Gut bacteria identified in colorectal cancer patients promote tumourigenesis via butyrate secretion

Menée à partir de l'analyse de l'ADN extrait d'échantillons fécaux provenant de patients atteints d'un cancer colorectal ou de personnes en bonne santé puis menée à l'aide d'un modèle murin, cette étude met en évidence un mécanisme par lequel des bactéries intestinales favorisent la tumorigenèse via la sécrétion de butyrate

Résumé en anglais

Emerging evidence is revealing that alterations in gut microbiota are associated with colorectal cancer (CRC). However, very little is currently known about whether and how gut microbiota alterations are causally associated with CRC development. Here we show that 12 faecal bacterial taxa are enriched in CRC patients in two independent cohort studies. Among them, 2 Porphyromonas species are capable of inducing cellular senescence, an oncogenic stress response, through the secretion of the bacterial metabolite, butyrate. Notably, the invasion of these bacteria is observed in the CRC tissues, coinciding with the elevation of butyrate levels and signs of senescence-associated inflammatory phenotypes. Moreover, although the administration of these bacteria into ApcΔ14/+ mice accelerate the onset of colorectal tumours, this is not the case when bacterial butyrate-synthesis genes are disrupted. These results suggest a causal relationship between Porphyromonas species overgrowth and colorectal tumourigenesis which may be due to butyrate-induced senescence.