Faecalibacterium duncaniae as a novel next generation probiotic against influenza.

The gut-lung axis is critical during viral respiratory infections such as influenza. Gut dysbiosis during infection translates into a massive drop of microbially produced short-chain fatty acids (SCFAs). Among them, butyrate is important during influenza suggesting that microbiome-based therapeutics targeting butyrate might hold promises. The butyrate-producing bacterium Faecalibacterium duncaniae (formerly referred to as F. prausnitzii) is an emerging probiotic with several health-promoting characteristics. To investigate the potential effects of F. duncaniae on influenza outcomes, mice were gavaged with live F. duncaniae (A2-165 or I-4574 strains) five days before infection. Supplementation of F. duncaniae was associated with less severe disease, a lower pulmonary viral load, and lower levels of lung inflammation. F. duncaniae supplementation impacted on gut dysbiosis induced by infection, as assessed by 16S rRNA sequencing. Interestingly, F. duncaniae administration was associated with a recovery in levels of SCFAs (including butyrate) in infected animals. The live form of F. duncaniae was more potent that the pasteurized form in improving influenza outcomes. Lastly, F. duncaniae partially protected against secondary (systemic) bacterial infection. We conclude that F. duncaniae might serve as a novel next generation probiotic against acute viral respiratory diseases.

Endothelial expression of endocan is strongly associated with tumor progression in pituitary adenoma.

Although benign, pituitary adenomas frequently invade adjacent sinuses or recur after first surgery. To date, there is no histological marker predictive of recurrence. Angiogenic factors are candidate markers. Endocan is a proteoglycan secreted by endothelial cells, associated with an aggressive behavior in several tumor types. Endocan expression was investigated by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) in 18 normal post-mortem pituitaries and in 107 patients operated for a pituitary adenoma (with a follow-up of at least 8 years after surgery). In normal pituitaries, endocan was never observed in vessels but was detected in isolated endocrine cells. In adenoma tissue, we found a strong association between endocan immunoreactivity in endothelial cells and progression (P = 0.0009), as well as tumor size (P = 0.0012), raised mitotic count (P = 0.02) and p53 expression (P = 0.032). Morphometric analysis of the microvessels showed that the mean vessel area was significantly higher in the subgroup of tumors with an endothelial expression of endocan (P = 0.028), coherent with the neoangiogenesis process occurring in the pituitary. The immunolabeling of endocan in endothelial cells may therefore appear to be a relevant marker of aggressive behavior in pituitary tumors.