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Abstract
PURPOSE OF REVIEW Recent findings substantiate that the optimal method of nourishing preterm, very low birth weight infants (VLBW, born <1500 g) is through appropriately nutrient-enriched human milk, which is frequently provided as pasteurized donor milk. The availability of donor milk for VLBW infants during initial hospitalization continues to increase with the launch of new milk banks in North America. The majority of North American neonatal ICUs now have written policies governing the provision of donor milk. The purpose of this review is to summarize recent evidence regarding the risks and benefits of pasteurization of human milk and outcomes associated with its provision to VLBW preterm infants. RECENT FINDINGS Studies investigating the impact of collection, storage and pasteurization on the bacteriostatic, immunologic and nutritional aspects of human milk continue to be published, generally revealing a partial, but not complete reduction in bioactivity. Risk of contamination of pasteurized donor human milk with pathogenic agents is mitigated through pasteurization. New pasteurization methods aiming to maintain the safety of pooled human milk while better preserving bioactivity are under investigation. SUMMARY Provision of a human milk-derived diet to preterm VLBW infants is associated with improved outcomes.
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Affiliation(s)
- Deborah L O'Connor
- aDepartment of Nutritional Sciences bDepartment of Paediatrics and Neonatology, University of Toronto cPhysiology and Experimental Medicine Program, The Hospital for Sick Children, Toronto dDepartment of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton eDepartment of Paediatrics, Mount Sinai Hospital, Toronto, Ontario, Canada
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2
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Abstract
Image-based methods such as computed tomography for assessing body composition enables quantification of muscle mass and muscle density and reveals that low muscle mass and myosteatosis (fat infiltration into muscle) are common in people with cancer. Myosteatosis and low muscle mass have emerged as independent risk factors for mortality in cancer; however, the characteristics and pathogenesis of these features have not been resolved. Muscle depletion is associated with low plasma eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) in cancer and supplementation with n-3 fatty acids has been shown to ameliorate muscle loss and myosteatosis in clinical studies, suggesting a relationship between n-3 fatty acids and muscle health. Since the mechanisms by which n-3 fatty acids alter body composition in cancer remain unknown, related literature from other conditions associated with myosteatosis, such as insulin resistance and obesity is considered. In these noncancer conditions, it has been reported that n-3 fatty acids act by increasing insulin sensitivity, reducing inflammatory mediators, and altering adipokine profiles and transcription factors; therefore, the plausibility of these mechanisms of action in the neoplastic state are considered. The aim of this review is to summarize what is known about the effects of n-3 fatty acids with regards to muscle condition and to discuss potential mechanisms for effects of n-3 fatty acids on muscle health.
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Affiliation(s)
- Julia B Ewaschuk
- Department of Agricultural, Food, and Nutritional Science, Faculty of Agricultural, Life, and Environmental Science, Division of Human Nutrition, 4-002 Li Ka Shing Center for Research Innovation, University of Alberta, Edmonton, AB T6G 2R3, Canada
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3
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Ewaschuk JB, Newell M, Field CJ. Docosahexanoic Acid Improves Chemotherapy Efficacy by Inducing CD95 Translocation to Lipid Rafts in ER− Breast Cancer Cells. Lipids 2012; 47:1019-30. [DOI: 10.1007/s11745-012-3717-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 08/31/2012] [Indexed: 11/28/2022]
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Field CJ, Ewaschuk JB, Nelson R, Newell M, Jacobs R. Docosahexaenoic acid alters cell death, cancer and cell‐cycle signaling networks in breast cancer cell lines. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.366.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Catherine J Field
