Article Figures & Data
Figures
- FIG. 1.
Dynamics of killing and recovery of intestinal microbial populations upon antibiotic treatment. The numbers of microbial cells present in feces were determined through Sybr green staining before and several time points after mice received 20 mg of streptomycin through oral gavage. The numbers of mice used were 3 (0.25 and 1 day after treatment), 4 (0.5, 4, and 6 days after treatment), and 7 (0 and 2 days after treatment). ns, not significant (P > 0.05); *, P < 0.04; **, P < 0.002.
- FIG. 2.
Antibiotic treatment has a profound impact on the chemical composition of feces. (A) The heat maps show the impact of streptomycin treatment on the levels of metabolites from mouse feces. Data were median centered using cluster analysis, and heat maps were constructed using Java TreeView (http://rana.lbl.gov/eisensoftware.htm). Masses are presented from lowest (top) to highest (bottom). Green, masses with signal intensities higher than the median; red, signal intensities lower than the median; black, missed values or values with no difference from the median signal intensity. Each of the letters above the map (A, B, C, and D) indicates one mouse used. Each letter corresponds to the two columns of data under it in the heat map due to the duplicate data acquisitions performed. (B) Distribution of metabolites affected, based on fold changes. Numbers inside and around the pie charts represent the percentage of the total number of metabolites affected.
- FIG. 3.
Multiple metabolic pathways are affected by antibiotic treatment. Masses of interest were searched against the KEGG database using MassTrix (http://masstrix.org). Bars indicate the percentage of metabolites from each KEGG pathway that was affected by treatment.
- FIG. 4.
Bile acid metabolism is disturbed by antibiotic treatment. (A) Schematic of the bile acid synthetic pathway. Red, metabolites decreased by antibiotic treatment; green, metabolites increased upon treatment; black, metabolites not detected or unchanged. Masses (Da) for metabolites affected are shown in parentheses. Solid arrows, direct steps; dashed arrows, multiple steps that are not shown. (B) Levels of masses affected by antibiotic treatment. Masses (Da) are shown at the top of each graph. The y axis indicates mass signal intensity. Dark gray bars, levels before treatment; light gray bars, levels after antibiotic treatment. Four mice (n = 4) were used, and averages with standard errors of the means are shown. Because masses 392.2925, 408.2876, 430.3083, 432.324, and 499.2965 were detected in both positive and negative ionization modes, the intensities of these masses in both ionization modes were combined before analysis (n = 8). All differences were statistically significant (P < 0.05). CoA, coenzyme A.
- FIG. 5.
Antibiotic treatment disrupts steroid hormone metabolism. (A) Schematic of the steroid hormone metabolic pathway. Red, metabolites decreased by antibiotic treatment; green, metabolites increased upon treatment; black, metabolites not detected or unchanged. Masses (Da) for metabolites affected are shown in parentheses. Solid arrows, direct steps; dashed arrows, multiple steps that are not shown. (B) Levels of masses affected by antibiotic treatment. Masses (Da) are shown at the top of each graph. The y axis indicates mass signal intensity. Dark gray bars, levels before treatment; light gray bars, levels after antibiotic treatment. Four mice (n = 4) were used, and averages with standard errors of the means are shown. All differences were statistically significant (P < 0.025).
- FIG. 6.
Antibiotic treatment has a profound impact on eicosanoid hormone metabolism. (A) Schematic of the eicosanoid hormone metabolic pathway. Red indicates metabolites decreased by antibiotic treatment whereas green indicates metabolites increased upon treatment. Black indicates metabolites not detected or unchanged. Masses (Da) for metabolites affected are shown in parentheses. Solid arrows indicate direct steps and dashed arrows indicate multiple steps that are not shown. (B) Levels of masses affected by antibiotic treatment. Masses (Da) are shown at the top of each graph. The y axis indicates mass signal intensity. Dark gray bars, levels before treatment; light gray bars, levels after antibiotic treatment. Four mice (n = 4) were used, and averages with standard errors of the means are shown. Mass 326.2093 was detected in both positive- and negative-ion modes, and therefore, its intensity values from both ionization modes were combined before analysis (n = 8). All differences were statistically significant (P ≤ 0.006). PG, prostaglandin; LT, leukotriene; TX, thromboxane; EET, epoxyeicosatrienoic acid; HETE, hydroxyeicosatetraenoic acid; HPETE, hydroperoxyeicosatetraenoic acid; DHET, dihydroxyeicosatrienoic acid.
- FIG. 7.
Clinically relevant doses of antibiotics affect eicosanoid metabolism. (A) Fecal levels of multiple eicosanoids were measured through ELISAs before and after high-dose streptomycin treatment. Dark gray bars, levels before treatment; light gray bars, levels after antibiotic treatment. Averages with standard errors of the means are shown. The numbers of mice used were as follows: CysLT before treatment, 11; CysLT after treatment, 6; PGE2 before and after treatment, 4 each; PGF2α before and after treatment, 6 each; LTB4 before and after treatment, 6 each. (B) Fecal levels of LTB4 were measured in groups of untreated mice and mice treated with clinically relevant doses of streptomycin (Strep), metronidazole (Met), vancomycin (Van), and tetracycline (Tet). Each dot represents one mouse, and bars indicate the averages of the results. **, P < 0.009; ***, P < 0.0001.
Tables
- TABLE 1.
Overview of DI-FT-ICR-MS results and impact of antibiotic treatment on the intestinal metabolomea
Metabolites No. of metabolite masses Metabolites detected Negative ionization 1,043 Positive ionization 1,386 Overlap 199 Total 2,230 Metabolites changed Untreated > treated 793 Treated > untreated 1,165 Total changed 1,958 ↵a The total number of changed metabolites represents 87.8% of all metabolite masses detected.
