PLMI Blog

Nutrition provides the foundation for healthy bones through a number of interconnected mechanisms, and an emerging body of research highlights the microbiome specifically (1). Novel findings underscore the role nutrition has in modulating this vast ecosystem and thereby influencing bone metabolism and absorption of vital nutrients for bone health.

The Intricacies of Bone Health

Bone health is intricately tied to various factors, including genetics, sleep, stress, physical activity, and nutrition (2). Osteoporosis is the most common metabolic bone disease in the US and globally (3). It is characterized by alterations in bone homeostasis, resulting from an imbalance between osteoclastic bone resorption and osteoblastic bone formation (4). Deterioration of bone mass and skeletal microarchitecture—key determinants of bone strength and overall health—are often hallmarks of this condition, increasing susceptibility to fractures (5).

Osteoporosis is often associated with aging and hormonal alterations from marked reductions in estrogen in postmenopausal women, as well as low levels of testosterone in men (6). It can also be related to inadequate nutrition, lack of exercise, excessive alcohol consumption, and smoking (7- 8).

The Role of the Gut Microbiome

While a nutrient dense diet is foundational for bone health, the body can only assimilate these vital nutrients provided digestion and absorption are adequate. The gut microbiome is a primary modulator of these processes, emerging as a key player in bone health, and is strongly influenced by diet, among other factors. Emerging research reveals that the gut microbiome is a central contributor to regulating bone metabolism (9). This complex ecosystem supports bone health in various ways.

The gut microbiome governs an array of biological processes, including metabolism, immune function, hormonal balance, and through these interconnected pathways, bone health. Imbalances in the microbiome (dysbiosis), impeded gut barrier function (intestinal permeability), and systemic inflammation can all wreak havoc on the regulatory mechanisms necessary for bone health. Aside from nutrient absorption, the gut microbiome plays roles in bone remodeling and metabolism, as gut microbiota metabolites support the modulation of bone turnover (7). Alterations in microbiota composition have been found to contribute to bone loss. In fact, dysbiosis has been implicated in the development of osteoporosis (10).

Disruptions to the gut microbiome can also lead to systemic inflammation and immune dysregulation, both of which contribute to the disruption of bone remodeling. Dysbiosis can further trigger an inflammatory response that increases the activity of osteoclasts, often resulting in bone resorption and a reduction in bone density (11). In contrast, a balanced and diverse microbiome may help maintain bone health by supporting immune function and modulating bone turnover.

Research shows that the gut microbiome influences bone metabolism, including formation and resorption, as well as skeletal balance, by modulating host metabolism, immune functions, and hormone secretion (12). The synthesis of short-chain fatty acids (SCFAs) from the fermentation of dietary fibers by gut microbiota has been linked to the modulation of bone turnover. SCFAs can enter the bloodstream, affecting distant organs, including the bones, by influencing the differentiation and activity of osteoclasts (bone-resorbing cells) and osteoblasts (bone-forming cells). Through these mechanisms, SCFAs have important implications in the modulation of bone cell metabolism (13).

The gut microbiome also has a significant influence on the immune system and, therefore, bone turnover and density, further impacting bone health (11).

The Gut-Bone Axis

A growing body of research highlights the gut microbiome as being a contributing factor to osteoporosis and impeded bone health (7). An intricate relationship between the gut microbiota and bone homeostasis has been established, involving host-microbiota crosstalk. The gut-bone axis refers to this communication between the gut and bone, where gut-derived hormones influence both bone formation and resorption (14).

Gut hormones that are secreted by enteroendocrine cells following nutrient ingestion play a critical role in modulating these metabolic processes. Several of these hormones are also involved in supporting bone health by regulating bone remodeling and are suggested to be involved in this crosstalk in governing bone health (14).

The Influence of Nutrients on the Gut Microbiome and Bone Health

Nutrition has various impacts on the microbiome and, thereby, the influence of bone metabolism through interconnected mechanisms.

Vitamin D and Calcium – Vitamin D and calcium are two of the most well-known nutrients for bone health. They are crucial for maintaining bone density and preventing bone loss, especially in individuals at risk for osteoporosis. However, recent research suggests that the efficacy of these nutrients is influenced by the gut microbiome.

Vitamin D not only facilitates calcium absorption in the intestines but also plays a role in modulating the gut microbiome. Studies have shown that vitamin D deficiency is associated with dysbiosis, which may contribute to bone loss and other metabolic disorders (15). Conversely, sufficient levels of vitamin D help maintain a healthy gut composition, which in turn supports optimal calcium absorption and bone metabolism.

Similarly, calcium intake is crucial for bone health. However, its absorption is influenced by the gut microbiome. Beneficial microbiota play roles in the degradation and fermentation of dietary fibers, enhancing calcium bioavailability (12). A healthy gut microbiome optimizes calcium absorption while modulating the synthesis of gut serotonin, which can interact with bone cells and has been implicated in functioning as a bone mass modulator. It can improve bone health by increasing calcium absorption (11). Rich sources of calcium include leafy greens and chia seeds.

