title: Molecular and microbiological analysis of caecal microbiota in rats fed with diets supplemented either with prebiotics or probiotics.
abstract: The potential health-improving effects of both a prebiotic and a probiotic infant formula have been evaluated in a rat model. Two groups of 10 rats were fed with either prebiotics containing fructo-oligosaccharides or probiotics containing viable Bifidobacterium lactis and Streptococcus thermophilus. The composition of their caecal microbiota was analyzed both by classical plate count of the main bacterial groups and by PCR amplification of a V3 fragment of 16S rRNA genes and denaturing gradient gel electrophoresis (DGGE). Both diets induced a significant reduction of clostridia and Bacteroides spp. compared to a control diet, whereas prebiotics were also able to reduce the number of coliforms and to increase the presence of bifidobacteria. DGGE analysis showed a significant increase of 16S rRNA gene fragments in rats fed with either probotics or prebiotics. Nineteen bands were sequenced and most of them showed similarity to cultured bacteria. Detection of Bifidobacterium spp. by this technique using genus-specific primers only permitted these bacteria to be detected in prebiotics-fed rats, whereas the use of Lactobacillus group-specific primers gave similar results in rats fed with any diet, in agreement with the plate count results.
authors.affiliation: Departamento de Biología Celular, Bioquímica y Biología Molecular, Facultad de Ciencias Experimentales y de la Salud, Universidad San Pablo-CEU, Urbanización Monte Príncipe, Boadilla del Monte, 28668 Madrid, Spain.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Montesi
authors.forename: Raimundo
authors.initials: R
authors.lastname: García-Albiach
authors.forename: María José
authors.initials: MJ
authors.lastname: Pozuelo
authors.forename: Concepción
authors.initials: C
authors.lastname: Pintado
authors.forename: Isabel
authors.initials: I
authors.lastname: Goñi
authors.forename: Rafael
authors.initials: R
authors.lastname: Rotger
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000254:growth & development*; D002432:Cecum / Q000382:microbiology*; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis*; D019587:Dietary Supplements; D004591:Electrophoresis, Polyacrylamide Gel; D005516:Food Microbiology; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000382:microbiology*; D007231:Infant, Newborn; D007778:Lactobacillus / Q000254:growth & development*; D008297:Male; D023421:Models, Animal; D019936:Probiotics / Q000008:administration & dosage*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004269:DNA, Bacterial