Gut Microbes and Microbial Metabolites in Colorectal Cancer Complicated with Different Serum Albumin Levels

Abstract Background Patients with colorectal cancer (CRC) are at risk of malnutrition. Gut microbes and microbial metabolites are involved in the initiation and development of CRC. Purpose To investigate serum protein levels in CRC patients and explore the role of gut microbes and microbial metabolites in CRCs complicated with different serum albumin levels. Methods Overall, 398 CRC patients and same number of healthy volunteers in Huzhou Central Hospital from January 2016 to December 2018 were recruited to compare serum protein levels. The serological indicators were detected by Abbott Automatic Biochemical Analyzer(HCHL-YQ-SH-01). A total of 30 and 56 stool samples from CRC patients were used to detect intestinal microbes and microbial metabolites, respectively. Bacterial 16S V3-V4 and fungal ITS ribosomal DNA genes were sequenced and gas chromatography/mass spectrometry (GC/MS) was performed to detect microbial metabolites. Results Some serum protein-related indicators in the CRC group were lower than those in the control group (p༜0.05). The total protein and albumin levels in colon cancer patients were lower than those in rectal cancer patients (p༜0.05). The higher abundance of Sutterella is correlated with lower serum albumin level in CRCs. There were statistically significant differences in the abundance of fungi including Agaricomycetes, Simplicillium, Sclerotiniaceae, and Exophiala among patients with different serum albumin levels. Multiple gut bacteria and fungi are closely related to serum albumin levels.We found some characteristic microbial metabolites in CRCs complicated with different serum protein levels. Conclusions The different serum albumin levels were associated with the gut microbes and microbial metabolites in CRCs. It may provide novel ideas for basic research and clinical application.