- Agricultural, Food and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
| | - Julia B Ewaschuk
- Agricultural, Food and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
| | - Randy Nelson
- Agricultural, Food and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
| | - Marnie Newell
- Agricultural, Food and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
| | - Rene Jacobs
- Agricultural, Food and Nutritional ScienceUniversity of AlbertaEdmontonABCanada
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Ewaschuk JB, Johnson IR, Madsen KL, Vasanthan T, Ball R, Field CJ. Barley-derived β-glucans increases gut permeability, ex vivo epithelial cell binding to E. coli, and naive T-cell proportions in weanling pigs. J Anim Sci 2012; 90:2652-62. [PMID: 22393029 DOI: 10.2527/jas.2011-4381] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Weaning in young animals is associated with an increased incidence of gastrointestinal infections. β-glucans exert numerous physiological effects, including altering immune function. The objective of this study was to determine the effects of feeding barley (Hordeum vulgare L.)-derived β-glucans on immune and intestinal function in weanling pigs (Sus scrofa). Thirty-one individually-housed Dutch Landrace pigs (21 d; initial BW, 6,298 ± 755 g) were weaned and fed a wheat-based diet (control) or a low (Lo-BG), medium (Med-BG), or high β-glucan-containing barley-based diet (Hi-BG) for 2 wk with 7 or 8 pigs/treatment. Intestinal segments were analyzed for permeability using Ussing chambers and K88 Escherichia coli adhesion to enterocytes was assessed ex vivo. Immune cells from mesenteric lymph nodes, peripheral blood, and Peyer's patches were analyzed for lymphocyte subsets by indirect immunofluorescence and the ability to respond ex vivo to mitogens by (3)H-thymidine incorporation. Hematology and neutrophil function were determined by flow cytometry. Neutrophil burst, size, and granularity, lymphocyte proliferation, and B-cell distribution in peripheral blood lymphocytes, Peyer's patches, and mesenteric lymph nodes were not affected by β-glucans content of the diet. The β-glucans content of the diet altered blood concentrations of erythrocytes and leukocytes, CD4, CD45RA, and CD8 blood cells (P < 0.05). In addition, feeding β-glucan resulted in increased (P < 0.05) percentage CD45RA positive cells in peripheral blood lymphocytes, Peyer's patches, and mesenteric lymph nodes. Mannitol permeability and tissue conductance were increased (P < 0.05) in Hi-BG fed pigs compared with control pigs. Percentage maximum K88-E.coli binding was increased in proportion to the β-glucan content of the diet (P < 0.05). Although β-glucan feeding during the weaning period increased blood lymphocytes and the proportion of naïve T-cells, it also increased E. coli-enterocyte binding and intestinal permeability. β-glucan may alter immune and intestinal function of weaning pigs.
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Affiliation(s)
- J B Ewaschuk
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton T6G 2P5, Canada
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Ewaschuk JB, Unger S, Harvey S, O'Connor DL, Field CJ. Effect of pasteurization on immune components of milk: implications for feeding preterm infants. Appl Physiol Nutr Metab 2011; 36:175-82. [PMID: 21609278 DOI: 10.1139/h11-008] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been unequivocally proven that human breast milk is the ideal source of nutrition for infants. However, mothers of preterm infants face a number of barriers to providing sufficient milk volume to their babies, who are at risk for developing necrotizing enterocolitis (NEC). Donated milk, distributed through milk banks, is becoming a desirable alternative to formula feeding, and is increasingly being considered for hospitalized, preterm infants in North America. Donor milk in North America is pasteurized (62.5 °C, 30 min) to remove possible infectious contaminants; a number of immune and bioactive components are either partially or entirely inactivated by this process. Identifying the impact of pasteurization on immune components of breast milk has been the focus of numerous research studies over the past several decades. The objective of this review is to summarize the literature on the feeding of pasteurized donor milk to preterm infants and the current understanding of the impact of pasteurization on immune components of breast milk, with particular reference to those implicated in the prevention of NEC.
