title: Differences in the composition of intestinal Bifidobacterium species and the development of allergic diseases in infants in rural Japan.
abstract: BACKGROUND
  Bifidobacterium is a dominant genus in the intestinal microbiota of infants and comprises many different species. A series of studies performed in northern Europe showed differences in the composition of Bifidobacterium species between allergic infants and healthy controls. Additional studies are needed to confirm this observation.
  
  
  OBJECTIVE
  To investigate the composition of fecal Bifidobacterium species in allergic infants and healthy controls in Japan, using molecular methods.
  
  
  METHODS
  Full-term born babies were followed up to 6 months of age at a local hospital in rural Japan. The presence or absence of allergy was determined based on allergic symptoms and skin prick tests. Fecal Bifidobacterium species in allergic infants (n=10), and healthy controls (n=16) were evaluated using nine Bifidobacterium species-specific or group-specific primers based on 16S rDNA sequences at 1, 3, and 6 months of age.
  
  
  RESULTS
  The number of the infants in whom no Bifidobacterium species could be found was four (15.4%) at 1 month, two (7.7%) at 3 months, and one (3.3%) at 6 months of age, all of whom were healthy controls. At 1 month of age, allergic infants had a higher prevalence f the Bifidobacterium catenulatum group than healthy controls (60.0% vs. 6.3%, P<0.01). At 6 months of age, allergic infants had a higher prevalence of B. bifidum than healthy controls (70.0% vs. 12.5%, P<0.01). These differences were not related to feeding method.
  
  
  CONCLUSIONS
  Our results in infants in rural Japan support the hypothesis that a compositional difference in intestinal Bifidobacterium species may be associated with the development of allergy in early infancy, although the responsible species might vary among countries or races.
authors: Department of Pediatrics, Graduate School of Medicine Chiba University, Inohana, Chuo-ku, Chiba, Japan.
authors: S
authors: S
authors: Suzuki
authors: N
authors: N
authors: Shimojo
authors: Y
authors: Y
authors: Tajiri
authors: M
authors: M
authors: Kumemura
authors: Y
authors: Y
authors: Kohno
mesh_terms: D001644:Bifidobacterium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007422:Intestines / Q000382:microbiology*; D007564:Japan; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012423:Rural Health / Q000706:statistics & numerical data; D012882:Skin Tests
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S