title: Cultivable and pyrosequenced fecal microflora in centenarians and young subjects.
abstract: OBJECTIVE
  The aim of this study was to characterize the composition of the intestinal microbiota in healthy centenarians in comparison with younger adults, considering both quantitative and qualitative aspects of gut community structure.
  
  
  BACKGROUND
  The gut microbiota plays an essential role in human health. Toward seniority, its balance is affected by deep physiological changes. Long-lived people (age >90 y) have unusual features that differ from the younger elderly, so they should be considered separately when analyzing age-related features. However, they have been included in few studies and they have usually been grouped together with the younger elderly.
  
  
  METHODS
  The gut microbiota of 14 centenarians and 10 younger adults was analyzed. Cultivable bacteria belonging to the following groups were enumerated: enterobacteriaceae, Enterococcus, Staphylococcus, Lactobacillus, Bifidobacterium, Clostridium, Bacteroides, and yeast. Lactobacilli and Bifidobacteria were further characterized at the species level by pyrosequencing.
  
  
  RESULTS
  : In centenarians, we observed a reduction in the quantity of enterobacteriaceae, bifidobacteria, and bacteroides and an increase in clostridia sensu stricto (P<0.05). The number of Lactobacillus and Bifidobacterium species isolated in centenarians and younger adults was similar. The composition of the Lactobacillus subpopulation was quite different between the groups. The presence of Bifidobacterium longum in the gut seems to be a particular feature in centenarians. It is interesting to note that only 1 strain of B. longum was isolated from each centenarian subject.
  
  
  CONCLUSIONS
  The gut microbiota of centenarians has particular features that differ from both younger adults and the younger elderly. Further studies would help to understand whether the intestinal microbiota can influence life expectancy and whether the administration of probiotic bacteria could help to extend the longevity of human life.
authors.affiliation: Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Institute, Milan, Italy. lorenzo.drago@unimi.it
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Drago
authors.forename: Marco
authors.initials: M
authors.lastname: Toscano
authors.forename: Valentina
authors.initials: V
authors.lastname: Rodighiero
authors.forename: Elena
authors.initials: E
authors.lastname: De Vecchi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mogna
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000254:growth & development* / Q000302:isolation & purification; D001431:Bacteriological Techniques; D001644:Bifidobacterium; D015169:Colony Count, Microbial; D003470:Culture Media; D005243:Feces / Q000382:microbiology*; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans; D054892:Metagenome; D008875:Middle Aged; D019936:Probiotics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000379:methods*; D055815:Young Adult
chemical_list: D003470:Culture Media; D012336:RNA, Ribosomal, 16S