Oral health. In addition to the microflora that reside in the large intestine, bacteria populate the mouth as well. An increasing number of probiotic lozenges and gums are thus being promoted for oral health—for example, to reduce periodontal disease, throat infections and bad breath. There’s preliminary evidence that certain strains may have some benefits, but commercial products may not have the same strains and formulations as those tested in published studies. Don’t expect these products to replace brushing and flossing.