What’s the difference between kestose and lactic acid bacteria or bifidobacteria supplements? Let’s clarify the difference between “food for the bacteria” and the bacteria themselves.

Drugstores and supermarkets are filled with countless products touting “lactic acid bacteria” and “bifidobacteria.” At the same time, words like “kestose,” “oligosaccharides,” and “prebiotics” have been appearing more often.

“They all sound good for the gut, but what’s the difference, really?” “If I’m already taking lactic acid bacteria, do I also need kestose?” Many people may have questions like these.

Here are three things you’ll learn from this article:

• “The bacteria themselves” and “food for the bacteria” are two different things
• Which category kestose belongs to
• The idea behind taking both together, and how to incorporate them into your daily routine

We’ll explain technical terms with analogies as we go. Let’s take a look, step by step.

First, the takeaway: It’s easiest to understand if you think of “seeds” and “fertilizer”

Supplements containing lactic acid bacteria or bifidobacteria provide “the bacteria themselves,” while kestose is “food for the bacteria.” To use a gardening analogy, the bacteria are the “seeds,” and their food is the “fertilizer.”

The important thing to remember is that your gut is already home to many bacteria. This community of bacteria is called the “gut microbiota.” The word “flora” means “flower garden,” and the term imagines the gut as a flower garden where different kinds of bacteria grow in groups.

What you do for this “garden” differs depending on your approach:

• Sowing seeds = introducing live bacteria from outside the body
• Adding fertilizer = providing ingredients that bacteria already in the gut can use to grow
• Combining both = sowing seeds and adding fertilizer

Each of these three approaches has a name.

Probiotics = live bacteria themselves (seeds)

Probiotics are “live microorganisms” that provide a health benefit when consumed in adequate amounts. This definition was established in 2014 by the International Scientific Association for Probiotics and Prebiotics (ISAPP).

The Japanese Ministry of Health, Labour and Welfare’s information site, eJIM, also describes them in its Japanese-language introduction to materials from U.S. public agencies as live microorganisms found in fermented foods such as yogurt and in supplements.

Let’s clarify a couple of terms that are often confused:

• Lactic acid bacteria: A general term for microorganisms that ferment sugars to produce lactic acid.
• Bifidobacteria: Representative beneficial bacteria found primarily in the intestines of humans and animals. Unlike lactic acid bacteria, they produce acetic acid as well as lactic acid.

These are the explanations provided by the Ministry of Health, Labour and Welfare’s e-Health Net. Lactic acid bacteria and bifidobacteria are commonly used as probiotics. “Probiotics” is a collective term for live bacteria that provide health benefits.

Prebiotics = ingredients that serve as food for bacteria (fertilizer)

Prebiotics are ingredients that are selectively used by microorganisms living in the body. The same international association established a definition in 2017. Put simply, they are “ingredients that serve as food for beneficial bacteria.” “Beneficial bacteria” is a general term for bacteria said to have favorable effects in the gut. Bifidobacteria are considered one of the representative examples.

The Ministry of Health, Labour and Welfare’s eJIM, which provides Japanese-language information from U.S. public agencies, describes them as “non-digestible food ingredients that selectively promote the activity or growth of beneficial microorganisms.” The important points here are that they are not the bacteria themselves and that our bodies have difficulty digesting them. Because they pass through the digestive system undigested and reach the large intestine, the bacteria living there can use them.

Some dietary fibers and oligosaccharides fall into this category. Kestose is one of them.

Synbiotics = seeds and fertilizer combined

Synbiotics are a combination of live bacteria and ingredients that are selectively used by those bacteria. A definition was established in 2020.

“Adding oligosaccharides to yogurt” is an approach that’s similar to this idea. In other words, you’re taking seeds (the bacteria in the yogurt) and fertilizer (the oligosaccharides) together.

It’s also worth knowing the “limits” of the analogy

The “seeds and fertilizer” analogy is easy to understand, but there’s one difference: seeds in a garden take root and grow in the soil, whereas many of the bacteria in supplements and yogurt are thought to pass through the gut without taking up residence. We’ll discuss this in more detail in a later section.

Kestose belongs on the “fertilizer” side: an oligosaccharide that is a prebiotic

Kestose is not bacteria itself; it is an ingredient that serves as food for bacteria. It is a type of oligosaccharide and belongs to the prebiotic family.

