Metabolites and gut microbial composition among leptospirosis patients

The diagnosis of human leptospirosis diagnosis is challenging the disease has similar clinical presentations to other infectious diseases such as dengue and influenza. Current laboratory diagnostic tests for leptospirosis based on the detection of antigen, antibodies and DNA signatures are generally plagued by low sensitivity and specificity. Metabolomics and metagenomics have been suggested to be used as diagnostic tools for some infectious diseases. The revealing of fascinating changes between potential and expressed biochemical pathways detected in microbial communities can be achieved through the combination of both omics. In this study, we characterised the faecal and urine metabolomic profiles of leptospirosis patients. The faecal bacterial composition was elucidated using PacBio-based next-generation sequencing. Using Partial Least Square analysis of the urine and faeces metabolome, a significant separation between leptospirosis patients and healthy subjects was observed. Few metabolites were found to be overly abundant only in among leptospirosis patients. They were found to harbour significantly different bacterial composition as opposed to healthy subjects. A significantly higher number of Ruminococcus gnavus was detected among them and higher Enterobacter in the healthy subjects. To our best knowledge, this is the first report of human metabolomics and metagenomics using long 16S amplicon library approximate 1500bp for leptospirosis. The results from this study may help to further the understanding of human metabolic response and changes of gut microbial composition toward leptospiral infection, and also highlight a few candidates of significant metabolites and bacterial species which may have potential to be used as biomarkers for diagnostic purposes.