Strengths and Limitations
anxiety/depression, fatigue
POST-VIRAL FATIGUE SYNDROME
This study has several strengths and some limitations that must be considered. To the best of our knowledge, this trial is the first clinical evaluation of the effects of beta-glucan supplementation with multivitamins (including vitamin D3, vitamin B6, and zinc) involved in energy metabolism and immune function enhancement on ME/CFS patients’ perceptions of their neurocognitive symptoms, fatigue, sleep quality, and anxiety/depression. It should be noted that a cognition improvement found through percentage differences of 5.7% in active arm is more likely to be due to a real treatment effect using beta-glucans plus multivitamins among the participants. In addition, study participants were assessed according to the ME/CFS case criteria based on the 1994 CDC/Fukuda definition, and a potential gender bias was avoided by restricting the study to females.The main limitation of this study was the relatively small sample size. In addition, these participants were recruited from a single tertiary referral center, so the results cannot be generalized to other ME/CFS populations. It should also be noted that the primary endpoint, the perception of fatigue assessed with the FIS-40 questionnaire, was a self-reported parameter. Finally, the lack of statistical differences between groups may suggest a placebo effect for microcrystalline cellulose and plant capsule.In future studies, the doses and follow-up timing of the intervention should be pre-established, so as to ensure appropriate monitoring beyond the intervention. In addition, objective physiological and biological parameters should be used to evaluate beneficial effects of beta-glucan in ME/CFS and other post-viral fatigue syndromes.