Effects of Fermented Milk Products on Bone

Chronic pancreatitis-associated metabolic bone diseases: epidemiology, mechanisms, and clinical advances

Chronic pancreatitis (CP) is a progressive inflammatory disease with an increasing global prevalence. In recent years, a strong association between CP and metabolic bone diseases (MBDs), especially osteoporosis, has been identified, attracting significant attention in the research field. Epidemiological data suggest a rising trend in the incidence of MBDs among CP patients. Notably, recent studies have highlighted a profound interplay between CP and altered nutritional and immune profiles, offering insights into its linkage with MBDs. At the molecular level, CP introduces a series of biochemical disturbances that compromise bone homeostasis. One critical observation is the disrupted metabolism of vitamin D and vitamin K, both essential micronutrients for maintaining bone integrity, in CP patients. In this review, we provide physio-pathological perspectives on the development and mechanisms of CP-related MBDs. We also outline some of the latest therapeutic strategies for treating patients with CP-associated MBDs, including stem cell transplantation, monoclonal antibodies, and probiotic therapy. In summary, CP-associated MBDs represent a rising medical challenge, involving multiple tissues and organs, complex disease mechanisms, and diverse treatment approaches. More in-depth studies are required to understand the complex interplay between CP and MBDs to facilitate the development of more specific and effective therapeutic approaches.

Role of fermented dairy products in the health benefits of a mediterranean diet

Mediterranean diet includes fermented dairy products like yogurt and cheese. These foods provide calcium, phosphorus, fat, carbohydrates and protein, all nutrients influencing various systems including bone, cardiovascular system, intermediary metabolism, cancer, central nervous system, and inflammation. In addition, they contain prebiotics and provide probiotics which are capable of modifiying microbiota composition and metabolism, potentially acting also indirectly on the various systems. A large body of evidence indicates that fermented dairy products consumption significantly contributes to the beneficial effects of a Mediterranean diet on various systems' health.

Nutritional and potential health benefits of fermented food proteins

BACKGROUND

Protein fermentation continues to gain popularity as a result of several factors, including the cost-effectiveness of the process and the positive correlation of fermented protein consumption, with a reduced risk of developing diet-related diseases such as diabetes and cardiovascular disorders, as well as their enhanced nutritional and techno-functional properties. Nonetheless, the nutritional and health benefits of food protein fermentation such as enhanced nutrient bioavailability, reduced antinutritional factors (ANFs) and enriched bioactive peptides (BAPs) are often overlooked. The present study reviewed recent work on the influence of protein fermentation on nutrition and health. In total, 322 eligible studies were identified on the Scopus and Google Scholar databases out of which 69 studies were evaluated based on our inclusion criteria.

RESULTS

Fermented protein ingredients and products show reduced ANF content, enhanced digestibility and bioavailability, and increased antioxidant and other biological activities, such as probiotic, prebiotic, angiotensin-converting enzyme inhibitory and antihypertensive properties. In addition, co-products in protein fermentation such as BAPs possess and could contribute additional sensory and flavor properties, degrade toxins, and reduce allergens in foods.

CONCLUSION

Thus, fermentation is not only a method for food preservation, but also serves as a means for producing functional food products for consumer health promotion and nutrition enrichment. © 2023 Society of Chemical Industry.

Types of dairy foods and risk of fragility fracture in the prospective Nurses' Health Study cohort

BACKGROUND

Fragility fractures present enormous health challenges for women. Dairy products provide many bone-beneficial nutrients, such as calcium and vitamin D. Individual dairy foods may exert different effects on bone health.

OBJECTIVES

The aim of this study was to investigate the associations between total dairy, yogurt, milk, and cheese and fragility fracture risk among females in the prospective Nurses' Health Study (NHS) conducted in the United States.

METHODS

In the current analysis, 103,003 females with mean age of 48 y were followed from 1980-2004. Proportional hazards models were used to estimate risk of first fracture (of the wrist, hip, or vertebrae) by intakes of dairy foods (total dairy, milk, yogurt, or cheese) obtained from a food frequency questionnaire. Fractures that were caused by high-trauma events were not included. We relied on self-reported data for wrist and hip fractures whereas for vertebral fractures, medical records were used to confirm cases.

RESULTS

A total of 5495 incident fracture cases were documented during follow-up. After controlling for relevant confounding variables, consumption of ≥2 servings/d of total dairy (compared with <1 serving/d) was associated with lower fracture risk (hazard ratio [HR]: 0.74; 95% confidence interval [CI]: 0.61, 0.89). More than 2 servings of milk per day (compared with <1 serving/d) were associated with a lower fracture risk (HR: 0.85; 95% CI: 0.77, 0.94). Intakes of calcium, vitamin D, and protein from nondairy sources did not modify the effects of total dairy or milk on fracture risk. There was no association between yogurt intake and fracture risk. Intake of cheese (≥1 servings/d compared with <1 serving/wk) was weakly associated with lower fracture risk (HR: 0.89; 95% CI: 0.79, 0.99).

CONCLUSIONS

Higher total dairy, milk, and cheese intakes are associated with lower risks of fracture in females in the NHS.

Is diet related to osteoarthritis? A univariable and multivariable Mendelian randomization study that investigates 45 dietary habits and osteoarthritis

Background

Diet is a safe intervention for many chronic diseases as a modifiable lifestyle. However, the potential causal effect of many dietary intake habits on the risk of osteoarthritis has not been fully understood. The purpose of this study was to reveal the potential causal relationship of 45 genetically predicted dietary intakes with osteoarthritis and its subtypes.

Methods

Data on 45 dietary intakes were obtained from the UK Biobank study of approximately 500,000 participants, and data on six osteoarthritis-related phenotypes were obtained from the Genetics of Osteoarthritis Consortium study of 826,690 participants. We performed univariable Mendelian randomization (MR), multivariable MR and linkage disequilibrium score regression (LDSC) analyses.

Results

In univariate analyses, 59 potential associations between diet and osteoarthritis were found. After false discovery rate (FDR) correction and sensitivity analyses, 23 reliable causal evidence were identified. In multivariate analyses, controlling separately for the effects of body mass index, total body bone mineral density, and smoking status, eight robust causal relationships remained: Muesli intake was negatively associated with knee osteoarthritis, spine osteoarthritis and total knee replacement. Dried fruit intake had a negative association with osteoarthritis of knee and total knee replacement. Eating cheese may reduce the risk of osteoarthritis in the knee and spine. And alcohol usually taken with meals was associated with a reduced risk of total knee replacement. LDSC analyses showed significant genetic correlations between all exposures and their corresponding outcomes, respectively, in these eight causal relationships.

Conclusion

Evidence of dietary effects on osteoarthritis is provided in our study, which has important implications for the prevention, management, and intervention of osteoarthritis in common sites through rational dietary modification.

A systematic review on selection characterization and implementation of probiotics in human health

Probiotics are live bacteria found in food that assist the body's defence mechanisms against pathogens by reconciling the gut microbiota. Probiotics are believed to aid with gut health, the immune system, and brain function, among other factors. They've furthermore been shown to help with constipation, high blood pressure, and skin issues. The global probiotics market has been incrementally growing in recent years, as consumers' demand for healthy diets and wellness has continued to increase. This has prompted the food industry to develop new probiotic-containing food products, as well as researchers to explore their specific characteristics and impacts on human health. Although most probiotics are fastidious microorganisms that are nutritionally demanding and sensitive to environmental conditions, they become less viable as they are processed and stored. In this review we studied the current literature on the fundamental idea of probiotic bacteria, their medical benefits, and their selection, characterization, and implementations.

