Fermented Foods for Immune System

Tateki Matsuda

August 10, 2022

Last October, American food professionals visited fermented food producers to deepen their knowledge of Japanese fermentation culture during the “Hakko Tourism in Japan” tour campaign. As part of the tour, organizers held a tasting session where guests gave candid advice from the perspective of the American market to food product manufacturers looking to enter the United States market.

The immune system is a complex network of cells, tissues, and organs that work together to protect the body from foreign invaders. These foreign invaders can include bacteria, viruses, and other harmful microbes. The gut is home to many of these foreign invaders, which is why gut health is so important for immune system function. The gut flora (the bacteria that live in the gut) plays a critical role in immune system function. Probiotics are live microorganisms similar to the beneficial microorganisms found in the human gut. Consuming probiotic-rich foods can help to boost the immune system and reduce the risk of infections. Fermented foods are an excellent source of probiotics.
Gut microbiota modulation
Probiotics maintain gut epithelial barrier.

Fermented food is rich in probiotics.

Fermented food is rich in probiotics, which are beneficial active microorganisms that colonize the human intestines and change the composition of the flora in particular parts of the host. Recent evidence has shown that probiotics play significant roles in gut microbiota composition, which can inhibit the colonization of pathogenic bacteria in the intestine, help the host build a healthy intestinal mucosa protective layer, and enhance the host immune system. Therefore, consuming fermented food regularly may help to maintain a strong and healthy immune system. Scientific research highlights the significance of gut microbiota-directed interventions by diet enrichment with functional natural products such as probiotics and phytochemicals as a promising strategy to promote immune system performance, modulate inflammatory responses, and improve human health.
According to Stanford School of Medicine researchers, a diet rich in fermented foods enhances the diversity of gut microbes and decreases molecular signs of inflammation. Eating foods such as yogurt, kefir, fermented cottage cheese, kimchi, and other fermented vegetables, vegetable brine drinks, and kombucha tea led to an increase in overall microbial diversity, with more potent effects from larger servings.
Another study showed that consuming fermented food can help promote gut health and modulate the immune system. Consumption of specific probiotics may represent a powerful tool to re-establish gut homeostasis and promote gut health because probiotics can help fight inflammation and support the immune system.
"PROBIOTICS" written on a paper

The growth of beneficial bacteria.

Fermentation breaks down the sugars in food, allowing beneficial bacteria to grow. These bacteria produce compounds that can help to boost the immune system. Different types of bacteria promote the fermentation of foods, and their functions are also different. Here is the relationship between each type of bacteria and immunity.

Lactic acid bacteria

Lactobacillus is a general term for bacteria that break down sugars and other carbohydrates to produce lactic acid. There are more than hundreds of types of lactobacilli, including Bulgaria, Gasseri, and Labre bacteria. Lactobacilli are also representatives of beneficial bacteria, which increase the number of helpful bacteria, improve the intestinal environment, and activate immune cells. It also works to activate “macrophages,” immune cells that exist in the blood and tissues, and their ability to attack foreign substances is further enhanced. Lactic acid bacteria are essential in food production, as they can convert milk into yogurt, cheese, and other fermented milk products. These products are not only delicious but also easier to digest and full of probiotics, which are beneficial for gut health. Lactic acid bacteria are also used in the production of sourdough bread and kimchi.
In addition to their culinary uses, lactic acid bacteria have many potential health benefits. Some research suggests that they can help improve digestion, boost immunity, and even prevent certain types of cancer. The exact mechanisms are still under research, but studies have demonstrated that certain members of Lactobacillus decrease the levels of carcinogenetic enzymes produced by colonic flora through normalization of intestinal permeability and microflora balance through production of antimutagenic organic acids and enhancement of the host’s immune system. However, more research is needed to confirm these potential health benefits.

