FIG. 7.

Inhibition of Stx2 synthesis by factors produced by the human fecal microbiota in cecal contents of rats. E. coli EDL933 (4 × 10⁶ bacteria/ml) was grown in the cecal contents of germfree rats (GFC) or in the cecal contents of human microbiota-associated rats (HMC) obtained with an adult's or child's fecal microbiota. At the indicated times, Stx2 concentration in culture supernatants (A), stx₂ mRNA levels (B), and stx₁ mRNA levels (C) in bacteria were determined. Data represent the mean ± SEM of three independent experiments performed in duplicate.*, a P value of <0.05 for GFC versus that for HMC.