BACKGROUND Colitis-associated cancer(CAC)accounts for 2%-3%of colorectal cancer(CRC)cases preceded by inflammatory bowel diseases(IBD)such as Crohn's disease and ulcerative colitis.Intestinal microbiota has been r...BACKGROUND Colitis-associated cancer(CAC)accounts for 2%-3%of colorectal cancer(CRC)cases preceded by inflammatory bowel diseases(IBD)such as Crohn's disease and ulcerative colitis.Intestinal microbiota has been reported to play a central role in the pathogenesis of IBD and CAC.Recently,numerous prebiotics and probiotics have being investigated as antitumor agents due to their capacity to modulate inflammatory responses.Previous studies have indicated that lactic acid bacteria could be successfully used in managing sporadic CRC,however little is known about their role in CAC.AIM To investigate the effect of the probiotic Lactobacillus bulgaricus(L.bulgaricus)during the development of an experimental model of colitis associated colon cancer(CAC).METHODS C57BL/6 mice received an intraperitoneal injection of azoxymethane(10 mg/kg),followed by three cycles of sodium dextran sulphate diluted in water(5%w/v).Probiotic group received daily L.bulgaricus.Intestinal inflammation was determined by scoring clinical signs.Cytokines levels were determined from colon and/or tumor samples by ELISA BD OptEIATM kits.The level of significance was set at P<0.05.Graphs were generated and statistical analysis performed using the software GraphPad Prism 6.0.RESULTS L.bulgaricus treatment inhibited of total tumor volume and mean size of tumors.In addition,the probiotic also attenuated the clinical signs of intestinal inflammation inducing a decrease in intestinal and tumor levels of IL-6,TNF-α,IL-17,IL-23 and IL-1β.CONCLUSION Our results suggest a potential chemopreventive effect of probiotic on CAC.L.bulgaricus regulates the inflammatory response and preventing CAC.展开更多
Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of L. bulgaricus wh...Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of L. bulgaricus which decreased with increasing NaCl concentration. In the MRS, NaCl of 1.0 mol·L-1 was the biggest salt stress concentration; in the CDM, 0.8 mol·L-1 was the biggest inhibition concentration. In contrast to what was observed in other lactic acid bacteria, proline, glycine betaine and related molecules were unable to relieve inhibition of growth of L. bulgaricus under osmotic constraint. This was correlated to the absence of sequences homologous to the genes coding for glycine-betaine and/or proline transporters described in Lactococcus lactis and Bacillus subtilis. The amino acid aspartate and alanine were proved to be osmoprotective under NaCl stress. Addition of peptone (0.25% w/v) in the presence of salt led to a stimulation of the growth, as the decrease of the lag time and generation time, and the final biomass increased from 0.31 to 0.64.展开更多
Consu<span>mption of flaxseed provides health benefits. Bile tolerance allows </span>survival of probiotics in the intestinal tract. The objective was to determine whether or not flaxseed enhances bile tol...Consu<span>mption of flaxseed provides health benefits. Bile tolerance allows </span>survival of probiotics in the intestinal tract. The objective was to determine whether or not flaxseed enhances bile tolerance of </span><span style="font-family:""><i></span><i><span style="font-family:"">Lactobacillus acidophilus</span></i><span style="font-family:""> (<i>L. acidophilus</i></span><i><span style="font-family:""></i></span></i><span style="font-family:"">) LA-K<i>, </i></span><i><span style="font-family:""><i></span></i><i><span style="font-family:"">Lactobacillus delbruekii</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> ssp.<i> </i></span><i><span style="font-family:""><i></span></i><i><span style="font-family:"">bulgaricus </span></i><span style="font-family:"">(</span><i><span style="font-family:"">L. bulgaricus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:"">) LB-12,<span> </span></span><span style="font-family:"">and </span><span style="font-family:""><i></span><i><span style="font-family:"">Streptococcus salivarius</span></i><i><span style="font-family:""></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:"">ssp.<i> </i></span><i><span style="font-family:""><i></span></i><i><span style="font-family:"">thermophilus </span></i><span style="font-family:"">(<i>S. </i></span><i><span style="font-family:"">thermophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:"">) ST-M5</span><i><span style="font-family:"">. </span></i><span style="font-family:"">Control and experimental (62 g flaxseed/L) broths containing 0.3% oxgall were prepared for each culture, sterilized, cooled, inoculated, and plated for 8 h. <span>Growth of each microorganism in both the control and </span>experimental broths was evaluated by the slope of the regression line of its log count versus time after inoculation. Flaxseed significantly enhanced growth of </span><span style="font-family:""><i></span><i><span style="font-family:"">L.</span></i><i><span style="font-family:""> acidophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> but not </span><span style="font-family:""><i></span><i><span style="font-family:"">L. </span></i><i><span style="font-family:"">bulgaricus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> and </span><span style="font-family:""><i></span><i><span style="font-family:"">S. thermophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> over 8 h compared to its corresponding control. Therefore, flaxseed improved the bile tolerance of </span><span style="font-family:""><i></span><i><span style="font-family:"">L. acidophilus</span></i><i><span style="font-family:""></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:"">but not of </span><span style="font-family:""><i></span><i><span style="font-family:"">S. thermophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> and </span><span style="font-family:""><i></span><i><span style="font-family:"">L. bulgaricus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:"">.展开更多
基金Supported by Brazilian National Council for Scientific and Technological Development(CNPq),No.140152/2013-0.
