Heterobasidiomycetes, including the jelly, rust and smut fungi; Previously the entire Basidiomycota were called Basidiomycetes, an invalid class level name coined in 1959 as a counterpart to the Ascomycetes, when neither of these taxa were recognized as divisions.
Too much of anything is bad is general rule of thumb. I found several articles which favour eating peppermint and detail side effects of over consumption. But in general there are some side effects of eating altoids and other mint gums. Mouth sores, headaches, stomach burns are few of them. Check out following links for more information. peppermint: Uses, Side Effects, Interactions and Warnings.
If you have an upset stomach, your first instinct may be to suck on a peppermint candy or brew a soothing cup of peppermint tea. However, while the minty treat can help some digestive conditions, like indigestion and gas, it may hurt others, such as heartburn due to gastroesophogeal reflux disease (GERD). A study from 2011 published in Pain showed why peppermint might help people with irritable bowel syndrome, or IBS.