Microorganisms in Hindgut Fermentors

Stewart, C. S.

doi:10.1007/978-1-4757-0322-1_4

Cited by 34 publications

(39 citation statements)

References 162 publications

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“…Along with the improvements in nutrient utilisation in the small intestine, LRFI pigs had increased lactobacilli numbers in the caecum which is of interest as lactobacilli spp. have been attributed to increased gut function and health (Stewart, 1997). The results from this study suggest that more efficient pigs have improved nutrient digestibility which can be attributed to changes in multiple physiological variables including improved nutrient utilisation and improved intestinal health.…”

Section: Resultsmentioning

confidence: 65%

“…In this study, LRFI pigs had increased lactobacilli numbers in the caecum compared to HRFI pigs with no differences between the other measured bacteria in either the caecum or colon (P < 0.05; Table 4). Lactobacilli are of class bacilli and phylum Firmicutes and have been attributed to increased gut function and health (Stewart, 1997). The increased lactobacilli numbers in the caecum suggests improved intestinal health in LRFI pigs and could contribute to the increased efficiency in LRFI pigs, as increased lactobacilli is known to improve the nutritional value of foods and control intestinal infections (Gilliland, 1990).…”

Section: Nutrient Digestibilitymentioning

confidence: 99%

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Pigs that are divergent in feed efficiency, differ in intestinal enzyme and nutrient transporter gene expression, nutrient digestibility and microbial activity

Vigors

Sweeney

O’Shea

et al. 2016

Animal

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Feed efficiency is an important trait in the future sustainability of pig production, however, the mechanisms involved are not fully elucidated. The objective of this study was to examine nutrient digestibility, organ weights, select bacterial populations, volatile fatty acids (VFA's), enzyme and intestinal nutrient transporter gene expression in a pig population divergent in feed efficiency. Male pigs (n = 75; initial BW 22.4 kg SEM 2.03 kg) were fed a standard finishing diet for 43 days before slaughter to evaluate feed intake and growth for the purpose of calculating residual feed intake (RFI). Phenotypic RFI was calculated as the residuals from a regression model regressing average daily feed intake (ADFI) on average daily gain (ADG) and midtest BW 0.60 (MBW). On day 115, 16 pigs (85 kg SEM 2.8 kg), designated as high RFI (HRFI) and low RFI (LRFI) were slaughtered and digesta was collected to calculate the coefficient of apparent ileal digestibility (CAID), total tract nutrient digestibility (CATTD), microbial populations and VFA's. Intestinal tissue was collected to examine intestinal nutrient transporter and enzyme gene expression. The LRFI pigs had lower ADFI ( P < 0.001), improved feed conversion ratio ( P < 0.001) and an improved RFI value relative to HRFI pigs (0.19 v. −0.14 SEM 0.08; P < 0.001). The LRFI pigs had an increased CAID of gross energy (GE), and an improved CATTD of GE, nitrogen and dry matter compared to HRFI pigs ( P < 0.05). The LRFI pigs had higher relative gene expression levels of fatty acid binding transporter 2 ( FABP2) ( P < 0.01), the sodium/glucose co-transporter 1 ( SGLT1) ( P < 0.05), the glucose transporter GLUT2 ( P < 0.10), and the enzyme sucrase-isomaltase (SI) ( P < 0.05) in the jejunum. The LRFI pigs had increased populations of lactobacillus spp. in the caecum compared with HRFI pigs. In colonic digesta HRFI pigs had increased acetic acid concentrations ( P < 0.05). Differences in nutrient digestibility, intestinal microbial populations and gene expression levels of intestinal nutrient transporters could contribute to the biological processes responsible for feed efficiency in pigs.

