Thesis Defense - Judah Bates, Goentoro Lab (BE)

"A bacterium promotes partial limb regrowth in Drosophila"

Microbiome modulation can inhibit regeneration, but can microbiome modulation induce regeneration? I present evidence that feeding a Lactobacillus brevis strain alters wound healing, decreases tissue loss, and activates partial limb regrowth. To assess the ways with which L. brevis may alter the host response to injury, I combined genome-scale metabolic modeling with experimental measurements and found that L. brevis secretes the amino acid ornithine. Directly administering ornithine can recapitulate the effect of L. brevis. In addition to ornithine, other work in this research explores how other compounds related to feeding L. brevis, specifically lactate and ecdysone, can promote partial limb regrowth in Drosophila. This research presents evidence that supplying a bacterium can profoundly alter the host response to injury, and that the effects of the bacterium can be recapitulated by metabolites the bacterium secretes. Moreover, day-scale exposure to the bacterium prior to the injury is sufficient to produce the month-scale limb growth, opening up possibilities for prophylactic, regenerative treatments that can be beneficial for populations with high injury risk, such as surgical patients or athletes.

Zoom link: https://caltech.zoom.us/j/82809608221