Vitamin K – Vitamin K plays a vital role in bone health by promoting the activity of osteocalcin, a protein that is essential for bone mineralization. Vitamin K1, found primarily in green leafy vegetables, and vitamin K2, found in fermented foods like natto and dairy products, both support bone health but have distinctive roles. Notably, Vitamin K2 has been shown to influence bone metabolism by activating osteocalcin and reducing bone resorption (15).

Research suggests that vitamin K’s effects on bone health may be modulated by the gut microbiome. Vitamin K2 is synthesized by gut microbiota, further underscoring the role of a healthy and diverse microbiome in contributing to adequate levels of this nutrient that is vital for bone health (16). Thus, the interplay between diet, gut microbiota, and vitamin K is significant in modulating optimal bone health and preventing osteoporosis.

Supporting Gut Health, Immune Function, & Reduced Inflammation

Inflammation plays a central role in the development of osteoporosis. Chronic low-grade inflammation, often resulting from dysbiosis and oxidative stress, can accelerate bone loss by enhancing osteoclast activity and inhibiting osteoblast function. The gut microbiome is intricately involved in modulating appropriate immune responses and inflammation. Particular strains of beneficial microbiota produce anti-inflammatory metabolites such as SCFAs, which can suppress the production of pro-inflammatory cytokines and therefore reduce systemic inflammation (13).

A Mediterranean diet, abundant in an array of colorful plants, fiber, polyphenols, and omega-3 fatty acids, has been shown to support the growth of beneficial gut microbiota that produce anti-inflammatory metabolites (14). Magnesium is also important in modulating inflammation while supporting gut microbiome and bone health (1). Nutrients that support immune function are also significant, including sources of Vitamins A, C, and D, zinc, and selenium. Sufficient amounts of quality proteins are also vital for supporting bone health.

Consuming nutrient-dense foods that support the gut microbiome, bone, and immune health—while reducing inflammation—can contribute to improved bone metabolism. Whereas, a diet high in processed foods, refined sugars, and inflammatory fats can promote the growth of pathogenic microbiota that contribute to inflammation and bone loss (7).

The Potential of Synbiotic Therapy

Given the strong connection between gut health and bone metabolism, a growing body of research is in support of synbiotic therapy—the combination of prebiotics and probiotics—as a therapeutic approach for osteoporosis. Prebiotics, non-digestible food components that promote the growth of beneficial microbiota, and probiotics, live microorganisms that confer various health benefits, may help restore a healthy and diverse gut microbiome and thereby improve bone health.

Recent studies suggest that probiotics and prebiotics can influence bone metabolism by modulating immune function, reducing inflammation, and enhancing the production of beneficial metabolites, such as SCFAs (17). Notably, specific strains of probiotics have been shown to stimulate the activity of osteoblasts and inhibit osteoclasts, thereby promoting bone formation and reducing bone resorption (15). Clinical trials are ongoing to assess the efficacy of synbiotic therapies in mitigating osteoporosis, and early results are promising relative to enriching metabolic pathways for Vitamin K2 synthesis (18).

Lifestyle Approaches

Nutrition, in conjunction with regular exercise and healthy lifestyle choices, provides a comprehensive approach to modulating and supporting bone health. Sleep, physical activity, and reducing stress are significant for maintaining healthy bones. Resistance training has been shown to increase bone density and improve bone strength (19). Adequate sleep is vital for promoting bone health, as it supports the body’s ability to repair and regenerate bone tissue (20). Sleep is also imperative for governing the balance of all of the body’s systems—particularly the microbiome—a hallmark of bone health. Maintaining a consistent sleep schedule that promotes circadian rhythm balance further supports bone health, as supported by a recent study published in Metabolism (20).

Mitigating stress may help prevent the adverse effects of chronic stress on bone health. In fact, a recent 2021 study published in The International Journal of Medical Sciences demonstrates that psychological stress may be responsible for epigenetic modulation of skeletal development, further underscoring the role stress has in impeding bone health. The active form of vitamin D from the sun is also significant for bone health, as well as in modulating gut and immune functions (21).

The Gut Microbiome: A Key Player in Bone Health

The emerging research on the gut microbiome’s influence on bone health is reshaping our understanding of bone metabolism and overall bone health. A healthy gut microbiome plays a crucial role in maintaining bone homeostasis by enhancing nutrient absorption, modulating metabolism, immune function, hormone secretion, and bone cell activity.

By combining evidenced-based nutrition, synbiotic therapies to enrich gut health, and lifestyle factors, we can optimize bone health and mitigate the risk of osteoporosis in aging.

Join us for this webinar, Enhancing Bone Health: Exploring the Role of Synbiotic Therapy, occurring on January 14th from 5-7 pm, where experts Susan Bukata, MD, Eric Schott, PhD, and Jeffrey Bland, PhD dive further into this compelling topic, providing novel insights into synbiotic therapies for improving comprehensive bone health.

References:

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