I know this whole subject seems confusing (I am not a microbiologist). I have been trying to learn more about this. Here is a list of the bacteria in EM according to Vinney's website: "For the USA regional EM microbial inoculant, which currently contains nine (9) claimed primary organisms, the exact species claimed in the formula are shown below. Incidentally, at this time, the Japanese formula for EM as produced by EM Laboratory for EMRO Japan (please recall that there are plenty of other producers of EM culture in the world as well) consists of the same nine organisms. The organisms are listed below, broken into classes: * Lactic acid bacteria (these are beneficial organisms widely found in fermented foods, and in the GI tract of healthy humans and animals): * Lactobacillus plantarum * Lactobacillus casei * Lactobacillus fermentum * Lactobacillus salivarius * Lactobacillus delbrueckii * Phototrophic purple non-sulfur bacteria, aka PNSB (these are widely found in ponds, soil, on plant leaves, in ice, snow and in icicles): * Rhodopseudomonas palustris * Rhodobacter sphaeroides (aka R. spheroides) * Rhodobacter capsulatus * Yeast: * Saccharomyces cerevisiae (these are beneficial organisms widely found in fermented foods, and in the GI tract of healthy humans and animals)" I believe that the production of EM involves a special way of fermenting organisms, from 3 different classes: Lactic acid producing organisms, Phototrophic organisms, and Yeasts. You could take any number of different organisms from these same 3 groups and use the EM fermentation process to make a different product. Although Primal Defense doesn't contain the phototrophic bacteria, the SBO's it does contain have many of the same properties as the phototrophic bacteria. They have the capability to break down organic material, and produce antibiotic substances which suppress the growth of pathogenic organisms. Primal Defense also contains the lactic acid producing bacteria, and one yeast. On another interesting note, these two organisms (bacillus subtilis, and bacillus licheniformis) are used in many different commercial feeds for cattle, horses, pets etc. It's ironic that livestock breeders know more about health and nutrition than doctors. Read this page for a good laugh at how pathetic our medical system is: Note the article listed at the bottom "Why probiotics and enzymes are important feed additives." http://www.wingedwolf.citymax.com/catalog/item/3445329/3043962.htm