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Affiliation(s)
- Julia B Ewaschuk
- Department of Agricultural, Food, and Nutritional Sciences, University of Alberta, 4126 HRIF East, Edmonton, AB T6G 2E1, Canada
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Zello GA, Abeysekara S, Ewaschuk JB, Alcorn J, Naylor JM, Lohmann KL. The determination of a fecal D‐lactate threshold in neonatal ruminants with diarrhea. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.919.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | - Katharina L Lohmann
- Western College of Veterinary MedicineUniversity of SaskatchewanSaskatoonSKCanada
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Ewaschuk JB, Diaz H, Meddings L, Diederichs B, Dmytrash A, Backer J, Looijer-van Langen M, Madsen KL. Secreted bioactive factors from Bifidobacterium infantis enhance epithelial cell barrier function. Am J Physiol Gastrointest Liver Physiol 2008; 295:G1025-34. [PMID: 18787064 DOI: 10.1152/ajpgi.90227.2008] [Citation(s) in RCA: 385] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Live probiotic bacteria are effective in reducing gut permeability and inflammation. We have previously shown that probiotics release peptide bioactive factors that modulate epithelial resistance in vitro. The objectives of this study were to determine the impact of factors released from Bifidobacteria infantis on intestinal epithelial cell permeability and tight junction proteins and to assess whether these factors retain their bioactivity when administered to IL-10-deficient mice. B. infantis conditioned medium (BiCM) was applied to T84 human epithelial cells in the presence and absence of TNF-alpha and IFN-gamma. Transepithelial resistance (TER), tight junction proteins [claudins 1, 2, 3, and 4, zonula occludens (ZO)-1, and occludin] and MAP kinase activity (p38 and ERK) were examined. Acute effects of BiCM on intestinal permeability were assessed in colons from IL-10-deficient mice in Ussing chambers. A separate group of IL-1-deficient mice was treated with BiCM for 4 wk and then assessed for intestinal histological injury, cytokine levels, epithelial permeability, and immune response to bacterial antigens. In T84 cells, BiCM increased TER, decreased claudin-2, and increased ZO-1 and occludin expression. This was associated with enhanced levels of phospho-ERK and decreased levels of phospho-p38. BiCM prevented TNF-alpha- and IFN-gamma-induced drops in TER and rearrangement of tight junction proteins. Inhibition of ERK prevented the BiCM-induced increase in TER and attenuated the protection from TNF-alpha and IFN-gamma. Oral BiCM administration acutely reduced colonic permeability in mice whereas long-term BiCM treatment in IL-10-deficient mice attenuated inflammation, normalized colonic permeability, and decreased colonic and splenic IFN-gamma secretion. In conclusion, peptide bioactive factors from B. infantis retain their biological activity in vivo and are effective in normalizing gut permeability and improving disease in an animal model of colitis. The effects of BiCM are mediated in part by changes in MAP kinases and tight junction proteins.
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Ewaschuk JB, Backer JL, Churchill TA, Obermeier F, Krause DO, Madsen KL. Surface expression of Toll-like receptor 9 is upregulated on intestinal epithelial cells in response to pathogenic bacterial DNA. Infect Immun 2007; 75:2572-9. [PMID: 17325049 PMCID: PMC1865769 DOI: 10.1128/iai.01662-06] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Colonic epithelial cells are constantly exposed to high levels of bacterial DNA in the intestinal lumen and must recognize and respond appropriately to pathogens, while they maintain a tolerance to nonpathogenic commensal bacterial strains. Bacterial DNA is recognized by Toll-like receptor 9 (TLR9). The aim of this study was to investigate TLR9 expression and localization in colonic epithelial cells under basal conditions and in response to bacterial DNA. HT-29 cells were exposed to DNA from various strains of commensal and pathogenic microbes. TLR9 mRNA expression was determined by real-time reverse transcription-PCR, and interleukin-8 (IL-8) secretion was measured by an enzyme-linked immunosorbent assay. Localization of TLR9 was determined by flow cytometry in HT-29 cells and by immunofluorescence in HT-29 cells and mouse colonic tissue. Immunofluorescence and flow cytometric analyses demonstrated that there was intracellular and surface expression of TLR9 in HT-29 cells under basal conditions. Exposure of cells to DNA from pathogenic strains of Salmonella and Escherichia coli resulted in a significant increase in TLR9 mRNA expression. Salmonella enterica serovar Dublin DNA increased surface TLR9 protein and IL-8 secretion. There was no change in mRNA levels or localization of TLR9 in response to Bifidobacterium breve. Chloroquine did not block IL-8 secretion in response to S. enterica serovar Dublin DNA. TLR9 was expressed on the colonic apical surface in wild-type mice but not in germfree mice. These results demonstrate that intestinal epithelial cells recognize pathogenic bacterial DNA and respond by increasing surface localization and expression of TLR9, suggesting that the epithelial inflammatory response to pathogenic DNA is mediated at least in part by increased TLR9 expression.
