The connection between autism and candida is new and highly controversial, but backed by the findings of US laboratory director Dr William Shaw of the Great Plains Laboratory in Kansas. He became interested in the connection after noticing abnormal metabolites in the urine of two autistic children. He noticed that both had extremely high levels of tartaric acid 600 times more than normal children. Tartaric acid is a known toxin, so he wondered whether the tartaric acid could be causing symptoms of autism. He reasoned that, because humans do not produce this chemical and the only source of tartaric acid is yeast, reducing yeast in the gut might reduce the autistic behaviour. Treatment with the anti fungal drug nystatin was tried, with enough success to justify its further use. To date, over a thousand children with autism have been treated with anti fungal agents, with, Dr Shaw reports, "good clinical response in 80 to 90 per cent". In the absence of clinical trials, however, these results must be seen as anecdotal.
Although Truss's treatments have stood the test of time, numerous clinicians are beginning to modify his original therapy. Diets are now becoming less severe, partly because they are difficult to follow and partly because of practitioners' own preferences. There's a difference of opinion, for example, over whether milk and yeast products should be totally excluded (Environmental Medicine in Clinical Practice, BSAENM 1997). How long the diet should be maintained also differs between practitioners; Dr Keith Eaton still maintains a strict diet for three to six months, but Dr Harald Gaier says he now finds three weeks is all that is necessary.
Over the years, conventional anti fungals such as nystatin have gradually tended to fall out of favour. An increasing number of practitioners are now turning towards natural therapies. First and foremost are the "probiotics". These are specially cultured bacteria, identical to the ones in the gut that normally keep the C albicans yeast under control. Once the candida has been cleared by diet or drugs, probiotics are prescribed to repopulate the gut.
Chief among these are species of Lactobacillus and Bifidobacteria (see box, p 2). Apart from competing with C albicans for space, they have also been shown to increase intestinal acidity, creating a less favourable environment for candida. Probiotics can be taken either as dry capsules or liquid yoghurts. Although the anecdotal evidence for their effectiveness is overwhelming, there have been few clinical trials for their use in candidiasis.
A recent year long, crossover trial on candidal vaginitis, however, showed a three fold decrease in symptoms in patients who ate yoghurt containing Lactobacillus acidophilus (Annals of Internal Medicine 1992; 116: 353-7).
Besides using probiotics, many of today's candida practitioners are turning to new sources of anti fungal drugs, most of them extracted from plants. Caprylic acid, for example, is a fatty acid found in coconuts and palm oil; it was shown to have remarkable anti fungal properties 50 years ago (Bull Johns Hopkins Hospital, 1946; 78: 333-9). Eight years later, three cases of "severe intestinal candidiasis" were reported to be successfully treated (Arch Intern Med, 1954; 93: 53-60). Caprylic acid has since been shown to be harmless to friendly gut flora, and yet to kill both the yeast form of candida and the invasive mycelial form, because it is absorbed by the intestinal mucosal cells.