title: Comparison between cultured small-intestinal and fecal microbiotas in beagle dogs.
abstract: The microbiota of the small intestine is poorly known because of difficulties in sampling. In this study, we examined whether the organisms cultured from the jejunum and feces resemble each other. Small-intestinal fluid samples were collected from 22 beagle dogs with a permanent jejunal fistula in parallel with fecal samples. In addition, corresponding samples from seven of the dogs were collected during a 4-week period (days 4, 10, 14, and 28) to examine the stability of the microbiota. In the jejunal samples, aerobic/facultative and anaerobic bacteria were equally represented, whereas anaerobes dominated in the fecal samples. Despite lower numbers of bacteria in the jejunum (range, 10(2) to 10(6) CFU/g) than in feces (range, 10(8) to 10(11) CFU/g), some microbial groups were more prevalent in the small intestine: staphylococci, 64% versus 36%; nonfermentative gram-negative rods, 27% versus 9%; and yeasts, 27% versus 5%, respectively. In contrast, part of the fecal dominant microbiota (bile-resistant Bacteroides spp., Clostridium hiranonis-like organisms, and lactobacilli) was practically absent in the jejunum. Many species were seldom isolated simultaneously from both sample types, regardless of their overall prevalence. In conclusion, the small intestine contains a few bacterial species at a time with vastly fluctuating counts, opposite to the results obtained for the colon, where the major bacterial groups remain relatively constant over time. Qualitative and quantitative differences between the corresponding jejunal and fecal samples indicate the inability of fecal samples to represent the microbiotas present in the upper gut.
authors.affiliation: Anaerobe Reference Laboratory, National Public Health Institute (KTL), Mannerheimintie 166, FIN-00300 Helsinki, Finland. silja.mentula@ktl.fi
authors.forename: Silja
authors.initials: S
authors.lastname: Mentula
authors.forename: Jaana
authors.initials: J
authors.lastname: Harmoinen
authors.forename: Matti
authors.initials: M
authors.lastname: Heikkilä
authors.forename: Elias
authors.initials: E
authors.lastname: Westermarck
authors.forename: Merja
authors.initials: M
authors.lastname: Rautio
authors.forename: Pentti
authors.initials: P
authors.lastname: Huovinen
authors.forename: Eija
authors.initials: E
authors.lastname: Könönen
mesh_terms: D000818:Animals; D001420:Bacteria, Aerobic / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D001421:Bacteria, Anaerobic / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D003470:Culture Media; D004285:Dogs; D005243:Feces / Q000382:microbiology*; D007421:Intestine, Small / Q000382:microbiology; D007583:Jejunum / Q000382:microbiology*; D008297:Male
chemical_list: D003470:Culture Media