Journal of Probiotics & Health
Open Access

Lactobacillus Supplementation for the Respiratory Tract

Harika Chandran^{* *}Correspondence: Harika Chandran, Department of Biotechnology, University of Crete, Heraklion, Greece, Email:

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Description

Intestinal supplementation with Lactobacillus has been shown to promote respiratory health; however immunobiotic Lactobacillus's direct action on the respiratory mucosa may regulate local immunity of the respiratory tract. It has been identified that lactobacillus administered intranasally can enhance the respiratory immune response more than lactobacillus administered orally. Due to a lack of substrate, Lactobacillus administered via the nasal route typically does not result in SCFA (Short-Chain Fatty Acids) production. There are primarily two components to the potential methods via which they control respiratory immunity. Lactobacillus components can be detected by PRR’s (Pattern Recognition Receptor) in the respiratory tract, which eventually caused subsequent pathways to be activated. For instance, nasal priming with L. rhamnosus CRL1505 peptidoglycan elevates lung TNF- and IL-10 levels and upregulates TLR2 and TLR9 expression, which is comparable to intranasal delivery of entire bacteria. While this is happening, nasal priming with L. rhamnosus CRL1505 peptidoglycan can improve the TLR3/RIG-I-activate antiviral immune response by enhancing IFN- and NK cell activity, resulting in increased viral clearance and reducing lung tissue damage.

Peptidoglycan Recognition Proteins (PGRPs), a category of PRRs that mediates bactericidal action, can also detect lung peptidoglycan. For example, active PGRP2 cause neutrophil recruitment in the lung tissue of mice infected with S. pneumoniae. It is important to observe that not all Lactobacillus species' peptidoglycans function as protective agents. In immunodeficient mice, nasal treatment of the L. rhamnosus CRL534 peptidoglycan does not increase resistance to S. pneumoniae infection. This demonstrates that the Lactobacillus protective effect is strain-specific. Furthermore, several mechanisms may be used to activate PRR’s when Lactobacillus is administered by nasal. Even if one PRR is eliminated, another pathway may still be allowed to serve as a secondary protection. For instance, it demonstrates that L. plantarum BAA-793 only begins to have a protective function against pneumonia virus infection when both NOD2 and TLR2 are turned out. Therefore, a major element of the protective function provided by intranasal Lactobacillus administration may include components of Lactobacillus that activate PRR’s.

The ability of Lactobacillus attached to host cells and prevent pathogen adhesion or binding is the primary. In terms of the bacterium, studies have also shown that Lactobacillus can directly prevent the adherence of bacteria to respiratory epithelial cells. The adherence of S. pyogenes to pharyngeal epithelial cells can be prevented by L. rhamnosus Kx151A1, L. reuteri PTA-5289, and L. salivarius LMG9477. Furthermore, administering L. murinus CNCM I-5314, a eubacterium from the murine lung, intravenously can operate as a barrier to prevent S. pneumoniae from colonising the lung tissue. When it comes to viruses, Lactobacillus binds rapidly to the viral receptor molecule to prevent the virus from penetrating the host cell. Angiotensin-converting enzyme 2 is the receptor molecule for the SARS-CoV-2 spike glycoprotein, and lipopeptides generated by L. curvatus, L. sakei, and L. lactis can bind to it. This may prevent the virus from infecting host cells.

Conclusion

In addition to preventing pathogenic bacteria from sticking and adhering, Lactobacillus also directly exhibits antibiotic activity. In vitro, several Lactobacillus species have an antibacterial impact on group A Streptococcus. Similar to L. rhamnosus Kx151A1, L. reuteri PTA-5289 also greatly reduces S. pyogenes' in vitro hemolytic activity. Additionally, some of the proteins that Lactobacillus secretes have antibacterial properties. Reuterin, a substance released by L. reuteri, shows broad-spectrum antibacterial activity.