Figure 2.

Penetration of ¹³C-Labeled Bacterial Metabolites from the Intestine to Host Tissues and Fluids

Germ-free C57BL/6 mice were gavaged with ¹³C-labeled HA107 or PBS as control (n = 3–4 mice per group). Fluid samples were collected 2 or 18 hr later and analyzed with Q-TOF mass spectrometry. All ions which were annotated as metabolite isotopes ≥75% ¹³C labeled are plotted.

(A) Left panel shows samples from small intestinal fluid, peritoneal fluid, serum, and urine at 2 hr; lines connect identical metabolites. Inset shows small intestinal, cecal, and colon fluids also at 2 hr. Right panel shows 18 hr cecal, colon, peritoneal, serum, and urine fluid samples with (inset) small intestinal, cecum, and colon fluids.

(B) Cluster analysis heatmap of all ¹³C-labeled annotated metabolites (p < 0.05, ≥3 mice/group) in different host fluids at 2 hr and 18 hr after gavage. Metabolite classes are shown in the lower color bar and legend. Results are representative of three experiments.

(C) As for (B), except ¹³C-labeled annotated metabolites in host tissues are shown.

See also Figure S2.