Intestinal microbiota and colorectal cancer: changes in the intestinal microenvironment and their relation to the disease.
Reis Sandra Aparecida Dos,da Conceição Lisiane Lopes,Peluzio Maria do Carmo Gouveia
Journal of medical microbiology
Tools that predict the risk of colorectal cancer are important for early diagnosis, given the high mortality rate for this cancer. The composition of the intestinal microbiota is now considered to be a risk factor for the development of colorectal cancer. This discovery has motivated a growing number of studies to identify the micro-organisms responsible for the onset and/or progression of colorectal cancer. With this in mind, this review discusses the relationship between the composition of the intestinal microbiota and colorectal cancer risk. Prospective and case-control studies indicate that the intestinal microbiota of individuals with colorectal cancer usually contains a greater proportion of bacteria responsible for gastrointestinal tract inflammatory diseases, as well as bacteria that produce toxins and carcinogenic metabolites. In contrast, there tends to be a reduced presence of butyric acid-producing bacteria, probiotic bacteria and potentially probiotic bacteria. Despite these differences, the onset and development of colorectal cancer cannot be attributed to a specific micro-organism. Thus, studies focused on the formation of the intestinal microbiota and factors that modulate its composition are important for the development of approaches for colorectal cancer prevention.
Integrated microbiome and metabolome analysis reveals a novel interplay between commensal bacteria and metabolites in colorectal cancer.
Yang Yongzhi,Misra Biswapriya B,Liang Lei,Bi Dexi,Weng Wenhao,Wu Wen,Cai Sanjun,Qin Huanlong,Goel Ajay,Li Xinxiang,Ma Yanlei
: Colorectal cancer (CRC) is a malignant tumor with the third highest morbidity rate among all cancers. Driven by the host's genetic makeup and environmental exposures, the gut microbiome and its metabolites have been implicated as the causes and regulators of CRC pathogenesis. We assessed human fecal samples as noninvasive and unbiased surrogates to catalog the gut microbiota and metabolome in patients with CRC. : Fecal samples collected from CRC patients (CRC group, n = 50) and healthy volunteers (H group, n = 50) were subjected to microbiome (16S rRNA gene sequencing) and metabolome (gas chromatography-mass spectrometry, GC-MS) analyses. The datasets were analyzed individually and integrated for combined analysis using various bioinformatics approaches. : Fecal metabolomic analysis led to the identification of 164 metabolites spread across 40 metabolic pathways in both groups. In addition, there were 42 and 17 metabolites specific to the H and CRC groups, respectively. Sequencing of microbial diversity revealed 1084 operational taxonomic units (OTUs) across the two groups, and there was less species diversity in the CRC group than in the H group. Seventy-six discriminatory OTUs were identified for the microbiota of H volunteers and CRC patients. Integrated analysis correlated CRC-associated microbes with metabolites, such as polyamines (cadaverine and putrescine). : Our results provide substantial evidence of a novel interplay between the gut microbiome and metabolome (i.e., polyamines), which is drastically perturbed in CRC. Microbe-associated metabolites can be used as diagnostic biomarkers in therapeutic explorations.
Analysis of prognosis, genome, microbiome, and microbial metabolome in different sites of colorectal cancer.
Xi Yang,Yuefen Pan,Wei Wu,Quan Qi,Jing Zhuang,Jiamin Xu,Shuwen Han
Journal of translational medicine
BACKGROUND:The colorectum includes ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. Different sites of colorectal cancer (CRC) are different in many aspects, including clinical symptoms, biological behaviour, and prognosis. PURPOSE:This study aimed to analyse prognosis, genes, bacteria, fungi, and microbial metabolome in different sites of CRC. METHODS:The Surveillance, Epidemiology, and End Results (SEER) database and STAT were used to statistically describe and analyse the prognosis in different sites of CRC. RNA sequences of CRC from Broad Institute's GDAC Firehose were re-annotated and reanalysed based on different sites using weighted gene co-expression network analysis (WGCNA). The Kaplan-Meier method was used to analyse the prognosis and Cytoscape was used to construct a drug-target network based on DGIdb databases. Bacterial 16S V3-V4 and fungal ITS V3-V4 ribosomal RNA genes of stool samples were sequenced. Gas chromatography/mass spectrometry (GS/MS) was performed to detect the microbial metabolites in stool samples. Bioinformatics analysis was performed to compare distinct gut microorganisms and microbial metabolites between rectal and sigmoid cancers. RESULTS:The prognosis in CRC with different sites is significantly different. The closer to the anus predicted longer survival time. The difference between genes and co-expression pairs in CRC with different sites were constructed. The relative abundance of 112 mRNAs and 26 lncRNAs correlated with the sites of CRC were listed. Nine differentially expressed genes at different sites of CRC were correlated with prognosis. A drug-gene interaction network contained 227 drug-gene pairs were built. The relative abundance of gut bacteria and gut fungus, and the content of microbe-related metabolites were statistically different between rectal and sigmoid cancers. CONCLUSIONS:There are many differences in prognosis, genome, drug targets, gut microbiome, and microbial metabolome in different colorectal cancer sites. These findings may improve our understanding of the role of the CRC sites in personalized and precision medicine.
