The role of gut bacteria in illness and health is all the rage, and this new study suggests they may play a role in CFS. Bifidobacterium infantis 35624 modulates host inflammatory processes beyond the gut (2013, free full text) David Groeger, Liam O’Mahony, Eileen F. Murphy, John F. Bourke, Timothy G. Dinan, Barry Kiely, Fergus Shanahan, * Eamonn M.M. Quigley Abstract: Certain therapeutic microbes, including Bifidobacteria infantis (B. infantis) 35624 exert beneficial immunoregulatory effects by mimicking commensal-immune interactions; however, the value of these effects in patients with non-gastrointestinal inflammatory conditions remains unclear. In this study, we assessed the impact of oral administration of B. infantis 35624, for 6‒8 weeks on inflammatory biomarker and plasma cytokine levels in patients with ulcerative colitis (UC) (n = 22), chronic fatigue syndrome (CFS) (n = 48) and psoriasis (n = 26) in three separate randomized, double-blind, placebo-controlled interventions. Additionally, the effect of B. infantis 35624 on immunological biomarkers in healthy subjects (n = 22) was assessed. Results At baseline, both gastrointestinal (UC) and non-gastrointestinal (CFS and psoriasis) patients had significantly increased plasma levels of C-reactive protein (CRP) and the pro-inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) compared with healthy volunteers. B. infantis 35624 feeding resulted in reduced plasma CRP levels in all three inflammatory disorders compared with placebo. Interestingly, plasma TNF-α was reduced in CFS and psoriasis while IL-6 was reduced in UC and CFS. Furthermore, in healthy subjects, LPS-stimulated TNF-α and IL-6 secretion by peripheral blood mononuclear cells (PBMCs) was significantly reduced in the B. infantis 35624-treated groups compared with placebo following eight weeks of feeding. Conclusion These results demonstrate the ability of this microbe to reduce systemic pro-inflammatory biomarkers in both gastrointestinal and non-gastrointestinal conditions. In conclusion, these data show that the immunomodulatory effects of the microbiota in humans are not limited to the mucosal immune system but extend to the systemic immune system. My comments C-reactive protein is a very general marker of inflammation and doesn't seem to have been studied much in CFS (juding by a quick google). Eg this study found C-reactive protein was higher in CFS than healthy controls, and this study found the same, but also found no difference in C-reactive protein between CFS and chronically fatigued patients. Elsewhere, alex3619 has pointed out that the immune changes didn't correlate with symptom scores. Still, interesting stuff.