Lacticaseibacillus casei AMBR2 modulates the epithelial barrier function and immune response in a donor-derived nasal microbiota manner

Amairia

Journal of Medical Virology

2020

Coronavirus disease 2019 (COVID‐19) is caused by respiratory syndrome coronavirus qualified as SARS‐CoV‐2. Viral penetration requires binding of the viral spike (S) protein to a specific cellular receptor (ACE2) highly expressed in a nasal goblet and ciliated cells. In several countries, the COVID‐19 evolution was relatively benign compared to others and despite noncompliance with health recommendations on several occasions. In this overview, we attempt to define the criteria that could explain such a difference. Among these criteria, the specificity of Lactobacillus genus strains, as a part of nasal microbiota, could play a role of a barrier against viral penetration and could strengthen the host's immune system in some populations rather than others. In fact, several studies have shown the role of lactic acid bacteria, including lactobacilli, in the prevention of viral respiratory infections. This could provide important information on a possible mechanism of the virus spreading.

“…Moreover, Lactobacillus casei AMBR2 could survive in the upper respiratory tract using fimbriae for attachment and coping with oxidative stress through catalase genes 48 …”

Section: Outlook: “If We Started Developing Targeted Intranasal Dropsmentioning

confidence: 99%

Respiratory syndrome coronavirus‐2 response: Microbiota as lactobacilli could make the difference

Amairia

Journal of Medical Virology

2020

“…Nevertheless, we have recently isolated probiotic candidates Lacticaseibacillus casei AMBR2 [17] and Streptococcus salivarius strains [18] capable of respiratory pathogen inhibition from nasopharyngeal samples of healthy humans. Especially L. casei AMBR2 has shown potential as a live biotherapeutic product (LBP) due to its capacity to inhibit the growth and inflammatory characteristics of URT pathogens such as Staphylococcus aureus and promote epithelial barrier function [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Live biotherapeutic throat spray for respiratory virus inhibition and interferon pathway induction

Spacova

Boeck

Cauwenberghs

et al. 2022

Preprint

Self Cite

Respiratory viruses such as influenza viruses, respiratory syncytial virus (RSV), and coronaviruses initiate infection at the mucosal surfaces of the upper respiratory tract (URT), where the resident respiratory microbiome has an important gatekeeper function. In contrast to gut-targeting administration of beneficial bacteria against respiratory viral disease, topical URT administration of probiotics is currently underexplored, especially for the prevention and/or treatment of viral infections. Here, we report the selection and formulation of a broad-acting throat spray with live lactobacilli which induce interferon regulatory pathways and are able to inhibit respiratory viruses. Rational selection of Lactobacillaceae strains was based on safety, applicability, and potential antiviral and immunostimulatory efficacy in the URT. Three strains, Lacticaseibacillus casei AMBR2, Lacticaseibacillus rhamnosus GG and Lactiplantibacillus plantarum WCFS1 significantly reduced the cytopathogenic effects of RSV, influenza A/H1N1 and B viruses, and HCoV-229E coronavirus in co-culture models with bacteria, virus and host cells. Subsequently, these strains were formulated in a throat spray and human monocytes were employed to confirm the formulation process did not reduce the interferon regulatory pathway-inducing capacity. Administration of the throat spray in healthy volunteers revealed that the lactobacilli were capable of temporary colonization of the throat in a metabolically active form.

Trends in Molecular Medicine

“…Moreover, a positive correlation between epithelial barrier function and the relative abundance of Lactobacillaceae in chronic rhinosinusitis patients has been established [5]. Subsequently, L. casei AMBR2 isolated from the healthy human URT [5] enhanced and regulated the epithelial barrier function in differentiated human airway epithelium-based models [79].…”

Section: Prevention Of Uncontrolled Airway Inflammation and Barrier Dmentioning

confidence: 99%

Topical Microbial Therapeutics against Respiratory Viral Infections

Spacova

Boeck

Bron

et al. 2021

Self Cite

Emerging evidence suggests that microbial therapeutics can prevent and treat respiratory viral diseases, especially when applied directly to the airways. This review presents established beneficial effects of locally administered microbial therapeutics against respiratory viral diseases and the inferred related molecular mechanisms. Several mechanisms established in the intestinal probiotics field as well as novel, niche-specific insights are relevant in the airways. Studies at cellular and organism levels highlight biologically plausible but strain-specific and host and virus context-dependent mechanisms, underlying the potential of beneficial bacteria. Large-scale clinical studies can now be rationally designed to provide a bench-to-bedside translation of the multifactorial bacterial mechanisms within the host respiratory tract, to diminish the incidence and severity of viral infections and the concomitant complications. The Respiratory Microbiota and Viral InfectionsThe human airways represent an important ecological habitat consisting of the upper respiratory tract (URT) (the nose, paranasal sinuses, nasopharynx, and larynx above the vocal cords) and the lower respiratory tract (LRT) (the larynx below the vocal cords, tracheobronchial tree containing the trachea, bronchi, and bronchioles, and the alveoli) [1]. The airways, like the gut, host diverse communities of microorganisms, collectively forming the microbiota (see Glossary), that undergo continuous interactions with each other, the host, and exogenous microbes [1-3]. There are, however, notable differences between the gut and respiratory tract, including significantly lower microbial biomass and biodiversity in the airways and specific epithelial and immune cell types and mucus composition that impact the microbe-host interactions [1,3].The microbiota of the URT and LRT of healthy individuals are a continuum of taxa shared due to processes such as mucosal dispersion and micro-aspiration from the URT to the LRT [1,2]. As has been well-established in the gastrointestinal tract, emerging evidence suggests that endogenous microbial communities also play a pivotal role in airway health through preventing colonization by pathogens and maintaining immune homeostasis [1]. An increasing number of microbiome studies indicate that a healthy URT microbiota includes taxa such as Corynebacterium, Staphylococcus, Streptococcus, Fusobacterium, Moraxella, Prevotella, Rothia, and lactic acid bacteria (e.g., Lactobacillaceae and Dolosigranulum) [4-6]. It is not yet clear which of these taxa are key for maintaining respiratory health. Based on current evidence, Lactobacillaceae [5], Rothia [7], and Dolosigranulum [5,8] are generally associated with health, while the opportunistic pathogens Streptococcus pneumoniae, Haemophilus influenzae, and potentially Moraxella catarrhalis are linked with excessive inflammation and respiratory infection [2,9]. Respiratory tract infections are among the leading global causes of death [10]. Most acute URT infections and cases of bronchiti...