19-05-2025
What the Germans are getting right about gut health
It's hard to deny, fermented foods are having a moment. Once the preserve of niche health food stores, sourdough loaves, kefir, kimchi, and miso are fast becoming everyday items, celebrated for their gut health benefits.
But while our supermarket shelves might be groaning with trendy kefir 'gut health shots' and 'super-beet kimchi', a recent study shows we might be missing a trick when it comes to healthy ferments.
The study from the University of California suggests that an old-school staple – sauerkraut – packs an equally powerful probiotic punch, delivering myriad health benefits.
It's affordable, easy to make and teaming with gut-healthy live bacteria. Dr Hannah Richards, a gut nutrition specialist, explains that ferments like sauerkraut, 'support immune regulation and reduce inflammation, which can help prevent cancer'.
Literally translated as 'sour cabbage' in German (though the dish first originated in China over 2000 years ago) sauerkraut has been a beloved staple in Germany and Eastern Europe for hundreds of years, after it was brought to Europe by the Mongols in the 13th and 14th centuries.
Shredded, salted and fermented in its own brine before being ladled into stews and soups by devoted fraus to their young. Its cultural impact was so powerful that during the First World War, 'Kraut' became slang for German soldiers.
But don't be deterred by the name – or its ration-era connotations.
Tangy, salty, and with just the right bite, sauerkraut offers the same zing as any trendy pickle. But unlike the pickle (which is usually soaked in sugary vinegar) the health benefits are impressive. It all comes down to the fermentation process.
1. It improves digestion
As it ferments, sauerkraut becomes loaded with natural enzymes produced by the lactic acid bacteria. These enzymes help break down food into simpler, more absorbable forms, making it easier for your body to access all the vitamins and minerals in your meal, giving more bang for your nutritional buck.
Dr Richards explains, 'You want a really good varied amount of bacteria in your gut, the more you have, the better your digestion is going to be.'
On top of this, cabbage itself is a cruciferous vegetable, meaning it is naturally rich in the non-digestible fibres known as prebiotics. Unlike probiotics, which are live bacteria, prebiotics help your existing gut microbes thrive. Think of them as fertiliser for your gut ecosystem.
2. Boosts your immune system
As over 70 per cent of our immune system lives in the gut, a balanced gut microbiome – the millions of microbes including bacteria, viruses, and fungi that naturally live inside us – is essential. Research shows that sauerkraut's probiotic strains aid just that, and, in the process, strengthen the gut lining. This reduces the leaking of inflammatory toxins, such as lipopolysaccharides (LPS), into the bloodstream.
Dr Richards breaks it down: 'By having more bacteria, you have a more balanced microbiome and stronger immune system. Less LPS equals less immune activation, which then equals less inflammation.' Left untreated, inflammation can seriously damage our cells, leading to various health issues including an increased risk of cardiovascular disease, cancers, diabetes, and autoimmune disorders.
3. Can make you happier
There is no instant fix or miracle supplement when our mental health dips. Serotonin is the hormone responsible for mood regulation, sleep and appetite amongst other things; those deficient in it often experience symptoms of anxiety or depression. Since a staggering 95 per cent of our bodies' supply is made in the gut means that caring for our microbiomes should be a top priority when it comes to mental wellbeing.
Studies have also pointed to the fact that certain strains of probiotic bacteria, such as lactobacillus helveticus and bifidobacteria, longum, found in fermented food like sauerkraut, may also improve symptoms of anxiety and depression. This is because these bacteria produce compounds called short-chain fatty acids which help reduce inflammation. Studies suggest that increased inflammation can lead to higher levels of anxiety.
Sauerkraut is also rich in mood-balancing probiotics and minerals such as magnesium and zinc, commonly used by nutritionists to manage mood disorders.
4. Supports heart health
'The gut microbiota plays a really important role in regulating and lowering cholesterol,' says Haworth. 'They do this through the compounds they produce when breaking down the prebiotics found in sauerkraut.'
These compounds (short chain fatty acids) help regulate blood fat levels, including lowering LDL cholesterol, the so-called 'bad' kind that can clog up arteries and raise the risk of heart disease. At the same time, a healthy gut can support levels of HDL cholesterol – the 'good' kind – which helps sweep excess cholesterol back to the liver for processing.
A happier gut means a healthier heart – and all the more reason to keep an eye on your diet.
5. May reduce cancer risk
Cabbage is naturally rich in glucosinolates, found to have 'anti-cancer properties,' says Richards. They are powerful compounds that survive the fermentation process and help detoxify carcinogens, protecting cellular DNA in the process.
Research also points to sauerkraut's role in shielding colon cells from oxidative stress, thanks to its anti-inflammatory fibre content and antioxidant vitamins C and K.
It is no coincidence, Richard notes, that 'the natural diet, traditions, and culture of food in eastern Europe and parts of Asia are responsible for the lower prevalence of cancer'.
So yes please, pass the bigos (a Polish stew made from chopped meat and sauerkraut).
A spoonful will do…
While delicious, sauerkraut isn't a vegetable to heap onto your plate. Save the serving spoons for the leafy salads.
Dr Richards advises that less is more: 'Ferments are great for the gut, but too much can be an overload. You want it to be a pleasant surprise or aftertaste as opposed to overpowering and sour.'
Highly fermented foods are potent and medicinal and can have greater side effects than a few ginger shots or a kale binge. If overdone, they can trigger digestive issues like bloating and acid reflux, especially in people with small intestinal bacterial overgrowth (SIBO).
'They need to be seen as a supplement or as a medicinal offering,' advises Richards. 'A tablespoon [roughly 10g] mixed through your salad is enough.'
How to include sauerkraut in your diet
While perhaps a little scarier than the gut health titans sourdough and Greek yogurt, this superfood can be incorporated into your diet as a sprinkling or a dollop on most everyday dishes. Here's how:
As a topping: Sprinkle it on green salads, avocado toast, or a loaded baked potato for an extra zing.
In sandwiches or wraps: Pair with sliced chicken or turkey in a hearty sandwich, or add to a falafel and hummus wrap for some delicious depth.
In stews and soups: Stir into your pork stroganoff or chicken casserole with a dash of stock or wine.
As a replacement for ketchup: You will get the same vinegary hit, without the refined sugar.
How to maximise its benefits:
Pair it with a varied diet: You need lots of different bacteria in your gut for optimum health. This is achieved by eating a healthy diet varied in colour, texture and taste.
Build up slowly: Start with small amounts less often to let your digestive system adjust.
Look in the chilled section: Many varieties are pasteurised to extend their shelf-life, killing the majority of the bacteria within. Supermarkets will keep 'live' probiotics chilled.
Put the table salt down: Sauerkraut is high in sodium so be careful with over-seasoning the rest of your meal. If your recipe requires salt, use good quality sea salt rather than the processed alternatives.
FAQs
Is it OK to eat sauerkraut every day?
Sauerkraut is incredibly nutritious, and eating a tablespoon, roughly 10g, a day will strengthen your gut microbiome.
Is sauerkraut anti-inflammatory?
Sauerkraut is highly anti-inflammatory. It contains antioxidants like sulforaphane which help combat inflammation induced by cellular damage. This is because they combat the molecules that damage cells known as 'free radicals'.
What is the healthiest way to eat sauerkraut?
Raw and in small amounts, preferably just before or during meals to ensure probiotic benefits.
