Making the case for causality: what role do lung microbiota play in idiopathic pulmonary fibrosis?

Abstract

Yet more evidence that the lung microbiome plays a role in idiopathic pulmonary fibrosis. But how close are we to proving causality? An editorial from Dickson, Harari and Kolb in the ERJ. http://bit.ly/ 2Ps1ow4

The respiratory microbiota and its impact on health and disease in dogs and cats: A One Health perspective

“…Although familial IPF is uncommon in humans, 148 the predisposition of WHWT for CIPF raises suspicion for a genetic cause 143 . Although there is no evidence for causality, several studies have established that the lower airway microbiota of humans with IPF can be correlated to disease status, alveolar inflammation, and host genotype, among other factors 149 . Additionally, variation in the lung microbiota can predict disease progression and mortality among human patients with IPF 150‐152 …”

“…143 Although there is no evidence for causality, several studies have established that the lower airway microbiota of humans with IPF can be correlated to disease status, alveolar inflammation, and host genotype, among other factors. 149 Additionally, variation in the lung microbiota can predict disease progression and mortality among human patients with IPF. [150][151][152] To date, a single peer-reviewed study has been published characterizing the lower airway microbiota of WHWTs with CIPF.…”

Insights into the Role of Bioactive Food Ingredients and the Microbiome in Idiopathic Pulmonary Fibrosis

“…In this context, in the last decade, several studies have emerged, showing that lung microbiota plays an important part in airway diseases, including IPF, with a clear connection between lung dysbiosis, mortality and altered immune system pathways. As recently discussed by Dickson et al [ 156 ], the importance of lung microbiota in IPF is evident in the ongoing, current clinical trials, in which, instead of investigating immunosuppression-associated drugs, antibiotics for microbiota manipulation are being trialed.…”

“…Manipulation of lung microbiota has been achieved in other pulmonary diseases by means of antibiotic treatment; this, however, still needs to be determined whether it occurs in IPF [ 156 ]. For this, there are ongoing trials of antibiotic treatment in IPF, which will hopefully shed some light on this matter [ 166 , 167 ].…”

“…However, as with most data regarding host microbiota, discerning the causal relationship between pulmonary and gut microbiota and IPF progression and pathogenesis is still complicated and needs further study, in order to fully understand the mechanistic pathways. It is still unknown whether the impact observed after microbiome manipulation in IPF are due to indirect, off-target effects, mainly on gut microbiota; for this, more studies are required, that can selectively alter lung microbiota without changing gut bacterial composition [ 156 ], which is known to greatly interact with the immune system.…”