Elucidating the gut microbiome of ulcerative colitis: bifidobacteria as novel microbial biomarkers

• Published in: FEMS microbiology ecology Vol. 92; no. 12; p. fiw191
• Main Authors: Duranti, Sabrina, Gaiani, Federica, Mancabelli, Leonardo, Milani, Christian, Grandi, Andrea, Bolchi, Angelo, Santoni, Andrea, Lugli, Gabriele Andrea, Ferrario, Chiara, Mangifesta, Marta, Viappiani, Alice, Bertoni, Simona, Vivo, Valentina, Serafini, Fausta, Barbaro, Maria Raffaella, Fugazza, Alessandro, Barbara, Giovanni, Gioiosa, Laura, Palanza, Paola, Cantoni, Anna Maria, de'Angelis, Gian Luigi, Barocelli, Elisabetta, de'Angelis, Nicola, van Sinderen, Douwe, Ventura, Marco, Turroni, Francesca
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.12.2016
• Subjects: Animals; Bifidobacterium - genetics; Bifidobacterium - immunology; Bifidobacterium - isolation & purification; Bifidobacterium bifidum; Biodiversity; Biomarkers; cataloging; Colitis, Ulcerative - chemically induced; Colitis, Ulcerative - microbiology; Colon; Commensals; Digestive system; Dysbiosis - microbiology; Ecology; etiology; Female; fimbriae; Fimbriae, Bacterial - immunology; Gastrointestinal Microbiome - genetics; Gastrointestinal Microbiome - immunology; Gene expression; genes; histology; Humans; Immune response; Immune system; In vivo methods and tests; Inflammatory bowel disease; Innate immunity; Intestinal microflora; intestinal microorganisms; Intestinal Mucosa - microbiology; Intestinal Mucosa - pathology; Lymphocytes B; Mice; Mice, Inbred BALB C; Microbiology; Microbiomes; Microbiota; Microorganisms; Mucosa; oral administration; Patients; Physiological aspects; Pili; Probiotics; protective effect; Reduction; ribosomal RNA; RNA, Ribosomal, 16S - genetics; Rodents; rRNA 16S; Sortase; T-Lymphocytes - immunology; Ulcerative colitis; United States; ulcerative colitis; intestinal inflammation; probiotic bacteria; metagenomics; gut microbiota; dysbiosis
• ISSN: 1574-6941; 0168-6496; 1574-6941
• DOI: 10.1093/femsec/fiw191

Ulcerative colitis (UC) is associated with a substantial alteration of specific gut commensals, some of which may be involved in microbiota-mediated protection. In this study, microbiota cataloging of UC patients by 16S rRNA microbial profiling revealed a marked reduction of bifidobacteria, in particular the Bifidobacterium bifidum species, thus suggesting that this taxon plays a biological role in the aetiology of UC. We investigated this further through an in vivo trial by testing the effects of oral treatment with B. bifidum PRL2010 in a wild-type murine colitis model. TNBS-treated mice receiving 109 cells of B. bifidum PRL2010 showed a marked reduction of all colitis-associated histological indices as well as maintenance of mucosal integrity as it was shown by the increase in the expression of many tight junction-encoding genes. The protective role of B. bifidum PRL2010, as well as its sortase-dependent pili, appears to be established through the induction of an innate immune response of the host. These results highlight the importance of B. bifidum as a microbial biomarker for UC, revealing its role in protection against experimentally induced colitis. We present the first metagenomic study focusing on the biodiversity of the bifidobacterial communities of UC patients while also providing a detailed overview of possible UC-associated (bifido)bacterial biomarkers.