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Introducing inulin-type fructans

Published online by Cambridge University Press:  08 March 2007

Marcel B. Roberfroid*
Affiliation:
Université Catholique de Louvain, 7A rue du Rondia, B-1348, Louvain-La-Neuve, Belgium
*
*Corresponding author: Professor Marcel B. Roberfroid, fax +32 10 45 93 01, email, marcel@fefem.com
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Abstract

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Inulin is a generic term to cover all β(2 → 1) linear fructans. Chicory inulin is a linear β(2 → 1) fructan (degree of polymerisation (DP) 2 to 60; DPav = 12), its partial enzymatic hydrolysis product is oligofructose (DP 2 to 8; DPav = 4), and by applying specific separation technologies a long-chain inulin knownas inulin HP (DP 10 to 60; DPav = 25) can be produced. Finally, a specific product known as oligofructose-enriched inulin is obtained by combining chicorylong-chain inulin and oligofructose. Because of the b-configuration of the anomeric C2 in their fructose monomers, inulin-type fructans resist hydrolysis byintestinal digestive enzymes, they classify as ‘non-digestible’ carbohydrates, and they are dietary fibres. By increasing faecal biomass and water content ofthe stools, they improve bowel habits, but they have characteristic features different from other fibres. They affect gastrointestinal functions not because oftheir physico-chemical properties but rather because of their biochemical and physiological attributes. In the colon, they are rapidly fermented to produceSCFA that are good candidates to explain some of the systemic effects of inulin-type fructans. Fermentation of inulin-type fructans in the large bowel is aselective process; bifidobacteria (and possibly a few other genera) are preferentially stimulated to grow, thus causing significant changes in the compositionof the gut microflora by increasing the number of potentially health-promoting bacteria and reducing the number of potentially harmful species. Both oligofructosead inulin are prebiotic. They also induce changes in colonic epithelium stimulating proliferation in the crypts, increasing the concentration ofpolyamines, changing the profile of mucins, and modulating endocrine as well as immune functions. From a nutrition labelling perspective, inulin-typefructans are not only prebiotic dietary fibres; they are also low-calorie carbohydrates [6·3 kJ/g (1·5 kcal/g)]. Supported by the results of a large numberof animal studies and human nutrition intervention trials, the claim ‘inulin-type fructans enhance calcium and magnesium absorption‘ is scientifically substantiated, but different inulin-type fructans have probably a different efficacy (in terms of effective daily dose), the most active product being the oligofructose-enriched inulin. A series of animal studies demonstrate that inulin-type fructans affect the metabolism of lipids primarily by decreasingtriglyceridaemia because of a reduction in the number of plasma VLDL particles. The human data largely confirm the animal experiments. They demonstratemainly a reduction in triglyceridaemia and only a relatively slight decrease in cholesterolaemia mostly in (slightly) hypertriglyceridaemic conditions. Inulinappears thus eligible for an enhanced function claim related to normalization of blood triacylglycerols. A large number of animal data convincingly showthat inulin-type fructans reduce the risk of colon carcinogenesis and nutrition intervention trials are now performed to test that hypothesis in human subjectsknown to be at risk for polyps and cancer development in the large bowel.