Microbiome and colorectal cancer: Roles in carcinogenesis and clinical potential.
Saus Ester,Iraola-Guzmán Susana,Willis Jesse R,Brunet-Vega Anna,Gabaldón Toni
Molecular aspects of medicine
The gastrointestinal tract harbors most of the microbiota associated with humans. In recent years, there has been a surge of interest in assessing the relationships between the gut microbiota and several gut alterations, including colorectal cancer. Changes in the gut microbiota in patients suffering colorectal cancer suggest a possible role of host-microbe interactions in the origin and development of this malignancy and, at the same time, open the door for novel ways of preventing, diagnosing, or treating this disease. In this review we survey current knowledge on the healthy microbiome of the gut and how it is altered in colorectal cancer and other related disease conditions. In describing past studies we will critically assess technical limitations of different approaches and point to existing challenges in microbiome research. We will have a special focus on host-microbiome interaction mechanisms that may be important to explain how dysbiosis can lead to chronic inflammation and drive processes that influence carcinogenesis and tumor progression in colon cancer. Finally, we will discuss the potential of recent developments of novel microbiota-based therapeutics and diagnostic tools for colorectal cancer.
Developments in the study of gastrointestinal microbiome disorders affected by FGF19 in the occurrence and development of colorectal neoplasms.
Peng Meichang,Zheng Qiaowen,Liu Peiqi,Liang Xinyun,Zhang Min,Wang Yan,Zhao Yi
Journal of cellular physiology
Colorectal neoplasms are a type of malignant digestive system tumor that has become the third-highest morbidity tumor in China and the fourth leading cause of cancer-related death worldwide. The role of the gastrointestinal (GI) microbiome in bile acid metabolism, inflammation, and insulin resistance and its strong correlation with the occurrence and development of colorectal neoplasms have gradually led to it becoming a target area of tumor research. Fibroblast growth factor (FGF) 19 is a hormone that is secreted in mainly the ileum and can regulate bile acid biosynthesis, improve inflammation, and regulate insulin resistance. The relationship of the GI microbiome, FGF19 and its carcinogenic activities in colorectal neoplasms enticed us to search for potential targets and research ideas for the clinical diagnosis and treatment of colorectal neoplasms.
[Role of gut microbiota in carcinogenesis and treatment for colorectal cancer].
Zhang W,Jiang K W
Zhonghua wei chang wai ke za zhi = Chinese journal of gastrointestinal surgery
Colorectal cancer is one of the most common malignant tumors of digestive tract. There are a large number of microorganisms in the digestive tract. Under normal physiological conditions, intestinal microorganisms can help with digestion and absorption, resist pathogen invasion and regulate the proliferation of intestinal mucosal cells. However, intestinal microflora imbalance will affect the intestinal microenvironment and intestinal cell function, and is closely related to the incidence and progression of colorectal cancer. Firstly, this paper introduces the changes of intestinal flora in patients with colorectal cancer, and then summarizes the mode of intestinal flora participating in the occurrence of colorectal cancer from the macro level. Then, we elaborate the involvement of intestinal flora in colorectal cancer from the aspects of cytokine-dependent chronic inflammation, DNA damage of intestinal epithelial cells, carcinogenic metabolites of intestinal flora and cellular enzymes, and changes of intestinal immune system. The pathogenesis of colorectal cancer provides a reference for further study of the pathogenesis of colorectal cancer. Finally, from the perspective of intestinal flora and colorectal cancer treatment, we analyze the significance of probiotics and bacterial flora transplantation for the treatment of colorectal cancer, and provide some new treatment ideas and methods that may be useful for the treatment of colorectal cancer.