Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain brown coating over the tongue also known as
Black Hairy Tongue can occur due to a number of causes and the causes you have read are correct and also other causes can be poor
Oral hygiene causing bacterial and fungal growth on tongue, long term intake of soft foods, taking medication containing Bismuth, overgrown Papillae etc..
I would suggest you to maintain a good Oral hygiene..
Clean your tongue using a tongue scraper..
Gargle with 1:1 solution of
hydrogen peroxide and water..
You can dip a soft toothbrush brush in this solution and clean the tongue with it..
Eat more of raw fruits and vegetables..
Avoid tobacco, alcohol and tea and coffee..
Drink plenty of water and maintain a good hygiene..
Gargle with antiseptic mouthwash..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.