Treatment of wild-type mice with 2,3-butanediol, a urinary biomarker of Fmo5−/− mice, decreases plasma cholesterol and epididymal fat deposition

• Published in: Frontiers in physiology Vol. 13; p. 859681
• Main Authors: Veeravalli, Sunil, Varshavi, Dorsa, Scott, Flora H., Varshavi, Dorna, Pullen, Frank S., Veselkov, Kirill, Phillips, Ian R., Everett, Jeremy R., Shephard, Elizabeth A.
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 08.08.2022
• Subjects: antibiotic; fecal transplant; gut microbiome; metabolite; NMR; Physiology; stomach; antibiotic; NMR; gut microbiome; metabolite; urine; fecal transplant; cholesterol; stomach
• ISSN: 1664-042X; 1664-042X
• DOI: 10.3389/fphys.2022.859681

We previously showed that Fmo5 −/− mice exhibit a lean phenotype and slower metabolic ageing. Their characteristics include lower plasma glucose and cholesterol, greater glucose tolerance and insulin sensitivity, and a reduction in age-related weight gain and whole-body fat deposition. In this paper, nuclear magnetic resonance (NMR) spectroscopy-based metabolite analyses of the urine of Fmo5 −/− and wild-type mice identified two isomers of 2,3-butanediol as discriminating urinary biomarkers of Fmo5 −/− mice. Antibiotic-treatment of Fmo5 −/− mice increased plasma cholesterol concentration and substantially reduced urinary excretion of 2,3-butanediol isomers, indicating that the gut microbiome contributed to the lower plasma cholesterol of Fmo5 −/− mice, and that 2,3-butanediol is microbially derived. Short- and long-term treatment of wild-type mice with a 2,3-butanediol isomer mix decreased plasma cholesterol and epididymal fat deposition but had no effect on plasma concentrations of glucose or insulin, or on body weight. In the case of long-term treatment, the effects were maintained after withdrawal of 2,3-butanediol. Short-, but not long-term treatment, also decreased plasma concentrations of triglycerides and non-esterified fatty acids. Fecal transplant from Fmo5 −/− to wild-type mice had no effect on plasma cholesterol, and 2,3-butanediol was not detected in the urine of recipient mice, suggesting that the microbiota of the large intestine was not the source of 2,3-butanediol. However, 2,3-butanediol was detected in the stomach of Fmo5 −/− mice, which was enriched for Lactobacillus genera, known to produce 2,3-butanediol. Our results indicate a microbial contribution to the phenotypic characteristic of Fmo5 −/− mice of decreased plasma cholesterol and identify 2,3-butanediol as a potential agent for lowering plasma cholesterol.