title: 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)-1α, IL-6 and tumour necrosis factor-α 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.
authors.affiliation: Microbiology and Gut Biology Group, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Aileen Robertson
authors.initials: AR
authors.lastname: Smith
authors.affiliation: Microbiology and Gut Biology Group, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Sandra
authors.initials: S
authors.lastname: Macfarlane
authors.affiliation: Microbiology and Gut Biology Group, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Furrie
authors.affiliation: Microbiology and Gut Biology Group, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Shakil
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: Microbiology and Gut Biology Group, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Bahram
authors.initials: B
authors.lastname: Bahrami
authors.affiliation: Gastroenterology Department, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Nigel
authors.initials: N
authors.lastname: Reynolds
authors.affiliation: Microbiology and Gut Biology Group, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: George Tennant
authors.initials: GT
authors.lastname: Macfarlane
mesh_terms: D000368:Aged; D044822:Biodiversity; D016207:Cytokines / Q000096:biosynthesis; D004750:Enteral Nutrition; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology; D020869:Gene Expression Profiling; D006801:Humans; D018928:Immunity, Mucosal; D017403:In Situ Hybridization; D007413:Intestinal Mucosa / Q000276:immunology; D008297:Male; D054892:Metagenome; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D041742:Upper Gastrointestinal Tract / Q000276:immunology* / Q000382:microbiology*
chemical_list: D016207:Cytokines