A yoghurt containing galactooligosaccharides and having low-lactose level improves calcium absorption and retention during growth: experimental study

Abstract

Dairy products are essential to ensure calcium recommendations to achieve optimal peak bone mass and avoid bone loss. However, high prevalence of lactose malabsorption decreases milk-derived foods consumption. The use of β-galactosidase, which hydrolyses lactose to galactooligosaccharides (GOS) is an alternative to develop a low-lactose yoghurt (EY) where prebiotics (GOS) and probiotics (Lactobacilli) coexist. The effects of two diets based on EY or standard yoghurt without GOS (Y) on calcium absorption and bone retention were evaluated and compared, in growing rats. Control group received AIN 93-G diet. Male weaning rats were fed one of these three diets for 28 days. EY group showed the highest increase in faecal Lactobacillus colonies, in short-chain fatty acids production, in intestinal crypt deep, and the lowest caecum pH. Calcium absorption (%) increased significantly as follows: EY>Y>control (P < 0.05). EY and control showed similar calcium content in femur, bone mineral content and density, and total epiphyseal cartilage while Y showed the lowest value (P < 0.05). Conclusion: YE presented some advantages compared to Y regarding calcium absorption and bone retention since Y could not match bone growth and quality of control group. EY was an effective low lactose-dairy product for delivering prebiotics and probiotics into gut, to enhance gut health and calcium bioavailability that improved bone development in a period of high calcium requirements as growth stage. Even more important is that EY could represent an efficient therapeutic strategy to achieve calcium recommendations in people who avoid dairy product consumption due to unpleasant symptoms of lactose intolerance.