Fermentation Fever: Eating Fermented Foods for Gut Health
Sourdough bread, cheese, olives, wine, chocolate and coffee. Not only do these foods comprise a fabulous spread for happy hour, but they also are all made through the process of fermentation. Some fermented foods may be beneficial to our gut health. Let’s explore why!
What is fermentation?
Fermentation is a chemical process in which microbes in a food convert carbohydrates into alcohols, carbon dioxide and/or acids. The product of these reactions depends on which microbes are used, typically bacteria and/or yeast. In some fermented foods that are heated or processed in another way, the microbes are not living when the food is consumed. These foods include soy sauce, chocolate, bread, tempeh, beer, wine and shelf-stable fermented vegetables. However, in many other fermented foods, the microbes are still present when the food is eaten. Look for fresh kimchi, sauerkraut, yogurt, kefir, kombucha and miso paste. You may also look for certain clues on a food label that indicate living microbes: for example, “active cultures” in yogurt and “koji” in miso paste. Foods pickled in vinegar and those that have added probiotics are not fermented (1).
Why do we ferment foods?
Humans have fermented foods including dairy, vegetables, whole grains, meat, fish and fruit since the beginning of civilization (2). We ferment foods because:
Fermenting foods increases their storage time. However, this has become less imperative for most populations due to modern advances in technology including refrigeration and the use of chemicals to preserve foods (1).
Fermenting foods improves their nutritional qualities. The process of fermentation can enrich compounds in foods including some B vitamins (folate, riboflavin, B-12) and vitamin K (2).
Fermented foods have a great taste and texture. Fermenting foods even makes some foods palatable that otherwise are not. For example, fresh olives are bitter when they are harvested; it is only through fermentation that they become a delicious fruit.
Many individuals with lactose intolerance are able to tolerate fermented dairy foods only. In the process of making yogurt and kefir, microbes feed on lactose (the carbohydrate in milk), lowering the foods’ lactose content. Many individuals with lactose intolerance are then able to enjoy these foods without experiencing digestive symptoms.
Fermenting foods inhibits the growth of harmful bacteria (1).
Lastly, fermented foods are thought to impart beneficial effects on health, specifically gut health.
How do fermented foods benefit our health?
Eating fermented foods that contain live microbes, or probiotics, helps increase the diversity of our gut microbiota. Consuming foods with probiotics may also help reduce inflammation, support gut barrier function, improve digestion, promote better blood sugar control and improve the breakdown and storage of fat in the body, aiding in body weight management (1, 2, 3, 4, 5).
However, there is weak and inconsistent scientific evidence examining the impact of fermented foods on health. We are still learning about which strains and what amount of probiotics in foods may be beneficial. Emerging research may shed light on the potential health benefits of eating fermented foods (1).
To learn more, click here for our webinar on gut health. Read about Great Performances CEO Liz Neumark’s experiments with fermentation here.
5 Easy Ways to Eat More Fermented Foods
Enjoy yogurt as a snack. Choose plain Greek yogurt and add fruit and 1 Tb peanut butter.
Stir kimchi into a brown rice stir fry with tofu or chicken.
Use kefir instead of milk in a smoothie. Blend 1 cup ice, 1 cup kefir, ½ banana, ½ cup blueberries, 2 Tb almond butter and ½ tsp cinnamon.
Add sauerkraut to a salad for a tangy condiment.
Whisk 2 Tb miso with 2 Tb rice wine vinegar, juice of 1 lime, 2 tsp toasted sesame oil and 2 tsp grated ginger. Use as a marinade for a variety of proteins such as cod, shrimp, chicken or tempeh.
References
(1) Dennett C. The Facts about Fermented Foods. Today’s Dietitian 2018;20(4):24. Available from: https://www.todaysdietitian.com/newarchives/0418p24.shtml.
(2) Gille D et al. Fermented Food and Non-Communicable Chronic Disease: A Review. Nutrients 2018;10:448.
(3) Fernandez MA et al. Yogurt and Cardiometabolic Diseases: A Critical Review of Potential Mechanisms. American Society for Nutrition 2017;8:812-29.
(4) He M and Shi B. Gut microbiota as a potential target of metabolic syndrome: the role of probiotics and probiotics. Cell Biosci 2017;7:54.
(5) Valdes AM et al. Role of the gut microbiota in nutrition and health. BMJ 2018;361:k2179.
