When you stick out your tongue in front of the mirror, do you a white layer covering the top of your tongue? That's plaque and it's caused by leftover food debris and bacteria. Though it is not harmful, experts say, it does interfere with your sense of taste. To get rid of it, use a tongue scraper or a soft-bristled toothbrush and scrub your tongue twice daily. Chewing on a celery or a piece of hard bread can also do the job.