Isoflavones and probiotics effect on bone calcium and bone cells in rats

Lactobacilli and Their Fermented Foods as a Promising Strategy for Enhancing Bone Mineral Density: A Review

Lactobacilli fermentation possesses special nutritional and health values to food, especially in improving diseases related to the gut microbiota such as osteoporosis risk. Previous research indicates that lactobacilli-fermented foods have the potential to enhance the bone mineral density (BMD), as suggested by some clinical studies. Nonetheless, there is currently a lack of comprehensive summaries of the effects and potential mechanisms of lactobacilli-fermented foods on BMD. This review summarizes findings from preclinical and clinical studies, revealing that lactobacilli possess the potential to mitigate age-related and secondary factor-induced bone loss. Furthermore, these findings imply that lactobacilli are likely mediated through the modulation of bone remodeling via gut inflammation-related pathways. Additionally, lactobacilli fermentation may augment calcium accessibility through directly promoting calcium absorption or modifying food constituents. Considering the escalating global health challenge of bone-related issues among the elderly population, this review may offer a valuable reference for the development of food strategies aimed at preventing osteoporosis.

Impact of Lactobacillus acidophilus and Its Combination with Isoflavone Products on Calcium Status, Calcium Transporters, and Bone Metabolism Biomarkers in a Post-Menopausal Osteoporotic Rat Model

Osteoporosis in menopausal women requires alternatives to current medications, considering their adverse effects. In this context, probiotics and isoflavone products are promising dietary interventions. The objective of our study was to examine the impacts of Lactobacillus acidophilus and its combination with daidzein and tempeh on calcium status, calcium transporters, and bone metabolism biomarkers in a post-menopausal osteoporotic rat model. A total of 48 female Wistar rats were exposed to a two-stage experiment involving calcium deficit induction and subsequent dietary interventions across six groups. Calcium levels, the gene expression of TRPV5 and TRPV6 calcium transporters, bone histopathology, serum bone metabolism markers, and blood biochemistry were evaluated. The results revealed that, while decreasing serum calcium levels, the groups that received the probiotic L. acidophilus and isoflavone combination exhibited increased bone metabolism biomarkers and decreased calcium transporter expressions, akin to the effects of bisphosphonate. Additionally, significant improvements in bone histopathology were observed in these groups. However, the group receiving probiotic L. acidophilus alone did not exhibit significant changes in bone resorption biomarkers, calcium transporter expression, or various blood parameters. Meanwhile, the combination of probiotic L. acidophilus with tempeh positively influenced hematological parameters and reduced cholesterol and triglyceride levels, but it led to elevated blood glucose levels. Correlation analyses highlighted associations between serum calcium levels, calcium transporter expression, and bone metabolism biomarkers. In conclusion, our findings suggest that the daily consumption of probiotic L. acidophilus in combination with isoflavone products may improve bone health in ovariectomized rats, warranting further research to elucidate potential interactions with other nutrients.

Effects of daily probiotic supplementation with Lactobacillus acidophilus on calcium status, bone metabolism biomarkers, and bone mineral density in postmenopausal women: a controlled and randomized clinical study

Background

Menopause poses significant health risks for women, particularly an increased vulnerability to fractures associated with osteoporosis. Dietary interventions have emerged as promising strategies, focusing on mitigating the risk of osteoporosis rather than solely addressing the established disease. This 12-week randomized controlled trial aimed to analyze the effects of consuming Lactobacillus acidophilus probiotics on calcium levels, biomarkers of bone metabolism, and bone mineral density (BMD) profiles in postmenopausal women.

Methods

Fifty-five participants were randomly assigned to receive either a placebo (n = 25) or the probiotic L. acidophilus UALa-01™ (n = 30) daily via oral intervention. Throughout the study, evaluations included body composition, blood biochemical parameters, serum calcium levels, and biomarkers of bone metabolism. Additionally, Dual-energy X-ray absorptiometry was used to measure BMD profiles.

Results

The findings delineated that the probiotic group experienced a decrease in serum calcium levels compared to their initial levels. However, hair calcium levels and biomarkers related to bone metabolism showed no notable changes within this group. Consumption of probiotic L. acidophilus also seemed to prevent fluctuations in bone turnover markers. Moreover, there were no significant alterations in BMD levels at the lumbar spine, left femur, and total body in the probiotic group. Additionally, probiotic intake led to favorable outcomes by significantly reducing both body fat and visceral fat during the intervention period. Conversely, an adverse effect of consuming probiotic L. acidophilus was observed with a significant increase in glucose concentration.

Conclusion

In conclusion, the consumption of L. acidophilus probiotics daily for 12 weeks among postmenopausal women does not affect the profile of BMD, but it may help in stabilizing bone turnover. It is important to note that most measured parameters were within the normal range for this population. However, it is worth noting that 3 months of probiotic supplementation could potentially disrupt calcium and glucose status in postmenopausal women.

