As someone who frequently conducts literature searches, I find these review papers critical to my work. If taken at face value, a it lets me know that I need not look further. If not, it is a starting point for cross-references.

That said, I would have liked to see a methods section with a list of search terms.

What I read is that the _majority_ of the studies are not good quality. There are very few high-quality studies e.g. double-blind randomised controlled trials and crossover studies, etc and most studies have a very small number of subjects. However, it's hard to fault a double-blind RCT for low quality because it has few subjects. Low statistical power, OK, but if the methodology is sound then the paper has merit.

Given that these studies go back a number of years and there is still no conclusive evidence for any health benefits from the consumption of fermented foods it is useful to have a summary of the current state of research.

I don't have any feelings on possible health benefits either way, but I like some fermented foods and was curious if there was something to learn. Oh well.