Graphical Abstract

Effect of Lactobacillus Fermentum as a Probiotic Agent on Bone Health in Postmenopausal Women

BACKGROUND

Probiotics are live microorganisms that confer health benefits on the host. Many animal studies have shown that among the probiotics, lactobacilli exert favorable effects on bone metabolism. Herein, we report the results of a randomized controlled trial performed to investigate the effect of Lactobacillus fermentum (L. fermentum) SRK414 on bone health in postmenopausal women.

METHODS

The bone turnover markers (BTMs) and bone mineral density (BMD) in participants in the study group (N=27; mean age, 58.4±3.4 years) and control group (N=26; mean age, 59.5±3.4 years) were compared during a 6-month trial. BTMs were measured at pretrial, 3 months post-trial, and 6 months post-trial, while BMD was measured at pre-trial and 6 months post-trial. Changes in the gut microorganisms were also evaluated.

RESULTS

Femur neck BMD showed a significant increase at 6 months post-trial in the study group (P=0.030) but not in the control group. The control group showed a decrease in osteocalcin (OC) levels (P=0.028), whereas the levels in the study group were maintained during the trial period. The change in L. fermentum concentration was significantly correlated with that in OC levels (r=0.386, P=0.047) in the study group at 3 months post-trial.

CONCLUSIONS

Probiotic (L. fermentum SRK414) supplementation was found to maintain OC levels and increase femur neck BMD during a 6-month trial in postmenopausal women. Further studies with a larger number of participants and a longer study period are required to increase the utility of probiotics as an alternative to osteoporosis medication.

Growth and Metabolism of Lacticaseibacillus casei and Lactobacillus kefiri Isolated from Qymyz, a Traditional Fermented Central Asian Beverage

The growth characteristics of two strains of lactic acid bacteria (LAB), Lacticaseibacillus casei and Lactobacillus kefiri, isolated from qymyz, a traditional fermented mare milk beverage, were studied and modeled, including the effect of different carbohydrates, pH, and temperature. Along with population, substrates, and metabolites, lactic acid and ethanol were monitored by HPLC. Growth parameters were obtained from mono- and biphasic logistic growth models that fit the population evolution of L. casei and L. kefiri, respectively. The effect of temperature and pH on the growth rate was represented with the gamma concept model, while the effect of the limiting substrate was evaluated according to the Monod equation. Lastly, a simplified Luedeking and Piret equation was used to represent metabolite production. The optimum values of pH and temperature were 6.69 ± 0.20, 38.63 ± 0.32 °C, 5.93 ± 0.08, and 33.15 ± 0.53 °C, with growth rate values of 0.66 ± 0.01 h−1 and 0.29 ± 0.01 h−1 for L. casei and L. kefiri, respectively. L. casei had a homofermentative pathway, while L. kefiri was heterofermentative, with an ethanol production rate of 2.90 × 10−9 mg·CFU−1. The Monod model showed that L. casei had the lowest Ks value for lactose, while for L. kefiri, it was the highest among milk carbohydrates. These results show that the population of the two LAB strains and therefore the concentrations of acid and ethanol can be controlled by the fermentation conditions and that our model can help to significantly improve the production of qymyz.

An insight into the health beneficial of probiotics dairy products: a critical review

Probiotic dairy products satisfy people's pursuit of health, and are widely favored because of their easy absorption, high nutritional value, and various health benefits. However, its effectiveness and safety are still controversial. This proposal aims to analyze the effect of probiotics on the quality characteristics of dairy products, clarify a series of physiological functions of probiotic dairy products and critically evaluate the effectiveness and safety of probiotic dairy products. Also, dairy products containing inactivated microorganisms were compared with probiotic products. The addition of probiotics enables dairy products to obtain unique quality characteristics, and probiotic dairy products have better health-promoting effects. This review will promote the further development of probiotic dairy products, provide directions for the research and development of probiotic-related products, and help guide the general public to choose and purchase probiotic fermentation products.

Microbial Composition of a Traditional Fermented Wheat Preparation—Nishasta and Its Role in the Amelioration of Retinoic Acid-Induced Osteoporosis in Rats

Fermented foods have a long history of human use. The purpose of this study was to characterize the microbial composition of a traditional fermented wheat preparation—Nishasta— and to explore its effect in retinoic acid-induced osteoporosis in Wistar rats. The sample was suspended in sterile water (10% w/v), mixed thoroughly, filtered, and gradually diluted. Aliquots of dilutions were cultured in MRS (DeMan–Rogosa–Sharpe) medium, and colonies with similar morphologies were subjected to DNA extraction. The 16S rRNA gene of the isolates was amplified by polymerase chain reaction, checked by agarose gel electrophoresis, and finally identified by sequencing. Anti-osteoporosis screening of Nishasta was carried out in female Wistar rats using retinoic acid as an inducer (70 mg/kg, p.o. once a day for 14 days). Its effect on bone health parameters was determined. The bone metabolism markers such as hydroxyproline (HOP), tartrate-resistant acid phosphatase (TRACP), and alkaline phosphatase (ALP) were evaluated. The results of microbial characterization revealed the presence of ten clones of Lactobacillus plantarum in the fermented preparation with L. plantarum NF3 as the predominant strain. The average microbial count was 2.4 × 103 CFU/g. Retinoic acid administration led to a marked disorder of various bone health markers in rats. It also increased the levels of urine calcium and phosphorus, indicating increased bone destruction. Treatment with fermented wheat (at 200, 100, and 50 mg/kg doses, p.o. daily for 42 days after the induction of osteoporosis) improved bone mineral density in a dose-dependent manner. It also improved the bone microstructure and reduced the levels of ALP, TRACP, and HOP. Micro-CT revealed that it reduced trabecular separation and increased the percent bone volume, trabecular numbers, trabecular thickness, and bone mineral density in the rats. The results showed that the fermented wheat promoted bone formation and prevented bone resorption. Our findings clearly established the effectiveness of Nishasta against osteoporosis in Wistar rats that can be partly attributed to the improved gut calcium absorption and microbiota composition.

Associations of Calcium Intake and Calcium from Various Sources with Blood Lipids in a Population of Older Women and Men with High Calcium Intake

Promoting calcium intake is a cornerstone for osteoporosis management. Some individuals limit dairy product consumption, a major calcium source, due to their high content in saturated fats and their perceived negative impact on lipid profiles. This study explored the associations of calcium from various sources with blood lipids in community-dwelling elderly (n = 717) from the GERICO cohort. Dietary calcium intake was assessed at several timepoints using a validated food frequency questionnaire (FFQ) and calcium supplement use was recorded. Blood lipids were treated as categorical variables to distinguish those with normal and abnormal levels. Increasing total calcium intake was associated with lower risks for high total cholesterol (p = 0.038) and triglycerides (p = 0.007), and low HDL-cholesterol (p = 0.010). Dairy calcium (p = 0.031), especially calcium from milk (p = 0.044) and milk-based desserts (p = 0.039), i.e., low-fat (p = 0.022) and non-fermented (p = 0.005) dairy products, were associated with a lower risk of high total cholesterol. Greater calcium intakes from total dairies (p = 0.020), milk (p = 0.020) and non-fermented dairies (p = 0.027) were associated with a lower risk of hypertriglyceridemia. No association was observed between calcium from non-dairy sources, cheese or high-fat dairies and blood lipids. Increasing calcium through supplements was associated with lower risks for hypertriglyceridemia (p = 0.022) and low HDL-cholesterol (p = 0.001), but not after adjustments. Our results suggest that higher calcium intakes from dietary sources or supplements are not adversely associated with blood lipids in the elderly, whilst total, and particularly low-fat, dairy products are valuable calcium sources potentially related to favorable lipid profiles.

