Nutritional support in bone infections: mechanisms, strategies, and clinical practice

Bone infections, including osteomyelitis and periprosthetic joint infection (PJI), are characterized by prolonged treatment, high recurrence, and functional impairment. Persistent inflammation induces hypercatabolism, negative nitrogen balance, and micronutrient depletion, impairing immune defense and bone repair. Systematic nutritional assessment remains insufficient. This review elucidates metabolic mechanisms under infectious stress, evaluates macronutrients, micronutrients, and immunomodulatory nutrients in infection control and bone regeneration, and proposes a clinical nutritional management framework.

A structured literature search was conducted in PubMed, Web of Science, and CNKI from January 2020 to April 2026 to inform this narrative review. Studies on metabolic profiles, nutritional interventions, or nutritional status-outcome associations in osteomyelitis or PJI were included. Data were synthesized across five dimensions: molecular mechanisms, macronutrient therapy, micronutrient functions, immunonutrition, and implementation pathways, with evidence graded by OCEBM levels.

TNF-α and IL-6 drive muscle degradation via ubiquitin-proteasome activation and mTORC1 suppression, causing negative nitrogen balance; zinc, selenium, and 25-hydroxyvitamin D are depleted. Nutritional risk markers (albumin ≤ 3.5 g/dl and/or lymphocytes ≤ 1.5 × 10³/μl) are associated with 2--4-fold higher risks of postoperative infection, wound dehiscence, and sepsis, and increased 2-year osteomyelitis risk (RR = 2.55). Protein (1.5-2.0 g/kg/d) and energy (25-35 kcal/kg/d) correct nitrogen balance and support immunity and bone repair. Vitamin D induces cathelicidin via VDR, exerting mineralization and anti-infection effects; zinc/selenium alleviate oxidative damage; omega-3 PUFAs provide anti-inflammatory effects. Probiotics show gut-bone axis potential with limited evidence. High-quality RCTs for bone infections are lacking; most recommendations derive from observational studies (evidence levels C-D).

Nutritional support should be elevated to core status. We recommend routine albumin, prealbumin, and lymphocyte screening, and a "screening → assessment → stratified intervention → dynamic monitoring" pathway. Enteral nutrition is preferred perioperatively, with 1.5-2.0 g/kg/d protein and 25-35 kcal/kg/d energy, plus individualized correction of vitamin D, zinc, and selenium deficiencies. Multicenter RCTs are needed to validate immunonutrient efficacy and advance precision nutrition via metabolomics and gut-bone axis mechanisms.