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Affiliation(s)
- Julia B Ewaschuk
- Division of Gastroenterology, University of Alberta, Edmonton, Alberta T6G 2N8, Canada
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Ewaschuk JB, Tejpar QZ, Soo I, Madsen K, Fedorak RN. The role of antibiotic and probiotic therapies in current and future management of inflammatory bowel disease. Curr Gastroenterol Rep 2007; 8:486-98. [PMID: 17105688 DOI: 10.1007/s11894-006-0039-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abundant evidence indicates that the intestinal microflora have a role in the pathogenesis of inflammatory bowel disease (IBD). The composition of the gut microflora is altered in IBD patients with increased "pathogenic" bacteria and decreased bifidobacteria and lactobacilli. In light of this dysbiosis, various methods have been examined to alter the composition of the intestinal microflora, including the administration of antibiotics and introduction of probiotic species. This article summarizes studies evaluating the efficacy of antibiotics and probiotics in the induction and maintenance of remission of ulcerative colitis, Crohn's disease, and pouchitis.
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Affiliation(s)
- Julia B Ewaschuk
- Division of Gastroenterology, Zeidler Family Gastrointestinal Health and Research Centre, Zeidler Ledcor Building, 130 University Campus, Edmonton, AB, Canada T6G 2C8
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Abstract
The prokaryotic and eukaryotic cells of the colon exist in a highly complex, but harmonious relationship. Disturbances in this remarkable symbiosis can result in the development of inflammatory bowel diseases (IBD). Although the etiology of IBD is not entirely understood, it is known that the chronic inflammation of Crohn’s disease, ulcerative colitis and chronic pouchitis are a result of an overly aggressive immune response to the commensal intestinal flora in genetically susceptible hosts. Recent studies have enhanced our ability to understand the interaction between the host and its intestinal microflora and the role the microflora plays in maintaining intestinal homeostasis. As we begin to understand the benefits conferred to the intestine by the microflora, the notion of modifying the composition of the bacterial load to improve human health has arisen. A significant body of research now exists investigating the role of probiotics and prebiotics in ameliorating chronic intestinal inflammation. This article will begin with an overview of the role of the commensal microflora in maintaining mucosal immune homeostasis, and how a dysregulated immune response to the intestinal microflora results in IBD. This will be followed by a summary of the use of probiotics and prebiotics in experimental and human IBD.
