Dr. Natasha Campbell  - McBride, M.D. author of Gut and Psychology Syndrome (GAPS) book is a great educational tool and reference to why the gut plays an important part of our mental health.  Her and Donna Gates often lecture together on the benefits of fermented foods for children with autism.

Dr. Campbell-McBride holds a Degree in Medicine and a Postgraduate Degree in Neurology and has also completed a Postgraduate Degree in Human Nutrition. In her Cambridge Clinic she specializes in Nutrition for Children with Learning Disabilities, and Adults with Digestive and Immune System Disorders.

Her son, Nicholas was diagnosed with autism when he was 3 years old. Nicholas now attends a mainstream school.

In recent years, we have learned a lot about the biochemistry and physiology of autism and how to manipulate it with diet and supplementation. There is a clear, established link between digestive problems and autism.1, 2 A crucial part of a normal digestive tract is the 1.5 kg of beneficial bacteria that live there.3, 4, 5 Without them we simply cannot be healthy. The functions of normal gut flora, known to science so far, are multiple and far reaching. The Role of Normal Balanced Gut Bacteria (Gut Flora) in the Healthy Child • The normal Gut Flora have a protective and barrier role against invasive pathogenic microorganisms by producing antibiotic-like substances, antifungal volatiles (AFV), and surfactins that dissolve the lipid membrane of envelope viruses and bacteria. • They play a major role in the digestion and absorption of all nutrients. • They provide a major source of nourishment and energy for the gut lining. • They synthesise various amino acids, Vitamin K, panthotenic acid, thiamin, riboflavin, niacin, folic acid, pyridoxine, and cyancobalamine. • They help recycle bile acids and assist normal cholesterol metabolism. • They have a major immuno-modulating role by stimulating antibody production, interferon synthesis, and inhibition of IgA degradation (IgA is secreted into the lumen of the digestive tract in response to approaching food and is essential for the proper digestion of that food). This microscopic world within us is highly organized. In healthy people it is dominated by "good" bacteria which keep under control a huge variety of pathogenic "bad" bacteria. For whatever, yet unknown reason, autistic children develop deficient gut flora.1, 2 While purely breast fed, children may develop normally, as mother's milk is the easiest thing on Earth for the baby to digest and absorb. It also provides that essential initial immune protection to keep the "bad" bacteria under control. As these babies get weaned off the breast to other foods, things can go terribly wrong. Lacking properly established "good" bacteria in the gut, so essential for appropriate food digestion and absorption, an autistic child can develop multiple nutritional deficiencies (vitamins, minerals, essential amino acids and fatty acids) which have a drastic effect on it's development.1, 6, 7 In parallel, pathogenic and opportunistic microbes can develop and grow into large colonies and also transform into active states (e.g. Candida which transforms from its inactive single cell state into a highly invasive micelle). This growth produces a whole host of toxic substances which go into the blood stream and, to put it simply, poison the child. The developing brain is particularly sensitive to these "poisons" as well as to the nutritional deficiencies. As a result, whatever skills the child has developed, while exclusively breast fed, are gradually lost, there is no normal development of language, comprehension, behavior etc. Putting the gut flora right is the first and the most important step in the right direction in treating autism! Gut flora is a living organism very sensitive to the diet, antibiotics, steroids, vaccines and stress.8 When an efficient probiotic is introduced to the gut, over time it clears out the "bad" microbes together with old putrefaction and re-establishes the normal Gut Flora. Once the normal flora is established, the healing process starts and the child starts digesting and absorbing its foods appropriately. The immune system gets the right stimulation and the whole digestive tract changes from being a major source of toxicity (as is the case in autistic children) to a source of nourishment.9 References: Rimland B. New hope for safe and effective treatments for autism. Autism Research Review International 8:3, 1994. Shaw W. Biological Treatments for Autism and PDD. 1998. ISBN 0-9661238-0-8 Cummings JH, Macfarlane GT (1997). Role of intestinal bacteria in nutrient metabolism. (Review)(104 refs). Journal of Parenteral & Enteral Nutrition.1997, 21(6):357-65. Cummings JH, Macfarlane GT (1997). Colonic Microflora: Nutrition and Health. Nutrition. 1997; vol.13, No.5, 476-478. Finegold SM, Sutter VL, Mathisen GE (1983). Normal indigenous intestinal flora in: Human intestinal flora in health and disease (Hentges DJ, ed), pp3-31. Academic press, London, UK. Roberfroid MB, Bornet F, Bouley C, Cummings JH (1995). Colonic microflora: nutrition and health. Summary and conclusions of an International Life Sciences Institute (ILSI) [Europe] workshop held in Barcelona, Spain. [Revew][33 refs]. Nutrition Revews. 53(5): 127-30, 1995. Vorobiev AA, Pak SG et al. (1998). Disbacteriosis in children. A textbook for doctors and medical students. (Russian). M.: "KMK Lt.", 1998. 64p. ISBN 5-87317-049-5. Samonis G, Gikas A, and Toloudis P. Prospective evaluation of the impact of broad-spectrum antibiotics on the yeast flora of the human gut. European Journal of Clinical Microbiology and Infectious Diseases 13:665-7, 1994. Dunne C, Murphy L, Flynn S, O’Mahony L, O’Halloran S, Feeney M, Morissey D, Thornton G, Fitzerald G, Daly C, Kiely B, Quigley EM, O’Sullivan GC, Shanahan F, Collins JK 1999. Probiotics: from myth to reality. Demonstration of functionality in animal models of disease and in human clinical trials. (Review) (79 refs) Antonie van Leenwenhoek. 76(104):279-92, 1999 Jul-Nov.