Colorectal cancer (CRC) is a malignant digestive tract tumor resulted from genetic and environmental factors and can be accompanied by a series of gene mutations.The etiology of CRC,particularly the role of gut microbiota imbalance,has became a hot research topic along with the increase of its prevalance.In this article,we elucidate the potential roles and mechanisms of streptococcus gallolyticus,fusobacterium,Escherichia coli,Bacteroides fragilis,and helicobacter wlori in the development of CRC,with an attempt to further understand the functions of microbiota,search for possible specific carcinogenic strains,and improve the management of CRC.

Objective To investigate the distribution of gut microbiota in obese patients with or without acanthosis nigricans .Methods Totally 131 obese patients and 25 healthy participants were divided into three groups:the obesity with acanthosis nigricans (AN) group (n=59), the simple obesity (OB) group (n=79), and the control (CON) group (n=25).The fresh stool samples were collected , and the clinical and biochemistry markers were measured .Pyrosequencing technology was performed based on the 16s rRNA of fecal samples to identify and analyze the distribution pattern of gut microbiota in each group .Results The AN group had signifi-cantly higher body mass index [ (37.45 ±5.12) kg/m2 vs.(33.34 ±2.54) kg/m2 vs. (20.35 ±1.68) kg/m2, P=0.045, P<0.001], insulin [32.77 (25.18) mU/L vs.20.73 (9.30) mU/L vs.8.70 (6.18) mU/L, P<0.001, P<0.001], insulin resistance [7.78 (6.87) vs.4.71 (2.88) vs.1.81 (1.40), P<0.001, P<0.001], and interleukin (IL) -6 [ (3.64 ±2.23) ng/L vs.(2.71 ±0.78) ng/L vs.(2.17 ±0.86) ng/L, P=0.040, P=0.009] levels than OB and CON groups compared with OB and CON groups , AN group had sig-nificantly decreased diversity of bacterial flora ( P=0.015 , P=0.001 ) , while no significant difference was observed in the abundance of bacterial flora .At the phylum level , the composition of flora among these three groups was similar, mainly including bacteroidetes , firmicutes, proteobacteria, and actinomycetes.Although the proportions of main bacteria flora were different , the difference was not statistically significant .At the genus level, the bacteria flora in AN and OB groups were primarily composed of Bacteroides, Megamonas, Faecalibac-terium and Escherichia-Shigella.In addition, compared to OB and CON groups , AN group had significantly lower proportion of Ruminococcus ( P=0.023 , P=0.043 , respectively ) and higher proportion of Veillonella (P=0.048, P=0.043, respectively).Furthermore, the proportion of Weissella was higher in AN and OB groups than in CON group ( P=0.045 , P=0.025 ) .Conclusion Obese patients with AN have more severe in-sulin resistance and inflammation status than those with simple obesity , and the distribution feature of gut micro-biota also differ between these two patient populations .

Gut microbiota is one of the complicated eco-systems in human body.A large amount of bacteria colonize in the healthy human intestine, which not only play a variety of biological functions, but also are associated with various diseases.By adding microecological agents (probiotics, prebiotics, and synbiotics), we are able to improve the gut microbiota structure and reduce the related carcinogenic metabolites, and also to improve the clinical manifestations of certain diseases.Therefore, it is meaningful to apply microecological agents (probiotics, prebiotics, and synbiotics) both in healthy population and patients.We reviewed the researches on microecological aspect of gut microbiota-related diseases, aiming to shed some light on fully understanding and popularizing of the application of microecological agents among different populations.

Objective To study the distribution patterns of bacterial flora in sigmoid colon tissues and stools in normal population.Method Bacterial flora were identified and analyzed by using 16sDNA sequencing technology in fresh stool samples (n =13) and colon mucosa samples (n =10).Results The diversity and abundance of bacterial flora were significantly larger in the stool samples than in the sigmoid colon samples (P ＜ 0.001,P ＜ 0.001,P =0.042,P =0.006).The consititution of phylum flora between the two groups were same,including flrmicutes,bacteroides,proteobacteria,and actinomycetes.However,the proportions of firmicutes and bacteroides in stool samples were significantly higher than in the sigmoid colon samples,whereas the proportion of proteobacteria was significantly lower (P ＜ 0.001,P =0.025,P ＜ 0.001).At the genus level,faecalibacterium and bacteroides were the dominant flora in feces,whereas pseudomonas,lactococcus,acinetobacter,and flavobacterium were the most common flora in sigmoid colon mucosa.The amounts of bifidobacterium and lactobacillus were low in both two groups.Conclusion The distribution of bacterial flora remarkably differ in stools and sigmoid colon mucosa.

