In Ian Lipkin et al 2017 study, low Coprococcus Catus was reported (on average). [Index to all posts on Study] comparing all CFS patients against normal controls. As with many families, it is little studied in the past with just 5 PubMed citations despite being discovered in 1974.
- “the capacity to produce propionate or butyrate from hexose sugars resided in different species (C. Caus) 
- “Coprococcus catus, and Streptococcus mitis that were strongly ureolytic on isolation later lost this ability.”  – produces urease.
- “On teat skin… but not in milk”
- “uses lactate …known to be able to switch from butyrate ( butyryl-CoA:acetate CoA-transferase route when grown on fructose) to propionate(acrylate pathway) production on different substrates.” 
- “Next-generation sequencing revealed that obese and non-obese subjects had different gut microbiota compositions and that certain bacterial species were significantly associated with each group… C.Catus ..significantly associated with the obese group: ” 
- “with Preeclampsia ….a reduction in probiotic bacteria Coprococcus catus” 
The chart below shows its relationship to similar bacteria.
To grow more, we need to feed more — and acetate producing bacteria (upstream) are likely desired.
- E.Coli is an acetate producer  and also reported low in CFS
- Bifidobacterium longum subspecies: longum JCM 1217T (BL), infantis 157F (BF), or longum NCC 2705 (BN). are acetate producers  Other bifidobacterium are not.
What is the general impact of acetate?
- Reaches the portal vein and is metabolized in various tissues
- Is a minor energy source for the colon epithelial cells
- Decreases the pH of the colon (which decreases bile salt solubility, increases mineral absorption, decreases ammonia absorption, and inhibits growth of pathogens)
- Has anti-inflammatory effects
- Increases colonic blood flow and oxygen uptake
- Is used by cross-feeding species as a co-substrate to produce butyrate
- Is a substrate for cholesterol and fatty acid biosynthesis in the liver
Is an energy source for muscle and brain tissue
Oh boy! low acetate levels appears to be happening in CFS… and hence the low level of the bacteria consuming it. Two major families producing acetate (E.Coli, Bifido) are also known low, hence this appears to be a downstream cascade.
THIS IS NOT MEDICAL ADVICE — this post is an education summary of what has been reported on PubMed. Always consult with a knowledgeable medical professional before changing diet, supplements and prescription drugs.