Journal Article

Effect of inulin on the human gut microbiota: stimulation of Bifidobacterium adolescentis and Faecalibacterium prausnitzii

Louis, Petra, Holtrop, Grietje, Slezak, Kathleen, Ramirez-Farias, Carlett, Duncan, Alan, Fuller, Zoë

2009

Overview

Prebiotics are food ingredients that improve health by modulating the colonic microbiota. The bifidogenic effect of the prebiotic inulin is well established; however, it remains unclear which species of Bifidobacterium are stimulated in vivo and whether bacterial groups other than lactic acid bacteria are affected by inulin consumption. Changes in the faecal microbiota composition were examined by real-time PCR in twelve human volunteers after ingestion of inulin (10 g/d) for a 16-d period in comparison with a control period without any supplement intake. The prevalence of most bacterial groups examined did not change after inulin intake, although the low G+C % Gram-positive species Faecalibacterium prausnitzii exhibited a significant increase (10·3 % for control period v. 14·5 % during inulin intake, P = 0·019). The composition of the genus Bifidobacterium was studied in four of the volunteers by clone library analysis. Between three and five Bifidobacterium spp. were found in each volunteer. Bifidobacterium adolescentis and Bifidobacterium longum were present in all volunteers, and Bifidobacterium pseudocatenulatum, Bifidobacterium animalis, Bifidobacterium bifidum and Bifidobacterium dentium were also detected. Real-time PCR was employed to quantify the four most prevalent Bifidobacterium spp., B. adolescentis, B. longum, B. pseudocatenulatum and B. bifidum, in ten volunteers carrying detectable levels of bifidobacteria. B. adolescentis showed the strongest response to inulin consumption, increasing from 0·89 to 3·9 % of the total microbiota (P = 0·001). B. bifidum was increased from 0·22 to 0·63 % (P < 0·001) for the five volunteers for whom this species was present.

• Publisher: Cambridge University Press
• Subject: Adult / analysis / Analysis of Variance / Bacteria / Base Sequence / Bifidobacterium / Bifidobacterium - classification / Bifidobacterium - genetics / Bifidobacterium - physiology / Bifidobacterium adolescentis / Bifidobacterium animalis / Bifidobacterium bifidum / Bifidobacterium dentium / Bifidobacterium longum / Bifidobacterium pseudocatenulatum / Biological and medical sciences / classification / colon / Colony Count, Microbial / DNA Fingerprinting / DNA Primers / DNA Primers - genetics / DNA, Bacterial / DNA, Bacterial - analysis / Faecalibacterium prausnitzii / Fatty Acids, Volatile / Fatty Acids, Volatile - metabolism / feces / Feces - microbiology / Feeding. Feeding behavior / Fermentation / Firmicutes / Food Microbiology / Fundamental and applied biological sciences. Psychology / Gene Library / genetics / Gram-positive bacteria / human nutrition / Humans / Hydrogen-Ion Concentration / Ingestion / interspecific variation / intestinal microorganisms / Intestinal Mucosa / Intestinal Mucosa - microbiology / Inulin / Inulin - pharmacology / Linear Models / Metabolism / methods / microbial growth / Microbiology / Microbiota / Molecular Sequence Data / pharmacology / physiology / Prebiotic / Prebiotics / Probiotics / Reverse Transcriptase Polymerase Chain Reaction / Reverse Transcriptase Polymerase Chain Reaction - methods / species differences / Species Specificity / Stimulation, Chemical / Vertebrates: anatomy and physiology, studies on body, several organs or systems