Table 1. Activation of LEE1 transcription and bioluminescence in V. harveyi by intestinal flora.

Media	LEE1::lacZ transcription*	Luminescence V. harveyi BB170†
SHIME	239 ± 23	1 ± 0.1
PC§-SHIME-flora	2,910 ± 100	38 ± 3.5
PC-86-24	1,367 ± 209	78 ± 20
PC-DH5α	220 ± 20	1.5 ± 0.1

Expressed in fold-induction of bioluminescence compared with media alone.

^‡ SHIME media from the artificial intestine (Supporting Text)

^*LEE1::lacZ transcription is expressed in Miller units of β-galactosidase.

^†BB170 is a V. harveyi luxN::Tn5 that only produces light in response to AI-2.

^§PC, media preconditioned with the intestinal flora, EHEC strain 86-24 (which produces AI-2), or K-12 strain DH5α (which does not produce AI-2).