A reader forwarded to me a PubMed article about bicarbonate (for example, sodium bicarbonate aka baking soda)
“E. coli requires a supply of bicarbonate/CO2 as a metabolic substrate during normal growth. It is needed not only for biosynthesis of various small molecules but also for fatty acid biosynthesis and in central metabolism. The small molecules, which include arginine, pyrimidines, and purines, can be provided as supplements and, interestingly, certain mutants limited in the production of these nutrients can be suppressed with increased levels of CO2 (8). However, the need for CO2 in central metabolism cannot be replaced with supplements. The only known supply pathway for bicarbonate is via the hydration of CO2.” 
This relates to two separate items which have been reported on CFS groups to help:
- Various breathing techniques which increases CO2 levels, and also believed to change pH (acidity of the blood)
- The use of sodium bicarbonate (baking soda) – which some take for acid stomach.
FYI: “in DNA, the purines adenine (A) and guanine (G) pair up with the pyrimidines thymine (T) and cytosine (C), respectively.” [Wikipedia]
We do not know precisely why CFS patients have a massive drop of the E.Coli population. The initial speculation would be toxins produced by bad bacteria. The alternative explanation is that they are starved by changes caused by other bacteria. For example arginine:
- During onsets, I found an urge to eat peanut butter as cited in my 2013 post, a source rich in arginine.
- “Avoid arginine” is a frequent alternative recommendation(because it may encourage the herpes virus) – possibly making CFS worst.
- “humans, develop L-arginine deficiency, which is associated with intestinal mastocytosis, elevated levels of histamine, and enhanced intestinal permeability.”  from my 2015 post on histamines
- “Patients with PVFS(i.e. CFS) had significantly low baseline arginine-vasopressin levels when compared with healthy subjects.” 
- I could not find any studies on the impact of arginine supplementation on CFS/IBS/fibromyalgia.
You may wish to also read my earlier post on feeding E.Coli.
Baking Soda – Sodium Bicarbonate
- “If used in excessive amounts, baking soda has the potential to cause a variety of serious metabolic abnormalities. We believe this is the first reported case of hemorrhagic encephalopathy induced by baking soda ingestion.” 
- “…IC/BPS and common comorbidities (irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, neuropathic pain, vulvodynia, and headache) Current questionnaire-based data suggests…calcium glycerophosphate and sodium bicarbonate tend to improve symptoms.” 
- “Sodium bicarbonate [SB] supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤ 0.001); absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05)”
- “Sodium bicarbonate supplementation increased (P < 0.05) the final pH levels and concentrations of total volatile fatty acids and LPS, as well as the proportions of acetate, propionate, isobutyrate, isovalerate and valerate, and it decreased (P < 0.05) the proportion of butyrate and the levels of lactic acid, methylamine, tryptamine, tyramine, histamine and putrescine compared with the control…. increased (P < 0.05) the bacterial diversity index compared with the control…. also decreased (P < 0.05) the relative abundance of Streptococcus and Butyrivibrio and increased (P < 0.05) the proportions of Ruminococcus, Succinivibrio and Prevotella.” 
Supplementation with baking soda appears to be a rational action regardless of whether or not you have acid reflux. The rationale is:
- it shifts pH which means that it will impact the microbiome
- it improves symptoms
- it reduces histamine (a problem in a subset of CFS patients)
- Taking with L-arginine, would also be rational
- it reduces lactic acid (a problem for a major subset of CFS patients)
- it feeds E.Coli
Note: there have been no explicit studies reported on PubMed on the use of arginine or baking soda for CFS / fibromyalgia / Irritable Bowel Syndrome. There is a positive subjective study for baking soda with a co-morbid condition.