Fermented foods contain-health-supportive peptides.

Eating them can not only help the gut but also metabolic issues like blood pressure and metabolism.

Living in San Francisco during the 1990s, I was in a state of significant exploration. From dating, dining, traveling, exploring spirituality, nature, learning, and growing, the phases of my life were both invigorating and confusing. This was the wellspring of what eventually became my path to Naturopathic Medicine.

While I grew up around hippy attitudes towards life, I never really dove into the holistic healing arts when I lived in San Francisco.

When I met my wife, a West Coast transplant from the East Coast, we began exploring the diverse cuisines that San Francisco has to offer.

Turning right out of our San Francisco apartment was Geary Street, home to Asian cuisine from many regions of Asia. From Russian Cuisine to Singaporean cuisine, you could find it anywhere. Up until that point, I was a pretty simple guy; give me a burrito every day of the year, and I would be good to go!

However, being in San Francisco allowed me to explore this.

My first date with my wife was in a Singaporean restaurant called Stix, and we never forgot that meal.

Interestingly, my favorite dining cuisine was Korean. Regardless of what was on the plate, my eyes were drawn to all the delicious fermented vegetables that coincided with the meal.

I always loved the pickles, but this was the next level.

My gut, which had always faced challenges dating back to the earliest days of my life, felt tremendous after those meals.

Fast forward, we are learning about all the health benefits of ferments from a modern medicine perspective.

Fermented foods, such as yogurt, kimchi, and sourdough, have added flavor and preservation to our meals.

However, in addition to their tangy taste and probiotic benefits, fermented foods contain another category of potent compounds: bioactive peptides. These small proteins formed during fermentation may help support heart health, improve metabolism, and modulate immune function.

I thought it would be good to explore bioactive peptides, how they are created through fermentation, and where they are found in your diet. Other studies have examined how fermentation improves the diversity and abundance of the microbiome.

While we have to be careful with fermented foods for IBS and other digestive issues (due to their histamine content), they are ultimately something to try and incorporate at different stages.

Let us break down some core definitions and concepts related to the ferment:

Bioactive Peptides

Bioactive peptides are short chains of amino acids that are released when proteins are broken down during fermentation. Microorganisms such as bacteria, yeasts, and molds produce enzymes that release these peptides. Once released, these peptides may have various health-promoting effects, including anti-inflammatory, antioxidant, and blood pressure-lowering actions.¹

Fermentation Unlocks Peptides

Microbial waste for our benefit. During fermentation, microbes, such as lactic acid bacteria (LAB), secrete enzymes, such as proteinases and peptidases, that break down food proteins into smaller fragments. These fragments contain bioactive peptides that can exert physiological effects on the body.² LAB are especially important in this process as they also contribute to vitamin synthesis, reduction of anti-nutritional factors, and enhancement of bioavailability.³ This is similar to the ultimate composting system.

Types of Bioactive Peptides in Fermented Foods

ACE-Inhibitory Peptides

Peptides, such as valyl-prolyl-proline (VPP) and isoleucyl-prolyl-proline (IPP), found in fermented dairy products, inhibit angiotensin-converting enzyme (ACE), thereby lowering blood pressure.⁴⁻⁶ These peptides are also present in some fermented meats.⁷ Lower my blood pressure by eating kimchi? sign me up.

Conjugated Linoleic Acids (CLA)

CLA is a fatty acid that is formed by specific bacteria during fermentation. It has been associated with modest reductions in blood pressure and improved lipid profiles, although the results of human studies have been mixed.⁸. CLA has also been used in weight-management strategies.

Exopolysaccharides (EPS)

Produced by many microorganisms during fermentation, EPS are complex sugar polymers with antioxidant, anti-diabetic, and cholesterol-lowering effects.⁹

Bacteriocins

These antimicrobial peptides produced by fermentation bacteria can help inhibit harmful microorganisms, thereby improving food safety.¹⁰

Sphingolipids

These lipids, which are also formed during fermentation, exhibit potential anticancer and antimicrobial activities.¹¹

Other Bioactive Peptides

Fermented foods may also generate peptides with a wide range of health benefits, including antioxidant, antiallergenic, antithrombotic, and cholesterol-lowering effects.¹²

Types of Ferments

Fermented Dairy

Yogurt, kefir, and fermented milk contain ACE-inhibitory peptides and γ-aminobutyric acid (GABA), which may help reduce blood pressure and promote relaxation.¹³

Fermented Vegetables and Fruits

One typical example is kimchi, which is rich in phenolic compounds, such as HDMPPA, which is known for its anti-atherogenic effects. Sauerkraut contains fermentation-derived bioactive compounds, including sauerkraut, fermented radish, fermented pickles, and carrots.

Recently, I was introduced to fermented watermelons. I have to admit that I am going to go with regular watermelons for now!

Fermented Legumes, Seeds, and Nuts

Fermented soybeans and mung beans contain peptides with antidiabetic, antioxidant, and anti-inflammatory activities. The traditional Korean paste Cheonggukjang, made with Bacillus licheniformis, has shown promise for managing weight and blood sugar levels. Miso is the most common fermented form of soy. In addition, natto beans are a standard component of Japanese cuisine. Many traditional Indian cuisines contain fermented legumes.

Cacao bean, coffee bean, and vanilla bean are also fermented in various forms.

