High temporal and inter‐individual variation detected in the human ileal microbiota

Abstract

The diversity and temporal stability of the predominant bacteria in the human ileum was studied with the use of ileal effluent samples of seven individuals with Brooke ileostomies. The total number of bacteria within the ileal effluent was in the range of 10⁷ -10⁸ bacteria per gram (wet weight). The diversity of the bacteria in the ileal effluent showed marked differences compared with that in faecal samples from age-matched healthy adults. The ileal effluent had a higher relative abundance of species within the orders Lactobacillales and Clostridiales, mainly Streptococcus bovis-related species, and the Veillonella group, and a lower proportion of species related to Ruminococcus gnavus, R. obeum and Bacteroides plebeius. In addition, inter-individual differences were found, indicative of a highly personal ileal microbiota profile. Furthermore, temporal profiles showed large fluctuations per individual over a period of 9-28 days (average similarity over a period of 9 days was as low as 44%), and differences between morning and afternoon profiles were observed. Parallel cloning and sequencing efforts revealed several phylotypes that were not identified in previous studies (12 out of 65 phylotypes showed less than 97% sequence similarity with previously reported sequences). Achaea were found to be below detection limit by quantitative PCR. Overall, the results indicate that the microbiota of the human ileum is relatively unstable, less complex and consisting of different dominating phylotypes when compared with the colonic microbiota.

The human small intestinal microbiota is driven by rapid uptake and conversion of simple carbohydrates

“…), Clostridium clusters IX (Veillonella sp.) and XIVa (several genera), and several Gamma Proteobacteria, thereby displaying higher similarity with microbiota composition profiles obtained from ileostoma effluent samples (Booijink et al, 2010), which was supported by cluster analysis (Figure 1a). Principle component analysis analysis suggested that ileostomy effluent cluster closely to the jejunal sample, whereas the terminal ileum samples were more similar to feces as explained by 48% of the data along the first principle component (Figure 1b).…”

“…Hierarchical clustering of probe profiles was carried out using the Euclidian distance and Ward's minimum variance method. These small intestinal microbiota composition profiles generated for the samples obtained from healthy subjects were compared with the ileostoma effluent profiles that were already present in the database (Booijink et al, 2010). Multivariate statistical software Canoco 4.5 for windows (Leps and Smilauer, 2003;Biometrix, Plant Research International, Wageningen, The Netherlands) was used to perform the principle component analysis on log-transformed HITChip probe signal-intensity profiles.…”

“…For phylogenetic profiling ileostomy effluent, small intestinal content and feces was freshly collected from five healthy ileostomists (three male, two female; 60.2 ± 7.1 years; (Booijink et al, 2010); individuals A-E) and four healthy subjects (four male; 24±4.5 years; individuals F-I), and two healthy subjects (one male, one female; 56.6 ± 3.5 years; individuals J-K). All ileostomists had an intact small intestine with the exception of the terminal few centimeters of the ileum, which were removed during surgical removal of the colon.…”

“…In general, ileostomists that recover within months following the operation, can be considered healthy and enjoy an active life. A recent study suggested that oxygen might penetrate the small intestine via the stoma, resulting in increased facultative anaerobe populations (Hartman et al, 2009), but other studies have clearly established the significant abundance of typical strict anaerobes in effluent samples (Booijink et al, 2010).…”

Avaliação Dos Níveis Séricos De Vancomicina Em Pacientes Internados Em Um Hospital De Ensino Da Região Central Do Rio Grande Do Sul

“…S. aureus, principal representante dos microrganismos gram-positivos, é componente da microbiota normal e está presente na pele e nas narinas de aproximadamente um terço da população (PEACOCKET et al, 2001;NULENS et al, 2005;GORWITZ et al, 2008). E. faecalis e E. faecium também fazem parte da microbiota do trato gastrintestinal humano (BOOIJINK et al, 2010) e, assim como S. aureus, são típicos patógenos oportunistas que causam diversas infecções (WILLEMS et al, 2011).…”