Hi and welcome
Sadly we cannot give you an answer just from your description without a hands-on examination (not that we are qualified to replace any vet care!)
Is the gurgling coming from from the mouth/throat/nose area or from the belly area? In this case, it is likely something stuck or fluid ending up in the wrong place. If it persists, you may want to have the mouth checked. Teeth grinding is normally a sign of some pain, but in connection with gurgling in the mouth area, it could indicate an attempt to dislodge something stuck
Gurgling in the belly: The intestines should constantly glugger when you hold your ears against the belly, like a cow's guts. If they aren't or if there is very little activity then you are dealing with life-threatening GI stasis (the gut has stopped working fully or partly). If you are dealing with very audible gurgling, then your guinea pig is gassing. Please keep an eye out for serious bloating over the next 24 hours; a loud episode of gurgling can also precede the onset of GI stasis. In both cases see a vet asap; they are potentially life-threatening emergencies.