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Section: Resultsmentioning

confidence: 65%

Section: Nutrient Digestibilitymentioning

confidence: 99%

Pigs that are divergent in feed efficiency, differ in intestinal enzyme and nutrient transporter gene expression, nutrient digestibility and microbial activity

Vigors

Sweeney

O’Shea

et al. 2016

Animal

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Section: Introductionmentioning

confidence: 99%

“…These genera include the Bacteroides, Bifidobacterium and Clostridium. Lactobacilli establish early in the piglet's lifetime and they remain a predominant member of the small intestine microbiota (Tannock et al, 1990;Naito et al, 1995;Stewart, 1997).Considering the high complexity of the gut microbiota, the Lactobacillus and Bifidobacterium populations served as an index of a health-promoting microbiota. These microbial populations are polyfunctional bacteria with industrially important implications (Giraffa et al, 2010).…”

mentioning

confidence: 99%

Analysis of bacterial community shifts in the gastrointestinal tract of pigs fed diets supplemented with β-glucan from Laminaria digitata, Laminaria hyperborea and Saccharomyces cerevisiae

Murphy

Bello

O’Doherty

et al. 2013

Animal

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This study was designed to evaluate the effects of algal and yeast b-glucans on the porcine gastrointestinal microbiota, specifically the community of Lactobacillus, Bifidobacterium and coliforms. A total of 48 pigs were fed four diets over a 28-day period to determine the effect that each had on these communities. The control diet consisted of wheat and soya bean meal. The remaining three diets contained wheat and soya bean meal supplemented with b-glucan at 250 g/tonne from Laminaria digitata, Laminaria hyperborea or Saccharomyces cerevisiae. Faecal samples were collected from animals before feeding each diet and after the feeding period. The animals were slaughtered the following day and samples were collected from the stomach, ileum, caecum, proximal colon and distal colon. Alterations in Lactobacillus in the gastrointestinal tract (GIT) were analysed using denaturing gradient gel electrophoresis (DGGE) profiles generated by group-specific 16S rRNA gene PCR amplicons. Plate count analysis was also performed to quantify total coliforms. DGGE profiles indicated that all b-glucan diets provoked the emergence of a richer community of Lactobacillus. The richest community of lactobacilli emerged after feeding L. digitata (LD b-glucan). Plate count analysis revealed that the L. hyperborea (LH b-glucan) diet had a statistically significant effect on the coliform counts in the proximal colon in comparison with the control diet. b-glucan from L. digitata and S. cerevisiae also generally reduced coliforms but to a lesser extent. Nevertheless, the b-glucan diets did not significantly reduce levels of Lactobacillus or Bifidobacterium. DGGE analysis of GIT samples indicated that the three b-glucan diets generally promoted the establishment of a more varied range of Lactobacillus species in the caecum, proximal and distal colon. The LH b-glucan had the most profound reducing effect on coliform counts when compared with the control diet and diets supplemented with L. digitata and S. cerevisiae b-glucans.Keywords: b-glucans, pigs, algae, yeast, denaturing gradient gel electrophoresis ImplicationsAdministration of antibiotics to animals has come under intense scrutiny because of their contribution to the dissemination of antibiotic-resistant bacteria into the food chain. Algal and yeast b-glucans are biologically active resources from nature. With respect to animal production, an important goal is to determine the optimal microbiota for the animal and then be able to manipulate the microbiota through the diet, supplements, etc. to obtain the desired microbiota. b-glucans derived from macroalgae and yeast aid in gut health during periods of intestinal imbalance, leading to the alteration in the microbial community composition and hence offering an easily accessible alternative to antibiotics. This paper focuses on the use of a molecular and a cultivation-based method to monitor fluctuations in the gastrointestinal microbiota caused by algal and yeast b-glucan supplementation of the pig diet. Molecular analysis of the Lactobaci...

