Beneficial effects of probiotics in upper respiratory tract infections and their mechanical actions to antagonize pathogens

Abstract

Summary Probiotics are live micro‐organisms with beneficial effects on human health, which have the ability to counteract infections at different locations of the body. Clinical trials have shown that probiotics can be used as preventive and therapeutic agents in upper respiratory tract infections (URTIs) and otitis. Their mechanical properties allow them to aggregate and to compete with pathogens for nutrients, space and attachment to host cells. Consequently, they can directly antagonize pathogens and thus exert beneficial effects without directly affecting the metabolism of the host. An overview of the probiotics with such traits, tested up to date in clinical trials for the prevention or treatment of URTIs and otitis, is presented in this review. Their mechanical properties in the respiratory tract as well as at other locations are also cited. Species with interesting in vitro properties towards pharyngeal cells or against common respiratory pathogens have also been included. The potential safety risks of the cited species are then discussed. This review could be of help in the screening of probiotic strains with specific mechanical properties susceptible to have positive effects in clinical trials against URTIs.

Evaluation of probiotic potential of lactic acid bacteria isolated from traditional Malaysian fermentedBambangan(Mangifera pajang)

“…A probiotic must be able to survive through the intestinal tract with drastically low pH in the stomach environment as well as capable of tolerating the harmful effect of bile salts and gastrointestinal juices (Makinen, Berger, Bel-Rhlid, & Ananta, 2012). In addition, potential probiotics must be able to adhere and colonise the intestinal cell wall in order to trigger any direct interactions between probiotic and the host cells, leading to competitive exclusion of pathogens and modulation of host responses (Popova et al, 2012). The selected probiotic strain must be safe for human consumption and does not induce any potential harm to the hosts.…”

Recommending Oral Probiotics to Reduce Winter Antibiotic Prescriptions in People With Asthma: A Pragmatic Randomized Controlled Trial

“…23 Immune effects of probiotics may be species-or strain-rather than genus-specific. 24,25 It is also possible that publication bias, which is difficult to assess in meta-analyses of small numbers of studies, or time-lag bias may have contributed to the Cochrane review's findings. 26 We identified a data-entry error in the 2011 Cochrane review and an issue of differential loss to follow-up-an assumption that the 18.3% in the probiotic group and 4.6% in the control group who were lost to follow-up would all have had no URTIsboth relating to the included studies of Hao et al 2 and Cobo Sanz et al 27 (Supplemental Appendix 7, http:// www.annfammed.org/content/14/5/422/suppl/DC1).…”

Probiotic Agents in Critically Ill Patients

“…The potential mechanisms of action whereby probiotics provide health benefits to the host are poorly delineated but appear to be diverse and, at least partially, species specific (Popova et al 2012). The simplest way for probiotics to favorably affect the host is through direct manipulation of the intestinal microbiota composition resulting in pathogen colonization resistance.…”