Oligosaccharides are sugars made up of just a few sugar units, such as glucose and fructose, linked together. According to e-Health Net, they are difficult to digest.

What is kestose? A “three-unit sugar” made by adding one fructose unit to sucrose

Kestose is a trisaccharide oligosaccharide formed when one fructose unit binds to sucrose. It belongs to a group of oligosaccharides called “fructooligosaccharides,” and kestose is the smallest in this group. Other members of the same group are larger, with more sugar units linked together.

This description is based on a review by kestose researchers published in the Journal of Japanese Society of Nutrition and Food Science in 2020. The review also notes the following:

• It is found in small amounts in familiar foods such as onions and rye.
• It is difficult to digest, reaches the large intestine, and is selectively used by gut bacteria (it meets the criteria for a prebiotic).
• It has a sweetness similar to sugar and is heat-stable.

In other words, kestose is a food-derived ingredient with properties that allow it to serve as “food for bacteria.”

They behave differently in the gut: “bacteria that pass through” and “food for bacteria already there”

Bacteria themselves and food for bacteria behave differently in the gut. This is the key point to understanding the difference between the two.

Most probiotics “pass through”

According to ISAPP, probiotics generally do not colonize the gut. Materials published by the Japan National Committee of the International Dairy Federation also state that most probiotics are not thought to permanently colonize the gut.

However, this doesn’t mean that “passing through” is pointless. ISAPP explains that probiotics have effects while passing through the gut by interacting with gut cells, immune cells, and bacteria already living there.

Because they pass through, taking them consistently every day is considered important (according to materials from the Japan National Committee of the International Dairy Federation). ISAPP also notes that “more is not necessarily better.”

Prebiotics serve as food for bacteria that are “already there”

By contrast, prebiotics such as kestose are ingredients used by bacteria already living in the gut. Rather than bringing in new bacteria from outside, the idea is to provide food that the bacteria already in the “garden” can use.

What happens when you combine them?

This brings us to the idea of “taking both.” Take yogurt bacteria (seeds) along with kestose (fertilizer). This is a way of incorporating them that is similar to the synbiotic approach mentioned earlier.

The important thing is that neither one is better or worse than the other. They have different roles, so they are not things to compare; they are things to consider combining.

What does research say? (A look at test-tube studies)

Next, we’ll look at research on kestose. The information presented here is based on reported research findings. It does not demonstrate that Aidaya Shoten’s products have these effects.

The studies we’ll discuss are summarized in the kestose review mentioned earlier. The review’s authors include researchers from a company’s research and development center.

A study that grew and compared bacteria in test tubes

One study grew 18 strains of lactic acid bacteria and 15 strains of bifidobacteria (a “strain” is a particular lineage within a bacterial species) in test tubes with several types of oligosaccharides, then compared how much they grew.

The report states that among the several oligosaccharides tested, kestose led to the greatest number of bacterial strains growing well.

It’s important to note that these results came from “test tubes.” The gut inside the body is affected by many conditions, including food, other bacteria, and the state of the body. What happens in a test tube does not necessarily happen the same way in the human body.

Reports on butyrate-producing bacteria

The same review also describes reports on butyrate-producing bacteria.

• One test-tube study reported that one butyrate-producing bacterium (Anaerostipes caccae) could use only kestose among the oligosaccharides tested.

“Short-chain fatty acids,” such as butyrate, are substances produced by gut bacteria. The review also discusses reports suggesting that these substances are involved in beneficial effects on the body. However, these findings are also at an early research stage and do not allow us to draw firm conclusions about what happens as a result of everyday dietary intake.

How to incorporate it into your daily routine: a spoonful in your morning yogurt

From here, we’ll talk about everyday eating habits rather than research.

If you’re going to have something every day, the easiest approach is one you can maintain without strain. For example, you could add kestose to your breakfast yogurt.

Yogurt provides “live bacteria,” and kestose is “an ingredient that serves as food for bacteria.” So, in the terms we’ve been using, you’re taking seeds and fertilizer together.