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Affiliation(s)
- Julia B Ewaschuk
- Centre for Excellence for Gastrointestinal Inflammation and Immunity Research, University of Alberta, Edmonton, Alberta, T6G 2X8, Canada
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12
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Abstract
D-lactate, produced by gastrointestinal fermentation, is a major contributor to metabolic acidosis in diarrheic calves. Lactobacillus rhamnosus GG survives gastrointestinal transit in the neonatal calf and does not produce D-lactate. To determine whether this probiotic reduces gastrointestinal D-lactate production or severity of diarrhea or both, 48 calves (mean, 11 days old; range, 2-30 days) admitted to the clinic for treatment of diarrhea were randomly allocated to 2 groups. The experimental group was given Lactobacillus rhamnosus GG (1 x 10(11) cfu/d) PO, dissolved in milk or oral electrolyte solution, in addition to clinic treatment protocols; the other group served as a control. Serum and fecal samples were obtained at admission and at 24 and 48 hours after initial administration of Lactobacillus rhamnosus GG. All samples were analyzed for D- and L-lactate by using high-pressure liquid chromatography. Feces were also analyzed for pathogens, Lactobacillus rhamnosus GG recovery, and dry matter. D-lactic acidemia (>3 mmol/L) was present in 37/48 calves at admission. Lactobacillus rhamnosus GG was recovered in the feces of 13 experimental calves and 0 control calves 24 hours after administration. No difference in serum or fecal D- or L-lactate between the groups was detected at any time point. After therapy, D-lactic acidosis was absent at 48 hours in all but 1 calf. No relation between fecal pathogen (viral, bacterial, or protozoal) and degree of D-lactic acidosis was observed. The reduction in mortality and greater fecal dry matter in Lactobacillus rhamnosus GG-treated calves was not statistically significant.
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Affiliation(s)
- Julia B Ewaschuk
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
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Abstract
D‐lactate, produced by gastrointestinal fermentation, is a major contributor to metabolic acidosis in diarrheic calves. Lactobacillus rhamnosus GG survives gastrointestinal transit in the neonatal calf and does not produce D‐lactate. To determine whether this probiotic reduces gastrointestinal D‐lactate production or severity of diarrhea or both, 48 calves (mean, 11 days old; range, 2–30 days) admitted to the clinic for treatment of diarrhea were randomly allocated to 2 groups. The experimental group was given Lactobacillus rhamnosus GG (1×1011 cfu/d) PO, dissolved in milk or oral electrolyte solution, in addition to clinic treatment protocols; the other group served as a control. Serum and fecal samples were obtained at admission and at 24 and 48 hours after initial administration of Lactobacillus rhamnosus GG. All samples were analyzed for D‐and L‐lactate by using high‐pressure liquid chromatography. Feces were also analyzed for pathogens, Lactobacillus rhamnosus GG recovery, and dry matter. D‐lactic acidemia (>3 mmol/L) was present in 37/48 calves at admission. Lactobacillus rhamnosus GG was recovered in the feces of 13 experimental calves and 0 control calves 24 hours after administration. No difference in serum or fecal D‐ or L‐lactate between the groups was detected at any time point. After therapy, D‐lactic acidosis was absent at 48 hours in all but 1 calf. No relation between fecal pathogen (viral, bacterial, or protozoal) and degree of D‐lactic acidosis was observed. The reduction in mortality and greater fecal dry matter in Lactobacillus rhamnosus GG‐treated calves was not statistically significant.
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Affiliation(s)
- Julia B Ewaschuk
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
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Abstract
Probiotics have been shown to reduce the incidence of colon cancer in animal models. The mechanisms responsible for this activity are poorly defined. Conjugated linoleic acids (CLA) are a group of isomers of linoleic acid (LA) possessing anti-inflammatory and anticarcinogenic properties, which can be produced from LA by certain bacterial strains. In this study, the ability of probiotic bacteria to exert anticarcinogenic effects through the production of CLA was assessed. Incubation of probiotic bacteria (VSL3, Lactobacillus acidophilus, L. bulgaricus, L. casei, L. plantarum, Bifidobacterium breve, B. infantis, B. longum, and Streptococcus thermophilus) in the presence of LA yielded CLA production as measured by gas chromatography. Conditioned medium, containing probiotic-produced CLA, reduced viability and induced apoptosis of HT-29 and Caco-2 cells, as assessed by MTT assay and DNA laddering, respectively. Western blotting demonstrated an increased expression of PPARgamma in cells treated with conditioned medium compared with LA alone. Incubation of murine feces with LA after administering VSL3 yielded 100-fold more CLA than feces collected prior to VSL3 feeding. This study supports a role for supplemental probiotics as a strategy both for attenuating inflammation and for preventing colon cancer.
