Examining clinical similarities between myalgic encephalomyelitis/chronic fatigue syndrome and d-lactic acidosis: a systematic review

Abstract

BackgroundThe pursuit for clarity in diagnostic and treatment pathways for the complex, chronic condition of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) continues. This systematic review raises a novel question to explore possible overlapping aetiology in two distinct conditions. Similar neurocognitive symptoms and evidence of d-lactate producing bacteria in ME/CFS raise questions about shared mechanisms with the acute condition of d-lactic acidosis (d-la).Methods d-la case reports published between 1965 and March 2016 were reviewed for episodes describing both neurological symptoms and high d-lactate levels. Fifty-nine d-la episodes were included in the qualitative synthesis comparing d-la symptoms with ME/CFS diagnostic criteria. A narrative review of d-la mechanisms and relevance for ME/CFS was provided.ResultsThe majority of neurological disturbances reported in d-la episodes overlapped with ME/CFS symptoms. Of these, the most frequently reported d-la symptoms were motor disturbances that appear more prominent during severe presentations of ME/CFS. Both patient groups shared a history of gastrointestinal abnormalities and evidence of bacterial dysbiosis, although only preliminary evidence supported the role of lactate-producing bacteria in ME/CFS.LimitationsInterpretation of results are constrained by both the breadth of symptoms included in ME/CFS diagnostic criteria and the conservative methodology used for d-la symptom classification. Several pathophysiological mechanisms in ME/CFS were not examined.ConclusionsShared symptomatology and underlying microbiota–gut–brain interactions raise the possibility of a continuum of acute (d-la) versus chronic (ME/CFS) presentations related to d-lactate absorption. Measurement of d-lactate in ME/CFS is needed to effectively evaluate whether subclinical d-lactate levels affect neurological symptoms in this clinical population.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-017-1229-1) contains supplementary material, which is available to authorized users.

Open-label pilot for treatment targeting gut dysbiosis in myalgic encephalomyelitis/chronic fatigue syndrome: neuropsychological symptoms and sex comparisons

“…The d -lactate theory has been proposed as a possible mechanism for the neurological disturbances associated with gut dysbiosis in this population [ 23 , 34 , 42 ]. d -Lactic acidosis is an acute metabolic acidosis with associated encephalopathy that is observed in patients with a history of small bowel resections [ 43 ].…”

“…Within ME/CFS, an overgrowth of Streptococcus and Enterococcus species ( d -lactic acid producing bacteria) has been observed in culture-based microbial studies [ 23 ]. This bacterial imbalance, combined with overlapping neurological symptoms and possible mechanisms have contributed to the proposal that subclinical concentrations of d -lactate may play a role in ME/CFS presentations [ 42 ]. To date, measurement of d -lactate concentrations in ME/CFS have not been published.…”

Myalgic encephalomyelitis - enigma at the medicine’s crossroads

“…Clinical pictures of ME/CFS and d-lactic acidosis (d-la) are overlapping and there is evidence of d-lactate-producing bacteria dysbiosis [25]. Both conditions have neurological disturbances caused by microbiota-gut-brain system dysfunction.…”

“…Both conditions have neurological disturbances caused by microbiota-gut-brain system dysfunction. d-lactic acidosis is an acute condition causing encephalopathy while ME/CFS is a chronic state with possible subclinical levels od d-lactate making the two entities possibly the parts of the same continuum [25].…”

“…There are many proposed and studied compounds but with yet uncertain significance. Precise measures of potentially elevated d-lactic acid [25]. Human herpesviruses (HHV-1-8), HHV-4 (Epstein-Barr virus; EBV), HHV-6 (including HHV-6A and HHV-6B), and HHV-7 are associated with ME/CFS, but studies did not show significant differences between patients and healthy controls [27].…”