Hi there! Mammoth P contains several "plant growth promoting rhizobacteria" including Pseudomonas putida, which is one of the good ones. Most of these organisms work in the same way-increase uptake of nutrients, suppress pathogenic organisms, AND induce systemic resistance in plants. There are so many different products, and so many different PGPRs....plus you have the mycorrhizae and Trichoderma which are equally beneficial....there is a lot for a new grower to sort out. Here are a few studies
https://www.sciencedirect.com/science/article/pii/S0166248108702137 and
https://link.springer.com/article/10.1007/s00253-020-10516-z
I think mommoth P is a great product, though expensive-if you have the cash, you can't really go wrong with it. I would also suggest a Mycorrhizae product and one that contains Trichoderma-I'm actually leaning towards Trichoderma being the more effective of the two for indoor growing, but I plan on testing that out in the coming year. Check out a product called Soil Blast, it contains trichoderma and several PGPR bacillus species-it is quite reasonably priced and potent. Great White is another popular choice that works well, though the concentration of trichoderma and bacillus sp is quite low. Many roads to the same destination my friend!