Evaluation of the efficacy and safety of probiotics, traditional Chinese medicine and chelating agent in the treatment of occupational heavy metal poisoning—Randomized, Controlled, Multicenter Clinical Trial

INTERVENTION: Probiotic + Chelating Agent Treatment Group:Probiotic detoxification agent: 1 packet (containing probiotics and prebiotics), twice daily, oral; combined with conventional chelation therapy (CaNa2EDTA for lead poisoning, Na‐DMPS for arsenic/mercury/cadmium poisoning), total of 2 courses, one course lasting 1 week (treatment + interval period).;Traditional Chinese Medicine Formula + Chelating Agent Treatment Group:First course: Traditional Chinese medicine formula treatment for 3‐5 days, twice daily, oral, combined with conventional chelation therapy, total of 2 courses, one course lasting 1 week (treatment + interval period). Core formula: Poria cocos 15g, Astragalus membranaceus 15g, Poria 12g, Dioscorea opposita 15g, Oldenlandia diffusa 20g, Lycium barbarum 10g, Polyporus umbellatus 10g, Salvia miltiorrhiza 10g, Glycyrrhiza 6g (additions: add Chicken Blood Vine 30g, Ligusticum chuanxiong 10g, Angelica sinensis 10g for limb numbness; add Atractylodes macrocephala 12g, Codonopsis pilosula 15g for obvious fatigue; add Eucommia ulmoides 10g, Achyranthes bidentata 10g for waist and knee soreness; add Rheum palmatum 10g, Mirabilis 4g, Magnolia officinalis 10g for constipation and abdominal pain; add Hawthorn 10g, Barley sprout 10g, Fermented wheat bran 10g for poor appetite).;Chelating Agent Treatment Group (Control Group):Conventional chelation therapy only, total of 2 courses, one course lasting 1 week (treatment + interval period). CaNa2EDTA for lead poisoning, Na‐DMPS for arsenic/mercury/cadmium poisoning. Specific administration: CaNa2EDTA 1000mg/m2/day, dissolved in 5% glucose solution, slowly intravenous drip over 4‐6 hours, once daily, one course lasting 3‐4 days; Na‐DMPS 2.5‐5mg/kg per dose, dissolved in 5% glucose solution, intravenous drip, once daily, one course CONDITION: heavy metal poisoning PRIMARY OUTCOME: Blood and urine heavy metal load;Alpha/beta diversity index of gut microbiota; SECONDARY OUTCOME: Clinical Symptoms and Signs ;Traditional Chinese Medicine Syndrome Score ;Organ function: Complete blood count, liver and kidney function tests;Health‐related Quality of Life Score; INCLUSION CRITERIA: 1. Age: 18‐60 years old, occupational exposure workers. 2. Occupational exposure history: Engaged in heavy metal mining or metallurgical‐related industries, with exposure to lead >=3 months, mercury >=6 months, arsenic >=3 months, and cadmium >=1 year, and no withdrawal from the exposure environment within the past 3 months. 3. Patients who meet the criteria for chronic poisoning according to national occupational health standards such as the Diagnostic Criteria for Occupational Lead and Inorganic Compound Poisoning (GBZ 37‐2024), Diagnostic Criteria for Occupational Mercury Poisoning (GBZ 89‐2024), Diagnostic Criteria for Occupational Arsenic Poisoning (GBZ 83‐2025), and Diagnostic Criteria for Occupational Cadmium Poisoning (GBZ 17‐2015). 4. Heavy metal standards for human biological samples: 1) Blood lead level >=600 µg/L or urinary lead level >=120 µg/L; 2) Urinary mercury >=20 µmol/mol creatinine (>=35 µg/g creatinine); 3) Urinary arsenic >=32