Metabolomics analysis of plasma and adipose tissue samples from mice orally administered with polydextrose and correlations with cecal microbiota

Markku Tapani Saarinen,Kari Antero Mäkelä,Olli Kärkkäinen,Ghulam Shere Raza,Kati Hanhineva,Ashley Hibberd,Karl-Heinz Herzig,Heli Anglenius,Kirsti Tiihonen

doi:10.1038/s41598-020-78484-y

Abstract

Polydextrose (PDX) is a branched glucose polymer, utilized as a soluble dietary fiber. Recently, PDX was found to have hypolipidemic effects and effects on the gut microbiota. To investigate these findings more closely, a non-targeted metabolomics approach, was exploited to determine metabolic alterations in blood and epididymal adipose tissue samples that were collected from C57BL/6 mice fed with a Western diet, with or without oral administration of PDX. Metabolomic analyses revealed significant differences between PDX- and control mice, which could be due to differences in diet or due to altered microbial metabolism in the gut. Some metabolites were found in both plasma and adipose tissue, such as the bile acid derivative deoxycholic acid and the microbiome-derived tryptophan metabolite indoxyl sulfate, both of which increased by PDX. Additionally, PDX increased the levels of glycine betaine and l-carnitine in plasma samples, which correlated negatively with plasma TG and positively correlated with bacterial genera enriched in PDX mice. The results demonstrated that PDX caused differential metabolite patterns in blood and adipose tissues and that one-carbon metabolism, associated with glycine betaine and l-carnitine, and bile acid and tryptophan metabolism are associated with the hypolipidemic effects observed in mice that were given PDX.

Highlights

Polydextrose (PDX) is a branched glucose polymer, utilized as a soluble dietary fiber
These indigestible substrates are metabolized into a wide range of compounds, such as short-chain fatty acids (SCFAs), organic acids, biogenic amines, vitamins, ammonia, hydrogen sulfide, and phenols, by the microbes that reside in the colon[2]
Altered gut microbiota were associated with the differential expression of genes associated with lipid metabolism, which are regulated by S CFAs19 and associated with P DX17. Encouraged by these findings, we extended our previous study[17] to examine the metabolomics of mouse blood serum and epididymal fat tissue samples, to determine whether the hypolipidemic effects of PDX, changes in gene expression that are associated with lipid metabolism, and alterations in the gut microbiota could be observed at the molecular level

Summary

Introduction

Polydextrose (PDX) is a branched glucose polymer, utilized as a soluble dietary fiber. PDX was found to have hypolipidemic effects and effects on the gut microbiota To investigate these findings more closely, a non-targeted metabolomics approach, was exploited to determine metabolic alterations in blood and epididymal adipose tissue samples that were collected from C57BL/6 mice fed with a Western diet, with or without oral administration of PDX. Minor amounts of 13C-labeled lactate, formate, and succinate were detected[14] Another in vitro human colon simulator study using P DX15 showed higher levels of acetate, butyrate, propionate, and succinate, and lower levels of certain amino acids, valerate, formate, isovalerate, and trimethylamine in PDX samples compared to control samples

Methods

Results

Conclusion