Microbial flora of the normal esophagus

Abstract

The endogenous flora of the skin and some mucous membranes are well known, however, we were unable to find descriptions about normal esophageal flora in literature. We believe that knowledge about normal esophageal flora is important for therapeutic implications. We compiled data on 30 patients without infection of the oropharynx or esophagus who were admitted for an endoscopy of the upper digestive tract to determine normal esophageal flora. The samples were collected by injecting 10 ml of 0.9% physiological solution into the esophagus and oropharynx and removing it by suction. Esophageal samples from 30 patients and oropharingeal samples from 10 of these patients were collected. We identified mixed flora being Streptococcus viridans the most frequent microorganism found. Where samples from both the esophagus and oropharynx were collected, three occurrences of this same microorganism were found. We concluded that the isolation frequency of germs in the esophagus by the method used was high and the most frequently found germ was S. viridans. There is therefore a possible correlation between the flora from the oropharynx and the esophagus.

Bacterial biota in the human distal esophagus

“…Previous culture-based studies suggested that the esophagus is either sterile or contains only few transient bacteria (16,17). The specimens used in those studies were washes of the luminal esophageal contents, which might explain the failure to detect the presence or richness of the bacterial biota, because washes may not yield bacteria closely associated with the mucosa.…”

“…However, contrary to our hypothesis, the majority (82.1%) of 16S rDNA found in this study represent cultivatable bacterial species. The majority of these species are relatively easy to culture using the methods and conditions used in the previous studies (16,17). Although the exact reason for the failure to isolate these species is unclear, we speculate that (i) our ability to demonstrate a complex bacterial biota from the tissue biopsies suggests that esophageal bacteria are closely related to mucosal surfaces, consistent with, although not conclusive for, the existence of a residential bacterial biota in the normal distal esophagus; or (ii) the esophageal bacteria could also exist in vivo in a viable but nonculturable state (30), a recently recognized phenomenon in which nonsporulating bacteria persist as dormant vegetative cells with low metabolic activity, especially when they reside in a biofilm (31).…”

“…Distal esophagitis is generally considered to be a consequence of reflux of gastric acidity and is known as gastroesophageal reflux disease (15). Studies attempting to culture bacteria from luminal washes of the esophagus have reported poor yields; the washes, most likely reflecting transient bacteria of oropharyngeal origin, were either sterile or contained an average of 16 colony-forming units͞ml, with no common species found (16,17). These unsuccessful attempts in detecting bacteria in esophageal washes suggest that the passage of oropharyngeal bacteria is rapid, and͞or that the bacteria present in the washes were not cultivatable.…”

Review of the gut microbiome and esophageal cancer: Pathogenesis and potential clinical implications

“…These studies demonstrated that the esophagus is either sterile or contains only a few transient microbes swallowed from the oropharynx or ejected from the stomach by gastroesophageal reflux 34. Gagliardi et al 34.…”

Estudo da microflora do megaesôfago chagásico

“…Gagliardi 3 , estudando a flora bacteriana de indivíduos sem esofagopatia, encontrou uma flora esofagiana transitória e semelhante à da orofaringe. Bermudez et al 1 , ao estudarem doentes com tumor de esôfago, observaram que os microorganismos mais isolados foram a Cândida albicans (33,3%), Peptostrepcoccus e Bacteroides melanogenicos (22,2%), enterobactérias e Pseudomonas aeruginosa (11,1%).…”