I want to get back to the original question for a moment.
There are two ingredients on the market that will allow you to market “probiotic” claims in your skin cream. The fact that it’s all puffery and mostly nonsense is irrelevant - the ingredients make any number of claims which can transfer to a product that uses them.
To me, the easiest and most cost-effective way to do this is to select a contract manufacturer that is large enough to have its own R&D people, and negotiate a deal that includes your ownership of the formula, and any IP associated with it.
If I were you, I’d try to talk to as many consultants as possible. Consultants get paid in different ways, and they’re not always completely open about it - some have paid relationships with certain contract manufacturers, and they get a commission if they steer your business to them. Someone who has significantly lower than average prices may have an arrangement like this - or they may be semi-retired, and just consult for the fun of it. It’s wise to check.