Fermented foods, such as sauerkraut, contain probiotics, which are helpful live bacteria. Adding probiotic bacteria to the digestive system through food or supplements may benefit health and support the gut microbiome (community of microorganisms such as bacteria, fungi, and viruses obes living in the digestive system).

The time of day when sauerkraut is eaten for gut health is less important than how often. Eating fermented foods frequently, ideally on a daily basis, helps maintain their effects on the microbiome.

Consistency vs. Timing

There’s no recommendation on when eating sauerkraut is best for improving gut health or other health effects. What’s more important is the consistency of eating fermented foods. Adding fermented foods to a diet will nourish the gut microbiome, potentially maintaining its benefits.

People eat fermented foods both on an empty stomach and with a meal. Insufficient research has been conducted to determine which approach is most effective. Eating fermented foods daily is considered more important than the time of day at which they are eaten.

Eating a probiotic food or taking a supplement shifts the composition of the microbiome. This change is beneficial when helpful gut bacteria are depleted. This is an effect called dysbiosis. Dysbiosis occurs for many reasons, with the use of antibiotics being a common cause.

The shift in the microbiome from outside factors is not permanent, however. Some changes to the microbiome can reverse and return to baseline (where it started) or nearly baseline levels. Regularly eating probiotic foods is one way to continue colonizing the microbiome with helpful microorganisms.

Sauerkraut Nutrition

Sauerkraut is fermented cabbage. It contains both probiotics (beneficial living microbes) and prebiotics (nutrients that serve as food for bacteria in the gut). Sauerkraut also contains antioxidants, which neutralize free radicals. Free radicals are naturally occurring, unstable molecules that contribute to a process called oxidative stress, which can lead to cell and tissue damage.

Commercially made sauerkraut is sometimes pasteurized. Pasteurization may kill the living organisms. Finding sauerkraut that has not been heated or cooked helps ensure it contains living probiotics.

One cup of sauerkraut contains these nutrients:

• Calories: 54
• Protein 1.26 grams (g)
• Carbohydrates: 5.82 g
• Fat: 3.5 g
• Vitamin C: 18 milligrams (mg)
• Vitamin A: 34 micrograms (mcg)
• Folate: 31 mcg
• Vitamin K: 20 mcg
• Iron: 2 mg

Sauerkraut has a tangy taste that pairs well with other foods. People eat sauerkraut as a condiment or a side dish. Some ideas for eating sauerkraut include:

• In a salad
• In a sandwich
• Mixed into egg or tuna salad
• On top of hot dogs
• Paired with meatballs or sausage

Sauerkraut is made with salt and, therefore, has a high sodium content. People advised to avoid salt or lower sodium in their diet should be aware of this if considering eating sauerkraut.

The Gut Microbiome and Health

Many bacteria, viruses, and fungi live in and on your body. In the digestive system, these helpful microbes aid digestion. Every person has a unique balance of microorganisms in their digestive system within their gut microbiome.

The microbiome influences overall health. Researchers are still uncovering all the ways it interacts with body systems. Some of the things the microbiome affects include:

Many factors can influence the composition of the gut microbiome in ways that may be beneficial or detrimental. When the bacterial balance changes in an unhelpful direction, the result could be digestive problems. This disturbance in the microbiome is called dysbiosis.

For example, an overgrowth of the bacterium Clostridioides difficile causes diarrhea and other symptoms, which requires strong antibiotic treatment.

Factors affecting the microbiome of the digestive system include:

• Antibiotic use
• Diet
• Exercise
• Having a pet
• Occupation (such as farming or working with livestock)
• Sleep
• Stress

Probiotic Foods

Probiotics are beneficial bacteria that are found in certain foods and available as dietary supplements. A probiotic food contains living bacteria that are useful for the gut. Naturally fermented foods often contain probiotics. Other foods (such as some yogurt) may have added probiotics.

Researchers are studying probiotic foods. Studies finding evidence of the health benefits of probiotic foods are lacking. Potential health effects include reduced risk of:

Eating probiotic foods is considered a good way to introduce probiotics to the microbiome. No regulations exist around probiotic supplements, so they may not contain the types or numbers of bacteria listed on the label. Or, the bacteria in the supplement may no longer be alive.

Foods that contain probiotics include:

• Apple cider vinegar (if it contains the “mother,” by-products of fermentation)
• Fermented cabbage products, including kimchi and sauerkraut
• Fermented fish (utonga-kupsu)
• Fermented or cultured milk products, including cultured buttermilk, kefir, yogurt (including Greek yogurt) and some cottage cheese (ensure probiotics are listed on the label)
• Fermented soybean products, including miso and tempeh
• Kombucha (fermented, semi-effervescent black tea beverage)

Summary

The gut microbiome contains many microorganisms. The microbiome supports overall health. Eating fermented foods is one way to introduce beneficial bacteria, known as probiotics, to the gut. Sauerkraut is fermented cabbage that contains probiotics.

Regularly eating sauerkraut or other probiotic foods supports microbiome diversity. The microbiome changes with eating probiotic foods, but these changes are not permanent. Regularly eating fermented foods can sustain the bacterial diversity in the digestive system.