I came up with the idea for, and was in charge of planning and conducting, what is to my knowledge the first ever clinical research study that has looked into the efficacy of fermented vegetables in the treatment of Irritable Bowel Syndrome (IBS). The study, which was recently published in the journal Food & Function, has been in the works for quite some time, and several industrious individuals have contributed to its completion. It’s by no means the be-all and end-all of sauerkraut research; however, the trial may help draw attention to the potential uses of fermented vegetables in the treatment of gut-related health problems, as well as trigger further research.
(Note: If you want to read more about the therapeutic potential of fermented vegetables, then I suggest that you check out the eBook I published a short while back, which is entitled Heal Your Gut With Fermented Vegetables.)
Some important caveats & details:
- Sample size
The study is a pilot study. Given that the number of participants is fairly low, one should be somewhat cautious about drawing firm conclusions on the basis of the findings of the study. The study hints that both unpasteurized and pasteurized sauerkraut are useful in the treatment of IBS. I think it’s important to point out though, that in my mind, there’s no doubt that unpasteurized kraut packs more power.
- The intervention
As I point out in my recent article on fermented vegetables, as well as in my eBook on fermented vegetables and gut health, my general recommendation to people with a damaged gut microbiota is to consume small quantities of a diversity of traditionally fermented vegetables (not necessarily every day). The participants in the study didn’t do that. Rather, they consumed fairly large quantities of one sauerkraut product, either pasteurized or unpasteurized, depending on which study group they were in, for the duration of the trial. The main reason is that in a clinical trial, everything has to be measured and standardized and the exposure has to be potent enough to potentially cause an effect that is clearly detectable. One can’t simply tell the participants of a study that they should eat a few tablespoons in total of several different types of fermented vegetables every now and then.
- Placebo-related considerations
No true placebo product was used in the trial, for the simple reason that it’s impossible to create a sauerkraut product that’s completely devoid of anything that could potentially affect human health. All of the participants were instructed to eat a fermented vegetable product; however, only half of them received a product that hadn’t been pasteurized. One can’t exclude the possibility that some of the self-reported effects are placebo effects; however, the fact that the intervention induced gut microbiota modulation, suggests that it had a physiological impact.
It could be argued that we should have had one or more additional endpoints involving some type of biomarker. What’s important to point out though is that IBS is currently not classified as an organic disorder (i.e., a disorder involving measurable, structural change to some tissue or organ of the body), rather it’s considered to be a functional disorder (i.e., a condition in which there is abnormal functioning of some part of the body, but no clearly visible structural alteration of involved tissues). At present, there are no well-established, good biomarkers for IBS. This, coupled with the fact that it would have been fairly expensive and laborious to do additional measurements, is why we didn’t extract and analyze more biological material.
- The final manuscript and title of the study
I didn’t choose the title of the study, nor was I that involved in the preparation of the final manuscript. Hence, there’s a possibility that some of the statements in the article don’t completely align with those I’ve made here on the site.