Epidemiological Investigation And Human Microbiome Diversity Analysis Of Chronic Fatigue Syndrome Patients

Chronic Fatigue Syndrome(CFS)is a debilitating and multi-system disease.As multiple systems symptoms are involved,CFS can significantly reduce the quality of life,and even incapacitate in severe patients.As the long course of CFS,it increases the risk of other diseases and is accompanied with increasing financial burden.At the same time,due to the unknown etiology of CFS,the clinical implementation is limited,which may be easy to cause psychological problems,such as anxiety,depression,etc.This status containing physical and psychological symptoms,may bring great burden to patients,patients' families and society.CFS involves multi-system symptoms,and the consistency of patients' characteristics are poor,all of which may lead to a big challenge to the implementation of clinical diagnosis and treatment and the study on etiology.CFS,an invisible disease,which is widely distributed in communities and health care settings,is an unprecedented health problem that deserves high attention from governments,institutions and the public.In 2012,the CDC and IOM of the United States began to devote special research efforts to CFS,working on the fields of epidemiology,clinical diagnosis and treatment and etiology analysis.An IOM report published in 2015 indicated that 83,600 to 2.5 million americans were estimated to have CFS,but most have not been diagnosed yet.The CFS attacks people of all ages,races,ethnicities and socio-economic groups,and men are two to four times more likely than women to have CFS.Giving the high heterogeneity of CFS symptoms and the difficulty in clinical diagnosis,the IOM working group called for the adoption of big data model to develop a set of comprehensive characterization data to ensure the existence of CFS,and to identify various factors affecting CFS,the emphasis of which should focus on basic information such as baseline information,behavior,symptoms,course of disease,and biomarkers.The research on CFS is still on the initial stage in China,only a few studies have been reported.This study will focus on the characteristics and biomarkers of CFS patients based on epidemiological investigation.Based on the symptoms of CFS,serological immune index and inflammatory factors,the microbiota was utilized to further verify the abnormal physiological characteristics and biomarkers of CFS patients,laying a foundation for in-depth study of etiology and mechanism as well as the establishment of clinical detection technology.The results are listed as follows:1.A total of 477 CFS patients were recruited for our network research.Male and young and middle-aged were the main population,accouting for 85.53% and 80.08%,in addition,65.41% for married,and 59.12% for educated at junior college/undergraduate level or above.All the patients had a long course of disease and some other symptoms besides the symptoms of the diagnosis,such as white greasy tongue coating,and muscle pain,and bowel diarrhea,rash,joint ring,skin lesions,redness,nodules,night sweats,oral ulcer,gingival recession pain,numbness,subcutaneous ant line feeling,low thermal,mental symptoms(anxiety,depression,)etc.,involving multiple systems.The patient has a variety of symptoms and physical characteristics,and obvious heterogeneity.2.58 CFS patients were recruited for field survey,and the overall symptoms were basically consistent with the results of network survey.Symptoms may be divided into acute phase and chronic phase,more than 70% of which have a history of suspicious infection exposure before acute phase,and 60.34% are unsafe sex.Serological test showed that CFS patients had higher concentration of IgM,IgA and CRP than healthy controls,but no significant change was found in PCT,indicating that CFS cases may have pathogenic microorganism infection or inflammation.However,the intensity of inflammatory response is limited.3.Further combining clinical consultation and case investigation,we found that the clinical identification of CFS patients was difficult due to the heterogeneity of symptoms and limitations of conventional clinical detection indicators.Chinese medicine can identify CFS patients,and treating from the perspective of Chinese medicine can significantly improve the patient's symptoms scores.4.Compared with the healthy controls,the diversity analysis of gut microbiota in the CFS patients showed that the diversity indexes were different between two groups.There were many differences in Beta diversity and many bacteria between groups,for example,at the genus level,Escherichia-Shigella,Lachnoclostridium,Enterococcus,Bifidobacterium,Erysipelatoclostridium etc were higher in CFS patients,while Pseudobutyrivibrio and Alistipes were lowever in CFS patients.LEfSe analysis showed that many bacteria(a total of 30 species)have high influence(LDA>3.0)on distinguishing CFS patients from healthy controls,such as Bacteroides and Pseudobutyrivibrio,etc.5.Saliva microbita diversity analysis showed no difference in diversity index,some differences between groups existed in Beta diversity analysis,difference between group analysis showed a variety of bacteria had significant differences between groups,in the genus level,Fusobacterium,Prevotella,Bacteroides and so on were higher than in CFS patients,while Haemophilus,Bacillus and so on were lower in CFS patients.LEfSe analysis showed that 11 genera had high influence(LDA > 3.0)in two groups,such as Alkalibacillus,Bacteroides and Campylobacter.6.Comparing between oral and gut microbiota in LEfSe,the consistant changes of the two kinds of samples were Gammaproteobacteria,Bacteroidaceae,Bacteroides,etc,while inconsistant were Pasteurellales,Pasteurellaceae,Veillonellaceae,Haemophilus,etc.In addition,changes in diversity indexes in saliva and feces were also significantly different.From the results of diversity index,bacteria with different abundance and their taxonomic correlation,it can be found that oral and gut microbiota of CFS patients had complex changes,consistent characteristics and non-consistent characteristics.Overall,the changes of oral bacterial community are generally smaller than those of the intestinal tract.The changes of intestinal and oral microflora of CFS patients provide important clues for clinical identification and pathogenesis.7.Based on the PICRUSt forecast bacterial community function,feces has five altered functions from COG database(RNA synthesis and modification,nucleotide,transport and metabolism and reduce the energy production and conversion function,signal transduction mechanism and function of extracellular structure),five functions in saliva(cell cycle,differentiation and chromosome separation and replication,recombination and repair function increases,amino acid transport and metabolism,inorganic salt transport and metabolism and secondary metabolites synthesis,transport,decomposition function decrease)in two groups.In the analysis based on KEGG,four level-1 functions in feces,13 level-2 functions in feces,and 0 level-1 functions in saliva,and 6 level-2 functions in feces were found to be significantly different between two groups.These changes in function are closely related to the main symptoms and signs of CFS(fatigue,inflammatory response,immune dysfunction),but the mechanisms need to be further explored.