In reply to feeling ill when you begin your probiotic regime, please know this reaction can be common. Probiotics add healthy bacteria, as you know, but they also push through toxins as a form of detox.
Is your probiotic made with certified organic whole food sources? If not, you could be having a chemical reaction or allergy. I highly recommend finding a probiotic that is created with an all natural or organic fermentation process and is rich with amino acids - especially the 8 essentials.
If you would like more information on probiotics, let me know. I would be happy to send you a CD I have that has great information on how they work inside the body, why they are so vital with today's low nutrient food supply and how the right probiotic can replace all the supplements in your cupboard.
I don't think I can post my website on here (where I host a plethora of information on this) ... but please reply if you are interested and hopefully I will catch the post!