Type
Research Article
Copyright
Copyright © The Nutrition Society 2005

References

Apajalahti, JHA, Kettunen, H, Kettunen, A, Holben, WE, Nurminen, PH, Rautanen, N & Mutanen, M (2002) Culture-independent microbial community analysis reveals that inulin in the diet primarily affects previously unknown bacteria in the mouse cecum. Appl Environ Microbiol 68, 49864995.CrossRefGoogle ScholarPubMed
Berg, RD (1996) The indigenous gastrointestinal microflora. Trends Microbiol 4, 430435.CrossRefGoogle ScholarPubMed
Bielecka, M, Biedrzycka, E & Majkowska, A (2002a) Selection of probiotics and prebiotics and confirmation of their in vivo effectiveness. Food Res Int 35, 125131.CrossRefGoogle Scholar
Bielecka, M, Biedrzycka, E, Majkowska, A, Juskiewicz, J & Wroblewska, M (2002b) Effect of non-digestible oligosaccharides on gut microecosystem in rats. Food Res Int 35, 139144.CrossRefGoogle Scholar
Blaut, M, Collins, MD, Welling, GW, Doré, J, Van Loo, J & de Vos, W (2002) Molecular biological methods for studying the gut microbiota: the EU human gut flora project. Br J Nutr 87, S203S211.Google Scholar
Bouhnik, Y, Flourié, B, Riottot, M, Bisetti, N, Gailing, MF, Guibert, A, Bornet, F & Rambaud, JC (1996) Effects of fructooligosaccharides ingestion on fecal bifidobacteria and selected metabolic indexes of colon carcinogenesis in healthy humans. Nutr Cancer 26, 2129.CrossRefGoogle ScholarPubMed
Bouhnik, Y, Vahedi, K & Achour, L (1999) Short-chain fructo-oligosaccharide administration dose dependently increases fecal bifidobacteria in healthy humans. J Nutr 129, 113116.CrossRefGoogle ScholarPubMed
Brichard, S (1997) Influence de mesures nutritionnelles sur l'homéostasie glucidique du rat diabétique. PhD Thesis, Université Catholique de Louvain.Google Scholar
Buddington, KK, Donahoo, JB & Buddington, RK (2002) Dietary oligofructose and inulin protect mice from enteric and systemic pathogens and tumor inducers. J Nutr 132, 472477.Google Scholar
Buddington, RK, Williams, CH, Chen, SC & Witherly, SA (1996) Dietary supplement of Neosugar alters the faecal flora and decreases the activities of some reductive enzymes in human subjects. Am J Clin Nutr 63, 709716.CrossRefGoogle ScholarPubMed
Cashman, K (2002) Calcium intake, calcium bioavailability and bone health. Br J Nutr 87, Suppl. 2, S169S177.CrossRefGoogle ScholarPubMed
Coudray, C, Bellanger, J, Castíglia-Delavaud, C, Vermorel, V & Rayssiguier, Y (1997) Effect of soluble or partly soluble dietary fibres supplementation on absorption and balance of calcium, magnesium, iron and zinc in healthy young men. Eur J Clin Nutr 51, 375380.CrossRefGoogle ScholarPubMed
Coudray, C, Tressol, JC, Gueux, E & Rayssiguier, Y (2003) Effects of inulin-type fructans of different chain length and type of branching on intestinal absorption of calcium and magnesium in rats. Eur J Nutr 42, 9198.CrossRefGoogle ScholarPubMed
Coussement, P (1999) Inulin and oligofructose: safe intakes and legal status. J Nutr 129, 1412S1417S.CrossRefGoogle ScholarPubMed
Cummings, JH (1997) The Large Intestine in Nutrition and Disease Danone Chair Monograph. Brussels: Institut Danone.Google Scholar
Cummings, JH & Macfarlane, GT (1997) Colonic microflora: nutrition and health. Nutrition 13, 476478.Google Scholar
Daubioul, C, De Wispelaere, L, Taper, H & Delzenne, N (2000) Dietary oligofructose lessens hepatic steatosis, but does not prevent hypertriglyceridemia in obese Zucker rats. J Nutr 130, 13141319.CrossRefGoogle Scholar
De Leenheer, L (1996) Production and use of inulin: industrial reality with a promising future Carbohydrates as Organic Raw Materials III, 6792 [Van Bekkum, HRöper, HVoragen, F, editors]. New York: VCH Publishing Inc.Google Scholar
Delzenne, N & Roberfroid, MB (1994) Physiological effects of nondigestible oligosaccharides. Lebensm-Wiss Technol 27, 16.CrossRefGoogle Scholar
