Assessment of the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique

ArticleinAmerican Journal of Veterinary Research 66(9):1556-62 · October 2005with14 Reads
DOI: 10.2460/ajvr.2005.66.1556 · Source: PubMed
Abstract
To evaluate the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique. 14 dogs (similarly housed and fed identical diets). Samples of intestinal contents were collected from the duodenum, jejunum, ileum, colon, and rectum of each dog. Bacterial DNA was extracted from the samples, and the variable V6 to V8 region of 16S ribosomal DNA (gene coding for 16S ribosomal RNA) was amplified by use of universal bacterial primers; polymerase chain reaction amplicons were separated via denaturing gradient gel electrophoresis (DGGE). Similarity indices of DGGE banding patterns were used to assess variation in the bacterial microflora among different compartments of the intestine within and among dogs. Bacterial diversity was assessed by calculating the Simpson diversity index, the Shannon-Weaver diversity index, and evenness. DGGE profiles indicated marked differences in bacterial composition of intestinal compartments among dogs (range of similarity, 25.6% to 36.6%) and considerable variation among compartments within individual dogs (range of similarity, 36.7% to 579%). Similarities between neighboring intestinal compartments were significantly greater than those between non-neighboring compartments. Diversity indices for the colon and rectum were significantly higher than those of the duodenum, jejunum, and ileum. Results indicated that the different intestinal compartments of individual dogs appear to host different bacterial populations, and these compartmental populations vary among dogs. In dogs, fecal sample analysis may not yield accurate information regarding the composition of bacterial populations in compartments of the gastrointestinal tract.
    • "This is important when comparing studies with each other, as bacterial populations have been shown to differ between different substrates and intestinal sites (Momozawa et al. 2011). In general, bacterial number and diversity increase gradually along the GI tract (Suchodolski et al. 2005) (Fig. 1 ). In the healthy canine stomach, total bacterial load is comparably low (10 5 log10 16S rRNA copy numbers), and mostly belong to Proteobacteria (99.6% of obtained gene sequences) with only few Firmicutes (0.3%) (Garcia-Mazcorro et al. 2012). "
    [Show abstract] [Hide abstract] ABSTRACT: Interest in the composition of the intestinal microbiota and possibilities of its therapeutic modifications has soared over the last decade and more detailed knowledge specific to the canine microbiota at different mucosal sites including the gut is available. Probiotics, prebiotics or their combination (synbiotics) are a way of modifying the intestinal microbiota and exert effects on the host immune response. Probiotics are proposed to exert their beneficial effects through various pathways, for example production of antimicrobial peptides, enhancing growth of favourable endogenous microorganisms, competition for epithelial colonisation sites and immune-modulatory functions. Despite widespread use of pro-, pre- and synbiotics, scientific evidence of their beneficial effects in different conditions of the dog is scarce. Specific effects of different strains, their combination or their potential side-effects have not been evaluated sufficiently. In some instances, in vitro results have been promising, but could not be transferred consistently into in vivo situations. Specific canine gastrointestinal (GI) diseases or conditions where probiotics would be beneficial, their most appropriate dosage and application have not been assessed extensively. This review summarises the current knowledge of the intestinal microbiome composition in the dog and evaluates the evidence for probiotic use in canine GI diseases to date. It wishes to provide veterinarians with evidence-based information on when and why these products could be useful in preventing or treating canine GI conditions. It also outlines knowledge about safety and approval of commercial probiotic products, and the potential use of faecal microbial transplantation, as they are related to the topic of probiotic usage.
    Full-text · Article · Jan 2016
    • "Results from the dendrogram presented here indicate a certain intra-individual similarity, especially of the distal gut microbiota. As expected, bacterial compositions of consecutive intestinal compartments were more closely related to each other, as has been previously shown in dogs (Suchodolski et al., 2005) and humans (Andersson et al., 2008). Bacterial communities from feces were not significantly different from the ones found in the large colon, which agrees with the findings of Dougal et al. (2012) who reported similar TRFLP profiles from feces and large colon content of horses, but not from the cecum. "
    [Show abstract] [Hide abstract] ABSTRACT: The advance of new sequencing technologies has allowed more comprehensive characterization of complex microbial communities, including the ones inhabiting the intestinal tract. The presence of extreme environmental filters, such as low pH, digestive enzymes and anaerobic conditions along the tract, acts on the selection of unique bacteria in each compartment. The intestinal microbiota has an enormous impact on the maintenance of health. However, data about the bacteria present in the different intestinal compartments of horses are sparse. In this study, high throughput sequencing was used to characterize and compare bacterial profiles from different intestinal compartments of 11 horses scheduled for euthanasia for reasons other than gastrointestinal problems. Marked differences among compartments even at high taxonomic levels were found, with Firmicutes comprising the main bacterial phylum in all compartments. Lactobacillus spp. and Sarcina spp. predominated in the stomach and a marked increase of Streptococcus spp. occurred in the duodenum. Actinobacillus and Clostridium sensu stricto were the most abundant genera in the ileum and '5 genus incertae sedis', a genus from the Subdivision 5 class of the Verrucomicrobia, was the most abundant from the large colon through feces. There was a significant increase in diversity towards the distal gut with similar profiles observed from the cecum through feces at the class level. The bacterial population comprising the equine intestinal tract varies greatly among compartments and fecal samples may be useful as representative of changes occurring in the distal compartments. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Article · Mar 2015
    • "With respect to the variability of the composition of canine intestinal microbiota, considerable intraspecies differences have been observed in dogs housed under identical conditions and receiving the same diet, with very marked variations in the microbial species residing in the large intestine compared to those found in the small intestine. Moreover, there are large differences between the bacterial species that inhabit the different sections of the intestine and faecal microbiota (Suchodolski et al., 2005). The animal's age is one of the factors influ[page 170] [Ital J Anim Sci vol.13:2014] encing the composition of faecal microbiota: in older animals, lecithinase-positive clostridia and bacteria belonging to the class bacilli are found in higher concentrations than lactobacilli , pepto-streptococci and bifidobacteria (Benno and Mitsuoka, 1989; Benno et al., 1992; Mitsuoka, 1992); furthermore, faecal microbiota seems to be influenced not only by age, but also by the dog breed (Simpson et al., 2002). "
    [Show abstract] [Hide abstract] ABSTRACT: The microbiota of the large intestine plays a fundamental role in maintaining the state of health of the gastrointestinal tract and the host. The use of specific dietary supplements such as prebiotics and synbiotics might positively influence the composition and metabolism of the intestinal microbial population. Several studies have been conducted on the use of prebiotics in dogs. Most studies have aimed to assess whether using prebiotics brings about an improvement in the canine intestinal ecosystem. Moreover, the effect of prebiotics on canine immune system has also been investigated. Among the prebiotics used in the studies present in the literature, short-chain fructooligosaccharides and oligofructose seem to be the most effective in modulating the canine intestinal ecosystem and improving intestinal absorption of minerals but with little or no effect on canine immune system. Conversely, mannanoligosaccharides may have a positive influence on the immune system of dogs. Some positive effects of prebiotics on canine intestinal microbiota might be enhanced when these are used in combination with one or more probiotic strains (synbiotic). Clinical effects of prebiotics have been investigated in humans and animal models but little evidence exists that prebiotics may be helpful in canine diseases. Finally, most studies on canine intestinal microbiota were conducted using traditional culture methods, so that more research remains to be done with modern molecular identification methods to investigate the effects of prebiotic substances. This paper presents an overview of the scientific literature dealing with the use of prebiotics and synbiotics in the canine species.
    Full-text · Article · Mar 2014
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