from this page: http://articles.mercola.com/sites/articles/archive/2012/05/12/dr-campbell-mcbride-on-gaps.aspx?e_cid=20120512_DNL_artNew_1 which has transcript of the above interview.
“All diseases begin in the gut! The Father of modern medicine, Hippocrates, made this statement more than two thousand years ago. The more we learn with our modern scientific tools, the more we realise just how correct Hippocrates was: all diseases do begin in the gut! Science has discovered, that about 90% of all cells and all genetic material of the human body belongs to the gut flora – a mixture of various microbes, which live inside our digestive tract. So, in reality your body is just a shell, a 10%, providing a habitat for this mass of micro-creatures living inside you; and their role in your health and physiology is monumental. Our modern world poses many dangers for human gut flora, and once it is damaged, the health of the whole body enters a downward slide towards disease. “