The Cross-Talk Between Gut Microbiota and Lungs in Common Lung Diseases

Abstract

Emerging findings indicate there is a vital cross-talk between gut microbiota and the lungs, which is known as gut-lung axis. The gut disturbances in lung diseases including allergy, asthma, chronic obstructive pulmonary disease, cystic fibrosis and lung cancer were observed by extensive studies. Investigating how gut microbiota impact other distant organs is of great interest in recent years. Although it has not been fully understood whether the disturbance is the cause or effect of lung diseases, alterations in the gut microbial species and metabolites have been linked to changes in immune responses and inflammation as well as the disease development in the lungs. In this article, we systemically review the role and mechanisms underlying the changes in the constituent of gut microbiota and metabolites in lung diseases. In particular, the roles of gut-lung axis in mediating immune responses and reshaping inflammation are highlighted. Furthermore, we discuss the potential of strategies to manipulate the gut microbiota and metabolites as the therapeutic approach for lung diseases.

Alveolar Macrophages Are Key Players in the Modulation of the Respiratory Antiviral Immunity Induced by Orally Administered Lacticaseibacillus rhamnosus CRL1505

“…Of note, other probable mechanisms have been proposed, which are not mutually exclusive, to explain the effect of the intestinal beneficial microbes on the respiratory antiviral immunity. There is evidence that some microbial-associated molecular patterns (MAMPs) derived from the intestinal microbiota can be adsorbed and transported to extraintestinal sites where they stimulate pattern recognition receptors (PRRs) expressed in non-immune and immune cells influencing the immune responses ( 58 , 59 ). In addition, microbial metabolites that are adsorbed in the intestine have been associated to the differential modulation of respiratory immune responses.…”

The Human Respiratory System and its Microbiome at a Glimpse

“…Following airway immune stimulation, T-cells are activated in the GALT and MLN, move to the respiratory epithelium and provide protection and anti-inflammatory action. The SCFAs from the intestine reach the lungs and suppress inflammation [ 9 , 12 , 13 ].…”

“…In addition, the interaction between the intestine and the lungs plays an important role in pulmonary microbiome eubiosis and immunomodulation [ 8 , 9 , 10 ]. It then becomes important to investigate the role of: (a) pathogenic microbes that cause or contribute to disease development and/or progression, (b) commensal microbes that do not cause disease, (c) neutral or beneficial host interaction bacterial microbiota studies, (d) the recent reassessment of viruses and fungi [ 11 , 12 , 13 ].…”

The Effects of Corticosteroids on the Respiratory Microbiome: A Systematic Review

“…A randomized-controlled study of children suffering from acute lung injury found signi cantly lower levels of in ammatory factors and less small bronchial obstruction in children treated with probiotics when compared to placebo-treated controls, whose in ammatory factors did not drop as rapidly and whose pulmonary function was still limited after 10 days (15). Although some aspects of the interaction between the intestinal-and the lung microbiome have been described, the complex cross-talk, the causality between lung diseases and gut microbiota is still underexplored (16).…”