Metabolomic Alteration in the Mouse Distal Colonic Mucosa after Oral Gavage with Oxalobacter formigenes

Abstract

Oxalobacter formigenes has been investigated for years due to its proposed ability to produce a secretagogue compound that initiates net intestinal oxalate secretion, thereby theoretically reducing circulating oxalate and risk of kidney stone formation. Strains which have been shown to exhibit this function in vivo across native tissue include the human strain, HC1, and the wild rat strain, OxWR. While previous work on these secretagogue-relevant strains has focused on profiling their metabolome and lipidome in vitro, efforts to characterize their influence on host intestinal mucosal biochemistry in vivo are yet to be reported. Much work has been done over the years with O. formigenes in relation to the secretagogue hypothesis, but it has never been clearly demonstrated that this microorganism is capable of inducing metabolic changes in native host tissue, which would be expected with the production of a transport-inducing compound. In this work, we show how the distal colonic mucosal metabolomic profile in a mouse model exhibited significant changes in the levels of a variety of metabolites as a result of oral gavage with O. formigenes HC1. Among these significant metabolites was nicotinic acid, an essential nutrient shown in past work to be produced in the gut by the native microbiome. Our finding that the in vivo biochemical state of the distal colon was altered with O. formigenes lends support to the secretagogue hypothesis and serves as a pioneering step in characterizing the biochemical interplay between O. formigenes and the mammalian host.

Multi-omics of NET formation and correlations with CNDP1, PSPB, and L-cystine levels in severe and mild COVID-19 infections

“…Briefly, plasma samples were prepared and batched in a random order placing National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) for Human Plasma (SRM 1950) (NIST Office of Reference Materials, Gaithersburg, MD) aliquots at the beginning and end of each batch [ 56 ]. Plasma samples were thawed in a biosafety cabinet (BSC) and 110 μL of plasma was aliquoted into chloroform compatible microfuge tubes (Sorenson Biosciences, Salt Lake City, UT) along with 190 μL of a metabolite internal standard (in water) prepared as previously described [ [57] , [58] , [59] ] containing Leucine-13C6 (4 μg/mL), Creatine-D3 H2O (methyl-D3) (4 μg/mL), L-Leucine-D10 (4 μg/mL), L-Tryptophan-2,3,3-D3 (40 μg/mL), L-Tyrosine Ring-13C6 (4 μg/mL), L-Phenylalanine Ring-13C6 (4 μg/mL), N-BOC-L- tert -Leucine (4 μg/mL), N-BOC-L-Aspartic Acid (4 μg/mL), Propionic Acid 13C3 (8 μg/μL), Succinic Acid-2,2,3,3-d4 (4 μg/mL), Salicylic Acid D6 (4 μg/mL), Caffeine-d3 (1-methyl-d3) (4 μg/mL). 1190 μL of pre-made, cold chloroform/methanol mix (2:0.975 chloroform/methanol (v/v)) was added to each sample and NIST plasma along with 10 μL of SPLASH lipid standard in methanol (AVANTI polar lipids, Birmingham, AL) to make a final ratio of 3:4:8 H2O:methanol:chloroform (v/v).…”

Multi-omics Characterization of Neutrophil Extracellular Trap Formation in Severe and Mild COVID-19 Infections

“…Briefly, plasma samples were prepared and batched in a random order placing National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) for Human Plasma (SRM 1950) (NIST Office of Reference Materials, Gaithersburg, MD) aliquots at the beginning and end of each batch (58). Plasma samples were thawed in a biosafety cabinet (BSC) and 110 µL of plasma was aliquoted into chloroform compatible microfuge tubes (Sorenson Biosciences, Salt Lake City, UT) along with 190 µl of a metabolite internal standard (in water) prepared as previously described (59-61) containing Leucine-13C6 (4 µg/mL), Creatine-D3 H2O (methyl-D3) (4 µg/mL), L-Leucine-D10 (4 µg/mL), L-Tryptophan-2,3,3-D3 (40 µg/mL), L-Tyrosine Ring-13C6 (4 µg/mL), L-Phenylalanine Ring-13C6 (4 µg/mL), N-BOC-L-tert-Leucine (4 µg/mL), N-BOC-L-Aspartic Acid (4 µg/mL), Propionic Acid 13C3 (8 µg/uL), Succinic Acid-2,2,3,3-d4 (4 µg/mL), Salicylic Acid D6 (4 ug/mL), Caffeine-d3 (1-methyl-d3) (4 µg/mL). 1190 µL of pre-made, cold chloroform/methanol mix (2:0.975 chloroform/methanol (v/v)) was added to each sample and NIST plasma along with 10 µl of SPLASH lipid standard in methanol (AVANTI polar lipids, Birmingham, AL) to make a final ratio of 3:4:8 H2O:methanol:chloroform (v/v).…”

Extracellular Vesicle Analysis by Paper Spray Ionization Mass Spectrometry

“…Hence, in this report, we describe the first PSI-MS application to bacterial exometabolomics by demonstrating the generation, isolation, confirmation, and PSI-MS analysis of bacterial EVs. The experimental model for our study was Oxalobacter formigenes ( O. formigenes ), a commensal, Gram-negative resident of the human intestinal microbiome with significant interest in the impact of its secreted metabolome on human health [ 47 , 48 , 49 , 50 , 51 ]. O. formigenes has been suggested to produce and expel a secretagogue compound that potentially curtails the risk of calcium oxalate kidney stone disease by stimulating a net intestinal secretion of oxalate, a precursor and risk factor for stone formation, which theoretically reduces its concentration in circulation and renal excretion [ 47 , 48 , 52 , 53 , 54 ].…”