title: Microbial community and metabolomic comparison of irritable bowel syndrome faeces.
abstract: Human health relies on the composition of microbiota in an individual's gut and the synthesized metabolites that may alter the gut environment. Gut microbiota and faecal metabolites are involved in several gastrointestinal diseases. In this study, 16S rRNA-specific denaturing gradient gel electrophoresis and quantitative PCR analysis showed that the mean similarity of total bacteria was significantly different (P<0.001) in faecal samples from patients with irritable bowel syndrome (IBS; n = 11) and from non-IBS (nIBS) patients (n = 8). IBS subjects had a significantly higher diversity of total bacteria, as measured by the Shannon index (H') (3.36<H'<4.37, P = 0.004), Bacteroidetes and lactobacilli; however, less diversity was observed for Bifidobacter (1.7< H'<3.08, P<0.05) and Clostridium coccoides (0.9< H'<2.98, P = 0.007). In this study, no significant difference was found in total bacterial quantity (P>0.05). GC/MS-based multivariate analysis delineated the faecal metabolites of IBS from nIBS samples. Elevated levels of amino acids (alanine and pyroglutamic acid) and phenolic compounds (hydroxyphenyl acetate and hydroxyphenyl propionate) were found in IBS. These results were highly correlated with the abundance of lactobacilli and Clostridium, which indicates an altered metabolism rate associated with these gut micro-organisms. A higher diversity of Bacteroidetes and Lactobacillus groups in IBS faecal samples also correlated with the respective total quantity. In addition, these changes altered protein and carbohydrate energy metabolism in the gut.
authors.affiliation: Department of Bioscience and Biotechnology and Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Kannan
authors.initials: K
authors.lastname: Ponnusamy
authors.affiliation: Department of Bioscience and Biotechnology and Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Jung Nam
authors.initials: JN
authors.lastname: Choi
authors.affiliation: Department of Bioscience and Biotechnology and Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Konkuk University Medical Center, Seoul 143-701, Republic of Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Bioscience and Biotechnology and Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Choong Hwan
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000032:analysis; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D044822:Biodiversity; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000382:microbiology*; D008297:Male; D055442:Metabolome; D008875:Middle Aged; D008969:Molecular Sequence Data; D010636:Phenols / Q000032:analysis; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D000596:Amino Acids; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D010636:Phenols; D012336:RNA, Ribosomal, 16S