Delzenne, N, Kok, N, Deloyer, P & Dandrifosse, G (2000) Polyamines as mediators of physiological effects of dietary oligofructose in rats. J Nutr 130, 24562460.Google Scholar
Delzenne, NM, Daubioul, C, Neyrinck, M, Lasa, M & Taper, HS (2002) Inulin and oligofructose modulate lipid metabolism in animals: review of biochemical events and future prospects. Br J Nutr 87, Suppl. 2, S255S259.CrossRefGoogle ScholarPubMed
Demigné, C, Remesy, C & Morand, C (1999) Short chain fatty acids Colonic Microbiota, Nutrition and Health, 5570 [Gibson, GRoberfroid, M, editors]. Dordrecht: Kluwer Academic.CrossRefGoogle Scholar
Diplock, AT, Aggett, PJ, Ashwell, M, Bornet, F, Fern, EB & Roberfroid, MB (1999) Scientific concepts of functional foods in Europe: consensus document. Br J Nutr 81, Suppl. 1, S1S28.Google Scholar
Fairweather-Tait, SJ & Johnson, IT (1999) Bioavailability of minerals Colonic Microbiota: Nutrition and Health, 233244 [Gibson, GRRoberfroid, MB, editors]. Dordrecht: Kluwer Academic.CrossRefGoogle Scholar
Farnworth, ER (1993) Fructans in human and animal diets Science and Technology of Fructans, 258270 [Suzuki, MChatterton, NJ, editors]. Boca Raton, FL: CRC Press.Google Scholar
Fooks, LJ & Gibson, GR (2002) In vitro investigations of the effect of probiotics and prebiotics on selected human intestinal pathogens. FEMS Microbiol Ecol 39, 6775.CrossRefGoogle ScholarPubMed
Gibson, GR (1998) Dietary modulation of human gut microflora using prebiotics. Br J Nutr 80, S209S212.CrossRefGoogle ScholarPubMed
Gibson, GR & Roberfroid, MB (1995) Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr 125, 14011412.CrossRefGoogle ScholarPubMed
Gibson, G, Roberfroid, M(editors) (1999) Colonic Microbiota, Nutrition and Health, Dordrecht: Kluwer Academic.CrossRefGoogle Scholar
Gibson, GR, Beatty, ER, Wang, X & Cummings, JH (1995) Selective stimulation of bifidobacteria in the human colon by oligofructose and inulin. Gastroenterology 108, 975982.Google Scholar
Gibson, GR, Probert, HM, Rastall, R, Van Loo, JAE & Roberfroid, MB (2004) Dietary modulation of the human colonic microbiota: updating the concept of prebiotics. Nutr Res Rev 17, 257259.CrossRefGoogle ScholarPubMed
Griffin, IJ, Hicks, PMD, Heaney, RP & Abrams, SA (2003) Enriched chicory inulin increases calcium absorption in girls with lower calcium absorption. Nutr Res 23, 901909.CrossRefGoogle Scholar
Guigoz, Y, Rochat, F, Perruisseau-Carrier, G, Rochat, I & Schiffrin, EJ (2002) Effects of oligosaccharide on the faecal flora and non-specific immune system in elderly people. Nutr Res 22, 1325.CrossRefGoogle Scholar
Hanson, LA & Yolken, RH (1999) Probiotics and other Nutritional Factors, and Intestinal Microflora, Philadelphia, PA: Lippincott-Raven.Google Scholar
Harmsen, HJM, Raangs, GC, Franks, AH, Wildeboer-Veloo, CM & Welling, GW (2002) The effect of the prebiotic inulin and the probiotic Bifidobacterium longum on the fecal microflora of healthy volunteers measured by FISH and DGGE. Microb Ecol Health Dis 14, 211219.Google Scholar
Hidaka, H, Eida, T, Takizawa, T, Tokunahga, T & Tashiro, Y (1986) Effects of fructo-oligosaccharides on intestinal flora and human health. Bifidobacteria Microflora 5, 3750.CrossRefGoogle Scholar
Hidaka, H, Tashiro, Y & Eida, T (1991) Proliferation of bifidobacteria by oligosaccharides and their useful effect on human health. Bifidobacteria Microflora 10, 6579.CrossRefGoogle Scholar
Holloway, L, Moyniham, S & Friedlander, AL (2005) Effects of Raftilose synergy 1 on mineral absorption and markers of bone turnover in postmenopausal women.Google Scholar
Kennefick, S & Cashman, KD (2000) Investigation of an in vitro model for predicting the effect of food components on calcium availability from meals. Int J Food Sci Nutr 51, 4554.Google Scholar
