I had done a detail post on Saccharomyces boulardii in 2016 and concluded Do not explicitly take this probiotic. Looking at the overgrowth of several bacteria genus in uBiome samples from CFS patients, I keep finding this listed as enhancing the overgrowth bacteria. Almost all of these overgrowth bacteria suppresses bifidobacteria and thus appear to contribute to keeping supporting the CFS microbiome state.
Molecular Monitoring of the Fecal Microbiota of Healthy Human Subjects during Administration of Lactulose and Saccharomyces boulardii  found no impact on bifidobacteria but reading the study we read “”None of the subjects had a history of gastrointestinal or metabolic disease” as well as “it cannot be excluded that subtle changes in less predominant species or groups of species may remain undetected by this approach.” On both of these grounds, their conclusions likely do not apply to dysfunction when rare bacteria take over; bacteria that are our overgrowth.
What should be considered as alternatives?
Coconut oil /monolaurin Post
- “we showed that adding coconut oil to the diet could become the first drug-free way to reduce Candida albicans in the gut.” 
Lactobacillus Fermentum Post
- ““All Lactobacillus fermentum strains tested, namely LF5, LF09, LF10, and LF11, have the ability to significantly inhibit the growth of the five species of Candida of at least 4 logarithms (10000x). Furthermore, the best result obtained with miconazole on C. parapsilosis is still 2 logarithms lower.(100)” 
- “Orally administered E. coli strain Nissle 1917 [Mutaflor] reduced Listeria monocyto-genes and Candida albicans in a dose-dependent manner. Treatment with 10(9) cfu of E. coli bacteria led to a reduction of Listeria counts to 7.4% in spleen and 2.4% in liver. A more than 10-fold decrease of viable Candida albicans (residual parasitaemia 6.8%) in the kidneys of the infected animals was also achieved by this E. coli concentration.” 
- L. Reuteri, L. Rhamnosus, L. Plantarum
- Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 exhibit strong antifungal effects against vulvovaginal candidiasis-causing Candida glabrata isolates .
- “Prophylactic L. reuteri supplementation is as effective as nystatin, and more effective in reducing the incidence of proven sepsis in addition to its favorable effect on feeding intolerance.” 
Lactobacillus plantarum P17630 for preventing Candida vaginitis recurrence: a retrospective comparative study.
- ” A total of 65 patients were randomly assigned to receive oral local antifungal agents alone (gargle 2% sodium bicarbonate solution for 30 s, wait 10 min and then apply 2% nystatin paste) or these agents plus local probiotics (the mixture of Bifidobacterium longum, Lactobacillus bulgaricus and Streptococcus thermophilus) three times per day for 4 weeks… The detection rate of Candida spp. decreased (P = 0.000) in both groups and was significantly lower in the probiotic group than the control group (P = 0.038). ” 
- Probiotic interference of Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 with the opportunistic fungal pathogen Candida albicans .
Curcumin as a promising anticandidal of clinical interest.
- “In conclusion, curcumin is found to be active against all tested clinical and standard strains but is less effective than fluconazole. “
- Antifungal activity of turmeric oil extracted from Curcuma longa (Zingiberaceae).
Many things work against candida. Some researcher are happy to publish positive results that it reduces candida by 50% (1/2). When actual numbers are given, we want the one(s) with the best numbers. The clear winner is: Lactobacillus Fermentum reducing to 1/10000. This is available on Amazon.com in 6 BCFU capsules.The next one with numbers is Mutaflor, just reducing candida to 1/10.