Fermented Oyster (Crassostrea gigas) Extract Cures and Prevents Prednisolone-Induced Bone Resorption by Activating Osteoblast Differentiation

Osteoporosis is a bone resorptive disease characterized by the loss of bone density, causing an increase in bone fragility. In our previous study, we demonstrated that gamma aminobutyric acid-enriched fermented oyster (Crassostrea gigas) extract (FO) stimulated osteogenesis in MC3T3-E1 preosteoblast cells and vertebral formation in zebrafish. However, the efficacy of FO in prednisolone (PDS)-induced bone resorption remains unclear. In this study, we evaluated the osteogenic potential of FO in MC3T3-E1 preosteoblast cells and zebrafish larvae under both PDS-pretreated and PDS-post-treated conditions. We found that FO recovered osteogenic activity by upregulating osteoblast markers, such as alkaline phosphatase (ALP), runt-related transcription factor 2, and osterix, in both PDS-pretreated and post-treated MC3T3-E1 osteoblast cells and zebrafish larvae. In both conditions, PDS-induced decrease in calcification and ALP activity was recovered in the presence of FO. Furthermore, vertebral resorption in zebrafish larvae induced by pretreatment and post-treatment with PDS was restored by treatment with FO, along with the recovery of osteogenic markers and downregulation of osteoclastogenic markers. Finally, whether FO disturbs the endocrine system was confirmed according to the Organization for Economic Cooperation and Development guideline 455. We found that FO did not stimulate estrogen response element-luciferase activity or proliferation in MCF7 cells. Additionally, in ovariectomized mice, no change in uterine weight was observed during FO feeding. These results indicate that FO effectively prevents and treats PDS-induced osteoporosis without endocrine disturbances.

The Impact of Diet on Bone and Fracture Risk in Diabetes

PURPOSE OF REVIEW

The purpose of this review is to summarize the recently published scientific evidence on the effects of diet on diabetes and skeletal health.

RECENT FINDINGS

The impact of diet on overall health has been a growing topic of interest among researchers. An inappropriate eating habit is a relatively modified risk factor for diabetes in adults. Parallel with the significant increase in the incidence of diabetes mellitus worldwide, many studies have shown the benefits of lifestyle modifications, including diet and exercise for people with, or at risk of developing, diabetes. In the last years, accumulating evidence suggests that diabetes is a risk factor for bone fragility. As lifestyle intervention represents an effective option for diabetes management and treatment, there is potential for an effect on bone health. Healthy lifestyle is critical to prevent bone fragility. However, more studies are needed to fully understand the impact of diet and weight loss on fracture risk in diabetics.

Dairy products and bone health

Bone mineral mass, geometry and microstructure, hence determinants of fracture risk, result bone accrual during growth and bone loss later in life. Peak bone mass, which is reached by the end of the second decade of life, is mainly determined by genetic factors. Among other factors influencing bone capital, dietary intakes, particularly calcium and protein, play a significant role in peak bone mass attainment. Both nutrients are provided in dairy products, which accounts for 50-60% and 20-30% of the daily calcium and protein intakes, respectively. Children avoiding dairy products are at higher risk of fracture, as are adults or older individuals following a diet devoid of dairy products, like vegans. Various intervention trials have shown some beneficial effects of dairy products on bone capital accumulation during growth and on bone turnover in adults. In observational studies, dairy products intake, particularly the fermented ones, which also provide probiotics in addition to calcium, phosphorus and protein, appear to be associated with a lower risk of hip fracture.

Circulating Levels of Bone Markers after Short-Term Intense Training with Increased Dairy Consumption in Adolescent Female Athletes

Thirteen female adolescent soccer players (14.3 ± 1.3 years) participated in a cross-over, double-blind trial examining the effects of Greek yogurt (GY) consumption on bone biomarkers during 5 days of intense soccer training. The study took place over two intervention weeks, which consisted of a pre-training assessment day, 5 training days, and a post-training assessment day. Participants completed the GY condition and a carbohydrate isocaloric placebo control pudding condition (CHO) in random order, 4 weeks apart. Morning, fasted, resting blood samples were collected pre- and post-training in each condition. Total osteocalcin (tOC), undercarboxylated osteocalcin (unOC), C-terminal telopeptide of type 1 collagen (CTX), osteoprotegerin (OPG), and receptor activator nuclear factor kappa-β ligand (RANKL) were measured in serum. The results showed no effects for time (pre- to post-training) or condition, and no interaction for tOC, CTX, OPG, RANKL, and the OPG/RANKL ratio. A time-by-condition interaction (p = 0.011) was observed in unOC, reflecting a post-training decrease in the GY, but not the CHO condition (-26% vs. -3%, respectively). However, relative unOC (% of tOC) decreased post-training (-16%), with no differences between conditions. These findings suggest that short-term high-impact intense training had no direct catabolic impact on bone metabolism, with GY adding no benefit beyond that of the isocaloric CHO control pudding.

Nutritional intake and bone health

Osteoporotic or fragility fractures affect one in two women and one in five men who are older than 50. These events are associated with substantial morbidity, increased mortality, and an impaired quality of life. Recommended general measures for fragility fracture prevention include a balanced diet with an optimal protein and calcium intake and vitamin D sufficiency, together with regular weight-bearing physical exercise. In this narrative Review, we discuss the role of nutrients, foods, and dietary patterns in maintaining bone health. Much of this information comes from observational studies. Bone mineral density, microstructure-estimated bone strength, and trabecular and cortical microstructure are positively associated with total protein intake. Several studies indicate that fracture risk might be lower with a higher dietary protein intake, provided that the calcium supply is sufficient. Dairy products are a valuable source of these two nutrients. Hip fracture risk appears to be lower in consumers of dairy products, particularly fermented dairy products. Consuming less than five servings per day of fruit and vegetables is associated with a higher hip fracture risk. Adherence to a Mediterranean diet or to a prudent diet is associated with a lower fracture risk. These various nutrients and dietary patterns influence gut microbiota composition or function, or both. The conclusions of this Review emphasise the importance of a balanced diet including minerals, protein, and fruit and vegetables for bone health and in the prevention of fragility fractures.

Bioaccessibility and Bioavailability of Minerals in Relation to a Healthy Gut Microbiome

Adequate amounts of a wide range of micronutrients are needed by body tissues to maintain health. Dietary intake must be sufficient to meet these micronutrient requirements. Mineral deficiency does not seem to be the result of a physically active life or of athletic training but is more likely to arise from disturbances in the quality and quantity of ingested food. The lack of some minerals in the body appears to be symbolic of the modern era reflecting either the excessive intake of empty calories or a negative energy balance from drastic weight-loss diets. Several animal studies provide convincing evidence for an association between dietary micronutrient availability and microbial composition in the gut. However, the influence of human gut microbiota on the bioaccessibility and bioavailability of trace elements in human food has rarely been studied. Bacteria play a role by effecting mineral bioavailability and bioaccessibility, which are further increased through the fermentation of cereals and the soaking and germination of crops. Moreover, probiotics have a positive effect on iron, calcium, selenium, and zinc in relation to gut microbiome composition and metabolism. The current literature reveals the beneficial effects of bacteria on mineral bioaccessibility and bioavailability in supporting both the human gut microbiome and overall health. This review focuses on interactions between the gut microbiota and several minerals in sport nutrition, as related to a physically active lifestyle.