Khöler, H, McCormick, BA & Walker, WA (2003) Bacterial–enterocyte crosstalk: cellular mechanisms in health and disease. J Pediatr Gastroenterol 36, 175185.Google Scholar
Kleessen, B, Sykura, B, Zunft, HJ & Blaut, M (1997) Effects of inulin and lactose on faecal microflora, microbial activity and bowel habit in elderly constipated persons. Am J Clin Nutr 65, 13971402.Google Scholar
Kleessen, B, Hartmann, L & Blaut, M (2001) Oligofructose and long-chain inulin influence the gut microbial ecology of rats associated with a human faecal flora. Br J Nutr 86, 291300.CrossRefGoogle ScholarPubMed
Kleessen, B, Hartmann, L & Blaut, M (2003) Fructans in the diet cause alterations of intestinal mucosa architecture, released mucins and mucosa-associated bifidobacteria in gnotobiotic, rats. Br J Nutr 89, 597606.CrossRefGoogle ScholarPubMed
Kok, N, Morgan, L, Williams, C, Roberfroid, M, Thissen, JP & Delzenne, N (1998) Insulin, glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide and insulin-like growth factor I as putative mediators of the hypolipidemic effect of oligofructose in rats. J Nutr 128, 10991103.CrossRefGoogle ScholarPubMed
Kruse, HP, Kleessen, B & Blaut, M (1999) Effects of inulin on faecal bifidobacteria in human subjects. Br J Nutr 82, 375382.CrossRefGoogle ScholarPubMed
Langlands, SJ, Hopkins, MJ, Coleman, N & Cummings, JH (2004) Prebiotic carbohydrates modify the mucosa associated microflora of the human large bowel. Gut 53, 16101616.Google Scholar
Letexier, D, Diraison, F & Beylot, M (2003) Addition of inulin to a moderately high-carbohydrates diet reduces hepatic lipogenesis and plasma triacylglycerol concentrations in humans. Am J Clin Nutr 77, 559564.Google Scholar
Macfarlane, S, Cummings, JH & Macfarlane, GT (1999) Bacterial colonization of surfaces in the large intestine Colonic Microbiota, Nutrition and Health, 7188 [Gibson, GRRoberfroid, MB, editors]. Dordrecht: Kluwer Academic.Google Scholar
Mellander, O (1950) The physiologic importance of the casein phosphopeptide calcium salt, II: per oral calcium dosage of infants. Acta Soc Med (Uppsala) 55, 247255.Google Scholar
Menne, E, Guggenbuhl, N & Roberfroid, M (2000) Fn-type chicory inulin hydrolysate has a prebiotic effect in humans. J Nutr 130, 11971199.CrossRefGoogle Scholar
Menzies, IS (1974) Absorption of intact oligosaccharides in health and disease. Biochem Soc Trans 2, 10421047.Google Scholar
Mitsuoka, T, Hidaka, H & Eida, T (1987) Effect of fructo-oligosaccharides on intestinal microflora. Die Nahrung 31, 427436.Google Scholar
Moshfegh, AJ, Friday, JE, Goldman, JP, Chug, Ahuga JK (1999) Presence of inulin and oligofructose in the diets of Americans. J Nutr 129, Suppl. 7S, 1407S1411S.CrossRefGoogle ScholarPubMed
Ohta, A, Sakai, K, Takasaki, M & Tokunaga, T (1999) Evaluation of the action of calcium resorption enhancement of fructooligosaccharides in tablet candies for humans. Health Nutr Food Res 2, 3743.Google Scholar
Oku, T, Tokunaga, T & Hosoya, N (1984) Nondigestibility of a new sweetener ‘Neosugar’ in the rat. J Nutr 114, 15741581.CrossRefGoogle ScholarPubMed
Perrin, IV, Marchesini, M, Rochat, FC, Schiffrin, EJ & Schilter, B (2003) Oligofructose does not affect the development of type 1 diabetes mellitus induced by dietary proteins in the diabetes-prone BB rat model. Diabetes Nutr Metab 16, 94101.Google Scholar
Perrin, S, Warchol, M, Grill, JP & Schneider, F (2001) Fermentation of fructooligosaccharides and their components by Bifidobacterium infantis ATCC 15967 on batch culture in semi-synthetic medium. J Appl Microbiol 90, 859865.CrossRefGoogle Scholar
Poulsen, M, Molck, AM & Jacobsen, BL (2002) Different effects of short- and long-chained fructans on large intestinal physiology and carcinogen-induced aberrant crypt foci in rats. Nutr Cancer 42, 194205.CrossRefGoogle Scholar
