Lactic acid bacteria as probiotics for the nose?

Abstract

Several studies have recently pointed towards an increased occurrence and prevalence of several taxa of the lactic acid bacteria (LAB) in the microbiota of the upper respiratory tract (URT) under healthy conditions versus disease. These include several species of the Lactobacillales such as Lacticaseibacillus casei, Lactococcus lactis and Dolosigranulum pigrum. In addition to physiological studies on their potential beneficial functions and their long history of safe use as probiotics in other human body sites, LAB are thus increasingly to be explored as alternative or complementary treatment for URT diseases. This review highlights the importance of lactic acid bacteria in the respiratory tract and their potential as topical probiotics for this body site. We focus on the potential probiotic properties and adaptation factors that are needed for a bacterial strain to optimally exert its beneficial activity in the respiratory tract. Furthermore, we discuss a range of in silico, in vitro and in vivo models needed to obtain better insights into the efficacy and adaptation factors specifically for URT probiotics. Such knowledge will facilitate optimal strain selection in order to conduct rigorous clinical studies with the most suitable probiotic strains. Despite convincing evidence from microbiome association and in vitro studies, the clinical evidence for oral or topical probiotics for common URT diseases such as chronic rhinosinusitis (CRS) needs further substantiation.

Genomic Stability and Genetic Defense Systems in Dolosigranulum pigrum , a Candidate Beneficial Bacterium from the Human Microbiome

“…In stark contrast to the steadily increasing data in support of D. pigrum as a candidate beneficial bacterium ( 40 ), there is a dearth of information about the basic biology of this Gram-positive organism, including the organization and stability of its genome. Ideally, bacterial strains with therapeutic potential display a reliably stable genome structure and have the capacity to resist horizontal gene transfer (HGT), since the latter might lead to unanticipated effects.…”

Topical Microbial Therapeutics against Respiratory Viral Infections

“…First, application of microbial therapeutics into the airways can be more efficient by directly targeting the respiratory immune system and the viral particles in situ, thus bypassing the gut-lung axis [75]. This direct delivery to the airways could be particularly important for use of bacterial isolates from the airways, which could well be better adapted to the aerobic conditions, rapid nasal clearance, and interactions with the host airway cells, as demonstrated in [5] and reviewed in [106]. While the more widely studied lactobacilli represent promising candidates for topical microbial therapeutics in the airways [5], other airway commensals such as Dolosigranulum spp., Corynebacterium spp., and Rothia spp.…”

Exploiting the struggle for haem: a novel therapeutic approach against

“…Using a model designed to predict the risk of otitis media in children based on NTHi pharyngeal carriage load 30 , we could predict a %40% decrease in the risk of infection, provided the level of protection conferred by Hpl-producing Hh to model cell lines was preserved in the context of the respiratory tract. Hh also possesses favourable characteristics suited to probiotic applications; it has not been implicated as a causative agent of respiratory tract infection 33,34 and as a normal pharyngeal inhabitant, is able to thrive in the niche amongst other microbial inhabitants 35 . Additionally, probiotic-based therapies have a narrow spectrum of activity that do not damage host tissue, provoke collateral damage to the healthy microbiome or promote enrichment of resistant clones 36 ; properties which make them an asset against the emergence of antibiotic resistance.…”