Digestive Tract Microbiota in Healthy Volunteers

Abstract

PURPOSE:The aim of this study was to standardize the methods of sample collection of mucus from the digestive tract and to determine the microbiota in healthy volunteers from Brazil, collecting samples from the mouth, esophagus, stomach, duodenum, jejunum, ileum, colon, and rectum. METHODS: Microbiota of selected healthy volunteers from the oral cavity (n=10), the esophagus (n=10), the upper digestive tract (n=20), and the lower digestive tract (n=24) were evaluated through distinct collection methods. Collection methods took into account the different sites, using basic scraping and swabbing techniques, stimulated saliva from the oral cavity, irrigationaspiration with sterile catheters especially designed for the esophagus, a probe especially designed for upper digestive tract, and a special catheter for the lower digestive tract. RESULTS: (i) Mixed microbiota were identified in the oral cavity, predominantly Gram-positive aerobic and anaerobic cocci; (ii) transitional flora mainly in the esophagus; (iii) Veillonella sp, Lactobacillus sp, and Clostridium sp in the stomach and duodenum; (iv) in the jejunum and upper ileum, we observed Bacteroides sp, Proteus sp, and Staphylococcus sp, in addition to Veillonella sp; (v) in the colon, the presence of "nonpathogenic" anaerobic bacteria Veillonella sp (average 10 5 UFC) indicates the existence of a low oxidation-reduction potential environment, which suggests the possibility of adoption of these bacteria as biological markers of total digestive tract health. CONCLUSIONS: The collection methods were efficient in obtaining adequate samples from each segment of the total digestive tract to reveal the normal microbiota. These procedures are safe and easily reproducible for microbiological studies.

Intragenomic and intraspecific heterogeneity in rrs may surpass interspecific variability in a natural population of Veillonella

“…Six species, Veillonella dispar, Veillonella parvula, Veillonella atypica, Veillonella montpellierensis, Veillonella rogosae and Veillonella denticariosi have so far been isolated from human flora whilst Veillonella ratti, Veillonella criceti, Veillonella rodentium, Veillonella caviae and Veillonella magna were only reported from non-human animal flora. Species of the genus Veillonella are usually regarded as early colonizers and highly represented members of the human microbiome, particularly in the mouth (Könönen et al, 1999) and the gut (Favier et al, 2002;Zilberstein et al, 2007), and are frequently detected during cultureindependent studies of the diversity of different microbiotae during health and disease (Paster et al, 2001;Wang et al, 2004;Aas et al, 2005;Preza et al, 2008). More frequently isolated from human clinical specimens in aerobic-anaerobic polymicrobial cultures, these bacteria were recovered in pure culture and implicated in severe opportunistic human infections (Bhatti & Frank, 2000;Marchandin et al, 2001;Boo et al, 2005;Marriott et al, 2007).…”

In Vivo Analysis of the Viable Microbiota and Helicobacter pylori Transcriptome in Gastric Infection and Early Stages of Carcinogenesis

“…The discovery of Helicobacter pylori in 1983 revealed that bacteria can in fact colonize the stomach (1). Since then, several studies on the stomach microbiota have been performed both in gastric juice and in mucosal biopsy specimens, using culture-dependent methods (2,3) as well as analysis of DNA extracted from biopsy specimens (3)(4)(5)(6)(7)(8). These studies show a previously unappreciated richness of the stomach bacterial flora but also that the communities are highly uneven and have large interindividual variation.…”

“…These studies show a previously unappreciated richness of the stomach bacterial flora but also that the communities are highly uneven and have large interindividual variation. Commonly detected phyla include Firmicutes, Bacteriodetes, Actinobacteria, Fusobacteria, and Proteobacteria (4,5,7). These phyla are represented mainly by the genera Streptococcus, Lactobacillus, Veillonella, Clostridium, Prevotella, Porphyromonas, Rothia, Neisseria, and Haemophilus, (4,5,9,10).…”

“…Commonly detected phyla include Firmicutes, Bacteriodetes, Actinobacteria, Fusobacteria, and Proteobacteria (4,5,7). These phyla are represented mainly by the genera Streptococcus, Lactobacillus, Veillonella, Clostridium, Prevotella, Porphyromonas, Rothia, Neisseria, and Haemophilus, (4,5,9,10). However, the Proteobacteria species H. pylori stands out as completely dominant in the microbiota of H. pylori-infected individuals, and its importance as an inhabitant of the human gastric microflora is further emphasized by the fact that it is estimated to colonize nearly 50% of the human population globally.…”

Mechanisms of Cellular Cytotoxicity Induction in Gastric Mucosal Inflammation

“…Согласно научным источникам [29,34,52,68], в неизмененной СОЖ наиболее распространены стрептококки, микрококки, вейлонеллы, акти-номицеты, фузобактерии, нейссерии и др.…”