The human intestinal microbiota functions essentially like an organ in the body. It has a vital function like our kidneys, liver, gall bladder etc. I would suggest those who want to learn more about this should read THE PROBIOTIC REVOLUTION, a book that gives lots of info on how important our gut flora are to our immune system. I would also encourage folks to check out the PROBIOTIC THERAPY RESEARCH CENTRE, founded by Tom Borody. He is doing some incredible work at his clinic down under. To quote Him: " Human Probiotic Infusion uses normal "good" Human Flora introduced into the patients bowel to "beat" the bad bacteria. The use of healthy human flors appears to be the most effective probiotic treatment available today. Healthy human flora acts as a "broad" spectrum Antibiotic against pathogens with the added benefit of being able to implant missing bacteria". Aso, Dr. Johannes Aas in Duluth Minnesota is doing this procedure. Both are having great success in treating people with serious bowel disorders such as ulcerative colitis and c. difficile infection. Another book I highly recomend is GOOD GERMS, BAD GERMS. This book could save your life. I hope this helps. My heart goes out to you.