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Khan, Khalid M.; Edwards, Christine A. (2011)
Publisher: Microbial Ecology in Health and Disease
Journal: Microbial Ecology in Health and Disease
Languages: English
Types: Article

Classified by OpenAIRE into

mesheuropmc: food and beverages, digestive, oral, and skin physiology
Objective: Fermentation of unabsorbable carbohydrate produces short chain fatty acids (SCFA) and rapidly lowers human colonic pH. SCFA produced in vivo will be absorbed. However, in vitro batch cultures are often used for assessing the fermentation characteristics of a carbohydrate. These models have several limitations. The accumulation of fermentation products due to increased substrate concentration may transform bacterial activity. In addition the enzymes involved in the fermentation process may become saturated producing misleading results. The objective of this study was to determine the effect of substrate concentration on SCFA production in vitro. Design: The effect of substrate concentration was estimated using incremental portions of lactulose in an in vitro fermentation model. Comparison of the total SCFA produced from increasing amounts of carbohydrate with those calculated by multiples of that produced from 2.5 mg/ml lactulose showed a progressive decrease in the production of SCFA with increasing lactulose. Results: The SCFA production from 10 mg/ml lactulose was significantly less than that from 7.5 mg/ml and when compared with amounts predicted from multiples of 2.5 mg/ml lactulose, was significantly reduced by 40–60%. Conclusion: Substrate concentration must be carefully selected to give a true index of SCFA production from rapidly fermentable carbohydrates.Keywords: fermentation, lactulose, short chain fatty acids, bacteria.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • 1. Cummings JH, Pomare EW, Branch WJ, Naylor CPE, Macfarlane GT. Short chain fatty acids in human large intestine, portal, hepatic and venous blood. Gut 1987; 28: 1221 - 7.
    • 2. Hague A, Singh B, Paraskeva C. Butyrate acts as a survival factor for colonic epithelial cells: further fuel for the in vivo versus in vitro debate. Gastroenterology 1997; 112: 1036 - 40.
    • 3. Re´me´sy C, Demigne´ C, Morand C. Metabolism and utilisation of short chain fatty acids produced by colonic fermentation. In: Schweizer TF, Edwards CA, eds. Dietary Fibre- a Component of Food. London: Springer, 1992: 137 - 50.
    • 4. Adiotomre J, Eastwood MA, Edwards CA, Brydon WG. Dietary bre: in vitro methods that anticipate nutrition and metabolic activity in humans. Am J Clin Nutr 1990; 52: 128 - 34.
    • 5. Barry J-L, Hoebler C, Macfarlane GT, Macfarlane S, Mathers JC, Reed KA, et al. Estimation of the fermentability of dietary bre in vitro : a European interlaboratory study. Br J Nutr 1995; 74: 303 - 22.
    • 6. Edwards CA, Gibson G, Champ M, Jensen BB, Mathers JC, Nagengast F, et al. In vitro method for quanti cation of the fermentation of starch by human faecal bacteria. J Sci Food Agric 1996; 71: 209 - 17.
    • 7. Mortensen B, Hove H, Rye Clausen M, Holtug K. Fermentation to short chain fatty acids and lactate in human faecal batch cultures: intra- and inter-individual variations versus variations caused by changes in fermented saccharides. Scand J Gastroenterol 1991; 26: 1285 - 94.
    • 8. Stevenson A, Buchanan CJ, Abia R, Eastwood MA. A simple in vitro fermentation system for polysaccharides - the effects of fermenter uid surface area: uid volume ratio and amount of substrate. J Sci Food Agric 1997; 73: 101 - 5.
    • 9. Gibson GR, Roberfroid MB. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr 1995; 125: 1401 - 12.
    • 10. Vince AJ, McNeil NI, Wager ID, Wrong DM. The effect of lactulose, pectin, arabinogalactan and cellulose on the production of organic acids and metabolism of ammonia by intestinal bacteria in a faecal incubation system. Br J Nutr 1990; 63: 17 - 26.
    • 11. Spiller GA, Chernoff MC, Hill RA, Gates JE, Nasser JJ, Shipley EA. Effect of puri ed cellulose, pectin and a lowresidue diet on faecal volatile fatty acids, transit time and faecal weight in humans. Am J Clin Nutr 1980; 33: 754 - 9.
    • 12. Edwards CA, Duerden BI, Read NW. The effects of pH on colonic bacteria grown in continuous culture. J Med Microbiol 1985; 19: 169 - 80.
    • 13. Padan A, Zilberstein D, Shuldiner S. pH homeostasis in bacteria. Biochim Biophy Acta 1981; 650: 151 - 66.
    • 14. Sherman JM, Holm GE. Salt effects in bacterial growth. II. The growth of bacterium coli in relation to H-ion concentration. J Bacteriol 1922; 7: 465 - 70.
    • 15. Chung KC, Geopfert JM. Growth of Salmonella at low pH. J Food Sci 1970; 35: 326 - 8.
    • 16. Jay JM. Intrinsic and extrinsic parameters of foods that affect microbial growth. In: Modern Food Microbiology, 4th edn. New York: Van Nostrand Reinhold, 1996: 38 - 66.
    • 17. Mortensen PB, Holtug K, Ramussen HS. Short chain fatty acid production from mono- and disaccharides in a fecal incubation system: implications for colonic fermentation of dietary bre in humans. J Nutr 1988; 118: 321 - 5.
    • 18. Daly J, Tomlin J, Read NW. The effect of feeding xanthan gum on colonic function in man: correlation with in vitro determinants of bacterial breakdown. Br J Nutr 1993; 69: 897 - 902.
    • 19. Mortensen PB, Nordgaard-Anderson I. The dependence of the in vitro fermentation of dietary bre to short chain fatty acids on the contents of soluble non-starch polysaccharides. Scand J Gastroenterol 1993; 28: 418 -22.
    • 20. McBurney MI, Horvath PJ, Jeraci JL, Van Soest PJ. Effect of in vitro fermentation using human faecal inoculum on the water-holding capacity of dietary bre. Br J Nutr 1985; 53: 17 - 24.
    • 21. McBurney MI, Thompson LU. Effect of human faecal inoculum on in vitro fermentation variables. Br J Nutr 1987; 58: 233 - 43.
    • 22. McBurney MI, Thompson LU. Effect of human faecal donor on in vitro fermentation variables. Scand J Gastroenterol 1989; 24: 359 -67.
    • 23. Rasmussen HS, Holtug K, Anderson JR, Krag E, Mortensen PB. The in uence of ispaghula husk and lactulose on the in vivo and the in vitro production capacity of short chain fatty acids in humans. Scand J Gastroenterol 1987; 22: 406 - 10.
    • 24. Salvador V, Cherbut C, Barry J-L, Bertrand D, Bonnet C, Delort-Laval J. Sugar composition of dietary bre and short chain fatty acid production during in vitro fermentation by human bacteria. Br J Nutr 1993; 70: 189 - 97.
    • 25. Tomlin J, Read NW. The relation between bacterial degradation of viscous polysaccharides and stool output in human beings. Br J Nutr 1988; 60: 467 - 75.
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