CCK and hydrops fetalis: Microbiota-depleted rats colonized with a HF-type microbiota also display reduced sensitivity to the GI satiety peptide CCK37 and dampened food -associated reward.15 Conversely, normalizing microbiota composition or inhibition of immune cells in HF rats prevented the loss of vagal innervation at the level of the NTS and preserved CCK sensitivity.13,40 These data show that HF-driven changes in microbiota composition and associated inflammation are necessary and sufficient to alter vagal signaling.