Microbiological and immunological effects of enteral feeding on the upper gastrointestinal tract

Abstract

Enteral feeding via a percutaneous endoscopic gastrostomy tube is required for nutritional support in patients with dysphagia. Enteral tube feeding bypasses the innate defence mechanisms in the upper gastrointestinal tract. This study examined the surface-associated microbial populations and immune response in the gastric and duodenal mucosae of eight enteral nutrition (EN) patients and ten controls. Real-time PCR and fluorescence in situ hybridization were employed to assess microbiota composition and mucosal pro-inflammatory cytokine expression. The results showed that EN patients had significantly higher levels of bacterial DNA in mucosal biopsies from the stomach and duodenum (P,0.05) than the controls, and that enterobacteria were the predominant colonizing species on mucosal surfaces in these individuals. Expression of the pro-inflammatory cytokines interleukin (IL)-1a, IL-6 and tumour necrosis factor-a was significantly higher in gastric and small intestinal mucosae from patients fed normal diets in comparison with those receiving EN (P,0.05). These results indicate that EN can lead to significant bacterial overgrowth on upper gastrointestinal tract mucosae and a significantly diminished pro-inflammatory cytokine response.

Effect of a synbiotic on microbial community structure in a continuous culture model of the gastric microbiota in enteral nutrition patients

“…Abnormal upper GI microbiotas, mainly comprising enterobacteria, streptococci, staphylococci, lactobacilli and candidas, have been reported in association with EN (Gottlieb et al, 1992;Dautle et al, 2002Dautle et al, , 2003O'May et al, 2005a;Smith et al, 2011). In this study, a continuous culture model of the upper GI tract microbiota containing a defined population that resembled the simplified microbiota of patients receiving EN was used to investigate the effects of synbiotic feeding on microbial community structure and metabolism.…”

“…Enteral tube feeding (ETF) bypasses several of the body's innate defences, including low gastric pH, peristalsis and enterosalivary nitrate circulation, which normally prevent the permanent microbial colonization of the proximal gut, and has been shown to be associated with significant overgrowth (Gottlieb et al, 1994;O'May et al, 2005a;Smith et al, 2011). Owing to the lack of salivary nitrate, the production of nitrite from nitrate by facultative anaerobes on the tongue is also reduced, and it is therefore unavailable for conversion to nitric oxide and other antimicrobial compounds in the stomach (O'May et al, 2005a;Smith et al, 2011). Owing to the lack of salivary nitrate, the production of nitrite from nitrate by facultative anaerobes on the tongue is also reduced, and it is therefore unavailable for conversion to nitric oxide and other antimicrobial compounds in the stomach (O'May et al, 2005a;Smith et al, 2011).…”

“…Owing to the lack of salivary nitrate, the production of nitrite from nitrate by facultative anaerobes on the tongue is also reduced, and it is therefore unavailable for conversion to nitric oxide and other antimicrobial compounds in the stomach (O'May et al, 2005a;Smith et al, 2011). EN has also been shown to lead to significant bacterial overgrowth on the stomach and duodenal mucosae, compared with individuals fed a normal diet, with enterobacteria being the predominant colonizing species (Smith et al, 2011). The study by O'May et al (2005a) on ETF patients showed that bacterial profiles of gastric and duodenal aspirates had similar microbial densities and generic distributions, and evidence suggests that microorganisms isolated from EN patients are similar to those cultured from the upper GI tract of critically ill surgical people in the intensive care unit (Marshall et al, 1993).…”

Impact of direct drug delivery via gastric access devices

“…Continuous infusion provides patients with feed over 24 h and is most frequently reserved for very ill patients [21]. This regimen is associated with an increased risk of drug--nutrient interactions (discussed later) and can also increase intragastric pH leading to bacterial overgrowth [22].…”

Study of Feeding Jejunostomy as an Add on Procedure in Upper Gastrointestinal Surgeries

“…Enteral nutrition is considered to be better than total parenteral nutrition for providing feeding in various clinical settings because it is less expensive, safer and maintains the nutritional, metabolic, immunological and barrier function of the intestines with fewer septic complications [6][7][8][9][10]. Jejunostomy is a surgical procedure by which a tube is situated in the lumen of proximal jejunum, primarily to administer enteral nutrition or sometimes medications and on rare occasion to aspirate intestinal contents.…”