Objective To explore the effect of fat on 1,2-dimethylhydrazine (DMH)-induced colon tumors.Methods A total of 50 7-week-old male Wistar rats were further divided into four groups:standard diet feed control group (n =10),standard diet feed plus DMH-induced tumor group (SDT,n =15),high-fat diet feed control group (n =10) and high-fat diet feed plus DMH-induced tumor group (HFDT,n =15).Rats were killed 18 weeks later,and enzyme-linked immunosorbent assay was used to detect serum triglyeeride,tumor necrosis factor (TNF-α),and colonic TNF-α,interleukin-6.After the intestinal tracts were removed,the location,amount,and size of the tumors were observed.The pathological changes of the tissue sections were observed,and the distributions of TNF-α and Ki-67 in the normal tissues and tumors were detected by immunohistochemistry.Results Upon the completion of the study,the mortality rate of rats was 20.00％ in the SDT group and 26.67％ in the HFDT group,the tumor formation rate was 75.00％ in the SDT group and 81.82％ in the HFDT group,and the tumor-bearing rate was 117％ in the SDT group and 191％ in the HFDT group.No statistical significance difference between the two groups in mortality rate,tumor formation rate (P =0.545) and tumor bearing rate (x2 =1.343,P =0.247).The average tumor volume was significantly different between the standard diet feed control group and high-fat diet feed control group (28.57％ vs 66.67％,P =0.030).Also,the serum triglyceride and TNF-α levels significantly differed between the SDT group and HFDT group [TG (1.39 ± 0.31) mmol/L and TNF-α (124.80 ± 21.69) ng/L in the HFDT group and TG (0.46 ±0.20) mmol/L and TNF-α (85.83 ± 17.45) ng/L in the SDT group] (P =0.000).The expressions of TNF-α,IL-6,and Ki-67 in colonic mucosa were significantly higher in the high-fat diet feed control group than in the standard diet feed control group [TNF-α:(6.22 ± 0.63) ng/g vs (2.33 ± 0.44) ng/g,P=0.020; IL-6:(13.50±0.67) ng/gvs (7.31 ±0.41) ng/g,P=0.000; and Ki-67:40％ vs 10％,P =0.028].The Ki-67 expression rate was 90.48％ in the HFDT group,compared to 50％ in the SDT group (P =0.015).Conclusions High-fat diet can increase the serum triglyceride and TNF-α levels in rats,upregulate the expressions of TNF-α,IL-6 and Ki-67,and thus promote inflammation and cell proliferation,and ultimately affect the tumor formation and development.However,the effect of fat on DMH-induced colon tumors warrants further studies.

Objective To explore the association between white matter hyperintensities volume and cognitive function in patients with hypertension.Methods Eighty-two patients with hypertension enrolled from the Department of Neurology of Nanjing Drum Tower Hospital from January 2017 to December 2017 were recruited in this study sequentially,who aged between 50 and 80 years.All subjects used automatic white matter quantitative technique to get their personal whole white matter hyperintensities volume,periventricular white matter hyperintensities volume and deep white matter hyperintensities volume.Neuropsychological scales were used to evaluate their global cognitive function,memory function,fluency,executive function and processing speed.The association between white matter hyperintensities volume and cognitive function via linear regression analysis was assessed.To explore whether the association between white matter hyperintensities volume and cognitive function be affected by the duration of hypertension,stratification analyses were conducted using the median of the duration of hypertension as separation.Results After adjusting for age,sex,education,lacunar infarctions and global cortical atrophy grade,the Trail Marking Test (2-1) score which reflects executive function was found to be related to whole white matter hyperintensities volume (standardized beta-value=0.268,P=0.019),periventricular white matter hyperintensities volume (standardized beta-value=0.243,P=0.037) and deep white matter hyperintensities volume (standardized beta-value=0.243,P=0.021).Victorial Snoop Test-2 score which reflects processing speed was found to be related to periventricular white matter hyperintensities volume (standardized beta-value=0.270,P=0.023).After additional adjusting for the duration of hypertension,the Trail Marking Test (2-1) score was still found to be related to whole white matter hyperintensities volume (standardized beta-value=0.277,P=0.016),periventricular white matter hyperintensities volume (standardized beta-value=0.251,P=0.032) and deep white matter hyperintensities volume (standardized beta-value=0.248,P=0.019).The Victorial Stroop Test-2 score was found to be related to whole white matter hyperintensities volume (standardized beta-value=0.237,P=0.041) and periventricular white matter hyperintensities volume (standardized beta-value=0.290,P=0.013).Conclusion Whole white matter hyperintensities volume,periventricular white matter hyperintensities volume and deep white matter hyperintensities volume are related to executive function,periventricular white matter hyperintensities volume is also related to processing speed in patients with hypertension,and the association between white matter hyperintensities volume and cognitive domain is not influenced by the duration of hypertension.

