Kimchi, sauerkraut, kombucha, sourdough, tempeh, kefir… chances are good that lately you’ve seen a lot more of these fermented guys in the grocery aisles and on restaurant menus. Why the fizz? Food fermentation has been used for many ages in the production of food and was historically used to extend the shelf life of foods and to enhance its flavour.  

Nowadays these products usually come with long lists of health, especially gut health, and wellness claims such as “immune-boosting”, weight-loss inducing, anticancer, probiotic-rich and some of them are even referred to as the “Elixir of life”. However, do any of these claims hold water? The answer is a lot more complicated than a simple yes or no, at least in most cases.

While some studies have shown fermented foods to have higher levels of antioxidants, blood pressure lowering effect, increased vitamin content, probiotic properties or enhanced digestibility compared to their raw counterparts, these results vary across batches and often depend on the environment these foods were made in and the processes followed, making it difficult to generalize and ascertain the health claims (basically, not all kombucha is created equally). When it comes to benefits to your gut microbiota, research in this area is still very much in its infancy and currently, there is not enough evidence to suggest that one particular fermented food modifies the gut microbiota in a specific pattern.

So, the shot of kombucha you took at the farmers market might not “heal” your gut health as the sale’s lady claimed, however, compared to the raw ingredients from which they are made, fermented foods have unique flavors, textures, appearances, and functionalities and can be a great addition to your diet  

Over the next few #fermentationfridays I’ll introduce you to some of these fermented foods, their possible health benefits and how you can incorporate them into your diet or if, like in my case, your landlord has a strict no-pet policy, show you how a SCOBY, kefir culture or sourdough might act as a good, apartment-friendly, alternative.

Book an online or live nutrition consultation session with me when you want to find out more about fermentable foods.


Melini, F., Melini, V., Luziatelli, F., Ficca, A.G. and Ruzzi, M. (2019) ‘Health-promoting components in fermented foods: an up-to-date systematic review’, Nutrients, 11(1189), pp.1-24 [Online]. Available at: https://pubmed.ncbi.nlm.nih.gov/31137859/ (Accessed: 23 November 23, 2020)

Stiemsma, L.T., Nakamura, R.E., Nguyen, J.G. and Michels, K.B. (2020) ‘Does consumption of fermented food modify the human gut microbiota?’, The Journal of Nutrition, 150(7), pp.1680-1697 [Online]. Available at: https://pubmed.ncbi.nlm.nih.gov/32232406/. (Accessed: 23 November 2020)

About the author:

Tanya has been providing dietary guidance since 2009 as a registered dietician licensed in South Africa. Her goal is to help patients understand the connection between diet and diagnosis for improved nutritional well being.

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