Microbial modulation of host body composition and plasma metabolic profile

Abstract

The gut microbiota is a critical mediator of nutrition and disease risk. Like most complex traits, the microbiome is under genetic regulation and differs between inbred strains of mice. We tested the effect of fecal microbiota transplantation (FMT) on obesity, and plasma glucose. For this study, we collected microbiota from 2 inbred strains of mice which differ in adiposity and glucose tolerance, C57BL/6J and WSB/EiJ. C57BL/6J female mice (n = 18) were first treated with antibiotics for 4 weeks to ablate the microbiota. Following ablation, the mice were transplanted with microbiota from a C57BL/6J or a WSB/EiJ mouse and clinical traits and plasma metabolomic profiles were interrogated at 2- and 4-weeks post-transplantation. Unexpectedly, the mice receiving WSB/EiJ microbiota increased adiposity but decreased plasma glucose. Metabolomic and 16S microbiota profiling indicated broad metabolic changes occurred during and after FMT. Detailed analysis of these interactions demonstrated specific microbiota-host metabolite interactions which may alter disease susceptibility.

Figure 1

Effect of antibiotics treatment and fecal microbial transplantation (FMT) from a C57BL/6J or a WSB/EiJ mouse on recipient mice’s gut microbiota. (a) Mean relative abundance of top 20 genera in mice at baseline, after 4 wk antibiotic treatment, 2 wk, and 4 wk post fecal microbial transplantation by FMT groups. (b) Shannon diversity and (c) observed ASV, and (d) Faith’s Phylogenetic Diversity indices by time points and FMT groups. (e) Bray-Curtis beta diversity principal coordinate plot at different time points by the FMT groups. Red and black dot on the 4 wk post fecal transfer plot represents the Bray-Curtis beta diversity measure for the donor WSB/EiJ and C57BL/6J, respectively. The ellipse on the principal coordinate analysis plot indicates 95% CI of the clusters by FMT groups. ** = P < 0.01, # = P < 0.10.

Figure 2

Effect of gut microbial depletion and re-colonization on body composition and plasma clinical biomarkers. (a) Body weight (b) percent of fat mass, and (c) percent of lean mass at baseline, after 4 wk antibiotics treatment, and after 1 and 2 wk post fecal microbiota transplant. (d) Body weight, (e) percent of fat mass, and (f) percent of lean mass at 1 and 2 wk post fecal microbiota transplant by the FMT groups. (g) Plasma glucose level at baseline, after 4 wk antibiotics treatment, and after 2 wk post fecal microbiota transplant. (h) Comparison of plasma glucose levels at 2 wk post-FMT between FMT groups. (i) Plasma cholesterol level at baseline, after 4 wk antibiotics treatment, and after 2 wk post-FMT. (j) Comparison of plasma cholesterol levels at 2 wk post-FMT between FMT groups. Boxes with no common letter indicate significant differences. *P < 0.05, #P < 0.10.

Figure 3

Association between microbiota and phenotypes. (a) Spearman correlation between microbial diversity and body composition or plasma clinical parameters at 2 wk post-FMT. “*”P < 0.05, “.”P < 0.10 (b) Heatmap showing the ANCOM detected differential bacterial abundance at ASV level between higher (above median) and lower (below median) plasma biochemical parameters at 2 wk FMT. Color key represents ANCOM W value. For easier presentation, ANCOM W values were converted to negative if the mean abundance of the bacteria is lower in the above median group. Red indicates higher ASV abundance in the above median group and blue bacteria represents higher ASV abundance in the below median group. White represents non-significant result obtained  from ANCOM analysis. Red and blue represent significant association determined by ANCOM after FDR correction for multiple comparisons at a significant level adj.P < 0.05.

Figure 4

Principal component analysis plot of plasma metabolites. (a) Scores are shown for the two first PCs from the PCA of data on plasma metabolites at baseline and after depletion of gut microbiota by 4-wk antibiotics treatment. Each point represents a sample at baseline (blue) or after 4 wk ABX (red). The ellipse on the principal coordinate analysis plot indicates 95% CI of the clusters by study time points. (b) Comparison of the contribution of baseline and gut microbiota depleted samples on the PC1, PC2, and PC3. (c) Correlation between corresponding PC1, PC2, and PC3 and plasma clinical parameters. (d) Scores are shown for the two first PCs from the PCA of data on plasma metabolites after depletion of gut microbiota by 4-wk antibiotics treatment and 2 wk post-FMT. Each point represents a sample after 4 wk ABX (red) or at 2 wk post-FMT (green). The ellipse on the principal coordinate analysis plot indicates 95% CI of the clusters by study time points. (e) Comparison of the contribution of baseline and gut microbiota depleted samples on the PC1, PC2, and PC3. (f) Correlation between corresponding PC1, PC2, and PC3 and plasma clinical parameters. (g) Scores are shown for the two first PCs from the PCA of data on plasma metabolites at 2 wk post fecal microbial transplantation. Each point represents a mouse that received FMT from either a WSB/EiJ (pink) or a C57BL/6J (gray) mouse donor. The ellipse on the principal coordinate analysis plot indicates 95% CI of the clusters by FMT groups. (h) Comparison of the corresponding PC1, PC2, and PC3 between samples collected from FMT groups after at 2 wk fecal transplantation. (i) Correlation between corresponding PC1, PC2, and PC3 and plasma clinical parameters at 2 wk post-FMT. “***”P < 0.001, “**”P < 0.01, “*”P < 0.05, “.”P < 0.10.

Figure 5

Heatmap showing the ANCOM detected top 20 (based on cumulative ANCOM W value) differential bacterial abundance at ASV level between high (above median) and low (below median) top 30 microbiota associated plasma metabolites at 2 wk FMT. Color key represents ANCOM W value. For easier presentation, ANCOM W values were converted to negative if the mean abundance of the bacteria is lower in the above median group. Red indicates higher ASV abundance in the above median group and blue represents higher ASV abundance in below median group. White color represents non-significant results. Red and blue represent significant association determined by ANCOM after FDR correction for multiple comparisons at a significant level adj.P < 0.05.