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

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 1 H 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.