Rectal sampling and ambient ionization based metabolomics for point-of-care precision medicine in children.

While recent advent of hyphenated high-resolution mass spectrometry empowered the new analytical reality of holistic

metabolite fingerprinting, there are at present no tools available for point-of-care minimally invasive sampling of the gut

metabolome. The gut metabolome harbors a rich source of data that allows complex interactions between the diet, gut

microbes and host to be studied. Numerous chronic conditions including food allergies, obesity, diabetes, inflammatory

bowel disease etc. are intimately linked to imbalances of the gut microbiome. While metabolites, as the end products of our

own and microbial inhabitant gene-transcript-protein cascade, provide the most revealing assessment of our biochemical

state, there are currently no methods available for in-situ metabolic profiling of the gut. In RECSAMPROCHILD, I propose

the development of a rectal swab with electrospun nanofibrous polymer tip surface, customized for maximal extraction of

the gut metabolome in terms of chemical diversity and polarity (incl. lipidome) and direct ambient surface-assisted laser

desorption ionization. I plan to combine this RECSAMP with HRMS-based untargeted discovery of biomarkers for

unambiguous identification of a number of conditions in children including cow’s milk allergy and obesity/prediabetes.