Sauerkraut: what one good trial actually found

Most of what sauerkraut is praised for rests on a single careful trial, and its result is smaller than the jar suggests. 87 healthy adults ate 100 g a day for four weeks, fresh sauerkraut in one period and pasteurised in another. There was no period without sauerkraut to compare against, so every change is measured against how people were before they started. Their gut microbiome as a whole stayed resilient, with only single species shifting. Systolic blood pressure fell slightly compared with before, and the abstract we read does not give the size of the drop. Gut barrier markers did not change, and the authors found no appreciable systemic health benefit. The surprise is which jar did more. Only the pasteurised sauerkraut, which held no living bacteria, raised short-chain fatty acids in the blood, and the authors saw more pronounced changes after it than after the fresh one. The small blood pressure drop showed up with it too. In this trial, then, the live bacteria were not needed for the small blood pressure drop or the rise in short-chain fatty acids. Every trial on this page fed people sauerkraut itself, as food. None of them tested a capsule or a supplement.

The numbers, per 100 g

How much is actually in it

• Fresh sauerkraut kept changing in the fridge, with Limosilactobacillus reuteri at 60.8% of bacteria after 7 weeks, while the pasteurised product held no living bacteria. — 87 healthy adults aged 21-69, 100 g fresh or pasteurised sauerkraut a day for 4 weeks each (n = 87) Evidence D source
  L. reuteri 60.8% mean relative abundance after 7 weeks cooled storage
• Across 121 sauerkraut samples, tyramine averaged 174 mg per kg with very wide variation, and the lowest concentrations were found in home-made sauerkraut. — 121 sauerkraut samples, Czech and Austrian manufacturers, household and jarred (n = 121) Evidence D source
  Tyramine mean 174 mg/kg, putrescine 146, cadaverine 50
• Histamine in 121 sauerkraut samples was below 2 mg per kg in 44% of them and above 10 mg per kg in only 19%. — 121 sauerkraut samples, Czech and Austrian manufacturers, household and jarred (n = 121) Evidence D source
  Histamine mostly low

What a real portion looks like

• A daily 100 g portion of sauerkraut for 4 weeks was tolerated by 95% (fresh) and 90% (pasteurised) of participants, with no change in stool form, frequency or faecal pH. — 87 healthy adults aged 21-69, 100 g fresh or pasteurised sauerkraut a day for 4 weeks each (n = 87) Evidence B source
  Contentment 95% and 90%, no significant stool changes

What cooking and storage change

• In the 87-person crossover trial, changes were more pronounced after pasteurised sauerkraut than after fresh, and only the pasteurised version raised serum short-chain fatty acids. — 87 healthy adults aged 21-69, 100 g fresh or pasteurised sauerkraut a day for 4 weeks each (n = 87) Evidence B source
  Serum SCFA increased after pasteurised arm only
• The small blood pressure drop in the 87-person trial appeared with pasteurised sauerkraut too, so live bacteria were not needed for it. — 87 healthy adults, 100 g fresh or pasteurised sauerkraut a day for 4 weeks each (n = 87) Evidence B source
  Effect present in both arms

What it does to your health

• Eating 100 g of sauerkraut a day for 4 weeks changed only single bacterial species in the gut of 87 healthy adults, and the microbiome as a whole stayed resilient. — 87 healthy adults aged 21-69, 100 g fresh or pasteurised sauerkraut a day for 4 weeks each (n = 87) Evidence B source
  Single species changes, no broad shift
• In 87 healthy adults, 100 g of fresh or pasteurised sauerkraut a day for 4 weeks slightly lowered systolic blood pressure but gave no appreciable systemic health benefit and did not change gut barrier markers. — 87 healthy adults, 100 g fresh or pasteurised sauerkraut a day for 4 weeks each (n = 87) Evidence B source
  Small SBP reduction, no change in gut barrier integrity
• Polish migrant women who ate more than 4 servings a week of cabbage and sauerkraut as teenagers had lower odds of breast cancer (OR 0.36) than those eating 2 or fewer. — 131 breast cancer cases and 284 controls, Polish-born women in the US (n = 415) Evidence C source
  OR 0.36 (95% CI 0.18-0.71) adolescence, 0.50 (0.23-1.06) adulthood

Safety, limits and interactions

• Sauerkraut is listed among histamine-rich foods, and a 75 mg oral histamine dose caused symptoms in 5 of 10 healthy women without known intolerance. — 10 healthy women aged 22-36 (n = 10) Evidence B source
  5 of 10 reacted to 75 mg histamine, none to placebo
• More than 50% of 139 psychiatric patients assessed before possible MAOI treatment ate sauerkraut at least monthly. — 139 psychiatric patients before possible MAOI treatment (n = 139) Evidence C source
  Monthly use > 50%