Impact of Mediterranean Diet on Chronic Non-Communicable Diseases and Longevity

The average life expectancy of the world population has increased remarkably in the past 150 years and it is still increasing. A long life is a dream of humans since the beginning of time but also a dream is to live it in good physical and mental condition. Nutrition research has focused on recent decades more on food combination patterns than on individual foods/nutrients due to the possible synergistic/antagonistic effects of the components in a dietary model. Various dietary patterns have been associated with health benefits, but the largest body of evidence in the literature is attributable to the traditional dietary habits and lifestyle followed by populations from the Mediterranean region. After the Seven Countries Study, many prospective observational studies and trials in diverse populations reinforced the beneficial effects associated with a higher adherence to the Mediterranean diet in reference to the prevention/management of age-associated non-communicable diseases, such as cardiovascular and metabolic diseases, neurodegenerative diseases, cancer, depression, respiratory diseases, and fragility fractures. In addition, the Mediterranean diet is ecologically sustainable. Therefore, this immaterial world heritage constitutes a healthy way of eating and living respecting the environment.

Impact of Mediterranean Diet on Chronic Non-Communicable Diseases and Longevity

The average life expectancy of the world population has increased remarkably in the past 150 years and it is still increasing. A long life is a dream of humans since the beginning of time but also a dream is to live it in good physical and mental condition. Nutrition research has focused on recent decades more on food combination patterns than on individual foods/nutrients due to the possible synergistic/antagonistic effects of the components in a dietary model. Various dietary patterns have been associated with health benefits, but the largest body of evidence in the literature is attributable to the traditional dietary habits and lifestyle followed by populations from the Mediterranean region. After the Seven Countries Study, many prospective observational studies and trials in diverse populations reinforced the beneficial effects associated with a higher adherence to the Mediterranean diet in reference to the prevention/management of age-associated non-communicable diseases, such as cardiovascular and metabolic diseases, neurodegenerative diseases, cancer, depression, respiratory diseases, and fragility fractures. In addition, the Mediterranean diet is ecologically sustainable. Therefore, this immaterial world heritage constitutes a healthy way of eating and living respecting the environment.

Milk proteins and their derived peptides on bone health: Biological functions, mechanisms, and prospects

Bone is a dynamic organ under constant metabolism (or remodeling), where a delicate balance between bone resorption and bone formation is maintained. Disruption of this coordinated bone remodeling results in bone diseases, such as osteoporosis, the most common bone disorder characterized by decreased bone mineral density and microarchitectural deterioration. Epidemiological and clinical evidence support that consumption of dairy products is beneficial for bone health; this benefit is often attributed to the presence of calcium, the physiological contributions of milk proteins on bone metabolism, however, are underestimated. Emerging evidence highlighted that not only milk proteins (including individual milk proteins) but also their derived peptides positively regulate bone remodeling and attenuate bone loss, via the regulation of cellular markers and signaling of osteoblasts and osteoclasts. This article aims to review current knowledge about the roles of milk proteins, with an emphasis on individual milk proteins, bioactive peptides derived from milk proteins, and effect of milk processing in particular fermentation, on bone metabolism, to highlight the potential uses of milk proteins in the prevention and treatment of osteoporosis, and, to discuss the knowledge gap and to recommend future research directions.

Nutritional Supplements and Skeletal Health

PURPOSE OF REVIEW

Nutrition influences skeletal health throughout the lifespan, from the impact of maternal intakes during development, through the development of peak bone mass, to the rate of bone loss during aging. However, there are limited data available on the effects of nutritional supplements on bone density, let alone fracture risk. This review will assess the current literature, focusing on human studies, and emphasizing nutrients where bone density or fracture data are available.

RECENT FINDINGS

Calcium and vitamin D supplements, in combination, reduce fracture risk, particularly in populations with low intakes. Extensive recent analyses have supported the safety of these interventions at recommended intakes. There is growing evidence that specific isoflavones may improve bone density although fracture data are lacking. Multiple other nutrient supplements may benefit skeletal health, but data are limited. The effect size of nutrient interventions are relatively small, requiring large sample sizes for trials with bone outcomes, may be difficult to blind, and the impact of supplementation may depend on baseline intake. However, nutrition is the only intervention that can be implemented life long and on a population wide basis. Further investigation is needed into the potential benefits of nutritional supplements to determine in which settings supplements may add benefit in addition to dietary intakes.

Lactobacillus-fermented milk products attenuate bone loss in an experimental rat model of ovariectomy-induced post-menopausal primary osteoporosis

AIM

In this study, we investigated the anti-osteoporotic effect of two fermented milk products (FMPs) fermented by Lactobacillus plantarum A41 and Lactobacillus fermentum SRK414 on a rat model of ovariectomy-induced post-menopausal primary osteoporosis.

METHODS AND RESULTS

The two Lactobacillus FMPs increased the bone volume and bone mineral density (BMD) in ovariectomized (OVX) rats, and normalized the bone biomarkers in the serum. Additionally, they altered the gene expression levels of bone-metabolism-related markers. Furthermore, the two Lactobacillus FMPs downregulated bone-apoptosis-related genes stimulated by ovariectomy. Interestingly, the Lactobacillus FMPs decreased the levels of inflammation markers in the serum, bone, ileum and colon of the rats. Gut bacterial populations were also affected upon FMP treatment due to increase in the abundance of the genus Lactobacillus and Faecalibacterium prausnitzii.

CONCLUSIONS

Milk products fermented by L. plantarum A41 and L. fermentum SRK414 can exhibit anti-osteoporotic effects on post-menopausal osteoporosis via regulating the expression of bone-metabolism-related markers.

SIGNIFICANCE AND IMPACT OF THE STUDY

The two Lactobacillus FMPs used in the study can be an ideal method that has its potential of treating post-menopausal osteoporosis instead of drug treatments.

Lactose intolerance in patients with inflammatory bowel diseases and dietary management in prevention of osteoporosis

Lactose intolerance affects 33% to 75% of the world population and may be associated with various genetic factors. Lactose in the diet can be found in milk and dairy products, which simultaneously constitute the primary sources of calcium. Gut microbiota also influences lactose tolerance. Patients with lactose intolerance often stop consuming milk and dairy products, which may lead to calcium and vitamin deficiency and osteoporosis. Insufficient production of lactase also occurs in patients with diseases of the gastrointestinal tract, such as inflammatory bowel diseases. Moreover, Crohn's disease and ulcerative colitis are risk factors for osteoporosis, and the intake of the proper amount of calcium is an essential element in preventing the decrease of bone mineral density. Diet may prevent the development of osteoporosis, thus, educating patients regarding proper diet should constitute a part of the treatment and prevention process. Patients should consume low-lactose, or lactose-free milk and bacterially fermented dairy products. Additionally, plant milk supplemented by calcium and vitamin D, mineral water with calcium, and certain vegetables also may be good sources of calcium.

Lactobacillus Fermentum ZS40 prevents secondary osteoporosis in Wistar Rat

Using retinoic acid to inducer, we successfully established a rat model of secondary osteoporosis and verified the preventive effect of Lactobacillus fermentum ZS40 (ZS40) on secondary osteoporosis. Serum biochemical indicators showed that ZS40 can effectively slow down bone resorption caused by retinoic acid, increase blood content of calcium, phosphorus, bone alkaline phosphatase, bone gla protein, and insulin-like growth factor 1, and decrease blood content of tartrate-resistant acid phosphatase (TRAP) 5b. qRT-PCR results showed that ZS40 could upregulate mRNA expressions of β-catenin, Wnt10b, Lrp5, Lrp6, Runx2, ALP, RANKL, and OPG, and downregulate mRNA expression of DKK1, RANK, TRACP, and CTSK in the rats' spinal cord. Results following TRAP staining showed that ZS40 could slow down retinoic acid-induced formation of osteoclasts. Micro-CT results showed that ZS40 could reduce Tb.Sp, increase BV/TV, Tb.N, Tb.Th, and ultimately increase bone mineral density of rats in vivo. These findings indicate that ZS40 might have a potential role in preventing retinoic acid-induced secondary osteoporosis in vivo.