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Affiliation(s)
- Julia B Ewaschuk
- Division of Gastroenterology, University of Alberta, Edmonton, Alberta, Canada
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Pinkoski C, Chilibeck PD, Candow DG, Esliger D, Ewaschuk JB, Facci M, Farthing JP, Zello GA. The Effects of Conjugated Linoleic Acid Supplementation during Resistance Training. Med Sci Sports Exerc 2006; 38:339-48. [PMID: 16531905 DOI: 10.1249/01.mss.0000183860.42853.15] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE We determined the effects of conjugated linoleic acid (CLA) supplementation during resistance training. METHODS Seventy-six subjects were randomized to receive CLA (5 g.d(-1)) or placebo (PLA) for 7 wk while resistance training 3 d.wk(-1). Seventeen subjects crossed over to the opposite group for an additional 7 wk. Measurements at baseline, 7 wk, and 14 wk (for subjects in the crossover study) included body composition, muscle thickness of the elbow flexors and knee extensors, resting metabolic rate (RMR), bench and leg press strength, knee extension torque, and urinary markers of myofibrillar degradation (3-methylhistidine (3MH) and bone resorption (cross-linked N-telopeptides (Ntx)). RESULTS After 7 wk the CLA group had greater increases in lean tissue mass (LTM) (+1.4 vs +0.2 kg; P < 0.05), greater losses of fat mass (-0.8 vs +0.4 kg; P < 0.05), and a smaller increase in 3MH (-0.1 vs + 1.3 micromol.kg LTM.d(-1); P < 0.05) compared with PLA. Changes between groups were similar for all other measurements, except for a greater increase in bench press strength for males on CLA (P < 0.05). In the crossover study subjects had minimal changes in body composition, but smaller increases in 3MH (-1.2 vs +2.2 micromol.kg LTM.d(-1); P < 0.01) and NTx (-4.8 vs +7.3 nmol.kg(-1) LTM.d(-1); P < 0.01) while on CLA versus PLA. CONCLUSIONS Supplementation with CLA during resistance training results in relatively small changes in body composition accompanied by a lessening of the catabolic effect of training on muscle protein.
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Affiliation(s)
- Craig Pinkoski
- College of Kinesiology, University of Saskatchewan, Saskatoon, Canada
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Abstract
D-lactate is normally present in the blood of mammals at nanomolar concentrations due to methylglyoxal metabolism; millimolar d-lactate concentrations can arise due to excess gastrointestinal microbial production. Grain overload in ruminants, short-bowel syndrome in humans, and diarrhea in calves can all result in profound D-lactic acidemia, with remarkably similar neurological manifestations. In the past, D-lactate was thought to be excreted mainly in the urine, and metabolized slowly by the enzyme d-alpha-hydroxy acid dehydrogenase. More recent studies reported that mammals have a relatively high capacity for D-lactate metabolism and identified a putative mammalian D-lactate dehydrogenase. A growing body of literature is also emerging describing subclinical elevation of D-lactate as an indicator of sepsis and trauma. This article describes advances in the understanding of D-lactate metabolism, D-lactic acidosis in ruminants and humans, and subclinical elevation of d-lactate.
