Dave Bonta's "Gastric" is a tiny poem about appetite, and how little it cares for being satisfied. The first two lines loop back on themselves: the stomach desires more, and the result is that it keeps on having more. Want and getting blur together, so the hunger seems to produce its own fuel. There's no sense of ever being full.
The second half widens the lens. "We" suddenly replaces the single stomach, so this isn't just one body's problem but something shared. The image of a moth heading toward a light is the key. Moths are drawn to a flame that can hurt them, and they can't seem to help it. Eating, and perhaps wanting more generally, is framed as a pull we follow almost without choosing. "To take it all up" suggests greed on a large scale.
The mood is quietly uneasy. The speaker sounds matter-of-fact, even a little wry, but the moth hints that this craving may be heading somewhere dangerous.