Systematic review and meta-analysis of the association between dairy consumption and the risk of hip fracture: critical interpretation of the currently available evidence

In the present meta-analysis, reductions in the risk of hip fracture with milk consumption were only observed among American adults, but not among Scandinavian adults, possibly because milk products are more commonly fortified with vitamin D in the former population than in Scandinavian countries. The reduction in the risk of hip fracture was also observed with yogurt consumption, which is often associated with healthy lifestyles and dietary patterns that contribute to improved bone health.

INTRODUCTION

Although dairy products contain bone-beneficial nutrients, the association between dairy consumption and the risk of hip fracture remains equivocal. Fueling this uncertainty, the elevated risk of hip fracture in association with milk consumption was observed in a cohort of Swedish women. A systematic review and meta-analysis of prospective cohort studies was performed to critically evaluate the association, or lack thereof, between dairy consumption (milk, yogurt, and cheese) and the risk of hip fracture.

METHODS

A random effects model was used to generate the summary relative risks (RRs) with their 95% confidence intervals (CIs) for the associations of interest.

RESULTS

In the meta-analysis of the highest versus lowest category of consumption, higher consumption of yogurt (RR 0.78, 95% CI 0.68, 0.90), but not milk (RR 0.86, 95% CI 0.73, 1.02) or cheese (RR 0.85, 95% CI 0.66, 1.08), was associated with a lower risk of hip fracture. For milk, the reduced risk of fracture with higher milk consumption was observed in the USA (RR 0.75, 95% CI 0.65, 0.87), but not in Scandinavian countries (RR 1.00, 95% CI 0.85, 1.17). These findings were further supported by the fact that American studies (RR 0.93, 95% CI 0.88, 0.98; per 1 glass/day), but not Scandinavian studies (RR 1.01, 95% CI 0.95, 1.07; per 1 glass/day), demonstrated a linear association between milk consumption and the risk of hip fracture.

CONCLUSIONS

The cumulative evidence from prospective cohort studies reassuringly suggests that the risk of hip fracture may not be elevated among people who consume milk, yogurt, and cheese, and that a greater consumption of milk or yogurt may even be associated with a lower risk of hip fracture depending on the factors that may differ across the population of interest.

A Dairy Product to Reconstitute Enriched with Bioactive Nutrients Stops Bone Loss in High-Risk Menopausal Women without Pharmacological Treatment

Osteoporosis is a multifactorial disease characterized by the loss of bone mass and deterioration of the internal structure of the bone, increasing the risk of fractures, and is becoming an economic and social problem. The main treatment is pharmacological, however, the population demands other therapies, such as foods with nutrients beneficial to bone health. Seventy-eight healthy menopausal women at risk of osteoporosis or untreated osteopenia were recruited for a randomized, parallel, double-blind clinical trial with two intervention groups: one group consumed a serving a day of the experimental enriched product (experimental group (EG)) and the other group (control group (CG)) consumed the same product without enrichment. The main objective was to compare the effect of consuming a dairy preparation to reconstitute, similar to yogurt when prepared, enriched in calcium, vitamin D, vitamin K, vitamin C, zinc, magnesium, L-leucine and probiotic (Lactobacillus plantarum 3547) on bone metabolism markers for 24 weeks. The EG showed a significantly increased bone mass compared to the CG (0.01 ± 0.03 vs. −0.01 ± 0.03 kg; p < 0.05). In addition, the EG maintained their bone mineral density (BMD) compared to the CG, whose BMD significantly decreased at the end of the study. For biochemical markers, the EG significantly increased the serum levels of the N-terminal propeptide of type I collagen (P1NP) bone formation marker (13.19 ± 25.17 vs. −4.21 ± 15.62 ng/mL; p < 0.05), and decreased the carbo-terminal telopeptide of type I collagen (CTx) bone resorption marker compared to the CG (−0.05 ± 0.19 vs. 0.04 ± 0.14 ng/mL; p < 0.05). On the other hand, the EG exhibited a significantly decreased systolic and diastolic blood pressure compared to the start of the study. Finally, the EG significantly increased their dietary calcium and vitamin D intake compared to the CG. In conclusion, the regular consumption of a dairy product to reconstitute enriched with bioactive nutrients improves bone health markers in menopausal women at risk of osteoporosis without pharmacological treatment.

Nutrients and Dietary Patterns Related to Osteoporosis

Osteoporosis is a common chronic disease characterized by a decrease in bone mineral density, impaired bone strength, and an increased risk of fragility fractures. Fragility fractures are associated with significant morbidity, mortality and disability and are a major public health problem worldwide. The influence of nutritional factors on the development and progression of this disease can be significant and is not yet well established. Calcium intake and vitamin D status are considered to be essential for bone metabolism homeostasis. However, some recent studies have questioned the usefulness of calcium and vitamin D supplements in decreasing the risk of fractures. The adequate intake of protein, vegetables and other nutrients is also of interest, and recommendations have been established by expert consensus and clinical practice guidelines. It is important to understand the influence of nutrients not only in isolation but also in the context of a dietary pattern, which is a complex mixture of nutrients. In this review, we evaluate the available scientific evidence for the effects of the main dietary patterns on bone health. Although some dietary patterns seem to have beneficial effects, more studies are needed to fully elucidate the true influence of diet on bone fragility.

Are Probiotics the New Calcium and Vitamin D for Bone Health?

PURPOSE OF REVIEW

Calcium and vitamin D supplementation is recommended for patients at high risk of fracture and/or for those receiving pharmacological osteoporosis treatments. Probiotics are micro-organisms conferring a health benefit on the host when administered in adequate amounts, likely by influencing gut microbiota (GM) composition and/or function. GM has been shown to influence various determinants of bone health.

RECENT FINDINGS

In animal models, probiotics prevent bone loss associated with estrogen deficiency, diabetes, or glucocorticoid treatments, by modulating both bone resorption by osteoclasts and bone formation by osteoblast. In humans, they interfere with 25-hydroxyvitamin D levels, and calcium intake and absorption, and slightly decrease bone loss in elderly postmenopausal women, in a quite similar magnitude as observed with calcium ± vitamin D supplements. A dietary source of probiotics is fermented dairy products which can improve calcium balance, prevent secondary hyperparathyroidism, and attenuate age-related increase of bone resorption and bone loss. Additional studies are required to determine whether probiotics or any other interventions targeting GM and its metabolites may be adjuvant treatment to calcium and vitamin D or anti-osteoporotic drugs in the general management of patients with bone fragility.

Ready to Use Therapeutical Beverages: Focus on Functional Beverages Containing Probiotics, Prebiotics and Synbiotics

The growing global interest in functional foods containing nutrients capable of adding possible beneficial health effects is rapidly increasing both interest and consumer demand. In particular, functionalized beverages for their potential positive effect on health e.g., decreasing cholesterol level, lowering sugar, high fiber content, ability to enhance the immune system, and help digestion, have recently received special attention. Among the different beverages available on the market, probiotic dairy and non-dairy products have attracted much attention because of their affordable cost and their numerous therapeutic activities. Fermented milk and yogurt are currently worth €46 billion, with 77% of the market reported in Europe, North America, and Asia. Consumption of dairy beverages has some limitations due for example to lactose intolerance and allergy to milk proteins, thereby leading consumers to use non-dairy beverages such as fruit, grains, and vegetable juices to add probiotics to diet as well as driving the manufacturers to food matrices-based beverages containing probiotic cultures. The purpose of this review article is to evaluate the therapeutic performance and properties of dairy and non-dairy beverages in terms of probiotic, prebiotic, and synbiotic activities.

