Due to the complexity of the cause of CFS it is not reasonable to believe that a pharmacological compound can be found that will cure all patients . Also, the high impact on society points at the necessity to find treatments through other mechanisms . As the bowel is an important organ for equilibrium in health  the use of probiotics as "anti-fatigue-food" is a temptating treatment both from the point of cost and availability as from biological functions as the neurocognitive system can be influenced through immune reactions involving cytokines and anti-oxidants. The theoretical background is thus solid enough to justify a performance of an intervention. Disturbances reported in the gut flora could not be reproduced in this study. The design included a period of baseline observation, treatment and a follow-up period. The patients became their own controls. The advantage here is that confounding factors that exist between individuals affecting the flora as diet and other daily behaviours are controlled for. However, as CFS has a fluctuating natural course it could affect the outcome. By including a satisfying large number of patients this could be controlled for. The present study is a pilot study.
Another comment that is frequently made is that the placebo effect should be high in this condition as it is of subjective nature. However, it has been demonstrated that the placebo effects in CFS is low .
The different responses in patients demonstrate the heterogeneity of the patient population. Recent studies have pointed out the need for subgrouping of patients or maybe even a new definition of the syndrome [2, 4, 33]. When the average is calculated there is no influence of the intervention but for individuals it can have a clear effect whether it is improvement or worsening. The low number of subjects makes it impossible to study gender differences. There is a significant improvement for the studied population for neurocognitive functions with sustainability as it is demonstrated at the end of the follow-up (day 70). Also almost half of the subjects report improvement on the four-item scale and a number of subjects report improvement in general health according to SF-12.
What is very clear is the severity of the condition as described through SF12 for both physical and mental health. For both women and men their report of physical and mental health is less than the norm for the general Swedish population age 75 years and above. Studies from the US show that CFS can be as disabling as multiple sclerosis, lupus, rheumatoid arthritis, heart disease, end-stage renal disease, chronic obstructive pulmonary disease and similar chronic conditions.
The high cost for society has been calculated by the Center for Disease Control, Atlanta to be more than 9 billion dollars in the US in lost productivity , not including medical costs or disability benefits. Our findings confirm that not only is this a costly condition for society but the impairment of reported physical and mental health for the individual is severe and a condition that should be taken seriously by the medical profession.