CI, 0.05 to 0.65). Higher complete remission of COVID-19-associated symptoms was observed in the study group than the control group (RR, 1.89; 95% CI, 1.40-2.55).

CONCLUSIONS

Although probiotics use did not improve clinical outcomes or reduce inflammatory markers, it may relieve COVID-19-associated symptoms.

The beneficial effects of spraying of probiotic Bacillus and Lactobacillus bacteria on broiler chickens experimentally infected with avian influenza virus H9N2

This study investigated the clinical, antiviral, and immunological effects of spraying Bacillus spp. and Lactobacillus spp. as a single or mixture probiotic compound on experimentally infected broiler chickens with AIV H9N2. Two hundred and forty 1-day-old broilers were randomly assigned to 6 groups as follows: Ctrl- (no challenge AIV; no spray probiotic), Ctrl+ (AIV challenged; no spray probiotic), AI+B (AIV challenged; daily spraying of probiotic Bacillus spp.), AI+L group (AIV challenged; daily spraying of probiotic Lactobacillus spp.), AIV+BL (AIV challenged; daily spraying of probiotic Bacillus spp. and Lactobacillus spp.), and G-DW (daily spraying of normal saline; no AIV challenged). The birds were reared for 35 d. On the 22nd day of age, broiler chickens were challenged by AIV H9N2. The probiotics were sprayed at 9×10⁹ CFU/m² daily for 35 d. Growth performance, clinical signs, virus shedding, macroscopic and microscopic lesions were evaluated at various days in all groups. Spraying with probiotics improved the body weight gain and food conversion ratio in the AI+B, AI+L, and AI+BL groups compared to the Ctrl+. The severity of clinical signs, gross lesions, pathological lesions and viral shedding in the probiotic treatment groups was lower than in the Ctrl+ group. The findings of this study suggest the daily spraying of Lactobacillus and Bacillus probiotics alone or in combination during the rearing period reduce clinical and nonclinical aspects of H9N2 virus infection; so, it can be effective as a preventive protocol for controlling the severity of AIV H9N2 infection in broilers.

In Vitro Screening of Antiviral Activity of Lactic Acid Bacteria Isolated from Traditional Fermented Foods

Studies of newly isolated strains of lactic acid bacteria (LAB) are a good basis for expanding the potential for their applications in functional foods, probiotic food supplements, and other probiotic products. They exhibit various functional properties, including such with antiviral activity. Probiotic strains can manifest their antiviral effects by various mechanisms, including direct interaction with viruses, production of antiviral compounds, or immune system modulation. Ten newly isolated LAB strains from traditional fermented food products have been tested for the determination of their antiviral activity. This study was performed to evaluate the effect of cell-free supernatants (CFSs) from the studied strains for the effect on viral replication of Human alphaherpesvirus—HHV-1 and HHV-2 as well as for direct virucidal activity. The CFSs of the LAB strains were used in non-toxic concentrations of 25%, 6.25%, and 1.6%. No direct virucidal activity was observed in tested CFSs, but five of the strains observed a well-defined effect of viral replication inhibition with the selective index (SI) from 4.40 to >54. For two of these five strains, Lactobacillus delbrueckii subsp. bulgaricus KZM 2-11-3 and Lactiplantibacillus plantarum KC 5-12 strong activity against HHV-2 with a selective index (SI) over 45 was detected, which is a good basis for further research.

The Efficacy of Probiotics as Antiviral Agents for the Treatment of Rotavirus Gastrointestinal Infections in Children: An Updated Overview of Literature

Enteric viruses, including the rotavirus, norovirus, and adenoviruses, are the most common cause of acute gastroenteritis. The rotavirus disease is especially prevalent among children, and studies over the past decade have revealed complex interactions between rotaviruses and the gut microbiota. One way to treat and prevent dysbiosis is the use of probiotics as an antiviral agent. This review focuses on the latest scientific evidence on the antiviral properties of probiotics against rotavirus gastroenteric infections in children. A total of 19 studies exhibited a statistically significant antiviral effect of probiotics. The main probiotics that were effective were Saccharomyces cerevisiae var. boulardii, Lacticaseibacillus rhamnosus GG, and various multi-strain probiotics. The underlying mechanism of the probiotics against rotavirus gastroenteric infections in children included immune enhancement and modulation of intestinal microbiota leading to shortening of diarrhoea. However, several clinical studies also found no significant difference in the probiotic group compared to the placebo group even though well-known strains were used, thus showing the importance of correct dosage, duration of treatment, quality of probiotics and the possible influence of other factors, such as the production process of probiotics and the influence of immunisation on the effect of probiotics. Therefore, more robust, well-designed clinical studies addressing all factors are warranted.