Hi Folks,
Just thought I'd add this to the posts, if it is of interest.
Many of you will know of the KDM/Sheedy paper which found an increase of d-lactic acid producing bacteria in the stools of CFS patient. D-lactic acid is usually only seen in short bowel patients, and is not commonly investigated outside of this. I wonder whether it can be seen in patients with with CFS as SIBO, where there is an overgrowth of bacteria in the small bowel, if this overgrowth was of a type which produced d-lactate, it might lead to similar symptoms. Given the stomach involvement in many CFS patients, it might be relevant. Treatment of d-lactic acid is antibiotics, however they need to be matched up with the bacteria, as some bacteria are resistant. Sodium bicarbonate is sometimes given, and oral feeding is suspended as part of the treatment, which might explain the easing of symptoms in CFS patients, when they do not eat, and sometimes a low carb diet is put in place.
Here is the paper, for people who have not already seen it.
http://www.cfids-cab.org/rc/Sheedy.pdf
The study above is being researched further in Australia, where a new study will measure d-lactate in stool, urine and blood samples of CFS patients, and compared to samples of healthy controls, to see whether CFS patients have a higher level of d-lactic acid. Here is their application, together with brief discussion.
http://sacfs.asn.au/download/Lactic%...pplication.pdf
As part of this study a questionnaire was given to the CFS patients, regarding lactic acid symptoms, you can find this here:
http://www.sacfs.asn.au/download/Lac...stionnaire.pdf
I wanted to also point out that research has also been carried out into lactate levels in the brain fluid of CFS patients, and was found to be higher. D-lactic acid crosses the bbb, and causes neurological changes that are said to be strikingly similar to CFS symptoms. Here is part of a thread here at PR that I found recently regarding this research.
Dr. Dikoma Shungu "will build on a preliminary study showing that brain fluid of CFS patients contains significantly elevated levels of lactic acid, or lactate, a substance important in metabolism." "If this study is successful, brain lactate levels could provide an objective diagnostic biomarker for CFS and evidence of a metabolic problem in these patients."
His 2009 study, also funded by the CAA, "Ventricular cerebrospinal fluid lactate is increased in chronic fatigue syndrome compared with generalized anxiety disorder: an in vivo 3.0 T (1)H MRS imaging study." Mathew SJ, Mao X, Keegan KA, Levine SM, Smith EL, Heier LA, Otcheretko V, Coplan JD, Shungu DC was followed in 2010 by "Increased ventricular lactate in chronic fatigue syndrome measured by 1H MRS imaging at 3.0 T. II: comparison with major depressive disorder." Murrough JW, Mao X, Collins KA, Kelly C, Andrade G, Nestadt P, Levine SM, Mathew SJ, Shungu DC.
The abstract says, "Ventricular CSF lactate was significantly elevated in CFS compared to healthy volunteers, replicating the major result of our previous study." and concludes, "Future (1)H MRS studies with larger sample sizes and well-characterized populations will be necessary to further clarify the sensitivity and specificity of neurometabolic abnormalities in CFS and MDD."
D-lactic acidosis is a condition that is almost exclusively taught to gastroenterologist's, however they only see it in patients with a shortened bowel, as these patients cannot fully digest carbohydrates due to surgery or disease of the small intestine. It is caused by d-lactic acid producing bacteria fermenting carbohydrates, which changes the pH of the bowel, favouring acid loving bacteria at the expense of other gut bacteria. D-lactic acidosis can present without a change in the anion gap, making it invisible in blood tests, unless specifically testing for. See below:
"There are two major ways acidosis is defined from routine laboratory data. First, organic acids may be added to the body so quickly that both the H and the anion are retained; this results in metabolic acidosis and an elevated value for the plasma anion gap.
Second, metabolic acidosis may be present without a rise in the plasma anion gap. In this latter setting, either the D-lactate anion was retained in the lumen of the GI tract (with the H being absorbed or titrated by bicarbonate in the lumen of the GI tract), or it was excreted in the urine, but in either case, the cation lost with it was Na and/or K ion (not a H or NH4 ion). This latter type of metabolic acidosis is akin to the over-production of hippuric acid in glue sniffers. Since D-lactate anions are reabsorbed by the kidney much less readily than is L-lactate, as time progresses, the anion gap may decline without resulting in a rise in the plasma bicarbonate concentration-that is, D-Iactate is excreted as its Na or K salt. Hence there are a number of mechanisms that may contribute to the presentation whereby the rise in the plasma anion gap might not match the fall in the plasma bicarbonate concentration. Not only might this lead to a diagnostic problem, it has implications for therapy because, once the organic anions are excreted as their Na or salts, these anions are no longer available for metabolism to regenerate bicarbonate, and the patient might have developed a deficit of Na and/or K4."
Many Path labs are not usually able to test for d-lactic acid, as they do not have the d-lactate assy kit required and would have to ship a test in, although I believe d-lactic acid can also be screened for in urine tests, where a high total lactate result would suggest further testing for d-lactic acid. However I should also point out that if anyone is interested in testing for d-lactate, they should do so in the late afternoon, as d-lactate has a circadian rythm, and builds up during the day, after each meal that contains carbohydrates, reaching a peak in early evening. It might not show up in early morning urine tests, see the paper below.
http://www.clinchem.org/cgi/reprint/41/1/107.pdf
Here are some papers regarding d-lactic acidosis, however they are all in patients with a shortened bowel. The first one has a good graph of symptoms, which are very similar to some CFS symptoms. I would imagine that in a short bowel patient, their symptoms would be very severe, more so than in CFS.
http://hkjpaed.org/details.asp?id=577&show=1234
This paper talks of the possibility that d-lactic acidosis may occur in a human with a complete bowel, when they were investigating d-lactic acidosis in a calf model. "The mechanism is likely similar to that documented for D-lactic acidosis in SBS in humans except the etiology of the malabsorption is viral infectioninduced villous atrophy rather than surgical removal of the small intestine."
It goes on to say
"There is a possibility, although it has not been described, that a similar scenario could occur in diarrheic monogastrics, including humans"
http://jn.nutrition.org/content/135/7/1619.full
I wonder whether people are finding that their CFS symptoms are improving when they do not eat because they have a small bowel bacterial overgrowth of d-lactic acid producing bacteria as in the first study, and their improvement is due to the bacteria being starved out, reducing CFS symptoms.
Best Wishes
Glynis x