文摘BACKGROUND Colitis-associated cancer(CAC)accounts for 2%-3%of colorectal cancer(CRC)cases preceded by inflammatory bowel diseases(IBD)such as Crohn's disease and ulcerative colitis.Intestinal microbiota has been reported to play a central role in the pathogenesis of IBD and CAC.Recently,numerous prebiotics and probiotics have being investigated as antitumor agents due to their capacity to modulate inflammatory responses.Previous studies have indicated that lactic acid bacteria could be successfully used in managing sporadic CRC,however little is known about their role in CAC.AIM To investigate the effect of the probiotic Lactobacillus bulgaricus(L.bulgaricus)during the development of an experimental model of colitis associated colon cancer(CAC).METHODS C57BL/6 mice received an intraperitoneal injection of azoxymethane(10 mg/kg),followed by three cycles of sodium dextran sulphate diluted in water(5%w/v).Probiotic group received daily L.bulgaricus.Intestinal inflammation was determined by scoring clinical signs.Cytokines levels were determined from colon and/or tumor samples by ELISA BD OptEIATM kits.The level of significance was set at P<0.05.Graphs were generated and statistical analysis performed using the software GraphPad Prism 6.0.RESULTS L.bulgaricus treatment inhibited of total tumor volume and mean size of tumors.In addition,the probiotic also attenuated the clinical signs of intestinal inflammation inducing a decrease in intestinal and tumor levels of IL-6,TNF-α,IL-17,IL-23 and IL-1β.CONCLUSION Our results suggest a potential chemopreventive effect of probiotic on CAC.L.bulgaricus regulates the inflammatory response and preventing CAC.
基金Supported by the National Natural Science Funds (31201397)Science Fund for Distinguished Young Scholars Program for Changjiang Scholars and Innovative Research Team in University (IRT0959)Doctor Start Fund of Northeast Agricultural University (2010RCB59)
文摘Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of L. bulgaricus which decreased with increasing NaCl concentration. In the MRS, NaCl of 1.0 mol·L-1 was the biggest salt stress concentration; in the CDM, 0.8 mol·L-1 was the biggest inhibition concentration. In contrast to what was observed in other lactic acid bacteria, proline, glycine betaine and related molecules were unable to relieve inhibition of growth of L. bulgaricus under osmotic constraint. This was correlated to the absence of sequences homologous to the genes coding for glycine-betaine and/or proline transporters described in Lactococcus lactis and Bacillus subtilis. The amino acid aspartate and alanine were proved to be osmoprotective under NaCl stress. Addition of peptone (0.25% w/v) in the presence of salt led to a stimulation of the growth, as the decrease of the lag time and generation time, and the final biomass increased from 0.31 to 0.64.
文摘Consu<span>mption of flaxseed provides health benefits. Bile tolerance allows </span>survival of probiotics in the intestinal tract. The objective was to determine whether or not flaxseed enhances bile tolerance of </span><span style="font-family:""><i></span><i><span style="font-family:"">Lactobacillus acidophilus</span></i><span style="font-family:""> (<i>L. acidophilus</i></span><i><span style="font-family:""></i></span></i><span style="font-family:"">) LA-K<i>, </i></span><i><span style="font-family:""><i></span></i><i><span style="font-family:"">Lactobacillus delbruekii</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> ssp.<i> </i></span><i><span style="font-family:""><i></span></i><i><span style="font-family:"">bulgaricus </span></i><span style="font-family:"">(</span><i><span style="font-family:"">L. bulgaricus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:"">) LB-12,<span> </span></span><span style="font-family:"">and </span><span style="font-family:""><i></span><i><span style="font-family:"">Streptococcus salivarius</span></i><i><span style="font-family:""></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:"">ssp.<i> </i></span><i><span style="font-family:""><i></span></i><i><span style="font-family:"">thermophilus </span></i><span style="font-family:"">(<i>S. </i></span><i><span style="font-family:"">thermophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:"">) ST-M5</span><i><span style="font-family:"">. </span></i><span style="font-family:"">Control and experimental (62 g flaxseed/L) broths containing 0.3% oxgall were prepared for each culture, sterilized, cooled, inoculated, and plated for 8 h. <span>Growth of each microorganism in both the control and </span>experimental broths was evaluated by the slope of the regression line of its log count versus time after inoculation. Flaxseed significantly enhanced growth of </span><span style="font-family:""><i></span><i><span style="font-family:"">L.</span></i><i><span style="font-family:""> acidophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> but not </span><span style="font-family:""><i></span><i><span style="font-family:"">L. </span></i><i><span style="font-family:"">bulgaricus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> and </span><span style="font-family:""><i></span><i><span style="font-family:"">S. thermophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> over 8 h compared to its corresponding control. Therefore, flaxseed improved the bile tolerance of </span><span style="font-family:""><i></span><i><span style="font-family:"">L. acidophilus</span></i><i><span style="font-family:""></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:"">but not of </span><span style="font-family:""><i></span><i><span style="font-family:"">S. thermophilus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> and </span><span style="font-family:""><i></span><i><span style="font-family:"">L. bulgaricus</span></i><i><span style="font-family:""></i></span></i><span style="font-family:"">.
