In my book, The Whole-Body Approach to Osteoporosis, I write about the importance of gut health when treating osteoporosis. An unhealthy digestive tract can not only interfere with optimal nutrient absorption but it disrupts the immune system and can lead to chronic systemic inflammation. As with the loss of estrogen at menopause, another common cause of osteoporosis is when the immune system gets out of balance (especially in postmenopausal women). Since 70% of the immune system is housed in the gut, keeping it healthy is critical for skeletal health. In a study published recently in The Journal of Clinical Investigation, researchers (Jau-Yi Li et al) working with mice reaffirm this premise and suggest that giving the mice probiotics improved the immune response and improved bone density. In this blog, I would like to help readers better understand how ahealthy gut keeps chronic systemic inflammation at bay, and why it is so important to keepinflammation to a minimum if you want healthy bones.
The gastrointestinal tract is home to literally billions of bugs. Some good...some not so good. When the gut is over run by the not so good ones, (often due to a poor diet, allergies to foods and/or frequent use of antibiotics)it can be damaged and begin to leak. A chronically inflamed digestive tract causes gaps to form through which partially digested food particles and microbes can pass. Now, instead of being a protective barrier, this "leaky gut" becomes a portal to ill health. The particulate and microbial toxins that filter through these newly opened gaps set off reactions, which are a constant source of inflammation that insidiously permeate the entire body. This "leaking gut syndrome" or intestinal dysbiosis not only causes a chronic inflammatory reaction and a disruption of proper immune function in the person but when the gut is damaged it can no longer absorb nutrients effectively. So we NEED "good" bacteria to thrive in the gut. When healthy microbiota predominate in the gastrointestinal tract we are much healthier and so are our bones.
Our immune system and bone cells use the same signaling molecules (cytokines) to relay messages. When the immune system is out of balance it sends out way too many abnormal signaling molecules and the bone cells, especially the osteoclasts (the cells that break down bone), "hear" these abnormal signals and become hyper aggressive, eating up excessive amounts of bone. In chronic systemic inflammation, a condition I talk a lot about in my book, the "out of wack" immune system ends up being the cause of excessive bone loss. With too much inflammation in the body the osteoclasts become turned on ALL the time and the result is bone loss...osteoporosis. People often think that the most important thing they can do for osteoporosis is to take supplemental calcium. Yes, calcium is important but it isn't the whole story. We need to take in approximately 1,200 mg/day which is best achieved through a combination of dietary and supplemental sources. But we also need to make sure we get enough magnesium and vitamins D and K. AND we also mustmake sure our gut and immune systems are functioning optimally. Having all the nutrients available won't help much if the gut can't absorb them or if there are so many inflammatory cytokines circulating in the blood that the osteoclasts just destroy all the bone that is being made. When we give the body the minerals and vitamins it needs, PLUS have a healthy gut and immune system...then better bones will follow. Take out just one of those from the equation and the whole system falls apart.
Postmenopausal osteoporosis is typically the result of two things: 1) the loss of estrogen production from the ovaries, and 2) chronic systemic inflammation. Often, these go together as estrogen helps to reduce inflammation. In the published study using mice, researchers found that with the loss of estrogen there was an increase in ‘gut leakage’ and the subsequent inflammation resulted in increased osteoclastic or bone resorbing activity. After giving the mice probiotics, there was improvement in the immune response and improved bone density.
Taking oral probiotics and eating fermented or cultured foods such as yogurt, kefir, sauerkraut, and miso encourages healthy gut microbiota which in turn helps gut function (as a barrier to pathogens and for improved digestion and absorption of nutrients) and regulation of the body's immune system. The bottom line from this study is that the use of probiotics has potential in the treatment of postmenopausal osteoporosis.
Jau-Yi Li, et al. Sex steroid deficiency-associated bone loss is microbiota dependent and prevented by probiotics. The Journal of Clinical Investigations.2016;10.1172/JCI86062.