What people believe that the data does not support

• The EU did not authorise the claim that sauerkraut juice supports digestion. — EU health claim applicants (n = -) Evidence E source
  Non-authorised

Who this works differently for

• In 34 people with IBS, 6 weeks of daily sauerkraut cut symptom scores by 38.57 (pasteurised) and 56.99 (unpasteurised) points, with no difference between the two and a study too small to be sure. — 34 Norwegian adults with irritable bowel syndrome, 6 weeks (n = 34) Evidence B source
  IBS-SSS -38.57 +/- 17.08 vs -56.99 +/- 16.92, both P < 0.04, no between-group difference
• Among 3204 children and teenagers, higher intake of Chinese sauerkraut and pickled foods went with better lung function ratio FEV1/FVC. — 3204 children and adolescents in China (n = 3204) Evidence C source
  Positive association per SD, P < 0.05

What is still unknown

• In a US cohort (MESA), eating from a food group that pooled broccoli, cabbage, sauerkraut and kimchi was linked with lower inflammation and mortality odds, with sauerkraut not analysed on its own. — MESA cohort, US adults (n = -) Evidence C source
  Lower mortality odds for the pooled category

The bottom line

If you want to try it, the 100 g a day portion was easy to live with. 95 percent of people were content with the fresh version and 90 percent with the pasteurised one, and stool form, frequency and faecal pH did not change. We hold no card on how much salt sauerkraut carries, so this page cannot tell you what that 100 g adds to your day. People with irritable bowel syndrome have one small trial of their own. In 34 Norwegian adults, six weeks of daily sauerkraut lowered symptom scores by about 39 points on the pasteurised version and 57 on the unpasteurised one, with no real difference between the two. So it is a hint, and not yet an answer. The trial had no group without sauerkraut, and the authors say it was too small to be sure. Fresh sauerkraut keeps fermenting in the fridge. After seven weeks one species, Limosilactobacillus reuteri, made up 60.8 percent of its bacteria. What builds up in a jar varies too. Across 121 samples, tyramine, one of the amines the survey measured, averaged 174 mg per kg and varied very widely. Home-made sauerkraut had the lowest levels, but lower on average does not make any single jar low. Two groups should be careful. If you take an MAOI antidepressant, tyramine is the concern. At that average level, a 100 g portion like the one in the trial carries about 17 mg, and a given jar can hold much more or much less. Follow the food list your prescriber gave you. Sauerkraut is also named among histamine-rich foods. Most samples were low, with 44 percent under 2 mg per kg and only 19 percent above 10. At 10 mg per kg, a 100 g portion carries about 1 mg of histamine. In a test on 10 healthy women with no known intolerance, a 75 mg dose of pure histamine, which the authors call a dose found in normal meals, gave symptoms to 5 of them. That dose is about 75 times what such a portion carries. In the same test, blood histamine and the enzyme that breaks it down (DAO) did not differ from placebo. If histamine bothers you, sauerkraut is worth watching. The rest is weaker. Polish-born women who ate more than four servings a week of cabbage and sauerkraut as teenagers had lower odds of breast cancer (odds ratio 0.36). That study compared people after the fact and counted cabbage and sauerkraut together, and the link for adult eating did not reach significance. A US cohort (MESA) tied lower mortality odds to a food group that pooled broccoli, cabbage, sauerkraut and kimchi, without looking at sauerkraut alone. In Chinese children, more Chinese sauerkraut and pickled food went with better lung function, which is an association and nothing more. Chinese pickled cabbage differs from European sauerkraut, so the result does not carry over to the jar this page is about. The EU did not authorise the claim that sauerkraut juice supports digestion, and the register entry does not say why. What we could not answer: we hold no study on how well the body absorbs anything from sauerkraut, and no card on pregnancy or on kidney disease, so this page says nothing about them.