Poxton, IR, Brown, R, Sawyer, A & Fergusson, A (1997) Mucosa-associated bacterial flora of the human colon. J Med Microbiol 46, 8591.CrossRefGoogle ScholarPubMed
Quemener, B, Thibault, JF & Coussement, P (1994) Determination of inulin and oligofructose in food products and integration in the AOAC method for the measurement of total dietary fibre. Lebensm-Wiss Technol 27, 125132.Google Scholar
Rao, V (2001) The prebiotic properties of oligofructose at low intake levels. Nutr Res 21, 843848.CrossRefGoogle Scholar
Reddy, BS, Hamid, R & Rao, CV (1997) Effect of dietary oligofructose and inulin on colonic preneoplastic aberrant crypt foci inhibition. Carcinogenesis 18, 13711374.CrossRefGoogle ScholarPubMed
Roberfroid, M (1993) Dietary fiber, inulin, and oligofructose: a review comparing their physiological effects. CRC Crit Rev Food Sci Nutr 33, 103148.CrossRefGoogle ScholarPubMed
Roberfroid, MB (1998) Prebiotics and synbiotics: concepts and nutritional properties. Br J Nutr 80, S197S202.CrossRefGoogle ScholarPubMed
Roberfroid, M (2002) Functional foods: concepts and application to inulin and oligofructose. Br J Nutr 87 Suppl. 2 S139S143.Google Scholar
Roberfroid, M (2004) Inulin-type Fructans as Functional Food Ingredients, Boca Raton, FL: CRC Press.Google Scholar
Roberfroid, MB (2004) Prebiotics: the concept revised. J Nutr.Google Scholar
Roberfroid, MB & Delzenne, N (1998) Dietary fructans. Annu Rev Nutr 18, 117143.Google Scholar
Roberfroid, MB & Slavin, J (2000) Nondigestible oligosaccharides. Crit Rev Food Sci Nutr 40, 461480.Google Scholar
Roberfroid, MB, Van Loo, JAE & Gibson, GR (1998) The bifidogenic nature of chicory inulin and its hydrolysis product. J Nutr 128, 1119.CrossRefGoogle Scholar
Roberfroid, M, Champ, M & Gibson, G (2002) Nutritional and health benefits of inulin and oligofructose. Br J Nutr 87 Suppl. 2 S139S311.Google Scholar
Rowland, IR (1988) Interactions of the gut microflora and the host in toxicology. Toxicol Pathol 16, 147153.CrossRefGoogle ScholarPubMed
Rycroft, CE, Jones, MR, Gibson, GR & Rastall, RA (2001) A comparative in vitro evaluation of the fermentation properties of prebiotic oligosaccharides. J Appl Microbiol 91, 878887.CrossRefGoogle ScholarPubMed
Saavedra, JM & Tschernia, A (2002) Human studies with probiotics and prebiotics: clinical implications. Br J Nutr 87 Suppl. 2 S241S246.CrossRefGoogle ScholarPubMed
Saavedra, JM, Tschernia, A, Moore, N, Abi-Hanna, A, Coletta, F & Emenheiser, C (1999) Gastrointestinal function in infants consuming a weaning food supplemented with oligofructose. J Paediatr Gastroenterol Nutr 29 A95.Google Scholar
Salminen, S, Bouley, C, Boutron-Ruault, MC (1998) Functional food science and gastrointestinal physiology and function. Br J Nutr 80, Suppl. 1, S147S171.Google Scholar
Sano, T (1986) Effects of Neosugar on constipation, intestinal microflora, and gall bladder contraction in diabetics.In Proceedings of the Third Neosugar Research Conference 109117Tokyo: Meiji-Seika Publications.Google Scholar
Stürup, S, Hansen, M & Molgaard, C (1997) Measurement of 44 Ca, 43 Ca and 42 Ca 43 Ca isotopic ratios in urine using high resolution inductively coupled plasma mass spectrometry. J Anal At Spectrom 12, 919923.CrossRefGoogle Scholar
Tahiri, M, Tressol, JC & Arnaud, J (2003) Effect of short-chain fructooligosaccharides on intestinal calcium absorption and calcium status in postmenopausal women: a stable-isotope study. Am J Clin Nutr 77, 449457.Google Scholar
Takahashi, Y (1986) Effects of fructo-oligosaccharides in the chronic-failure patient.In Proceedings of the Third Neosugar Research Conference, 2130Tokyo: Meiji-Seika Publications.Google Scholar
