I am by academic training a mathematician and accustomed to working logically after axioms to derive theorems. That same mind is applied to Chronic Fatigue Syndrome and autoimmune conditions. The axioms or facts, are actual PubMed studies, ideally with real CFS patients. PubMed studies appear to be full of contradictory results for many simple models, yet, I believe that there appears to be a model that appears in full agreement with almost all of the studies.
Note: “Effort Syndrome” appears to be an old name for CFS in some circles,s ee [Why did the entity of effort syndrome disappear] 1997.
This is a statement of what my model is, which will revised(typically tuned) as more facts come:
CFS (and likely IBS and FM) is a case of mild to severe Lactic Acidosis. Lactic acid is typically produced exercising.
- Loss of capacity to recover from acidosis on repeat exercise in chronic fatigue syndrome: a case-control study.
- Increased d-lactic Acid intestinal bacteria in patients with chronic fatigue syndrome.  [Full text]
- “CFS simulations exhibited an increased acidosis and lactate accumulation consistent with experimental observations.” 
- Is chronic fatigue syndrome synonymous with effort syndrome? 
The associated change of pH has been attempted with various breathing techniques (I did Hale’s breathing during one onset of CFS, it was popular for a while) with some reduction of symptoms. By altering of pH alone by breathing is unlikely to address the root cause.
- Hyperventilation and chronic fatigue syndrome. 
- The grey area of effort syndrome and hyperventilation: from Thomas Lewis to today. 
The cause of this lactic acidosis appears to be a shift of gut bacteria   2001] (see my earlier posts for more references). Gut bacteria is well known to shift due to stress, viral infections, bacterial infections, and even immunizations. In general, the shift returns to normal in > 99% of the cases, but 0.1 – 5.0% do not within 6 months (depending on infections), with roughly 50% of these returning in the next 6 months (with decreasing odds after that). The low incidence of the gut bacteria being stuck in a dysfunction often falls in the experimental error rate of studies and thus “no evidence”.
Lab results: With a shift of bacteria, the ability for bacteria to extract and process food is altered. In short, increases and decreases of amino acids, vitamins, minerals can all be explained by this — including contradictory results because the shift of bacteria will not be identical for all CFS patients.
Treatment of lactic acidosis
This is where the pain begins, a successful treatment is described in this pubmed article , unfortunately the probiotics described are not available in the US. Additionally, the high dosages of antibiotics are unlikely to be acceptable to MDs for a CFS diagnosis.
- Fasting reduces the food to the bacteria, and can improve symptoms temporarily 
A better understanding of lactic-acidosis can be obtained here .
- “Type A lactic acidosis—due to hypoperfusion and hypoxia—occurs when there is a mismatch between oxygen delivery and consumption, with resultant anaerobic glycolysis.”
A significant (but not 100%) remission rate has been reported using antibiotic regimes (Prof. Garth Nicolson, Cecile Jadin MD, Phillipe Bottero, MD … see here. I did notes up on some of them a few years ago), with those regimes that use multiple antibiotics in rotation having the best success rates. Everyone knows that “antibiotics kills gut bacteria” — more accurately, “antibiotics kills selected gut bacteria strains”. These corollary are also very true:
- “Many herbs and spices kills selected gut bacteria strains”.
- “All probiotics kills selected gut bacteria strains”.
- “Many antivirals kills selected gut bacteria strains”.
The challenge is that you want the right ones to be killed. This typically means killing and then repopulating with suitable replacements who will hopefully become sufficiently established to kill off the bad ones.
A: In general, all lactobacillii produce lactic acids (with exception for a few strains), lactic acidosis is TOO MUCH lactic acid. Do you really want to compound the problem. I remember reading a conference paper where one of the CFS MDs committed heresy to the alternative medicine principles and stated “I have not seen any benefits to any CFS patients from taking [common] probiotics”.
There are probiotics on the market that do not contain any Lactobacilli — those are what you need to seek out. My own preferences (and documented to help) are:
Killing with spices and herbs: See this earlier post for a starting point.