Fig 1. Bacterial contamination differs between R03 and ST1 diets.

(A) DNA isolated from R03 and ST1 diets was diluted in ddH₂O (1:10 and 1:100) and PCR was performed with Bacteria-specific primers. PCR products were separated by 1.2% agarose gel electrophoresis. E. coli DNA was used as positive control, H₂O as negative control. (B) Endotoxin levels in R03 and ST1 diet extracts (eR03, eST1 respectively) were determined by the fluorescent PyroGene™Recombinant Factor C Assay. Data are plotted as mean values ± SEM. Representative results from five independent experiments are shown. (C-D) Human embryonic kidney cells (HEK293) stably transfected with an expression vector for human TLR4 (HEK293-hTLR4/MD2/CD14; HEK293/TLR4) and TLR2 (HEK293-hTLR2/CD14; HEK293/TLR2) were cultured for 20 h with 10 μg/ml or 100 μg/ml of respective diet extracts (eR03, eST1). Ultra-pure lipopolysaccharide from E. coli (LPS; 1 μg/ml) and Pam3CSK4 (PAM, 1 μg/ml) were used as positive controls for TLR4 and TLR2, respectively. Unstimulated cells (M) were used as controls. Results are expressed as mean values ± SEM, representative results from three independent experiments are shown. *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, n.s = not significant.