Taper, HS & Roberfroid, MB (1999) Influence of inulin and oligofructose on breast cancer and tumour growth. J Nutr 129, 1488S1491S.Google Scholar
Taper, HS & Roberfroid, MB (2000) Inhibitory effect of dietary inulin or oligofructose on the development of cancer metastases. Anticancer Res 20, 42914294.Google ScholarPubMed
Taper, HS & Roberfroid, MB (2002a) Non-toxic potentiation of cancer radiotherapy by dietary oligofructose and inulin. Anticancer Res 22, 33193324.Google ScholarPubMed
Taper, HS & Roberfroid, MB (2002b) Inulin/oligofructose, and anticancer therapy. Br J Nutr 87, Suppl. 2, S283S286.CrossRefGoogle ScholarPubMed
Taper, HS, Delzenne, NM & Roberfroid, MB (1997) Growth inhibition of transplantable mouse tumors by non-digestible carbohydrates. Int J Cancer 71, 11091112.Google Scholar
Taper, HS, Lemort, C & Roberfroid, MB (1998) Inhibition effect of dietary inulin and oligofructose on the growth of transplantable mouse tumor. Anticancer Res 18, 41234126.Google Scholar
Teuri, U, Kärkkäinen, M, Lamberg-Allardt, C & Korpela, R (1999) Addition of inulin to breakfast does not acutely affect serum ionised calcium and parathyroid hormone concentrations. Ann Nutr Metab 43, 356364.CrossRefGoogle Scholar
Tuohy, KM, Finlay, RK, Wynne, AG & Gibson, GR (2001a) A human volunteer study on the prebiotic effects of HP-inulin – faecal bacteria enumerated using fluorescent in situ hybridization (FISH). Ecol Environ Microbiol 7, 113118.Google Scholar
Tuohy, KM, Kolida, S, Lustenberger, A & Gibson, GR (2001b) The prebiotic effects of biscuits containing partially hydrolysed guar gum and fructooligosaccharides – a human volunteer study. Br J Nutr 86, 341348.CrossRefGoogle ScholarPubMed
Uenishi, K, Ohta, A, Fukushima, Y & Kagawa, Y (2002) Effect of a malt drink containing fructooligosaccharides on calcium absorption and safety of long term administration. Jpn J Nutr Diet 60, 1118.Google Scholar
Van den, Heuvel, EG, Schaafsma, G, Muijs, T, van & Dokkum, W (1998) Non-digestible oligosaccharides do not interfere with calcium and nonheme-iron absorption in young, healthy men. Am J Clin Nutr 67, 445451.CrossRefGoogle Scholar
Van Loo, J & Jonkers, N (2001) Evaluation in human volunteers of the potential anticarcinogenic activities of novel nutritional concepts: prebiotics, probiotics and synbiotics (the SYNCAN project QLK1-1999-00346). Nutr Metab Cardiovasc Dis 11, Suppl.8793.Google Scholar
Van Loo, J, Coussement, P, De Leenheer, L, Hoebregs, H & Smits, G (1995) On the presence of inulin and oligofructose as natural ingredients in the Western diet. Crit Rev Food Sci Nutr 35, 525552.Google Scholar
Waterhouse, AL & Chatterton, NJ (1993) Glossary of fructan terms Science and Technology of Fructans, 27 [Suzuki, MChatterton, NJ, editors]. Boca Raton, FL:CRC Press.Google Scholar
Weaver, CM & Liebman, M (2002) Biomarkers of bone health appropriate for evaluating functional foods designed to reduce risk of osteoporosis. Br J Nutr 88, Suppl. 2, S225S232.Google Scholar
Whiting, SJ & Wood, RJ (1997) Adverse effects of high calcium diets in humans. Nutr Rev 55, 19.Google Scholar
Williams, CH, Witherly, SA & Buddington, RK (1994) Influence of dietary Neosugar on selected bacteria groups of the human fecal microbiota. Microb Ecol Health Dis 7, 9197.Google Scholar
Wolf, BW, Firkins, JL & Zhang, X (1998) Varying dietary concentrations of fructooligosaccharides affect apparent absorption and balance of minerals in growing rats. Nutr Res 18, 17911806.Google Scholar
Yamada, S (1994) 45 Ca kinetics and balance study. A useful method for analysing the effects of drugs on calcium metabolism.In Pharmacological Approach to Study the Formation and the Resorption Mechanism of Hard Tissues, 7592 [Ogura, H, editors]. Tokyo: EuroAmerica Publishers.Google Scholar