Fig. 1
Microbiota depletion impairs weight loss and metabolic improvements resulting from RYGB surgery in diet-induced obesity. a–f Relative body weight change (in %; average body weight (øBW) per group: RYGB(ABx) week (W)0: 385.6 g, W5: 454.3 g; DIO W0: 681.3 g, W5: 762.3 g; RYGB W0: 415.3 g, W5: 437.7 g; # DIO vs. RYGB; * RYGB vs. RYGB(ABx)) (a), final body composition with lean and fat mass (in g), b cumulative energy intake (in kcal) (c), cumulative energy intake of high fat diet (HFD) and standard chow (SC) (in g) (d), energy assimilation (in kJ/24 h) (e), oral glucose-tolerance tests (oGTT) (f), and insulin-sensitivity assessed by insulin-tolerance tests (ITT) (g) in RYGB-operated rats with 35-day antibiotic-treatment (ABx) compared to their respective controls (RYGB-operated rats without ABx). h–k Fasting plasma triglyceride concentrations (in ng/μl) (h), representative images (at least 4 images per group) of liver Oil Red O staining (scale bars 200 μm) with quantification of hepatic lipid accumulation (in %) (i), and relative mRNA expression of hepatic pro- and anti-inflammatory cytokines (j) in RYGB(ABx) compared to RYGB rats. Plasma cytokine concentrations in RYGB(ABx) and RYGB rats (in pg/ml) (k). l-n Representative images of H&E and UCP1 staining in BAT (scale bars 200 μm) (l), total energy expenditure (TEE; in kcal/day) (m) and infrared images of representative RYGB(ABx) or RYGB rats after 6 h of cold-exposure (n). Mouse primary brown adipocytes were treated for 6 h with 50% (vol/vol) of rat serum from RYGB(ABx) or RYGB rats (or with PBS as control). Oxygen consumption rate was measured on a respirometry Seahorse XF Cell Mito Stress Test (Agilent) as described in the “Methods” section (o). Experiments were performed in three independent cohorts. Data are mean ± s.e.m; n = 3–8 animals per group with pooled data from 2 to 3 independent experiments. *,#P < 0.05, **,## P < 0.01, ***,### P <0.001 as assessed by unpaired Student’s t test (for two groups) or two-way ANOVA (multiple groups) with Tukey correction for multiple testing