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Packer RA, Cohn LA, Wohlstadter DR, Shelton GD, Naylor JM, Zello GA, Ewaschuk JB, Williams DA, Ruaux CG, O'Brien DP. D-lactic acidosis secondary to exocrine pancreatic insufficiency in a cat. J Vet Intern Med 2005; 19:106-10. [PMID: 15715057 DOI: 10.1892/0891-6640(2005)19<106:dastep>2.0.co;2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Rebecca A Packer
- Department of Veterinary Medicine and Surgery, Veterinary Medical Teaching Hospital, Columbia, MO 65211, USA
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Packer RA, Cohn LA, Wohlstadter DR, Shelton GD, Naylor JM, Zello GA, Ewaschuk JB, Williams DA, Ruaux CG, O'Brien DP. D-Lactic Acidosis Secondary to Exocrine Pancreatic Insufficiency in a Cat. J Vet Intern Med 2005. [DOI: 10.1111/j.1939-1676.2005.tb02667.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Abstract
The origin of D-lactate, the most important acid contributing to metabolic acidosis in the diarrheic calf, is unknown. We hypothesized that because D-lactate is produced only by microbes, gastrointestinal fermentation is the source. The objective of this study was to determine whether D-lactate production occurs in the rumen, colon, or both, and to measure D- and L-lactate concentrations in urine. Fecal, rumen, blood, and urine samples were obtained from 16 diarrheic and 11 healthy calves. Serum electrolyte concentrations were measured in both groups, and blood gas analyses were performed for diarrheic calves. All samples were analyzed for D- and L-lactate by high performance liquid chromatography (HPLC). Diarrheic calves were generally hyperkalemic with high serum anion gap, depressed serum bicarbonate, and low blood pH. L-lactate was markedly higher in rumen contents (22.7 mmol/ L [median]) and feces (8.6 mmol/L) of diarrheic calves than healthy calves (0.5 mmol/L and 5.1 mmol/L, respectively), but not different in serum or urine. Rumen, fecal, serum, and urine D-lactate concentrations were all significantly higher (P < .05) in diarrheic calves (17.0, 25.4, 13.9, and 19.2 mmol/L, respectively) than in healthy calves (0.5, 9.1, 1.4, and 0.5 mmol/L, respectively). Higher D-lactate concentrations in the rumen and feces of diarrheic calves suggests these sites as the source of D-lactate in blood and urine.
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Affiliation(s)
- Julia B Ewaschuk
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Ewaschuk JB, Naylor JM, Chirino-Trejo M, Zello GA. Lactobacillus rhamnosus strain GG is a potential probiotic for calves. Can J Vet Res 2004; 68:249-53. [PMID: 15581218 PMCID: PMC1111354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Diarrhea is a common occurrence in neonatal calves. Several veterinary probiotics claiming to prevent or treat calf diarrhea are available, but have not been well studied. This study assessed the capability of Lactobacillus rhamnosus strain GG (LGG) to maintain viability in the gastrointestinal tract of calves. We also determined whether LGG can be administered in an oral rehydration solution (ORS) without compromising the efficacy of the ORS or the viability of LGG, and whether LGG produces D-lactate or not. To investigate the intestinal survival of LGG, 15 calves were randomized into 3 groups and LGG was administered orally with their morning milk feeding on 3 consecutive days at a low (LD), medium (MD), or high (HD) dosage. Fecal samples were collected on days 0 (control), 1, 2, 3, 5, and 7 and incubated for 72 h on deMan, Rogosa, Sharpe agar. Twenty-four hours after the 1st feeding, LGG was recovered from 1 out of 5 calves in the LD group, 4 out of 5 calves in the MD group, and 5 out of 5 calves in the HD group. To determine if LGG caused the glucose levels in the ORS to drop below effective levels, 1.5 L of the ORS was incubated with LGG for 2 h at 37 degrees C and the glucose concentration was measured every 20 min using a glucose meter. This ORS was then further incubated for 10 h and aliquots analyzed by high performance liquid chromatography to determine if D-lactate was produced by LGG. Glucose concentrations did not change over the 2 h of incubation, and no D-lactate was produced after 48 h. The LGG maintained viability in ORS. Therefore, this study demonstrated that LGG survives intestinal transit in the young calf, produces no D-lactate, and can be administered in an ORS.
