The Effects of Soy Milk Enriched with Lactobacillus casei and Omega-3 on the Tibia and L5 Vertebra in Diabetic Rats: a Stereological Study

Bone fragility, despite relatively high BMD values, is an important complication related to insulin resistance and oxidative stress in diabetes mellitus type 1. The present study aimed to compare the effects of soy milk (SM), soy milk containing Lactobacillus casei (PSM), and soy milk enriched with Lactobacillus casei and omega-3 (OPSM) on the stereology of the tibia and vertebra, and antioxidant activity in type 1 diabetic rats. Sixty-five male Sprague Dawley rats were randomly assigned into 5 groups of 13 animals each. Diabetes was induced by a single injection of STZ (60 mg/kg); two control groups (non-diabetic: CN and diabetic: CD) were selected and then fed with 1 mL of distilled water. Three treatment groups were fed 1 ml of SM, PSM, and OPSM via intragastric gavage for 60 days. Treatment with SM, PSM, and OPSM significantly decreased (P < 0.05) the number of the osteoclasts in both tibia and L5 vertebra, and plasma alkaline phosphatase level. Also, the osteoblast number, calcium level, catalase activity, and total antioxidant capacity were increased in the SM, PSM, and OPSM groups compared to the STZ group. OPSM had the greatest effects on the stereological and biochemical parameters compared to the SM and PSM groups. Soy milk combination with Lactobacillus casei and omega-3 can ameliorate the stereological changes in the tibia and vertebra. In addition, this combination increased the antioxidant activity and improved the redox homeostasis in diabetic rats. These results suggest the potential role of soy milk containing Lactobacillus casei enriched with omega-3 in preventing and delaying osteoporosis in diabetic patients.