Effect of Lactulose on Calcium and Magnesium Absorption: A Study Using Stable Isotopes in Adult Men

Abstract

SummaryTo evaluate the effect of lactulose on calcium (Ca) and magnesium (Mg) absorption, we performed a clinical trial with a double-blind, randomized, crossover design in 24 healthy adult male volunteers. The absorptions of Ca and Mg were evaluated by a single-labeling method using stable isotopes. The test foods, containing lactulose at a dose of 0 g (placebo), 2 g (low-dose), or 4 g (high-dose) together with 300 mg of Ca containing 20 mg of Mg) increased with lactulose dosage. Significant differences were observed in the Ca ratio between placebo and high-dose lactulose ( p Ͻ 0.01), and in the Mg ratio between placebo and low-dose lactulose and between placebo and high-dose lactulose ( p Ͻ 0.01). Lactulose ingestion did not change the levels of bone-resorption markers (type I collagen cross-linked N -telopeptide and deoxypyridinoline) in urine. The test foods did not cause any side effects. This study demonstrates that lactulose enhances the absorptions of Ca and Mg in adult men.

Production and physiological action of the disaccharide lactulose

“…Following a week-long adaptation to the lactulose-containing diet, they found a significant increase of calcium absorption only for the higher intake of 10 g d À1 (adult). In contrast, Seki et al (2007), who studied the absorption of calcium and magnesium in 24 healthy men, achieved significant improved calcium absorption with 4 g lactulose while a dose of 2 g significantly enhanced magnesium absorption (administering single doses). The variation between the reported threshold doses of lactulose may originate from differences in gender and colonic adaptation to lactulose of human subjects.…”

“…The improved absorption of minerals has been generally described for prebiotics and is presumably mediated by an increased permeability of intestinal mucosa and an enhanced solubility of minerals in the colon at low pH (MacFarlane et al, 1991;Seki et al, 2007). Brommage, Binacua, Antille, and Carrié (1993) fed rats a diet containing different percentages of lactulose and a stable calcium isotope.…”

Biotechnological approaches for the production of prebiotics and their potential applications

“…Prebiotics (inulin-type fructans, galacto-oligosaccharides, isomalto-oligosaccharides, lactitol and lactulose) can also help in the enhancement of mineral absorption, especially calcium and magnesium (Beynen et al, 2002;Chonan et al, 1995;Mineo et al, 2002;Coxam, 2007;Seki et al, 2007). The combination of inulin and oligofructose was found to be more effective to increase the calcium and magnesium absorption than either oligosaccharide alone (Younes et al, 2001).…”

Lactose as a source for lactulose and other functional lactose derivatives

“…Examples include: (i) enhancement of mineral absorption (Seki et al, 2007;Suzuki et al, 1986;Van den Heuvel, Muijs, Van Dokkum, & Schaafsma, 1999); (ii) effects on bone (Igarashi et al, 1994); (iii) blood Glu lowering effects (Bianchi et al, 1994;Brighenti et al, 2006;Genovese, Riccardi, & Rivellese, 1992); (iv) hypocholesterolemic effects (Conte, Bardella, Bernardi, Pasetti, & Bianchi, 1977); (v) reduction in the lithogenic index (Thornton & Heaton, 1981); (vi) Fig. 3.…”