Impact of whole dairy matrix on musculoskeletal health and aging-current knowledge and research gaps

Dairy products are included in dietary guidelines worldwide, as milk, yoghurt, and cheese are good sources of calcium and protein, vital nutrients for bones and muscle mass maintenance. Bone growth and mineralization occur during infancy and childhood, peak bone mass being attained after early adulthood. A low peak bone mass has consequences later in life, including increased risk of osteoporosis and fractures. Currently, more than 200 million people worldwide suffer from osteoporosis, with approximately 9 million fractures yearly. This poses a tremendous economic burden on health care. Between 5% and 10% of the elderly suffer from sarcopenia, the loss of muscle mass and strength, further increasing the risk of fractures due to falls. Evidence from interventional and observational studies support that fermented dairy products in particular exert beneficial effects on bone growth and mineralization, attenuation of bone loss, and reduce fracture risk. The effect cannot be explained by single nutrients in dairy, which suggests that a combined or matrix effect may be responsible similar to the matrix effects of foods on cardiometabolic health. Recently, several plant-based beverages and products have become available and marketed as substitutes for dairy products, even though their nutrient content differs substantially from dairy. Some of these products have been fortified, in efforts to mimic the nutritional profile of milk, but it is unknown whether the additives have the same bioavailability and beneficial effect as dairy. We conclude that the dairy matrix exerts an effect on bone and muscle health that is more than the sum of its nutrients, and we suggest that whole foods, not only single nutrients, need to be assessed in future observational and intervention studies of health outcomes. Furthermore, the importance of the matrix effect on health outcomes argues in favor of making future dietary guidelines food based.

Involvement of the Gut Microbiota and Barrier Function in Glucocorticoid-Induced Osteoporosis

Glucocorticoids (GCs) are potent immune-modulating drugs with significant side effects, including glucocorticoid-induced osteoporosis (GIO). GCs directly induce osteoblast and osteocyte apoptosis but also alter intestinal microbiota composition. Although the gut microbiota is known to contribute to the regulation of bone density, its role in GIO has never been examined. To test this, male C57/Bl6J mice were treated for 8 weeks with GC (prednisolone, GC-Tx) in the presence or absence of broad-spectrum antibiotic treatment (ABX) to deplete the microbiota. Long-term ABX prevented GC-Tx-induced trabecular bone loss, showing the requirement of gut microbiota for GIO. Treatment of GC-Tx mice with a probiotic (Lactobacillus reuteri [LR]) prevented trabecular bone loss. Microbiota analyses indicated that GC-Tx changed the abundance of Verrucomicobiales and Bacteriodales phyla and random forest analyses indicated significant differences in abundance of Porphyromonadaceae and Clostridiales operational taxonomic units (OTUs) between groups. Furthermore, transplantation of GC-Tx mouse fecal material into recipient naïve, untreated WT mice caused bone loss, supporting a functional role for microbiota in GIO. We also report that GC caused intestinal barrier breaks, as evidenced by increased serum endotoxin level (2.4-fold), that were prevented by LR and ABX treatments. Enhancement of barrier function with a mucus supplement prevented both GC-Tx-induced barrier leakage and trabecular GIO. In bone, treatment with ABX, LR or a mucus supplement reduced GC-Tx-induced osteoblast and osteocyte apoptosis. GC-Tx suppression of Wnt10b in bone was restored by the LR and high-molecular-weight polymer (MDY) treatments as well as microbiota depletion. Finally, we identified that bone-specific Wnt10b overexpression prevented GIO. Taken together, our data highlight the previously unappreciated involvement of the gut microbiota and intestinal barrier function in trabecular GIO pathogenesis (including Wnt10b suppression and osteoblast and osteocyte apoptosis) and identify the gut as a novel therapeutic target for preventing GIO. © 2019 American Society for Bone and Mineral Research.

Fermented Milk Products and Bone Health in Postmenopausal Women: A Systematic Review of Randomized Controlled Trials, Prospective Cohorts, and Case-Control Studies

Milk and milk product consumption is positively associated with bone mineral density (BMD). Emerging evidence suggests that fermented milk products (FMPs) may have specific beneficial effects on skeletal health. We conducted a systematic review and meta-analysis to assess the effect of FMPs on bone health indicators in postmenopausal women given their increased risk for osteoporosis and fragility fractures. Electronic databases were searched for randomized controlled trials (RCTs) and prospective cohort and case-control studies that examined the relation between FMPs and bone health outcomes (fracture incidence, BMD, BMD T-score, and percentage change in bone turnover markers) in postmenopausal women. Two reviewers independently conducted abstract and full-text screenings and data extractions. Risk of bias was assessed using the RoB 2.0 tool and the Newcastle-Ottawa scale for interventional and observational studies. Pooled RRs were obtained using a random-effects model by the DerSimonian-Laird method. Three RCTs, 3 prospective cohorts, and 3 case-control studies met the inclusion criteria. Results of the meta-analysis of 3 cohort studies (n = 102,819) suggest that higher yogurt consumption was associated with reduced hip fracture risk (pooled RR: 0.76; 95% CI: 0.63, 0.92, I2 = 29%), but no difference in hip fracture risk was found between higher and lower cheese consumption (pooled RR: 0.89; 95% CI: 0.73, 1.10, I2 = 0%). Case-control studies revealed that cheese intake had either a null or a protective effect against osteoporosis (BMD T-score ≤-2.5). Daily yogurt or cheese intervention (<2 mo) decreased bone resorption marker concentrations, but had no effect on bone formation markers. In postmenopausal women, of the FMPs studied, only greater yogurt consumption was associated with a reduced risk of hip fracture compared with low or no intake. Daily cheese intake may be associated with higher BMD T-scores, but evidence was limited. Additional and longer-term trials examining these relations are warranted.

Probiotics and bone disorders: the role of RANKL/RANK/OPG pathway

The skeleton is the framework and in charge of body configuration preservation. As a living tissue, bones are constantly being formed and absorbed. Osteoblasts and osteoclasts are the main bone cells and balance between their activities indicates bone health. Several mechanisms influence the bone turnover and RANKL/RANK/OPG pathway is one of them. This system, whose components are part of the tumor necrosis factor (TNF) superfamily, exists in many organs and could play a role in bone modeling and remodeling. RANKL/RANK pathway controls osteoclasts activity and formation. In addition, they are identified as key factors on bone turnover in different pathological situations. At the same time, OPG (RANKL's decoy receptor) plays role as a bone-protective factor by binding to RANKL and prevention of extra resorption. The lack of balance between RANKL and OPG could result in excessive bone resorption. Probiotics, the beneficial microorganisms for human health, entail bones in their advantages. Recent studies suggest that probiotics could reduce inflammatory factors (for example TNF-α and IL-1β) and increase bone OPG expression. In addition, probiotics have shown to maintain bones in various ways. Although current evidence is not enough for definitive approval of probiotics' efficacy on RANKL/RANK/OPG, its positive responses from conducted studies are significant. Understanding of the probiotics' effects on RANKL/RANK/OPG pathway will help focus future studies, and assist in developing efficient treatment strategies.

