Probiotics make me even more acidic.

I have had a problem with probiotics for 40 years, and no health care practioner can answer it. When taking acidophilus or other forms of probiotics, and recently Lactic Acid Yeast wafers from Standard Process, I become very acidic. My gut feels acid, I cannot stomach my morning coffee and sores appear in my mouth. The sores are the least of my concern.
I should add that I am always very acidic. Use pH strips to test my saliva, I am always at 5.8 to 6.0.
Speak of my everyday acidic condition, nothing I have tried has ever made a difference with the exception of one thing: brown rice. If that is the only thing I eat all day, by mid-afternoon I become alkaline. pH strips put me up in the 7.0 area.
If anyone can offer some help solving this problem, it would be greatly appreciated. I don't have a lot of time left, and fear going to my grave without an answer to this life-long crippling condition that probiotics make even worse.
Thank you in advance for any information or suggestion you can offer.
Tweet