Intestinal metabolites of Farfarae Flos produce antitussive effect via
modulation of gut microbiota and short-chain fatty acids
Abstract
Background and Purpose Farfarae Flos (FF), derived from the flower buds
of Tussilago farfarae L., is used as a traditional folk medicine for the
treatment of cough, bronchitis and asthmatic disorders. However, its
antitussive mechanism is unknown yet. Experimental Approach The
antitussive mechanism of FF was investigated from the perspective of gut
microbiota. The antibiotic pretreatment and fecal microbiota
transplantation (FMT) were used to investigated the microbiota-host
interaction after FF treatment. The composition of gut microbiota was
detected by using 16S ribosomal RNA (rRNA) sequences. The gut
metabolites variations were evaluated by LC-MS based metabolomic
analysis and GC-MS based targeted short-chain fatty acids (SCFAs)
profiling. Key Results FF increased the abundance of SCFAs-producing
bacteria, which consequently led to the elevated SCFAs levels. SCFAs
supplementation further confirmed the importance of SCFAs for the
antitussive effect of FF. The antitussive effect of FF was gut
microbiota dependent, as demonstrated by antibiotic treatment and FMT.
FF could also probably regulate Argnine/NO metabolism by inhibiting
arginase which was confirmed by antitussive effect of Argnine
supplementation. Caffeic acid (CA) and quinic acid (QA), intestinal
metabolites of caffeylquinic acids metabolized by Lactobacillus and
Bifidobacterium, showed antitussive effect by increasing the butyrate,
and butyrate-producing bacteria (Clostridium and Ruminococcus) were also
enriched by QA. Conclusion and Implications Our study shows that CA and
QA were proved as the key bioactive metabolites for the antitussive
effect of FF. This study may present a novel approach for investigating
the antitussive mechanism of herbal drug from the perspective of gut
microbiota.