Donald Lewis

Dr Donald P. Lewis is a general practitioner specialising in ME/CFS working in Melbourne, Australia. He has been treating patients with ME/CFS, and researching the condition, since 1985.

International Consensus Criteria

Dr Lewis is one of the authors of the 2011 case definition, International Consensus Criteria.

Books

• 2017, Chapter 31 - Sleep, Cognitive and Mood Symptoms in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, in The Handbook of Stress and Health: A Guide to Research and Practice

  "Abstract - Sleep abnormalities, neurocognitive disturbances and comorbid depressive symptoms are some of the particularly debilitating symptoms experienced by patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This complex condition with currently evasive etiology involves a multisystemic symptom presentation that can reflect dysfunction in several organs and biological systems. The microbiota-gut-brain axis provides one possible pathway where dysfunction in communication between enteric microbiota, the gastro-intestinal system, and the brain may precipitate some ME/CFS symptoms. Sleep, neurocognitive and depressive symptoms are examined with recent microbiome research highlighting the potential etiological role of dysfunction in gut-brain communication. Treatment alternatives are reviewed with a focus on addressing underlying pathophysiology and possible causal mechanisms. The burgeoning field of microbiota research across diverse health fields provides an avenue of hope for future therapeutic advances and improved health outcomes for patients with ME/CFS.

Notable Studies

• 2017 - Examining clinical similarities between myalgic encephalomyelitis/chronic fatigue syndrome and d-lactic acidosis: a systematic review

  Abstract - Background: The 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. Results: The 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. Limitations: Interpretation 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. Conclusions: Shared 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.

• 2017 - The association of fecal microbiota and fecal, blood serum and urine metabolites in myalgic encephalomyelitis/chronic fatigue syndrome

  "Abstract - Introduction: The human gut microbiota has the ability to modulate host metabolism. Metabolic profiling of the microbiota and the host biofluids may determine associations significant of a host–microbe relationship. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a long-term disorder of fatigue that is poorly understood, but has been linked to gut problems and altered microbiota. Objectives: Find changes in fecal microbiota and metabolites in ME/CFS and determine their association with blood serum and urine metabolites. Methods: A workflow was developed that correlates microbial counts with fecal, blood serum and urine metabolites quantitated by high-throughput ¹H NMR spectroscopy. The study consists of thirty-four females with ME/CFS (34.9 ± 1.8 SE years old) and twenty-five non-ME/CFS female (33.0 ± 1.6 SE years old). Results: The workflow was validated using the non-ME/CFS cohort where fecal short chain fatty acids (SCFA) were associated with serum and urine metabolites indicative of host metabolism changes enacted by SCFA. In the ME/CFS cohort a decrease in fecal lactate and an increase in fecal butyrate, isovalerate and valerate were observed along with an increase in Clostridium spp. and a decrease in Bacteroides spp. These differences were consistent with an increase in microbial fermentation of fiber and amino acids to produce SCFA in the gut of ME/CFS patients. Decreased fecal amino acids positively correlated with substrates of gluconeogenesis and purine synthesis in the serum of ME/CFS patients. Conclusion: Increased production of SCFA by microbial fermentation in the gut of ME/CFS patients may be associated with deleterious effects on the host energy metabolism

• 2016, Widespread pain and altered renal function in ME/CFS patients

  Abstract - "Background: Widespread pain is noted in many patients with chronic fatigue syndrome (ME/CFS), fibromyalgia and temporomandibular disorders. These conditions usually start as a localized condition and spread to a widespread pain condition with increasing illness duration. Purpose: To aim was to assess the changes in biochemistry associated with pain expression and alterations in renal function. Methods: Forty-seven ME/CFS patients and age/sex-matched controls had a clinical examination, completed questionnaires, standard serum biochemistry, glucose tolerance tests and serum and urine metabolomes in an observational study. Results: Increases in pain distribution were associated with reductions in serum essential amino acids, urea, serum sodium and increases in serum glucose and the 24-hour urine volume; however the biochemistry was different for each pain area. Regression modelling revealed potential acetylation and methylation defects in the pain subjects. Conclusions: These findings confirm and extend our earlier findings. These changes appear consistent with repeated minor inflammatory-mediated alterations in kidney function resulting in essential amino acid deprivation and inhibition of protein synthesis and genetic translation within tissues."

• 2016 - Support for the Microgenderome: Associations in a Human Clinical Population
• 2015 - Sleep quality and the treatment of intestinal microbiota imbalance in Chronic Fatigue Syndrome: A pilot study
• 2015 - Metabolic profiling reveals anomalous energy metabolism and oxidative stress pathways in chronic fatigue syndrome patients
• 2014 - Comorbidity of postural orthostatic tachycardia syndrome and chronic fatigue syndrome in an Australian cohort
• 2009 - Increased d-lactic Acid intestinal bacteria in patients with chronic fatigue syndrome

Clinic location

Dr Lewis founded the CFS Discovery clinic, which is in Donvale, Melbourne.

Talks & interviews

• 2011 - Dr Don Lewis: Latest Understanding of ME/CFS (video)

Online presence

• Website
• PubMed
• Twitter
• Facebook
• YouTube

Learn more

• Wikipedia
• Institution

cognition Thought processes, including attention, reasoning, and memory.

myalgic encephalomyelitis (M.E.) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.

stress Stress can by either physical or psychological, or both. Stress is either 1) a state of emotional or psychological strain or 2) the physical stress (pressure or tension) that a physical object such the human body is placed under, e.g., a stress test is a medical test that monitors the cardiovascular system during strenuous exercise.

etiology The cause of origin, especially of a disease.

microbiome The full collection of microscopic organisms (especially bacteria and fungi) which are present in a particular environment, particularly inside the human body.

microbiome The full collection of microscopic organisms (especially bacteria and fungi) which are present in a particular environment, particularly inside the human body.

etiology The cause of origin, especially of a disease.

serum The clear yellowish fluid that remains from blood plasma after clotting factors have been removed by clot formation. (Blood plasma is simply blood that has had its blood cells removed.)

metabolite A chemical compound produced by, or involved in, metabolism. The term is often used to refer to the degradation products of drugs in the body.

myalgic encephalomyelitis (M.E.) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.

serum The clear yellowish fluid that remains from blood plasma after clotting factors have been removed by clot formation. (Blood plasma is simply blood that has had its blood cells removed.)

renal involving, related to or in the area of the kidneys

tachycardia An unusually rapid heart beat. Can be caused by exercise or illness. A symptom of postural orthostatic tachycardia syndrome (POTS). (Learn more: www.heart.org)

metabolomics The analysis of the chemical metabolism within cells, tissues or organisms. The term is often used to refer to the full set of metabolites found in a cell in a given environment.