New On Nature.com: Bifidobacteria Exhibit Social Behavior Through Carbohydrate Resource Sharing In The Gut
Published online on October 28, 2015 by Scientific Reports, this article by Christian Milani, Gabriele Andrea Lugli, Sabrina Duranti, Leonardo Mancabelli, Chiara Ferrario, Marta Mangifesta, Alice Viappiani, Stefania Arioli and Marco Ventura (University of Parma, Italy), Francesca Turroni and Douwe van Sinderen (National University of Ireland, Ireland), Arancha Hevia, Borja Sanchez and Abelardo Margolles (IPLA – CSIC, Spain), Matthias Scholz and Nicola Segata (University of Trento, Italy), Jonathan Lane and Rita Hickey (Teagasc Food Research Centre, Ireland), Doyle V. Ward (Broad Institute, US) and Diego Mora (University of Milan, Italy) is now available to view.
Bifidobacteria are common and frequently dominant members of the gut microbiota of many animals, including mammals and insects. Carbohydrates are considered key carbon sources for the gut microbiota, imposing strong selective pressure on the complex microbial consortium of the gut. Despite its importance, the genetic traits that facilitate carbohydrate utilization by gut microbiota members are still poorly characterized. Here, genome analyses of 47 representative Bifidobacterium (sub)species revealed the genes predicted to be required for the degradation and internalization of a wide range of carbohydrates, outnumbering those found in many other gut microbiota members. The glycan-degrading abilities of bifidobacteria are believed to reflect available carbon sources in the mammalian gut. Furthermore, transcriptome profiling of bifidobacterial genomes supported the involvement of various chromosomal loci in glycan metabolism. The widespread occurrence of bifidobacterial saccharolytic features is in line with metagenomic and metatranscriptomic datasets obtained from human adult/infant faecal samples, thereby supporting the notion that bifidobacteria expand the human glycobiome. This study also underscores the hypothesis of saccharidic resource sharing among bifidobacteria through species-specific metabolic specialization and cross feeding, thereby forging trophic relationships between members of the gut microbiota.