I've had CFS for over 8 years (together with constipation) and it has been very serious the last 4. I've have taken this particular probiotic (though in the now discontinued Blackmore's version) several times over the past 3 years and found that it caused a small but significant improvement (taking me from 20% to 25%). The dosage I used was 1 tab, 3 times a day, at the start of each meal. The last 3 weeks I've been on it this time have also brought improvement (from 17% to 20%). My constipation also improves while on this probiotic. However, after about 20-25 days the effect wears off every time.
I have taken dozens of other probiotics (various lacto-bifido mixes, single strains of lactbacillus & bifidobacterim like Meta-Align, other strains of l. reuteri, e. coli (Mutaflor), sacchromyces boulardii, clostridium butryicum, General Biotics Equilibrium) and none of them have had any clear benefit.
I initially thought the reason for the diminishing effect was that the probiotic was killing off harmful bacteria in my gut but that those bacteria were then developing resistance (although gut analysis has only shown that I have low diversity, but no obviously pathogenic species). My doctor (who is extremely knowledgeable - much better than many other doctors I have had) though thinks that the likely explanation is that my body is developing resistance to whatever beneficial substance the l. reuteri is producing. So I am now going to adopt a schedule of taking this probiotic for 3 weeks, then taking about 4 weeks off (while using an e. coli probiotic some of the time since l. reuteri kills e. coli & I have no e. coli in my gut). Hopefully this schedule will enable me to get benefits from the l. reuteri every 3 out of 7 weeks and gradually rachet up my condition.
The tablets are very easy to take and taste nice. Conveniently, they do not need refrigeration (although I keep mine in the fridge anyway to ensure maximum efficacy & longevity).