Effect of Tempeh and Daidzein on Calcium Status, Calcium Transporters, and Bone Metabolism Biomarkers in Ovariectomized Rats

Menopause marks a critical life stage characterized by hormonal changes that significantly impact bone health, leading to a heightened susceptibility to bone fractures. This research seeks to elucidate the impact of daidzein and tempeh on calcium status, calcium transporters, and bone metabolism in an ovariectomized rat model. Forty female Wistar rats, aged 3 months, participated in a two-phase experiment. The initial phase involved inducing a calcium deficit, while the second phase comprised dietary interventions across five groups: Sham (S) and Ovariectomy (O) with a standard diet, O with bisphosphonate (OB), O with pure daidzein (OD), and O with tempeh (OT). Multiple parameters, encompassing calcium levels, calcium transporters, bone histopathology, and serum bone metabolism markers, were evaluated. The findings revealed that the OT group showcased heightened levels of bone turnover markers, such as pyridinoline, C-telopeptide of type I collagen, bone alkaline phosphatase, and procollagen type I N-terminal propeptide, in contrast to S and O groups, with statistical significance (p < 0.05). Histopathologically, both the OD and OT groups exhibited effects akin to the OB group, indicating a decrease in the surface area occupied by adipocytes in the femoral bone structure, although statistically non-equivalent, supporting the directionally similar trends. Although TRPV5 and TRPV6 mRNA expression levels in the jejunum and duodenum did not display statistically significant differences (p > 0.05), the OD and OT groups exhibited increased expression compared to the O group. We hypothesized that obtained results may be related to the effect of isoflavones on estrogen pathways because of their structurally similar to endogenous estrogen and weak estrogenic properties. In conclusion, the daily consumption of pure daidzein and tempeh could potentially improve and reinstate calcium status, calcium transport, and bone metabolism in ovariectomized rats. Additionally, isoflavone products demonstrate effects similar to bisphosphonate drugs on these parameters in ovariectomized rats.

Effects of Daidzein, Tempeh, and a Probiotic Digested in an Artificial Gastrointestinal Tract on Calcium Deposition in Human Osteoblast-like Saos-2 Cells

Adequate calcium intake is crucial for the prevention and treatment of bone-related issues. Developing a nutritional source of readily bioavailable calcium is particularly significant for individuals deficient in this essential element and at risk of developing osteoporosis. This research aimed to evaluate the impact of tempeh (T), daidzein (D), and Lactobacillus acidophilus (LA) within a simulated intestinal environment consisting of Caco-2 epithelial and Saos-2 cells, focusing on their implications for bone mineralization mechanisms. In the initial phase, calcium bioaccessibility from calcium citrate (CaCt), LA, D, the daidzein combination D-CaCt-LA (D1:1:1), and the tempeh combination T-CaCt-LA (T1:1:1) was assessed through digestion simulation. The calcium content of both untreated and digested samples was determined using atomic absorption spectrometry (AAS). In the subsequent stage, the digested samples were used to induce intestinal absorption in differentiated enterocyte-like Caco-2 cells. The permeable fractions were then evaluated in a culture of osteoblast-like Saos-2 cells. Preliminary cellular experiments employed the MTT assay to assess cytotoxicity. The results indicated that the analyzed products did not influence the deposition of extracellular calcium in Saos-2 cells cultured without mineralization stimulators. The combined formulations of permeable fractions of digested CaCt, LA, D, and T demonstrated the capacity to enhance the proliferation of Saos-2 cells. In Saos-2 cells, D, D1:1:1, and LA showed no discernible impact on intracellular calcium accumulation, whereas T and T1:1:1 reduced the calcium deposits. Additionally, mRNA transcripts and alkaline phosphatase (ALP) activity levels in Saos-2 cells cultured without mineralization induction were unaffected by the analyzed products. An examination of the products revealed no discernible effect on ALP activity or mRNA expression during Saos-2 cell differentiation. Our findings suggest that tempeh, daidzein, and L. acidophilus did not positively impact cellular calcium deposition in Saos-2 cells. However, tempeh, daidzein and its combination, and L. acidophilus might enhance the process of osteogenic differentiation in Saos-2 cells. Nevertheless, this study did not identify any synergistic impact on calcium deposition and the process of osteogenic differentiation in Saos-2 cells of isoflavones and probiotics.

Association of probiotic ingestion with serum sex steroid hormones among pre- and postmenopausal women from the NHANES, 2013-2016

BACKGROUND

Sex hormone-related diseases, encompassing a wide range of conditions from reproductive disorders to certain cancers, pose significant health challenges worldwide. Recent scientific investigations have highlighted the intricate interplay between the gut microbiome and sex hormone regulation, indicating the potential for microbiota-targeted interventions in the management of such diseases. Although individual studies have elucidated the influence of the gut microbiome on sex hormones, a comprehensive cross-sectional examination of the population-wide prevalence of probiotic intake and its correlation with sex hormones is still lacking.

