Question: My daughter has developed dreadful bad breath. She cleans her teeth well, so we’re at a loss as to what's causing it.

Answer:
Bad breath is often a gut-related condition. When the billions of beneficial bacteria in your intestinal tract get out of balance with the bad bacteria, your daughter may have digestive problems, even if she doesn't experience the pain of indigestion.

If food is not digested properly, it can cause acid reflux, yeast overgrowth, or fermentation in the stomach; these all trigger bad-smelling by-products which rise up as bad breath.

• Try putting her on a course of probiotics that contain a range of beneficial bacteria, including Lactobacillus acidophilus and Bifido bacteria.
  
• You could also give her a chlorophyll supplement which helps counter yeast overgrowth and keeps the intestinal tract clean and healthy.
  
• Make sure she doesn’t skip meals; when you don't eat for a long period of time, your mouth can get very dry and becomes a perfect breeding ground for bacteria.
  
• Because dehydration produces bad breath, it's important to drink at least eight 250 ml glasses of water a day. Avoid alcohol, as it dries out the mouth and can cause more odours.
  
• Watch out for foods and beverages that have strong odours, such as onions, garlic, and coffee. Sugary foods can also be a problem, since sugar feeds the bacteria that grow in the mouth. Foods with antibacterial properties that reduce bad breath include green tea and cranberries, which seem to make bacteria less adhesive.
  
• Use a toothpaste that contains tea tree oil, a natural disinfectant. Chewing on liquorice-flavoured anise seeds is a handy emergency measure, and helps kill the bacteria that grow on the tongue.
  
• Keep sugarless chewing gum in your pocket or bag. Chewing a stick after meals will stimulate saliva flow and clear away food debris.
  
• To keep a toothbrush free from bacteria, store it, head down, in a lidded plastic tumbler of hydrogen peroxide. Rinse the brush well before using.

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