You post to so many threads that it becomes difficult to know what I have posted and what I have not. Keeping your posting concentrated to one thread would of been far more productive IMO.
Probiotics/bacteria/probiotic yeasts ie boulardii can all be cultured which would save a lot of money. They do need a food source and warmth such a temperature regulated heating element, there is a very good one which was designed for beer but could be used for other fermenting/culturing purposes. I have used probiotic capules to make yoghurts in the past and that includes S Boulardii which came out very well. Another food source might need to be used if you cannot tolerate milk. They do sell small trial sizes which can be used to culture them which is what I used. The first culture does take a lot of time but subsequent cultures using some of the previous batch is much quicker. Around 16 hours from the capsule and then 3 to 4 hours using some of the previous batch.
There are some forums which document the process of building this. Some form of yoghurt maker or heating chamber could be combined with the programmable heat regulator stc1000. I have an arduino and want to build a device using my old broken convection microwave oven to culture bacteria/ferments/yoghurts.