As a new mother you want to make sure that your baby is well taken care of and seeing a white layer on your baby's tongue might make you want to clean it off. As is natural when you see something you consider "dirty" on you little newborn, you don't want people thinking you can't take care of your baby and keep her clean.
Your breastmilk forms a protective layer in you baby's mouth, on her tongue, in her throat and all through her intestinal tract to protect her from illness. Thus the white build up on your baby's tongue is not dirty, it is a magical protective layer of breastmilk, fighting off viruses and fungi.
In the old days people often cleaned their babies' tongues with a mixture of Borax and Glycerin, you can be sure to hear from a couple of well meaning family members that you should use the solution as well. Although they mean well, most of these family members had formula fed babies or did not know a lot about what magical powers breastmilk has. Now I can't speak for the formula mom's, as I admittedly have no clue what a formula fed babies tongue looks like or should look like. But I can however tell you with certainty that you should not clean your Breastfed baby's tongue.
Breastmilk contains hundreds of antibodies that protects your baby from bacteria and viruses. Now comes the magic! Your breastmilk forms a protective layer in you baby's mouth, on her tongue, in her throat and all through her intestinal tract to protect her from illness. Thus the white build up on your baby's tongue is not dirty, it is a magical protective layer of breastmilk, fighting off viruses and fungi.
Furthermore, with glycerin being a natural sweetener and babies, like the majority of humans, will love sweet tastes. Therefore lots of mothers use glycerin on baby's dummy or on mom's nipples to encourage latching. While you firstly do not want to encourage your baby to start craving sweet things at such a young age, the glycerin has been known to increase "dry mouth", with dry mouth being one of the situations that lead to oral Thrush.
Thrush occurs when there is an overgrowth of the yeast germ candida. All people have a certain level of candida living in their mouths or on their skin, this is totally normal. It only turns to Thrush when there is a disturbance in the balance and an overgrowth occurs, causing painful white spots in your babies mouth. The candida also lives off of the sugar in glycerin, yet another reason to rather avoid glycerin all together.
If you are not certain if the white build up in your baby's mouth is the breastmilk layer or Thrush, you can usually check to see if you can scrape it off. The breastmilk layer can be scraped off, while the Thrush will stay put. If it is Thrush or you are still uncertain, it is best to seek medical help for a diagnosis and treatment.
(The protective layer of breastmilk is discussed in this article)