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“…M. elsdenii strains carrying tet(OWO) genes exhibited the highest tetracycline MICs (128 to >256 g/ml), suggesting that tet(O)-tet(W) mosaic genes provide the selective advantage of greater tetracycline resistance for this species. Seven tet genotypes are now known for M. elsdenii, an archetype commensal anaerobe and model for tet gene evolution in the mammalian intestinal tract.Megasphaera elsdenii is a commensal (mutualist) species in the gastrointestinal tracts of ruminant and nonruminant mammals, including humans (7,25,26). This anaerobic bacterium contributes to the overall metabolism that takes place in those microbial ecosystems (2,5,13,15).…”

mentioning

confidence: 99%

Diverse Tetracycline Resistance Genotypes of Megasphaera elsdenii Strains Selectively Cultured from Swine Feces

Stanton

McDowall

Rasmussen

2004

Appl Environ Microbiol

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A total of 30 Megasphaera elsdenii strains, selectively isolated from the feces of organically raised swine by using Me109 M medium, and one bovine strain were analyzed for tetracycline resistance genotypic and phenotypic traits. Tetracycline-resistant strains carried tet(O), tet(W), or a tet gene mosaic of tet(O) and tet(W). M. elsdenii strains carrying tet(OWO) genes exhibited the highest tetracycline MICs (128 to >256 g/ml), suggesting that tet(O)-tet(W) mosaic genes provide the selective advantage of greater tetracycline resistance for this species. Seven tet genotypes are now known for M. elsdenii, an archetype commensal anaerobe and model for tet gene evolution in the mammalian intestinal tract.Megasphaera elsdenii is a commensal (mutualist) species in the gastrointestinal tracts of ruminant and nonruminant mammals, including humans (7,25,26). This anaerobic bacterium contributes to the overall metabolism that takes place in those microbial ecosystems (2,5,13,15). M. elsdenii has been the focus of both prebiotic and probiotic applications for improving animal health (10,12,19,27).In a recent study of intestinal bacteria resistant to tetracycline, we detected resistant M. elsdenii strains at high population levels (approximately 10 7 CFU/g) in cecal samples from healthy swine (24). Eight strains were isolated and characterized. The M. elsdenii strains are highly resistant to chlortetracycline (MIC ϭ 256 to Ͼ256 g/ml) and carry one of two "tet(OWO)" genes for tetracycline resistance. [Throughout the manuscript, "tet(OW)" and "tet(OWO)" are used as convenient, practical terms for describing M. elsdenii recombinant tet genes and genotypes. As noted previously (24), these designations are not recognized under present tet classification guidelines (14). It is our hope that future guidelines will be developed to accommodate these novel interclass hybrid genes.] These tet genes are interclass mosaic genes apparently formed by doublecrossover recombinations between tet(O) and tet(W) genes.Our previous study used a nutritionally complex medium with high concentrations of chlortetracycline and, thus, was biased to select tetracycline-resistant M. elsdenii strains. In this study, Me109M medium was developed and used to select M. elsdenii strains without using chlortetracycline. The goals were twofold: first, to obtain tetracycline-sensitive strains of M. elsdenii useful both for investigating tet gene transfer and for probiotic applications, and second, to discover whether or not M. elsdenii strains have additional tet genotypes.Selective isolation of M. elsdenii-Me109M medium. On the basis of previous studies (4-6, 9, 14, 16, 17, 19-21) and preliminary experiments in our laboratory, Me109M medium was developed to selectively culture M. elsdenii. Me109M contained (per liter): tryptone-peptone, 4 g; yeast extract, 2 g; salts solution A (6 g of K 2 HPO 4 /liter of water), 40 ml; salts solution B [6 g of KH 2 PO 4 , 12 g of (NH 4 ) 2 SO 4 , 12 g of NaCl, 1.2 g of MgSO 4 -7H 2 O, 0.6 g of CaCl 2 /liter of water], 40 ml; ...

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Microorganisms in Hindgut Fermentors

Cited by 34 publications

References 162 publications

Pigs that are divergent in feed efficiency, differ in intestinal enzyme and nutrient transporter gene expression, nutrient digestibility and microbial activity

Pigs that are divergent in feed efficiency, differ in intestinal enzyme and nutrient transporter gene expression, nutrient digestibility and microbial activity

Analysis of bacterial community shifts in the gastrointestinal tract of pigs fed diets supplemented with β-glucan from Laminaria digitata, Laminaria hyperborea and Saccharomyces cerevisiae

Diverse Tetracycline Resistance Genotypes of Megasphaera elsdenii Strains Selectively Cultured from Swine Feces

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