Open AccessExploring the Diversity of the Bifidobacterial Population in the Human Intestinal Tract
Author(s) -
Francesca Turroni,
Elena Foroni,
Paola Pizzetti,
Vanessa Giubellini,
Angela Ribbera,
Paolo Merusi,
Patrizio Cagnasso,
Barbara Bizzarri,
G.L. De Angelis,
Fergus Shanahan,
Douwe van Sinderen,
Marco Ventura
Publication year - 2009
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02216-08
Subject(s) - biology , population , diversity (politics) , human feces , evolutionary biology , human gastrointestinal tract , genetics , zoology , microbiology and biotechnology , feces , computational biology , bacteria , medicine , environmental health , sociology , anthropology
Although the health-promoting roles of bifidobacteria are widely accepted, the diversity of bifidobacteria among the human intestinal microbiota is still poorly understood. We performed a census of bifidobacterial populations from human intestinal mucosal and fecal samples by plating them on selective medium, coupled with molecular analysis of selected rRNA gene sequences (16S rRNA gene and internally transcribed spacer [ITS] 16S-23S spacer sequences) of isolated colonies. A total of 900 isolates were collected, of which 704 were shown to belong to bifidobacteria. Analyses showed that the culturable bifidobacterial population from intestinal and fecal samples include six main phylogenetic taxa, i.e.,Bifidobacterium longum ,Bifidobacterium pseudocatenulatum ,Bifidobacterium adolescentis ,Bifidobacterium pseudolongum ,Bifidobacterium breve , andBifidobacterium bifidum , and two species mostly detected in fecal samples, i.e.,Bifidobacterium dentium andBifidobacterium animalis subp.lactis . Analysis of bifidobacterial distribution based on age of the subject revealed that certain identified bifidobacterial species were exclusively present in the adult human gut microbiota whereas others were found to be widely distributed. We encountered significant intersubject variability and composition differences between fecal and mucosa-adherent bifidobacterial communities. In contrast, a modest diversification of bifidobacterial populations was noticed between different intestinal regions within the same individual (intrasubject variability). Notably, a small number of bifidobacterial isolates were shown to display a wide ecological distribution, thus suggesting that they possess a broad colonization capacity.