Sources

1. skrt-b1-03 · lab analysis
   After 7 weeks of cooled storage—still before the expiration date—Limosilactobacillus reuteri was the dominant species (60.8% mean relative abundance)... The pasteurized sauerkraut contained no living bacteria and little bacterial DNA.
   Microbiome, 2025 · checked 2026-09-23
2. skrt-b1-09 · lab analysis
   Biogenic amines were determined in 121 sauerkraut samples... Mean concentrations were 174, 146 and 50 mg kg−1 for tyramine, putrescine and cadaverine, respectively. However, very wide variations occurred. The lowest concentrations were found in household-prepared sauerkraut.
   Food Chem, 1999 · checked 2026-09-23
3. skrt-b1-10 · lab analysis
   Histamine levels were below 2 mg kg−1 in 44% of samples and above 10 mg kg−1 in only 19%
   Food Chem, 1999 · checked 2026-09-23
4. skrt-b1-04 · RCT
   Consumption of 100 g fresh and pasteurized sauerkraut for 4 weeks was well received and tolerated by our study population (95% and 90% contentment after fresh and pasteurized intervention, respectively, assessed by a questionnaire). We did not observe a significant change according to the Bristol Stool Form, defecation frequency, or fecal pH after consuming either sauerkraut
   Microbiome, 2025 · checked 2026-09-23
5. skrt-b1-02 · RCT
   More pronounced changes were observed in the pasteurized sauerkraut intervention arm. Only pasteurized sauerkraut consumption increased serum short-chain fatty acids (SCFAs).
   Microbiome, 2025 · checked 2026-09-23
6. skrt-b1-06 · RCT
   Live bacteria are not essential for the hypotensive potential of sauerkraut.
   Eur J Clin Nutr, 2026 · checked 2026-09-23
7. skrt-b1-01 · RCT
   In this crossover intervention trial with 87 participants (DRKS00027007), we investigated the impact of daily consumption of fresh or pasteurized sauerkraut for 4 weeks on gut microbial composition and the metabolome in a healthy study population... The gut microbiome of healthy individuals is rather resilient to short-term dietary interventions even though single species might be affected by sauerkraut consumption.
   Microbiome, 2025 · checked 2026-09-23
8. skrt-b1-05 · RCT
   87 healthy participants consumed 100 g/day of fresh and pasteurized sauerkraut for four weeks... Consumption of both fresh and pasteurized sauerkraut was associated with a small reduction in systolic blood pressure... No change in gut barrier integrity was observed... Four weeks of daily consumption was not linked to an appreciable systemic health benefit in healthy individuals.
   Eur J Clin Nutr, 2026 · checked 2026-09-23
9. skrt-b1-12 · case-control
   The multivariate OR for total cabbage/sauerkraut consumption, high vs. low (>4 vs. ≤2 servings/week) during adolescence was 0.36 (95% CI = 0.18-0.71, ptrend < 0.01) and 0.50 (95% CI = 0.23-1.06, ptrend = 0.08) during adulthood.
   Int J Environ Res Public Health, 2021 · checked 2026-09-23
10. skrt-b1-08 · RCT
    Histamine-rich foods such as cheese, sausages, sauerkraut, tuna, tomatoes, and alcoholic beverages may contain histamine up to 500 mg/kg... After histamine challenge, 5 of 10 subjects showed no reaction... We conclude that 75 mg of pure liquid oral histamine--a dose found in normal meals--can provoke immediate as well as delayed symptoms in 50% of healthy females without a history of food intolerance.
    Allergy Asthma Proc, 2004 · checked 2026-09-23
11. skrt-b1-11 · cross-sectional
    Yeast products, dry sausage, corned beef, broad beans, sauerkraut, and beer were used at least monthly by more than 50% of patients.
    J Clin Psychiatry, 1995 · checked 2026-09-23
12. skrt-b1-15 · regulatory register
    POL-HC-7906 Sauerkraut Saft (milchsauer vergorener Weißkohl (Brassica oleracea var. capitata) [In German:] Sauerkrautsaft regt die Verdauung an. Clarification provided Helps to support the digestion / contributes to the normal function of intestinal tract / functioning of the stomach / sauerkaut juice activate the eupepsia. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7906, snapshot 2026-09-21 · checked 2026-09-23
13. skrt-b1-07 · RCT
    The mean change in IBS-SSS was -38.57 ± 17.08 PS vs. -56.99 ± 16.92 UPS and was significantly improved in both groups (P < 0.04), while the improvement in symptoms was not different between the intervention groups... In conclusion lacto-fermented sauerkraut had an effect on IBS patients' symptoms and gut microbiota even though the study was underpowered.
    Food Funct, 2018 · checked 2026-09-23
14. skrt-b1-14 · cross-sectional
    A total of 611 EAL cases occurred in 3,204 participants, with a prevalence of 19.07%... Every standard deviation increase in foods (Chinese sauerkraut, pickled foods) and nutrients (total dietary fiber, soluble dietary fiber, and pyridoxine) in plant foods was all positively associated with FEV1 /FVC (all P < 0.05).
    Eur J Nutr, 2025 · checked 2026-09-23
15. skrt-b1-13 · cohort
    Consumption of the MESA-defined food category "broccoli" (i.e., broccoli, cabbage, cauliflower, brussels sprouts, sauerkraut, and kimchee) was associated with lower inflammation and lower mortality odds.
    J Med Food, 2024 · checked 2026-09-23