Finding probiotics free of lactobacillus is a challenge. This probiotic is not available in Canada, but fortunately most Canadians live close to the border with the US.
So what do we know about these species/strains? (My earlier notes are here)
- [Preventive effect of Clostridium butyricum M588 against the proliferation of Clostridium difficile during antimicrobial therapy].
- “35 strains of bacteria were detected, but 3 days after administration [of Probiotic-3], 16/30 strains of Gram-positive bacteria, and 2 strains of Gram-negative bacteria disappeared.” 
- [Observation on intestinal flora in patients of irritable bowel syndrome after treatment of Chinese integrative medicine].
- C.Butyricum was combined with Tong xie Yao fang. C.B. by itself had impact, just not as much
- Probiotic Bio-Three induces Th1 and anti-inflammatory effects in PBMC and dendritic cells.
- Oral administration of Clostridium butyricum for modulating gastrointestinal microflora in mice.
- “The use of perioperative probiotics[Probiotc-3] reduced postoperative infectious complications after pancreaticoduodenectomy, making it a promising potential adjunct therapy for patients” 
- “This probiotics mixture[Probiotic-3] reduced the severity of diarrhea and length of hospital stay in children with acute diarrhea. In addition to restoring beneficial intestinal flora, probiotics may enhance host protective immunity such as down-regulation of pro-inflammatory cytokines and up-regulation of anti-inflammatory cytokines.”
- last, but not least, it is a butyric acid producer which is believed to help with “Gut inflammation in chronic fatigue syndrome“
A lot of this literature comes out of Russia/East Europe.
- [Antibiotic properties of Bacillus mesentericus].
- [Fibrinolytic activity of natural variants of Bacillus mesentericus]. 
- [Fibrinolytic activity of Bacillus mesentericus strains].
- Effectiveness of probiotic therapy for the prevention of relapse in patients with inactive ulcerative colitis .
- “The relapse rates in the Bio-Three and placebo groups were respectively 0.0% vs 17.4% at 3 mo, 8.7% vs 26.1% at 6 mo”
While there have not been studies for it’s effect on CFS, there is one study showing that it improves IBS (co-morbid with CFS often), and very good results for UC.