The work of the Mucosal and Microbiota Immunology Laboratory directed by Prof. Maria Rescigno at Humanitas Research Hospital and supported by the AIRC foundation, led to the publication in Nature Microbiology of the paper regarding the identification of endogenous antitumor bacterial strains. The results show that some bacterial strains that live inside the microbiota have a brake function against the development of intestinal tumors.
The microbiota has been shown to promote intestinal tumourigenesis, but a possible anti-tumorigenic effect has also been postulated. Here, it is shown that changes in the composition of the microbiota and mucus are concomitant with tumorigenesis. We identified two anti-tumourigenic strains of the microbiota—Faecalibaculum rodentium and its human homologue, Holdemanella biformis—that are strongly under-represented during tumourigenesis. Reconstitution of ApcMin/+ or azoxymethane- and dextran sulfate sodium-treated mice with an isolate of F. rodentium (F. PB1) or its metabolic products reduced tumour growth. Both F. PB1 and H. biformis produced short-chain fatty acids that contributed to control protein acetylation and tumour cell proliferation by inhibiting calcineurin and NFATc3 activation in mouse and human settings. We have thus identified endogenous anti-tumourigenic bacterial strains with strong diagnostic, therapeutic and translational potential.