I have yet to find a probiotic that does not produce lactic acid. Can someone point me to a probiotic that does not produce lactic acid? I know the yeasts might be a candidate. I have been doing loads better since avoiding probiotics and taking antibiotics. The probiotics actually make me feel almost drunk. I believe they are causing metabolic acidosis, which has symptoms quite similar to chronic fatigue. I seriously believe that chronic fatigue at its heart is caused by an overproduction of both D and L lactate producing bacteria. The question is, are there any probiotics that do not produce this? I believe that taking probiotics is possibly dangerous because while the large intestine may contain them, the small intestine probably should not contain fermenting bacteria generating lactic acid. Please let me know of your comments. I am not a formally trained scientist, but after scouring medical literature I ran across a paper showing many people getting metabolic acidosis from taking probiotics - and their cognitive and physical symptoms were identical to those shown in chronic fatigue. Most of us also enjoy taking probiotics. I have tried culturelle, which contains lactobacillus GG. It seems to make me feel worse as well, probably since it generates L-lactate.