Today I came across a new study that stated “To our knowledge, we are the first to test for levels of IL-16 in ME/CFS patients.”[Nov 2015] and found “our work suggests that the clustered reduction of IL-7, IL-16 and Vascular Endothelial Growth Factor A(VEGF-A) may have physiological relevance to ME/CFS disease. This profile is ME/CFS-specific since measurement of the same analytes present in chronic infectious and autoimmune liver diseases, where persistent fatigue is also a major symptom, failed to demonstrate the same changes.”
This new finding presents an opportunity to put my model to the test. Could one or more of these changes be ascribed to changes of the microbiome (gut bacteria) seen in CFS patients?
For IL-16, we find that “Gut BalanceTM, which contains Lactobacillus paracasei subsp paracasei (L. casei 431®), Bifidobacterium animalis ssp lactis (BB-12®), Lactobacillus acidophilus (LA-5®), Lactobacillus rhamnosus (LGG®),… increases in the concentration of serum IL-16″.  CFSers are low in both Lactobacillus and Bifidobacterium and thus would be low in IL-16. This study also found that acacia gum (gum arabic) increases IL-16 more (a good thing), which matches research reported earlier:
- “Ten grams of gum arabic may produce a prebiotic effect in humans by boosting gut populations of specific bacteria”
For IL-7, “Lactobacillus reuteri..modulate human cytokine production (tumor necrosis factor, monocyte chemoattractant protein-1, interleukin [IL]-1β, IL-5, IL-7, IL-12, and IL-13) by myeloid cells”  “probiotic potential of a large number of autochthonous lactic acid bacteria isolated from fruit and vegetables…Stimulation of IL-12, IL-2 and IL-7 was strain dependent” 
For Vascular Endothelial Growth Factor A(VEGF-A), “Lactobacillus rhamnosus GG… significantly stimulated together with the induction of vascular endothelial growth factor (VEGF) expression.” “VEGF expression was significantly increased in rats administered Lactobacillus beverage-A”  Plantaricin A synthesized by Lactobacillus plantarum induces in vitro proliferation and migration of human keratinocytes and increases the expression of TGF-β1, FGF7, VEGF-A and IL-8 genes .
All of the decreases of the above anti-inflammatory interleukins and VEGF-A could be logically ascribed to the low Lactobacillium and Bifidobacterium seen in CFS patients. Gum arabic is re-inforced as a good pre-biotic to help with correcting the gut bacteria (and also increasing IL-16 production, thus reducing symptoms).