Do Fermented Foods Affect Your Gut Health?

Fermented foods are created through allowing microorganisms (usually bacteria and/or fungi) to act on a food in order to change it. Cultures around the globe have developed ways to take advantage of fermentation to produce a huge variety of different foods, like yogurt, sauerkraut, kimchi, and miso.

As I frequently discuss, gut health is one of the most crucial factors for your skin health, and even your overall health and well-being. It turns out that fermented foods can have a significant impact on your gut health.

So how do fermented foods affect gut health? And how can you adjust your diet accordingly? 

Fermented foods can benefit gut health

Research has repeatedly shown that fermented foods can have beneficial effects. 

People who regularly consume fermented foods have lower levels of chronic inflammation. They also have more diverse gut microbiomes, meaning that their guts contain more different species of microorganisms. Studies have even shown that fermented foods can help to keep blood sugar under control.

For people living with chronic skin conditions, all of these benefits can potentially translate into fewer flares and healthier skin.

Can bacteria from fermented foods live in your gut?

Fermented foods are created using bacteria and/or fungi (such as yeast). When the fermented food is ready to eat, these microorganisms remain in the food (as long as they’re not destroyed by processing – more on that later). Eating this food brings these microorganisms into your gut.

Not all of them will be able to survive inside your gut. Your stomach acid destroys a lot of them, and then the digestive enzymes in your small intestine destroy even more. Only a few of them are able to make it to your large intestine (aka colon), where your beneficial gut bacteria live.

After eating a fermented food once, those bacteria are not likely to survive for very long inside your gut. Studies have found that they often disappear within 24 to 48 hours. However, if you eat fermented foods on a regular basis, then the situation gradually starts to change. The microorganisms from the fermented food slowly create an impact on the overall environment in your gut, which makes them more likely to get established and become a part of your microbiome.

Products of fermentation

The microorganisms found in fermented foods are not the only factor that can affect your gut microbiome. During the process of fermentation, a variety of different compounds are generated. These products can affect your gut microbiome, and they can have other health effects as well.

One example are bioactive peptides. Fermented foods contain a wide variety of these. They’re essentially very small proteins, and they can have a huge variety of actions. They can act as antioxidants (which protect cells from damage), modulate the immune system, and even lower blood pressure. Some bioactive peptides also act on your gut microbiome, promoting the growth of particular species. 

Another type of compound found in fermented foods are short chain fatty acids (SCFAs). SCFAs are important in strengthening the skin barrier, which keeps out allergens, toxins, and other potentially irritating or harmful substances. For those who experience inflammatory skin conditions like eczema, the SCFAs in fermented foods may help to reduce flares. SCFAs are also used as signaling molecules by the body, so they can affect immune system function, cardiovascular function, and more.

These are just a few examples. Fermented foods contain a huge variety of potentially beneficial substances, including vitamins, organic acids, polysaccharides, and more. This is how, even if the bacteria found in the food don’t end up living long-term inside your gut, fermented foods can still have an impact on your gut microbiome – and your overall health.

How to add fermented foods to your diet

So it’s clear that eating fermented foods can be beneficial for your microbiome. If you’re looking to take advantage of these benefits, how can you add fermented foods to your diet?

There are a huge variety of fermented foods, including:

• Yogurt

• Sauerkraut

• Kimchi

• Miso

• Kefir

• Kombucha

• Tempeh

• Natto

You can choose the foods from this list that most appeal to you. Because different types of bacteria are used for fermenting different foods, it may be beneficial to choose a variety of different foods. However, when you’re first getting started with eating fermented foods, you

If you’re not currently eating fermented foods on a regular basis, try starting by adding just one serving of a fermented food to your diet per day. You may want to work your way up to two or three servings per day, or potentially even more. Some of the studies on fermented foods have used even more – one study found significant benefits from eating six servings of fermented foods every day. 

Each time you add a serving of a new food, try it for a week or two and pay close attention to how you feel. If you notice benefits – maybe you have more energy, better digestion, or your skin is clearer – then keep that food in your diet for the long term.

What to watch out for in fermented foods

When you’re adding fermented foods to your diet, there are a few things to watch out for.

One of these is how the food is processed. In some cases, food is pasteurized after fermentation is complete. The process of pasteurization involves heating the food to a high temperature for a period of time, in order to kill off microorganisms. While this helps to prevent foods from spoiling on the grocery store shelf, it does also kill off the potentially beneficial bacteria in a fermented food. Foods will be labeled as “pasteurized” if they have been treated in this way.

In some cases, you can look for the words “live and active cultures” on the label. This lets you know that the bacteria used for fermentation are still present in the food. This labeling isn’t required, and it’s not always included, even on foods that do contain live bacteria. It’s commonly used on yogurt, but other types of foods don’t always have it. Still, if you see this label, then you know there are beneficial bacteria in the product.

Alcoholic beverages, such as beer, wine, and cider, are also fermented products. However, it’s important to be careful with alcohol. It can have a negative impact on your skin health, and other aspects of your health as well. Beyond this, the alcohol itself kills off the beneficial bacteria present in the beverage. That’s why, even though alcoholic beverages are definitely fermented, it’s really not recommended to consume them every day. Choose other fermented foods to get the benefits for your gut and skin.

Lastly, watch out for added calories. Whenever you add a new food to your diet, you’ll want to consider replacing less healthy options with your new choice. If you simply add it without changing anything else, then you’re likely to end up in a caloric surplus, which causes weight gain. If you decide to add a fermented food to your diet, consider which other food you can take out. For example, maybe you’d like to add yogurt to your diet. If you currently eat toast for breakfast, you could replace the toast with yogurt.

Choosing skin-healthy foods

Fermented foods are one category of foods that can be beneficial for people living with chronic skin conditions. Other types of foods, like healthy fats, can also have benefits. It’s important to make balanced food choices, to incorporate all of the important categories of nutrients.

Some people find it useful to have support as they work on improving their nutrition. At my integrative medicine clinic, I do a lot of work with my patients on creating a balanced and skin-healthy food plan. Whether you consult a health coach, an integrative medicine doctor, or a nutritionist, professional advice can make it much easier to design a healthy eating plan that’s full of delicious foods.