TNF and irritable bowel syndrome: In two clinical trials, the investigators intervened with FMT in 55 patients with fibromyalgia as well as 40 patients with IBS pain, and the results of the studies demonstrated that FMT significantly reduced pain scores (↓40%) and elevated pain thresholds (↑45%) in patients with fibromyalgia and IBS, accompanied by neurotransmitter improvements (↑28% for 5-HT, ↑31% for GABA) and inflammation suppression (TNF-α ↓36%), with efficacy lasting ≥12 months (3, 12).