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Affiliation(s)
- Julia B Ewaschuk
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9
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Ewaschuk JB, Naylor JM, Barabash WA, Zello GA. High-performance liquid chromatographic assay of lactic, pyruvic and acetic acids and lactic acid stereoisomers in calf feces, rumen fluid and urine. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 805:347-51. [PMID: 15135111 DOI: 10.1016/j.jchromb.2004.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2003] [Revised: 03/02/2004] [Accepted: 03/02/2004] [Indexed: 10/26/2022]
Abstract
To facilitate clinical investigation of metabolic acidosis, a high-performance liquid chromatographic method was adapted and validated for the chiral separation of D-(-) and L-(+)-lactic acid in calf feces, rumen fluid and urine. A non-chiral method was also adapted and validated for the separation of pyruvic, acetic and DL-(+/-)-lactic acids in calf feces and DL-(+/-)-lactic and pyruvic acids in rumen fluid. Separation and quantification were achieved using a reversed phase sulphonated polystyrenedivinylbenzene analytical column for pyruvic, acetic and racemic lactic acids and by a 3 microm octadecylsilane (ODS) packed analytical column coated with N,N-dioctyl-L-alanine as the chiral selector for the separation of lactic acid enantiomers with Cu(II)-containing eluents by stereoselective ligand exchange chromatography. Endogenous analytes were present in validation samples over a range of concentrations (0.2-14.8 mmol/l). For the stereoselective assay, mean intra-day accuracy ranged from 90.6 to 108.4% and intra-day precision from 0.3 to 13.8%. For the non-stereoselective assay, mean intra-day accuracy ranged from 90.4 to 108.8% and intra-day precision from 1.5 to 11.1%. The limit of quantitation was 1.0 mmol/l for D- and L-lactic acid, 0.06125 mmol/l for pyruvic acid, 1.0 mmol/l for DL-lactic acid and 1 mmol/l for acetic acid. These assays can be used to study the role of the gastrointestinal tract and kidney in metabolic acidosis.
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Affiliation(s)
- Julia B Ewaschuk
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C9
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Abstract
The objective of this study was to investigate the relationship between serum D- and L-lactate concentrations, and anion gap (AG) in neonatal calves. The association of AG with lactic acidosis in diarrheic calves has only been investigated by measurement of L-lactate in calves with experimentally induced diarrhea. D-lactate has recently been reported to be present in high concentrations in the serum of some diarrheic neonatal calves. The contribution of this acid to AG is not reported. The relationship between AG and L- and D-lactate concentrations was examined in 24 healthy calves and 52 calves with naturally occurring infectious diarrhea with metabolic acidosis. AG was calculated as [Na+ + K+] - [Cl- + HCO3-]. D- and L-lactate were quantified using high-performance liquid chromatography. There was no correlation between L-lactate and AG, contrary to previous reports in the literature. Moderate correlations between D-lactate concentration and AG (r = .74, P < .0001), and between DL-lactate and AG (r = .77), P < .0001) were detected. No differences existed due to the age or sex of the calf. This study indicates that AG provides information on the nature of acidosis in the diarrheic, neonatal calf and reinforces the importance of investigating clinical, in addition to experimental, populations.
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Affiliation(s)
- Julia B Ewaschuk
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Ewaschuk JB, Zello GA, Naylor JM, Brocks DR. Metabolic acidosis: separation methods and biological relevance of organic acids and lactic acid enantiomers. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 781:39-56. [PMID: 12450652 DOI: 10.1016/s1570-0232(02)00500-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Metabolic acidosis can result from accumulation of organic acids in the blood due to anaerobic metabolism or intestinal bacterial fermentation of undigested substrate under certain conditions. These conditions include short-bowel syndrome, grain overfeeding of ruminants and, as recently reported, severe gastroenteritis. Measuring fermentation products such as short-chain fatty acids (SCFAs) and lactic acid in various biological samples is integral to the diagnosis of bacterial overgrowth. Stereospecific measurement of D- and L-lactic acid is necessary for confirmation of the origin and nature of metabolic acidosis. In this paper, methods for the separation of SCFAs and lactic acid are reviewed. Analysis of the organic acids involved in carbohydrate metabolism has been achieved by enzymatic methods, gas chromatography, high-performance liquid chromatography and capillary electrophoresis. Sample preparation techniques developed for these analytes are also discussed.
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Affiliation(s)
- Julia B Ewaschuk
- College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
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