NEW DELHI: A healthy gut may be far more important for women’s bone health than previously believed. New research conducted by AIIMS has uncovered a critical immune mechanism linking gut bacteria to bone loss in postmenopausal women, raising the possibility of preventing osteoporosis through safer, non-hormonal approaches such as probiotics.For decades, osteoporosis was largely seen as a consequence of ageing and declining oestrogen levels. Scientists now say the disease is also driven by immune imbalance — a concept termed Immunoporosis by Dr Rupesh K Srivastava, Additional Professor in Translational Immunology, Osteoimmunology and Immunoporosis Lab, an ICMR-collaborative centre of excellence in bone health.The latest study shows that oestrogen deficiency after menopause triggers chronic inflammation, which disrupts immune cells responsible for maintaining bone strength. At the centre of this process are regulatory T cells, or Tregs — immune cells that normally help keep inflammation in check. Researchers found that menopause upsets the balance between different Treg populations, particularly those generated in peripheral tissues such as the gut. As this balance collapses, protective Tregs are diverted towards becoming inflammatory Th17 cells, which actively promote bone breakdown. This immune shift, Srivastava says, accelerates bone loss and plays a pivotal role in postmenopausal osteoporosis. Crucially, the study identifies the gut as the primary site where this damage unfolds. The breakthrough came when researchers tested the effect of Lactobacillus acidophilus, a commonly used probiotic. Supplementation with the beneficial bacteria restored immune balance in the gut, reversing the rise in Th17 cells and stabilising protective Tregs. This effect was driven by butyrate, a gut-derived compound known for its anti-inflammatory properties.Even more striking, immune cells “primed” by butyrate showed a significantly reduced ability to activate osteoclasts — the cells responsible for bone erosion — directly linking gut immunity to bone preservation. Researchers say this is the first study to clearly identify a gut-based immune pathway driving postmenopausal osteoporosis. The findings reinforce growing evidence that osteoporosis is not merely a bone disorder but a systemic immune condition influenced by gut health.With long-term safety concerns surrounding many osteoporosis drugs, experts believe the discovery could reshape future treatment strategies. Probiotics and other immune-modulating therapies may eventually complement — or in some cases reduce reliance on — conventional medications, offering women a safer way to protect bone health after menopause. The study adds to mounting scientific consensus: caring for the gut may be key to safeguarding skeletal health.
