Changes And Clinical Significance Of Specific Genera Of Gut Microbiota In Patients With Colorectal Cancer

Objective:Colorectal cancer is one of the most common malignancies,ranking third for incidence and second for mortality among all malignancies worldwide,and early diagnosis and treatment are of great importance for colorectal cancer.Disorder of gut microbiota can lead to a variety of disease occurrence,and studies have found gut microbiota disorder is closely related to the occurrence and development of colorectal cancer.In the present study,we focus on the differences in the abundance of Fusobacterium nucleatum as well as two classes of common probiotics(Bifidobacterium as well as Lactobacillus)between CRC patients and healthy controls,and compared the abundance of Fusobacterium nucleatum,Bifidobacterium,and Lactobacillus in CRC patients of different pathological stages,tumor sites,and ages,providing practical and effective biomarkers for diagnosis and treatment of colorectal cancer.Methonds:Feces were collected from patients with CRC,and clinical data such as age,gender,body weight as well as tumor location were recorded.The absolute content and relative quantification levels of the Fusobacterium nucleatum,Bifidobacterium,as well as Lactobacillus were determined by quantitative PCR in faecal samples from patients with colorectal cancer compared with those from healthy controls,and the differences in specific genera of gut microbiota between patients with colorectal cancer and healthy controls were compared.We also compared the differences in gut microbiota among colorectal patients with different pathological stages,ages as well as tumor sites.Results:1.There is no significant difference in the total content of gut microbiota between CRC patients and healthy controls(P > 0.05),the absolute content and relative quantification of Fusobacterium nucleatum was significantly higher in CRC patients than in healthy controls(P <0.01),and the absolute content and relative quantification of Bifidobacterium and Lactobacillus were significantly lower in CRC patients than in healthy controls(P < 0.01).2.In colorectal cancer group,the absolute content and relative quantity of Fusobacterium nucleatum in TNM pathological stage I and II patients were significantly lower than those in III and IV patients(P <0.01),the absolute content and relative quantity of Bifidobacterium were significantly higher than those in III and IV patients(P < 0.01),The absolute abundance of Lactobacillus was significantly higher(P < 0.01)and the relative quantification was higher(P < 0.05)in patients with stages III and IV disease;There was no significant difference between colorectal cancer patients over 50 years old and colorectal cancer patients under 50 years old in the absolute content and relative quantitative level of Fusobacterium nucleatum,Bifidobacterium and Lactobacillus(P >0.05);There was no significant difference in the absolute content and relative quantity of Fusobacterium nucleatum,Bifidobacterium and Lactobacillus between colon cancer patients and rectal cancer patients(P > 0.05).Conclusion:The changes of gut microbiota may be related to the occurrence and pathological stage of colorectal cancer,which can be used as a potential biomarker for early diagnosis and treatment of colorectal cancer.