A newly released study in The Journal of Nutrition shows that short-term daily consumption of yogurt containing both prebiotic and probiotic ingredients enhances calcium absorption.

Although calcium has many beneficial effects on human health, its protective role in bone health is particularly important. Poor dietary calcium bioavailability can limit acquisition of peak bone mass and maintenance of bone mass maturity. Functional foods containing both prebiotics and probiotics, referred to as synbiotic, have been shown to increase calcium bioavailability. Among prebiotics, inulin, which is a nondigestible carbohydrate produced by plants, has been associated with increased calcium absorption. Among the probiotics, Lactobacillus strains have been found to have beneficial effects on bone health, when used alone or in combination with prebiotics (synbiotics).

 Human studies addressing the relation between probiotics and/or synbiotics intake and calcium metabolism are limited. Furthermore, the effect of synbiotics on calcium absorption has not been tested in human studies. To bridge this knowledge gap, Carmen Marino Donangelo (Universidad de la República, Uruguay) and colleagues compared the effect of short-term daily consumption of a functional synbiotic yogurt containing inulin and Lactobacillus rhamnosus GG and a control yogurt on calcium absorption capacity in young women.  Participants ingested each of the study diets daily over a 3-week period. Dietary intake, bone mineral density, calcium biomarkers, and vitamin D levels were measured at baseline. Calcium absorption was tested after each phase of the study using an oral stable calcium isotope.  Urine samples were collected over the next 36 hours (0-4 hour, 0-24 hours, and 0-36 hours), and the cumulative recovery of the oral tracer in urine was measured.

After the 3-week treatment with the synbiotic yogurt, calcium absorption capacity increased 24% relative to the control yogurt.  For the control yogurt treatment, the majority of total tracer recovery in urine was found in the 0–24-hour urine pool, whereas for the synbiotic yogurt treatment, only half of the isotope was recovered in the 0-24 hour urine pool. Calcium recovery increased over time in each of the synbiotic and control urine pools with a trend for higher calcium recovery in the 0–36 hour synbiotic urine pool compared with the control urine pools.

Consumption of a synbiotic yogurt containing modest amounts inulin and Lactobacillus rhamnosus GG enhanced calcium absorption relative to a control yogurt treatment in young adult women.  The time course of the significant differences suggests the increased calcium absorption following the synbiotic yogurt treatment likely occurred in the large intestine. Further studies are needed to address the long-term effects and interactions of habitual diet and gut microbiota on the calcium absorption response to the synbiotic yogurt.


Rafael Cornes, Celia Sintes, Amparo Peña, Santiago Albin, Kimberly O O’Brien, Steven A Abrams, Carmen Marino Donangelo, Daily Intake of a Functional Synbiotic Yogurt Increases Calcium Absorption in Young Adult Women, The Journal of Nutrition, Volume 152, Issue 7, July 2022, Pages 1647–1654, https://doi.org/10.1093/jn/nxac088.

Images via canva.com.