Why do i have brownish goo on my teeth in the morning?

Probably plaque: I would assume that you may not be brushing well enough and that is plaque that accumulated and then shows up in morning from sleeping. Do you thoroughly brush and floss prior to going to bed? It could also come from meds and supplements. Hard to say. See a dentist for a thorough cleaning and checkup

Brown on teeth: This is probably plaque that has stained brown - either way make sure you are brushing 2 minutes at night and in the morniing and try not to eat anything after you brush at night.

Tooth goo: First, make sure you brush thoroughly before bedtime including the tongue. Food remaining overnight can make a sticky and adherent discolored film. Second, many patients mouth breathe for whatever reason--upper respiratory infections, nasal obstruction, sleep apnea. This aggravates film formation. Finally, smoking may turn a normal tongue brown as most tongues do have some film. Stop smoking.

See a dentist: Bleeding gums can be a sign that you are at risk for, or already have, gum disease. Untreated gingivitis can lead to the tooth loss and other health problems. See your dentist ASAP because the sooner you treat it the better the outcome.