Figure 6.

Effects of FMT in mice and mono-colonization of flies with E. cloacae on NAFLD features and histidine

(A) Schematic of FMT from patients with high and low plasma histidine levels to mice (2 human donors per group, 8 mice per human donor).

(B) Spearman correlation between the plasma levels of histidine in the human donor and the recipient mice.

(C) Recipient mouse hepatic TG content in the low- and high-histidine donor groups (Wilcoxon test).

(D) Volcano plot of the recipient mouse microbiota for the comparison between high-histidine donor vs. low-histidine donor groups, identified using ANCOM-BC. The log₂(FC) and the –log₁₀(p value) adjusted for multiple testing are plotted for each taxon. Significantly different taxa are colored according to phylum.

(E) Relative gene expression of hepatic genes involved in de novo lipogenesis (Acsl1, Srebf1, Dgat1, Prkaa2, and Acadsb), β-oxidation (Ppara and Cpt1a), mitochondrial function (Nfr1, Tfam, and Pgc1a), and glucose metabolism (Insr and Slc2a2).

(F‒N) Effects of mono-colonization with E. cloacae in germ-free D. melanogaster.

(F) Experimental scheme followed to generate wild-type Drosophila flies under sterile (germ-free) or mono-colonization conditions. After egg sterilization, these were transferred to fly food supplemented E. cloacae or the vehicle for the flies that were left sterile. All tests were performed on day 10 of adulthood.

(G) Boxplots represent TG content per fly.

(H and I) Boxplots represent (H) ALT and (I) AST enzymatic activity in 10-day-old Drosophila flies.

(J) RT-qPCR results. Bars represent relative gene expression of flies fed an SD and HFD and mono-colonized with E. cloacae or left sterile. Error bars represent SEM.

(K and L) Boxplots represent the amount of L-histidine per gram of tissue, measured either by ¹H NMR (K) or an ELISA kit (L) of sterile flies or flies mono-colonized with E. cloacae and supplemented with an SD.

(M and N) Boxplots represent TG content per gram of tissue of sterile flies or flies mono-colonized with E. cloacae fed (M) an SD and (N) an HFD and supplemented with 0, 1, 4, or 8 g/L L-histidine.

For all Drosophila experiments, samples contained a pool of 8 flies. Data are mean ± SEM. The p values were determined using Fisher’s LSD ANOVA test (#p < 0.1, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001). p_trend was calculated using the non-parametric Mann-Kendall trend test.