Consumption of Greek yogurt during 12 weeks of high-impact loading exercise increases bone formation in young, adult males – a secondary analysis from a randomized trial

Exercise combined with protein and calcium has been shown to benefit bone turnover and bone metabolism. Greek yogurt (GY) contains important nutrients that support bone but has yet to be studied with exercise for this purpose. Thirty untrained, university-aged, males were randomized to 2 groups (n = 15/group): GY (20 g protein, 208 mg calcium/dose) or placebo pudding (PP; 0 g protein, 0 g calcium/dose) consumed 3×/day on training days and 2×/day on nontraining days. Both groups underwent a resistance/plyometric training program for 12 weeks. Blood was obtained at weeks 0, 1, and 12 to measure procollagen-type-I-N-terminal-propeptide (P1NP) and C-terminal-telopeptide (CTX). After outlier treatment, P1NP increased more over time in GY versus PP (p = 0.002; interaction). Both groups decreased CTX over time (p = 0.046; time effect). Following 1 week of training, there was a trend towards a significant increase in CTX in PP with no change in GY (p = 0.062; interaction). P1NP changed more in GY than PP (baseline to week 12; p = 0.029) as did the P1NP/CTX ratio (p = 0.015) indicating a greater increase in formation with GY. Thus, GY added to a high-load, high-impact exercise program positively shifted bone turnover towards increased formation while attenuating resorption. GY could be a plausible postexercise food to support bone health in young adult males.

Novelty Greek yogurt, with exercise, increased bone formation in young adult males over 12 weeks. After 1 week of an osteogenic exercise program, Greek yogurt tended to blunt a rise in bone resorption seen with the placebo. Greek yogurt is a plausible postexercise food that supports bone.

Effects of Probiotics, Prebiotics, and Synbiotics on Calcium Homeostasis and Bone Health With Aging: A Systematic Review

BACKGROUND

Calcium homeostasis and bone health are an increasing concern for middle-aged and older adults. Many studies have explored the positive effects of probiotics, prebiotics, or synbiotics on serum calcium and bone mineral density (BMD) or other parameters related to bone health. However, the participants, the species, doses and duration of interventions, outcomes, and measurements varied among these studies.

AIMS

To systematically evaluate the effect of probiotics, prebiotics, or synbiotics on maintaining calcium homeostasis and improving bone health in middle-aged and older adults.

METHODS

We identified studies in Cochrane Library, Embase, PubMed, Web of Science, CINAHL, China National Knowledge Infrastructure, and Wanfang and articles in English and Chinese published from inception up to January 10, 2019. Randomized controlled trials (RCTs) involving probiotics, prebiotics, or synbiotics for middle-aged or older adults were employed for meta-analysis by using RevMan 5.3, and heterogeneity and risk of bias assessment were performed.

RESULTS

A total of eight studies, involving 564 participants, were included. Probiotics, prebiotics, or synbiotics supplementation was able to significantly elevate serum calcium levels (0.52 mg/dl, 95% CI [0.38, 0.66]), heterogeneity: p = .13, I²  = 44%), while the results of meta-analysis failed to support the effects of this supplementation on the parameters related to bone health in middle-aged and older adults, including BMD, parathyroid hormone, osteocalcin, and alkaline phosphatase.

LINKING EVIDENCE TO ACTION

Probiotics, prebiotics, or synbiotics supplementation exerts a facilitating influence on the level of serum calcium, while the present study has not yet supported the beneficial effects of such interventions on bone health. Therefore, further studies with high-quality RCTs are required to determine the effects of probiotics, prebiotics, or synbiotics supplementation on middle-aged and older adults.

Milk microbiota: Characterization methods and role in cheese production

Milk is a complex body fluid aimed at addressing the nutritional and defensive needs of the mammal's newborns. Harbored microbiota plays a pivotal role throughout the cheesemaking process and contributes to the development of flavor and texture typical of different type of cheeses. Understanding the dairy microbiota dynamics is of paramount importance for controlling the qualitative, sensorial and biosafety features of the dairy products. Although many studies investigated the contribution of single or few microorganisms, still there is some information lacking about microbial communities. The widespread of the omics platforms and bioinformatic tools enable the investigation of the cheese-associated microbial community in both phylogenetical and functional terms, highlighting the effects of the diverse cheesemaking variables. In this review, the most relevant literature is revised to provide an introduction of the milk- and cheese-associated microbiota, along with their structural and functional dynamics in relation to the diverse cheesemaking technologies and influencing variables. Also, we focus our attention on the latest omics technologies adopted in dairy microbiota investigation. Discussion on the key-steps and major drawbacks of each omics discipline is provided along with a collection of results from the latest research studies performed to unravel the fascinating world of the dairy-associated microbiota. SIGNIFICANCE: Understanding the milk- and cheese- associated microbial community is nowadays considered a key factor in the dairy industry, since it allows a comprehensive knowledge on how all phases of the cheesemaking process impact the harbored microflora; thus, predict the consequences in the finished products in terms of texture, organoleptic characteristics, palatability and biosafety. This review, collect the pioneering and milestones works so far performed in the field of dairy microbiota, and provide the basic guidance to whom approaching the cheese microbiota investigation by means of the latest omics technologies. Also, the review emphasizes the benefits and drawbacks of the omics disciplines, and underline how the integration of diverse omics sciences enhance a comprehensive depiction of the cheese microbiota. In turn, a better consciousness of the dairy microbiota might results in the application of improved starter cultures, cheesemaking practices and technologies; supporting a bio-safe and standardized production of cheese, with a strong economic benefit for both large-scale industries and local traditional dairy farms.

Nutritional influence on bone: role of gut microbiota

Gut microbiota (GM) located within the intestinal tract lumen comprises the largest number of cells (10^E14) in the human body. The gut microbiome refers to the collection of genomes and genes present in gut microbiota. GM can vary according to age, sex, genetic background, immune status, geography, diet, prebiotics, which are non-digestible fibers metabolized in the distal part of the gastrointestinal tract, probiotics, which are micro-organisms conferring a health benefit on the host when administered in adequate amounts, living conditions, diseases and drugs. A source of probiotics is fortified fermented dairy products, which in addition provide calcium, protein, phosphorus and various micronutrients. Bone homeostasis is influenced by GM composition and/or products. GM appears to be a major player in the various determinants of bone health. However, it remains to be demonstrated in well conducted long-term randomized controlled trials, whether interventions changing GM composition and/or function are capable of reducing fracture risk.

Greek Yogurt and 12 Weeks of Exercise Training on Strength, Muscle Thickness and Body Composition in Lean, Untrained, University-Aged Males

Milk and/or whey protein plus resistance exercise (RT) increase strength and muscle size, and optimize body composition in adult males and females. Greek yogurt (GY) contains similar muscle-supporting nutrients as milk yet it is different in several ways including being a semi-solid food, containing bacterial cultures and having a higher protein content (mostly casein) per serving. GY has yet to be investigated in the context of a RT program. The purpose of this study was to assess the effects of GY consumption plus RT on strength, muscle thickness and body composition in lean, untrained, university-aged males. Thirty untrained, university-aged (20.6 ± 2.2 years) males were randomized to 2 groups (n = 15/group): fat-free, plain GY or a Placebo Pudding (PP; isoenergetic carbohydrate-based pudding) and underwent a combined RT/plyometric training program 3 days/week for 12 weeks. They consumed either GY (20 g protein/dose) or PP (0 g protein/dose) daily, 3 times on training days and 2 times on non-training days. After 12 weeks, both groups significantly increased strength, muscle thickness and fat-free mass (FFM) (p < 0.05). The GY group gained more total strength (GY; 98 ± 37 kg, PP; 57 ± 15 kg), more biceps brachii muscular thickness (GY; 0.46 ± 0.3 cm, PP; 0.12 ± 0.2 cm), more FFM (GY; 2.4 ± 1.5 kg, PP; 1.3 ± 1.3 kg), and reduced % body fat (GY; −1.1 ± 2.2%, PP; 0.1 ± 2.6%) than PP group (p < 0.05 expressed as absolute change). Thus, consumption of GY during a training program resulted in improved strength, muscle thickness and body composition over a carbohydrate-based placebo. Given the results of our study, the general benefits of consuming GY and its distinctiveness from milk, GY can be a plausible, post-exercise, nutrient-rich alternative for positive strength, muscle, and body composition adaptations.

