GSE110794
Transcriptomics of gut microbiome of high fat diet mice supplemented with mannose.
Purpose: Using a C57BL6/J mouse model of diet-induced obesity, we observed that mannose supplementation of high fat diet-fed mice prevents weight gain, lowers adiposity, reduces liver steatosis, and improves glucose tolerance and insulin sensitivity. Mannose increases Bacteroidetes to Firmicutes ratio of the gut microbiota, a signature previously associated with the lean phenotype. These beneficial effects of mannose are observed when supplementation is started early (3 weeks post weaning) but are lost when started later in life (8 weeks post weaning). We profiled transcriptomes of gut microbiota from high fat diet mice supplemented with or without mannose to understand the functional differences of supplementation at 3 weeks post weaning and 8 weeks post weaning. Method: Mice were weaned on high fat diet (HFD) or high fat diet with 2% mannose in drinking water (HFDM). RNA from each mouse for each diet group was isolated individually using Ambion RiboPure Bacteria kit (ThermoFisher Scientific). 1 mg cecal RNA each from 8 mice/diet group was pooled to generate 1 pool/diet for library preparation. The quality of total RNA was assessed by the Agilent Bioanalyzer Nano chip (Agilent Technologies). Total RNA was Ribo-depleted using Ribo-Zero Gold rRNA kit (Epidemiology) (Illumina). RNA-Seq library was constructed from the recovered non-ribosomal RNAs using Truseq Stranded total RNA library preparation kit (Illumina) as per the instructions. Multiplexed libraries were pooled and single-end 50-bp sequencing was performed using an Illumina Hiseq 1500. Results: The comparison of transcriptome profiles of mice supplemented with mannose at 3 weeks post weaning and 8 weeks post weaning shows mannose reduced transcript abundance for glycosyl hydrolases and carbohydrate metabolism when supplied at 3 weeks post weaning. Conclusion: The beneficial effects of mannose in responsive mice (3 weeks post weaning) are at least in part due to reduced energy harvest by gut microbes. Overall design: RNASeq was done for HFD and HFDM samples for sets at 3 as well as 8 weeks post weaning. Differential transcript abundance was calculated for HFDM vs HFD for both sets (3 and 8 weeks post weaning) and functional comparisons were drawn.