Objective To explore the value of methylation of SDC2 and SFRP2 genes promoter in fecal DNA for colorectal cancer ( CRC) screening. Methods All stool samples were enrolled from Changhai Hospital of Naval Medical University, the Tenth People' s Hospital of Tongji University and the Seventh Medical Center of Chinese People's Liberation Army General Hospital. A total of 500 stool samples collected from March 2018 to December 2018 were allocated to CRC group ( 132 CRCs ) , adenoma group ( 38 advanced adenomas), healthy group (152 healthy individuals), interferential group (178 cases of benign colorectal disease or other non-colorectal tumors) and negative group (330 cases composed of healthy group and interferential group ) . The promoter methylation of fecal SDC2 and SFRP2 genes was detected by methylation-specific PCR (MSP) and compared with single gene methylation and the fecal immunochemical tests ( FIT) to evaluate its sensitivity and specificity. Results The stool sample analysis showed that the sensitivity of combined detection of SDC2 and SFRP2 in CRC group was 97. 73％ ( 129/132 ) , which was significantly higher than those of the single gene SDC2 test [ 70. 45％ ( 93/132) , P=0. 000] , single SFRP2 test [81. 82％ (108/132), P=0. 000] and FIT [69. 70％ (92/132), P=0. 000]. In adenoma group, the sensitivity of combined detection of SDC2 and SFRP2 was 57. 89％ (22/38), which was significantly higher than those of the single gene SDC2 test [ 15. 79％ ( 6/38 ) , P= 0. 000 ] and FIT [ 21. 05％ ( 8/38 ) , P=0. 021] , with no significant difference compared with that of SFRP2 test [ 47. 37％ ( 18/38) , P=0. 358] . In healthy group, the specificity of combined detection of SDC2 and SFRP2 was 98. 68％ (150/152), with no significant difference compared with those of single gene SDC2 test [ 100. 00％( 152/152) , P=0. 156] , single SFRP2 test [98. 68％ (150/152), P=1. 000] or FIT [95. 39％ (145/152), P=0. 091]. Specificities of combined detection of two genes in interferential and negative groups were 90. 45％ ( 161/178) and 94. 24％( 311/330) , which were significantly higher than 73. 03％( 130/178, P=0. 000) and 83. 33％( 275/330, P=0. 000) of FIT, respectively. Conclusion The combined detection test of methylation of SDC2 and SFRP2 is superior to single gene test, whose sensitivity of CRC and aggressive adenoma and specificity of distinguishing benign and malignant lesions are higher than FIT, which has potential application value.

Crohn's disease (CD) is a chronic nonspecific intestinal inflammatory disease with unclear etiology and pathogenesis. At present, it is believed that CD can cause different degrees of metabolic abnormalities, and that the related metabolites also play an important role in the development and progression of the disease. In recent years, metabonomics is becoming more and more well-developed and has provided guidance for clinicians on rational nutritional support. Here is a review on the metabolic changes of multiple systems in CD patients, the application of metabonomics in CD diagnosis and treatment, and the research progress of clinical nutrition intervention.

Crohn's disease (CD) is a chronic nonspecific inflammatory bowel disease that can involve the whole digestive tract. At present, the pathogenesis is believed to be mainly related to environment, genetics and intestinal microecology changes. Compared with healthy people, CD patients demonstrate different degrees of flora imbalance in the digestive tract, and the flora composition varies across different regions. In recent years, reconstruction of gastrointestinal microecological balance has become the focus of research. Fecal microbiota transplantation as a new treatment strategy has been gradually applied in clinical practice. Here we reviewed the changes of flora across different regions of digestive tract in patients with CD and the relevant pathogenic mechanism, as well as the progress of fecal microbiota transplantation in the treatment of CD.

Objective To investigate the beneficial role of synbiotics in the intestinal microbiota of patients with chronic functional constipation (CFC).Methods According to the inclusion and exclusion criteria,6 patients with CFC were enrolled with their fresh fecal samples collected,after a continuous treatment of one month their fresh fecal samples collected again.Meanwhile,6 healthy volunteers were enrolled as the control group with their fresh fecal samples collected.All samples were transported with ice and stored in -80 ℃ refrigerator,and were analyzed by metagenomics sequencing.Results After 4 weeks of symbiotic treatment,the intestinal microbiota had changed in species in patients with CFC.Bacteria of Escherichia_ coli,Clostridium_ sp._ SS2/1 and Clostridium_ sp._ 7_ 3_ 54FAA,which were rich in the people with constipation,decreased in abundance after the treatment.Bacteria of Lactobacillus_ oris and Bifidobacterium _ animalis,which were rich in the healthy people,increased in content after the treatment.Bacteria of Veillonella_ parvula,Veillonella_ sp._ 6_ 1_ 27,Veillonella_ sp._ 3 _ 1_ 44 which were rich in the healthy people,decreased in content after the treatment.LEfSe analysis showed that Parabacteroides distaso nis,Escherichia_ coli and Enterobacter-cloacae were the specific species of the three groups respectively.Conclusion Synbiotics can change the intestinal microbiota showing therapeutic effect,thus can be used as a novel clinical treatment method.