9. Fungal Infection

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A certain amount of fungus is present in our digestive system, and is necessary for us to properly digest and absorb nutrients from the food we eat. Fungus is usually kept under control by beneficial bacteria such as acidophilus, but when the good bacteria is in short supply, fungus like Candida albicans can run wild. This can cause a variety of symptoms including memory problems, anxiety, irritability, depression, delusions, psychosis, mania or even thoughts of suicide or violent acts.