OBJECTIVES

This study aimed to evaluate the association of probiotic ingestion with sex hormones in pre- and post-menopausal women.

METHODS

We conducted an observational cohort study comprising a nationally representative sample of adults who participated in the National Health and Nutrition Examination Survey between 2013 and 2016. Probiotic ingestion was considered when a subject reported yogurt or probiotic supplement consumption during the 24-h dietary recall or during the Dietary Supplement Use 30-Day questionnaire. A survey-weighted generalized linear model was used to analyze the association between probiotic intake and female/male sex hormones. To reduce selection bias, we used propensity score matching (PSM).

RESULTS

This study included 2,699 women, with 537 of them consuming yogurt and/or dietary supplements containing probiotics, while the remaining 2,162 women did not consume any probiotics. The findings indicated that there were associations between probiotic intake and sex hormone levels in premenopausal and postmenopausal women. For premenopausal women, probiotic intake was positively associated with estradiol (E2) levels. On the contrary, in postmenopausal women, probiotic intake was inversely associated with total testosterone (TT) levels.

CONCLUSIONS

This study indicated that probiotic consumption was associated with higher E2 level in premenopausal women and lower TT level in postmenopausal women. Probiotic intake might be a sensible strategy for preventing sex hormone-related diseases.

Influence of Isoflavones and Probiotics on Magnesium Status in Healthy Female Rats

Isoflavones and probiotics are promising nutrients for bone health, and magnesium (Mg) is essential for bone metabolism. This study aimed to determine the effects of daidzein, genistein and Lactobacillus acidophilus on the Mg status of healthy female rats. Forty-eight rats were randomly assigned to six groups, with the control group receiving a standard diet (AIN 93M). The remaining groups were fed the same diet with added ingredients such as tempeh flour; soy flour; pure daidzein and genistein; L. acidophilus or a combination of daidzein, genistein, and L. acidophilus. Tissue samples were collected after the eight-week intervention, and Mg concentrations were analysed using flame atomic absorption spectrometry. Myeloid and erythroid cells were determined using the haematoxylin and eosin bone staining method. Statistical analyses were conducted using one-way ANOVA with Tukey's post hoc test and Pearson's correlation coefficient. The threshold for significance was p < 0.05. Compared with the control group, adding tempeh to the diet of rats resulted in significant changes in Mg concentrations in various tissues, with a decrease in the kidneys and an increase in the fur. Although not statistically significant compared to the control group, the tempeh group showed increased Mg concentrations in the femur and spleen. The myeloid-to-erythroid cell ratio did not differ significantly among groups, but all intervention groups showed higher ratios than the control group. A strong negative correlation was observed between Mg concentrations in the kidneys and fur. Conversely, a positive correlation was identified between Mg concentrations in the pancreas and fur. Daily consumption of tempeh may improve Mg status in the organism. Intake of pure daidzein, genistein, or probiotic seems to have no effect on Mg concentrations in healthy rats.

Effects of isoflavone and probiotic intake on calcium transport and bone metabolism biomarkers in female rats

Calcium is essential for maintaining bone health as it contributes to bone formation, remodeling, strength, and density. This study investigated the effect of isoflavones and probiotics on calcium transporters' gene expression, serum calcium levels, and bone metabolism biomarkers in healthy female rats. Forty-eight female Wistar rats were classified into six groups. Bone metabolism biomarkers (pyridinoline, deoxypyridinoline, parathyroid hormone, and osteocalcin) and serum calcium levels were measured by enzyme-linked immunosorbent assay (ELISA) and atomic absorption spectroscopy (AAS), respectively. Gene expression of calcium transporters (Trpv5 and Trpv6) was evaluated in duodenum and jejunum tissue samples using quantitative polymerase chain reaction (qPCR). Trpv5 and Trpv6, epithelial calcium channels, play a crucial role in calcium transport and homeostasis in the body. The study consisted of a1-week adaptation period for the rats to adjust to the controlled conditions, followed by an 8-week intervention phase. The daidzein and genistein group showed a significant increase in the gene expression of the Trpv6 transporter in the duodenum and a marked decrease in serum pyridinoline levels compared to the control group. The tempeh and soybean groups showed a significant decrease in the gene expression of the Trpv5 calcium transporter in the jejunum. However, no significant influence of the Lactobacillus acidophilus diet on calcium transport and bone metabolism biomarkers was observed in the L. acidophilus group. The correlation analysis showed a significant positive relationship between serum calcium, bone metabolism biomarkers, and calcium transporters. In conclusion, our study demonstrates that the daidzein and genistein diet improves calcium transport in the duodenum and reduces pyridinoline serum concentrations, while tempeh and soybean diets reduce calcium transport in the jejunum. However, the combination of daidzein, genistein, and L. acidophilus did not demonstrate a synergistic effect on calcium transport and bone metabolism, suggesting that further investigations are needed to elucidate their potential interactions.