Hi.. Thanks for the query.. Well, sores in mouth after eating specific foods can be most probably due to intolerance or allergy to those specific foods. Infact, at times spicy, sour and acidic foods can cause inflammation and soreness inside mouth. So the best way to avoid the eruption of sores is to limit the intake of foods that cause such symptoms.. Also if you wish to take probiotics then natural probiotics are Yogurt and garlic and you can also take OTC probiotic pills like Lactobacillus Acidophillus.. Also start taking Vitamin B complex supplements daily.. Drink plenty of cool water and start doing warm saline gargles daily.. Hope you get well soon.. Regards..