Fermented Beverage

Besides Kefir, we will see many beverages like Kombucha, Tea’s, Kvass, Ginger Beer, and Ciders that use fermentation to produce

Fermented Grains

The most well-known grain ferment is sourdough bread. Sourdough fermentation promotes the breakdown of proteins into ACE-inhibitory peptides. Some evidence also suggests a lower glycemic response from sourdough than from conventional bread.¹⁸

In Indian cuisine, rice is fermented in dosa. Many other grains, such as grits, millet, sorghum, rice, congee, potatoes, and cassava, are fermented.

Fermented Fish, meat, and egg Products

Practices such as drying, salting, smoking, and curing are fermentation practices for fish, meat, and eggs.

If you have ever had sausages, pickled fish, or corned beef, then you have fermented versions of fish and meat.

Fermented fish sauces and oils have been shown to generate peptides that may reduce hypertension and improve insulin sensitivity. ¹⁹

Life happens

I no longer live within the stone’s throw on Geary Street. Interestingly, I still live in a region with a significantly diverse cuisine (the Seattle region).

However, my dietary needs have changed significantly since then. While gluten sensitivity was identified in the 2000s, it eventually led to Celiac. While I wait for one of the significant advances in the way to a Celiac, I can hardly ever step foot into a restaurant.

When I do, I usually pay the price for to 2-4 weeks.

For spiritual reasons, I observe the kosher dietary laws.

This adds a whole other aspect to my approach to eating and the availability of eating in restaurants.

Now I have the perfect opportunity make all of my meals. I often merge my former days in San Francisco with my current dietary needs. I have gratefully lived a very interesting life so I have a lot of experiences to pull from.

Recently, I picked up the Book, The Art of Fermentation by Sandor Ellix Katz. It feels like the ultimate guide for bringing fermentation into life.

I am interested as I love how I feel after I eat ferments and then there are the health benefits.

This fascination was amplified when I heard of the study by Wastyk HC, Fragiadakis GK, Perelman D, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021;184(16):4137–4153.e14. doi:10.1016/j.cell.2021.06.019

36 participants in this study were dramatically told to increase fiber and or increase ferments in their diet, and they saw the following

Fermented Food Arm:

• ↑ Microbiota diversity (p < 0.01)

• ↓ 19 inflammatory markers, including IL-6, IL-10, and IL-12b (q < 0.1)

• Immune modulation across multiple immune cell types

Fiber Arm:

• ↑ CAZyme gene expression (related to glycan degradation)

• No significant change in microbiota diversity or inflammatory markers

• Responses varied by baseline microbiota diversity

This shows the potential of fermented foods in the diet as functional foods that modulate inflammation in the short term.

Of course, we need the fiber, but it's for the long haul. Developing a microbiome that can produce short-chain fatty acids and beneficial bioactive metabolites is largely dependent on fiber consumption.

Before I leave this topic today, let us explore the gut connection and some precautions about fermentation.

The Gut Connection

Some bioactive peptides are absorbed into the circulation, whereas others act locally in the gut to influence microbial balance and gut barrier integrity. So the response varies.

We are beginning to learn about ways in which fermentation benefits the microbiome. For example, fermentation increases the bioavailability of polyphenols and dietary fiber, both of which positively influence the gut microbiome. ²⁰

Things to Consider

• Histamine content: Some fermented foods contain high levels of histamine, which can trigger symptoms in sensitive individuals. See the posts I have had on this subject.

• Microbial variability: Traditional fermentation can vary significantly in terms of microbial strains and peptide production. Products made with defined starter cultures are more consistent.

• Pasteurization: Post-fermentation pasteurization may eliminate beneficial microbes and reduce bioactive compound activity. We see this in many pickled products that add vinegar and high heat, essentially destroying the bacteria.

Bioactive peptides present in fermented foods represent an exciting frontier in nutritional science.

Are you incorporating fermented foods into your diet? Which Ones? What do you experience?

Let's keep talking about this over on my circle community page

Join our exclusive Gut Health community https://gastrointestinal-solutions.circle.so/feed

You can learn more about microbiome topics as well at my podcast

https://www.onethingpod.com/categories/digestive-and-gastrointestinal-health/

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References

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3. Marco ML, et al. Health benefits of fermented foods: microbiota and beyond. Curr Opin Biotechnol. 2017;44:94-102.

4. Nakamura Y, et al. Antihypertensive effect of sour milk and peptides isolated from it. J Dairy Sci. 1995;78(6):1253-1257.

5. Seppo L, et al. Fermented milk high in bioactive peptides has a blood pressure–lowering effect in hypertensive subjects. Am J Clin Nutr. 2003;77(2):326-330.

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10. Cotter PD, et al. Bacteriocins: developing innate immunity for food. Nat Rev Microbiol. 2005;3(10):777-788.

11. Vesper H, et al. Sphingolipids in food and the emerging importance of sphingolipids to nutrition. J Nutr. 1999;129(7):1239-1250.

12. Pihlanto A. Antioxidative peptides derived from milk proteins. Int Dairy J. 2006;16(11):1306-1314.

13. Li H, et al. GABA-enriched fermented milk improves sleep and reduces anxiety in humans. J Funct Foods. 2018;41:93-100.

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15. Martinsen BK, et al. Functional properties of sauerkraut. LWT Food Sci Technol. 2020;124:109186.

16. Jeong HR, et al. Antioxidant and anti-inflammatory effects of fermented mung bean. J Med Food. 2010;13(4):749-756.

17. Kim M, et al. Effects of Cheonggukjang on metabolic syndrome in overweight/obese subjects. Nutrients. 2018;10(10):1432.

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