I understand why you might think that Jorge. One needs to be cautious about people selling Candida products. However it does not appear that they sell Symbion. On the ordering page they have a link to the website that sells the product. So it is not immediately apparent how they profit from Symbion sales. In fact, one might argue that promoting Symbion eats into their own sales.
Further, for what it's worth, the Cobbs seem to be genuine. I know it is easy to be fooled by people selling natural health products, but I have more confidence in them than other health salespeople. I think they do want to help people.