IDDF2018-ABS-0227 Saccharomyces pombe may be a double-edge sword in the guts of malaysian adults: an evidence from the gut microbiome secretome study

Abstract

Background Dysbiosis of the gut microbiome has been postulated as the causative event of colorectal cancer (CRC). In recent years, consumption of certain strain of microbes in pursuit of correcting gut dysbiosis has been hyped up by the probiotics industry. However, little is known regarding the contribution of these naturally occurring microbes to the gut microenvironment and their pathophysiology interaction with the host in health and diseases, particularly at the molecular level in a chronic term. Therefore, we aim to identify the secreted proteins released from the human gut microflora by assessing the secretome in the stool samples. Methods Stools samples from 26 clinically-diagnosed patients with CRC and 20 non-CRC control individuals were collected, homogenised and filtered followed by protein extraction and profiling by quantitative label-free proteomics using Nano-Liquid Chromatography TripleTOF Mass Spectrometry. The mass spectra datasets were searched using MaxQuant against the microbial Uniprot Fasta database. Statistical analyses were performed using Mann-Whitney, Kruskal-Wallis and Spearman correlation with p-value less than 0.05. Results We have identified a total of 649 proteins secreted by the gut flora (253 from yeasts; 404 from bacteria) with 35 proteins specific to CRC, whereas 613 proteins were exclusive to the non-CRC control. Only one yeast protein was found to be secreted in both CRC and non-CRC groups. Interestingly, most significant proteins that were expressed independently in CRC and non-CRC were proteins secreted by Saccharomyces pombe (p Conclusions Saccharomyces pombe may play a major role in the human gut by distinguishing the CRC-stricken gut from the non-CRC, as was shown by the different set of proteins being released. However, it is still unknown whether the differences found in this study was the cause or effect of dysbiosis that eventually leads to CRC, thus warrants further investigation.