Bacteroides, butyric acid and t10,c12-CLA Changes in Colorectal Adenomatous Polyps

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background Colorectal adenomatous polyps (CAPs) are considered precancerous lesions of colorectal cancer (CRC). There are few studies on patients with CAPs, and studies on microbial communities in the intestinal tract of CAP patients are inconsistent. The gut microbiota participates in the process of digestion and, in the process, produces metabolites, mainly short-chain fatty acids (SCFAs), secondary bile acids and conjugated linoleic acid (CLA). These studies aimed to investigate the gut microbiota and metabolites in the faeces of CAP patients in order to identify microbiota or metabolites that can be used as sensitive biological predictors and to provide a theoretical basis for the clinical treatment of CAPs. Results faeces<jats:italic>Weissella</jats:italic> and <jats:italic>Lactobacillus</jats:italic> were present in the HC group, and the abundance of <jats:italic>Bacteroides</jats:italic> and <jats:italic>Citrobacter</jats:italic> was higher in the CAP group than in the HC group. The expression of butyrate-producing bacterial genes was significantly higher in the faeces of CAP patients, but that of secondary bile acid-producing bacterial genes and CLA-producing bacterial genes showed no differences in either faeces or biopsy tissues, and that of butyrate-producing bacterial genes showed no differences in biopsy tissues. The contents of acetic acid and butyric acid were increased in the faeces of the CAP group, and the HC group had higher contents of <jats:italic>t10,c12-CLA.</jats:italic> Conclusion The results of gut microbiota in faeces showed no specific correlation between CAP patients and healthy individuals, but there was indicate that changes of specific genus might be detrimental to intestinal health. In addition, <jats:italic>t10,c12-CLA</jats:italic> played an important role in protecting the intestine.</jats:p>

Emerging Evidence on the Effects of Dietary Factors on the Gut Microbiome in Colorectal Cancer

“…In colonic adenomatous polyposis (CAP), a precursor to CRC, there is an abundance of Bacteroides and Citrobacter taxa, as compared to Weissella and Lactobacillus, which are disproportionally low. The chief metabolite observed in the fecal samples of CAP patients is butyric acid while qPCR analysis shows lower butyrate producing bacteria [19]. Even though butyrate has pro-apoptotic and anti-proliferative role in CRC, it has paradoxically been shown to enhance polyp formation in APCmin/+MSH2−/−(adenomatous polyposis colimin/+MutS homolog 2−/−) mice having defective mismatch repair [20,21].…”