1. What I already mentioned above regarding the conflicting results of these two placebo controlled trials
2. The studies used in the nhs article are all done for patients that we're currently undergoing treatment for c diff, not after a long treatment time.
3. Meta analyses and systematic reviews are always going to be higher powered statistically speaking. As long as the papers looked at don't stink of publication bias it's a very valid way of looking at all the research done on fecal transplants for c diff.
I would definitely trust a small negative placebo controlled trial over a large meta-analysis that didn't include any placebo controlled trials, especially for a treatment that has a 90% placebo responder rate (as the trial posted by elsherbini shows).
"There have been a total of 2 placebo-controlled trials into fecal transplants for C.Diff AFAIK. One showed some benefit over placebo, and the other showed no difference."
https://news.ycombinator.com/item?id=10679823#10680173