European guidance for the diagnosis and management of osteoporosis in postmenopausal women

Guidance is provided in a European setting on the assessment and treatment of postmenopausal women at risk from fractures due to osteoporosis.

INTRODUCTION

The International Osteoporosis Foundation and European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis published guidance for the diagnosis and management of osteoporosis in 2013. This manuscript updates these in a European setting.

METHODS

Systematic reviews were updated.

RESULTS

The following areas are reviewed: the role of bone mineral density measurement for the diagnosis of osteoporosis and assessment of fracture risk; general and pharmacological management of osteoporosis; monitoring of treatment; assessment of fracture risk; case-finding strategies; investigation of patients; health economics of treatment. The update includes new information on the evaluation of bone microstructure evaluation in facture risk assessment, the role of FRAX® and Fracture Liaison Services in secondary fracture prevention, long-term effects on fracture risk of dietary intakes, and increased fracture risk on stopping drug treatment.

CONCLUSIONS

A platform is provided on which specific guidelines can be developed for national use.

Production of Bioactive Peptides by Lactobacillus Species: From Gene to Application

To compensate for their amino acid auxotrophy, lactobacilli have developed the ability to hydrolyze proteins present in their environment. This proteolytic activity not only generates the free amino acids needed by the bacteria, but also a large variety of peptides, some of which are endowed with biological activities. These so-called “bioactive peptides” (BAPs) are interesting from a nutrition and healthcare perspective. The use of lactic acid bacteria (LAB) such as lactobacilli is an effective strategy for production and valorization of new BAPs. The proteolytic activity of lactobacilli is exerted in a strain- and species-dependent manner: each species exhibits different proteinase content, leading to a large variety of proteolytic activities. This underlines the high potential of Lactobacillus strains to produce novel hydrolysates and BAPs of major interest. This review aims at discussing the potential of different Lactobacillus species to release BAPs from fermentation media and processes. Strategies used for peptide production are presented. Additionally, we propose a methodology to select the most promising Lactobacillus strains as sources of BAPs. This methodology combines conventional approaches and in silico analyses.

Benefits and safety of dietary protein for bone health-an expert consensus paper endorsed by the European Society for Clinical and Economical Aspects of Osteopororosis, Osteoarthritis, and Musculoskeletal Diseases and by the International Osteoporosis Foundation

A summary of systematic reviews and meta-analyses addressing the benefits and risks of dietary protein intakes for bone health in adults suggests that dietary protein levels even above the current RDA may be beneficial in reducing bone loss and hip fracture risk, provided calcium intakes are adequate. Several systematic reviews and meta-analyses have addressed the benefits and risks of dietary protein intakes for bone health in adults. This narrative review of the literature summarizes and synthesizes recent systematic reviews and meta-analyses and highlights key messages. Adequate supplies of dietary protein are required for optimal bone growth and maintenance of healthy bone. Variation in protein intakes within the "normal" range accounts for 2-4% of BMD variance in adults. In older people with osteoporosis, higher protein intake (≥ 0.8-g/kg body weight/day, i.e., above the current RDA) is associated with higher BMD, a slower rate of bone loss, and reduced risk of hip fracture, provided that dietary calcium intakes are adequate. Intervention with dietary protein supplements attenuate age-related BMD decrease and reduce bone turnover marker levels, together with an increase in IGF-I and a decrease in PTH. There is no evidence that diet-derived acid load is deleterious for bone health. Thus, insufficient dietary protein intakes may be a more severe problem than protein excess in the elderly. Long-term, well-controlled randomized trials are required to further assess the influence of dietary protein intakes on fracture risk.

Lifestyle Management of Diabetes: Implications for the Bone-Vascular Axis

PURPOSE OF REVIEW

To describe the main pathways involved in the interplay between bone and cardiovascular disease and to highlight the possible impact of physical activity and medical nutrition therapy on the bone-vascular axis.

RECENT FINDINGS

Diabetes increases the risk of both cardiovascular disease and bone fragility fractures, sharing common pathogenic pathways, including OPG/RANK/RANKL, the FGF23/Klotho axis, calciotropic hormones, and circulating osteogenic cells. This may offer new therapeutic targets for future treatment strategies. As lifestyle intervention is the cornerstone of diabetes treatment, there is potential for an impact on the bone-vascular axis. Evidence published suggests the bone-vascular axis encompasses key pathways for cardiovascular disease. This, along with studies showing physical activity plays a crucial role in the prevention of both bone fragility and cardiovascular disease, suggests that lifestyle intervention incorporating exercise and diet may be helpful in managing skeletal health decline in diabetes. Studies investigating the controversial role of high-fiber diet and dietary vitamin D/calcium on bone and cardiovascular health suggest an overall benefit, but further investigations are needed in this regard.

Fermented dairy products consumption is associated with attenuated cortical bone loss independently of total calcium, protein, and energy intakes in healthy postmenopausal women

A longitudinal analysis of bone microstructure in postmenopausal women of the Geneva Retirees Cohort indicates that age-related cortical bone loss is attenuated at non-bearing bone sites in fermented dairy products consumers, not in milk or ripened cheese consumers, independently of total energy, calcium, or protein intakes.

INTRODUCTION

Fermented dairy products (FDP), including yogurts, provide calcium, phosphorus, and proteins together with prebiotics and probiotics, all being potentially beneficial for bone. In this prospective cohort study, we investigated whether FDP, milk, or ripened cheese consumptions influence age-related changes of bone mineral density (BMD) and microstructure.

METHODS

Dietary intakes were assessed at baseline and after 3.0 ± 0.5 years with a food frequency questionnaire in 482 postmenopausal women enrolled in the Geneva Retirees Cohort. Cortical (Ct) and trabecular (Tb) volumetric (v) BMD and microstructure at the distal radius and tibia were assessed by high-resolution peripheral quantitative computerized tomography, in addition to areal (a) BMD and body composition by dual-energy X-ray absorptiometry, at the same time points.

RESULTS

At baseline, FDP consumers had lower abdominal fat mass and larger bone size at the radius and tibia. Parathyroid hormone and β-carboxyterminal cross-linked telopeptide of type I collagen levels were inversely correlated with FDP consumption. In the longitudinal analysis, FDP consumption (mean of the two assessments) was associated with attenuated loss of radius total vBMD and of Ct vBMD, area, and thickness. There was no difference in aBMD and at the tibia. These associations were independent of total energy, calcium, or protein intakes. For other dairy products categories, only milk consumption was associated with lower decrease of aBMD and of failure load at the radius.

CONCLUSION

In this prospective cohort of healthy postmenopausal women, age-related Ct bone loss was attenuated at non-bearing bone sites in FDP consumers, not in milk or ripened cheese consumers, independently of total energy, calcium, or protein intakes.

STUDY REGISTRATION

ISRCTN11865958 ( http://www.isrctn.com ).