Yeast fungi

Yeast fungi are single-celled fungi that reproduce by budding. Yeast cells are oval or spherical and range in size from 2 to 50 micrometers in diameter, depending on the species. Yeast is a eukaryotic microorganism classified in the kingdom Fungi, with 1,500 species currently described. They are distinguished from molds because they lack hyphae. Yeast inhabits multiple environments, including soil, water, plant surfaces, animal tissues, and body fluids. Yeast has been isolated from various sources, including air, water, plants, and animals. The most common isolation method employs selective media that favor yeast growth while inhibiting other microorganisms’ growth. Once isolated, yeast can be cultured on media that Yeast cells can metabolize a wide variety of sugars, including glucose, sucrose, maltose, and xylose. Yeast can also ferment some sugars to produce ethanol, although this is not as common in baker’s yeast.
Yeast fungi are used to brew alcohol and make bread. It also contains beta-glucan, which is not digested and absorbed but acts directly on immune cells in the intestines to enhance immunity.

Koji mold

Koji mold is a mold used to produce koji, used in seasonings and fermented foods of Japanese origin, such as miso, soy sauce, and mirin. It is made from rice inoculated with the Aspergillus oryzae mold. This mold breaks down the carbohydrates in the rice, which produces enzymes that give koji its unique flavor. Koji is used in many traditional Japanese dishes, such as miso soup, soy sauce, and mirin. It can also be used to make sake, a Japanese rice wine. Koji mold has many beneficial properties. The enzymes produced by the mold can improve digestion and absorption in the body. The oligosaccharides produced by the enzymes can be used as food to activate beneficial bacteria, which can lead to an increase in immunity. Koji mold is a versatile ingredient that can be used in many different dishes. It is a critical component of Japanese cuisine and has many health benefits. Try using koji mold the next time you cook a Japanese dish! You’ll be sure to enjoy the unique flavor it imparts.

Acetic acid bacteria

Acetic acid bacteria convert alcohol into acetic acid, a component of vinegar. These bacteria convert alcohol into acetic acid, which gives vinegar its characteristic sour taste. Acetic acid bacteria have been shown to possess probiotic properties and promote gut health. In addition, these bacteria stimulate and activate the immune system switch in the immune cells in the intestines, which enhances immunity and suppresses allergy symptoms. When adding vinegar to your diet, be sure to choose a quality product that contains live and active cultures of acetic acid bacteria.

Bacillus natto

Bacillus natto is a type of fungus that is essential for the fermentation of soybeans to create natto. This Bacillus subtilis fungus is resistant to heat and acid. It can reach the intestines alive, where it attaches to “M cells” that monitor foreign substances such as viruses on the outside of “Peyer’s patches,” the organ responsible for the immune function of the intestines entering into the Peyer’s patches. In this way, bacillus natto helps to activate immune cells, protect against foreign substances, and improve overall gut health.
Natto is a traditional Japanese food made from fermented soybeans with a strong, distinct flavor and slightly slimy texture. It is rich in nutrients like protein, fiber, and vitamins, making it a great addition to any meal. Thanks to its probiotic benefits, natto may also help to improve digestion and promote a healthy gut microbiome.
Variety of fruits and vegetables in jars
Fermented foods, made by different types of bacteria listed above, can benefit the microbiome by enhancing its function and reducing the abundance of disease-causing bacteria in the intestines. Fermented fruits, vegetables, and grains enrich our diet with beneficial microorganisms, vitamins, and minerals that can promote gut health, support the immune system, and help fight inflammation.
Fermented foods should be a part of a healthy diet for anyone interested in maintaining a robust immune system. These foods offer a variety of health benefits that can help to keep the body healthy and free from infection. Additionally, many fermented foods are rich in immune-boosting nutrients like vitamin C, iron, and zinc. Consuming these nutrients can help to keep the immune system functioning correctly. Stay healthy with fermented foods.
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Tateki "Tech" Matsuda | + posts

Tateki Matsuda is the founder of Biohacker Center Japan, holding degrees in Applied Nutrition and Sports Movement Science. As a Professional MMA fighter in the UFC and health consultant in Boston, he combines his expertise in biohacking, nutrition, and athletics to optimize performance and promote holistic wellness.