Gut Microbiota and SCFAs Play Key Roles in QingFei Yin Recipe Anti-Streptococcal Pneumonia Effects

Abstract

Emerging evidence has revealed the presence in animals of a bidirectional regulatory “lung-gut axis” that provides resistance to respiratory infections. Clues to the existence of this system stem from observations that respiratory infections are often accompanied by gastrointestinal symptoms, whereby intestinal microbiota appear to play pivotal roles in combating pathogenic infections. Importantly, short-chain fatty acids (SCFAs) produced by the gut microbiota appear to serve as the biological link between host immune defenses and gut flora. Streptococcus pneumoniae (S.pn), the main cause of lower respiratory tract infections, is involved in more than 1.189 million deaths per year. QingFei Yin (QFY) is known for its excellent therapeutic efficacy in combating bacterial lung infections. In this study, effects of S.pn infection on gut homeostasis were assessed using 16S RNA-based microbiota community profiling analysis. In addition, potential mechanisms underlying QFY recipe beneficial therapeutic effects against bacterial pneumonia were explored using S.pn-infected gut microbiota-depleted mice. Results of data analysis indicated that QFY treatment alleviated lung infection-associated pathogenic processes, while also promoting repair of disordered gut flora and counteracting S.pn infection-associated decreases in levels of SCFAs, particularly of acetate and butyrate. Mechanistically, QFY treatment suppressed inflammatory lung injury through inhibition of the host NF-κB-NLRP3 pathway. These results inspired us to identify precise QFY targets and mechanisms underlying QFY anti-inflammatory effects. In addition, we conducted an in-depth evaluation of QFY as a potential treatment for bacterial pneumonia.

Differential Gut Microbiota Compositions Related With the Severity of Major Depressive Disorder

“…Another shared differential genus Faecalibacterium is an important intestinal bacterium to produce butyric acid. Butyric acid is a major short-chain fatty acid (SCFA) produced by gut microbiota ( Sun et al., 2021 ). SCFAs are speculated to play an important role in the cross talk between the gut and brain.…”

Gut–brain axis volatile organic compounds derived from breath distinguish between schizophrenia and major depressive disorder

“…In addition, SCFAs have been found to act as bidirectional connecting agents between the gut and lung microbiota, which has since led to the discovery of a positive correlation between certain infectious bowel diseases and pulmonary infections and vice versa. 37 Given that m/z 90 was incidentally found to be decreased in both patient groups examined in this study, a possible disturbance in both the gut and lung microbiota may therefore be a confounding variable for the pathogenesis of schizophrenia and MDD. Appropriately, previous studies have indicated that elevated levels of butyric acid had a positive effect on several neurologic and psychiatric pathologies, such as Alzheimer disease, Parkinson disease and autism, as well as E123 schizophrenia and MDD.…”

The Effect of a Diet Enriched with Jerusalem artichoke, Inulin, and Fluoxetine on Cognitive Functions, Neurogenesis, and the Composition of the Intestinal Microbiota in Mice

“…Another bacterial taxon distinguishing the FLU group in our study was Faecalibacterium . It is well known that this bacterium is involved in the production of butyric acid, the main SCFA produced by the intestinal flora [ 80 ]. Moreover, in the studies involving patients with major depressive disorder (MDD), this bacterium was identified as a potential MDD biomarker [ 81 ].…”