title: Postoperative Changes in Fecal Bacterial Communities and Fermentation Products in Obese Patients Undergoing Bilio-Intestinal Bypass.
abstract: We assessed the gut microbial ecology of 11 severely obese patients before and after bilio-intestinal bypass (BIB). Fecal samples were evaluated for microbial communities using 16S rDNA Illumina sequencing, real-time PCR targeting functional genes, and gas chromatography of short chain fatty acids (SCFAs). At 6 months after surgery, subjects exhibited significant improvements in metabolic markers (body weight, glucose, and lipid metabolism) compared with baseline. The fecal microbiota of post-surgery individuals was characterized by an overall decrease of bacterial diversity, with a significant reduction in Lachnospiraceae, Clostridiaceae, Ruminococcaceae, Eubacteriaceae, and Coriobacteriaceae. On the contrary, there were significant increases of genera Lactobacillus, Megasphaera, and Acidaminococcus and the family Enterobacteriaceae. The pH was decreased in fecal samples from patients after BIB and SCFA profiles were altered, with lower percentages of acetate and propionate and higher levels of valerate and hexanoate. Some changes in the bacterial populations were associated with variations in the patients' metabolic health parameters, namely Gemmiger and glucose, Lactobacillus and glucose, and Faecalibacterium and triglycerides. The results from this study of BIB patients furthers our understanding of the composition of gut microbiota and the functional changes that may be involved in improving obesity-related conditions following weight-loss surgery.
authors.affiliation: Instituto di Microbiologia, Facoltà di Scienze Agrarie, Alimentari e Ambientali, Università Cattolica del Sacro Cuore Piacenza, Italy.
authors.forename: Vania
authors.initials: V
authors.lastname: Patrone
authors.affiliation: Istituto di Zootecnica, Facoltà di Scienze Agrarie, Alimentari e Ambientali, Università Cattolica del Sacro Cuore Piacenza, Italy.
authors.forename: Elia
authors.initials: E
authors.lastname: Vajana
authors.affiliation: Istituto di Zootecnica, Facoltà di Scienze Agrarie, Alimentari e Ambientali, Università Cattolica del Sacro Cuore Piacenza, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Minuti
authors.affiliation: Instituto di Microbiologia, Facoltà di Scienze Agrarie, Alimentari e Ambientali, Università Cattolica del Sacro Cuore Piacenza, Italy.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Callegari
authors.affiliation: Division of Hepatogastroenterology, Second University of Naples Naples, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Federico
authors.affiliation: Division of Hepatogastroenterology, Second University of Naples Naples, Italy.
authors.forename: Carmela
authors.initials: C
authors.lastname: Loguercio
authors.affiliation: Division of Hepatogastroenterology, Second University of Naples Naples, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Dallio
authors.affiliation: Division of General and Bariatric Surgery, Second University of Naples Naples, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Tolone
authors.affiliation: Division of General and Bariatric Surgery, Second University of Naples Naples, Italy.
authors.forename: Ludovico
authors.initials: L
authors.lastname: Docimo
authors.affiliation: Instituto di Microbiologia, Facoltà di Scienze Agrarie, Alimentari e Ambientali, Università Cattolica del Sacro Cuore Piacenza, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Morelli
keywords: 16S rRNA; bariatric surgery; gut microbiota; illumina sequencing; obesity; short chain fatty acids; weight loss