About Aidaya Shoten’s kestose

Aidaya Shoten’s kestose is made with 100% kestose, the smallest-unit oligosaccharide composed of three sugar units. It comes in 30 packets of 3 g each. The recommended amount is one packet per day, which you can add to yogurt or a drink, or consume as is. It has a subtly sweet taste.

Things to keep in mind

Taking a large amount of oligosaccharides at once may cause loose stools, depending on your body and condition. Start with a small amount and adjust as you see how your body responds.

As for probiotics (live bacteria), the Ministry of Health, Labour and Welfare’s eJIM, which provides Japanese-language information from U.S. sources, notes that people with weakened immune systems or those who are hospitalized may be at greater risk. If you have a chronic condition or are receiving treatment, consult your doctor before taking them.

If your digestive discomfort persists, don’t try to manage it through diet alone; seek medical care.

Frequently asked questions

Q. If I take lactic acid bacteria supplements, do I still need kestose?

They have different roles, so it’s not a matter of “if you have one, you don’t need the other.” Bacteria themselves and food for bacteria are different things. The idea of combining both is called synbiotics.

That said, what and how much is right for you depends on your body, your health, and your diet. If you’re unsure, consult your doctor or a registered dietitian.

Q. Is kestose alone enough?

Kestose is one “food” that you can include in your diet. If you’re thinking about your gut, your foundation should be your overall daily diet, including vegetables, beans, mushrooms, seaweed, and fermented foods. Think of kestose as an extra “spoonful” to add to that.

Q. Is kestose found in ordinary foods?

It is said to be found in small amounts in familiar foods such as onions and rye.

Summary: The difference is “the bacteria themselves” versus “food for bacteria”

Here are the three key points from this article:

• Probiotics are “live bacteria themselves” (seeds). Prebiotics are “food for bacteria” (fertilizer). A combination of the two is called synbiotics.
• Kestose is a type of oligosaccharide and falls on the food-for-bacteria side (prebiotics). It has a different role from lactic acid bacteria and bifidobacteria supplements.
• Research mainly consists of reports from test-tube studies and does not directly demonstrate the effects of a product. It’s important to choose an approach you can maintain comfortably as part of your overall daily diet.

One thing you can do today is add a spoonful of kestose to your usual yogurt. It’s one easy way to take “bacteria” and “food for bacteria” together.

Feel free to read these related articles as well.

• So, what aspects of daily life are behind constipation?

Why not try adding kestose to your daily gut-health routine?

Aidaya Shoten’s kestose is a powder made from 100% kestose. It comes in 30 packets of 3 g each, and the recommended amount is one packet per day, added to yogurt or a drink.

• Kestose, 3 g × 30 packets (one-time purchase)
• Kestose, 3 g × 30 packets (subscription)

Please see the product page for details such as pricing.

This article provides general information about diet. It is not intended to diagnose, treat, or prevent disease. If you have concerns about your health, a chronic condition, or persistent symptoms, please consult a doctor.

Sources

• ISAPP, “A roundup of the ISAPP consensus definitions” (definitions of probiotics, prebiotics, and synbiotics) https://isappscience.org/a-roundup-of-the-isapp-consensus-definitions-probiotics-prebiotics-synbiotics-postbiotics-and-fermented-foods/
• Ministry of Health, Labour and Welfare eJIM, “Oral Probiotics” (Japanese translation of materials from U.S. public agencies) https://www.ejim.mhlw.go.jp/public/overseas/c02/09.html
• Ministry of Health, Labour and Welfare e-Health Net, “Lactic Acid Bacteria” https://www.e-healthnet.mhlw.go.jp/information/keywords/lactic-acid-bacteria
• Ministry of Health, Labour and Welfare e-Health Net, “Bifidobacteria” https://www.e-healthnet.mhlw.go.jp/information/keywords/lactobacillus-bifidus
• ISAPP, “Probiotics: Common Misconceptions” (Japanese version) https://isappscience.org/wp-content/uploads/2020/06/Pro_Myths_Japanese.pdf
• Japan National Committee of the International Dairy Federation, “Probiotics FAQ (provisional translation)” https://www.j-milk.jp/jidf/wp-content/uploads/2015/06/j-probiotics.pdf
• Yoshihiro Kadota et al., “Elucidation of the Diverse Physiological Functions of Kestose and Efforts Toward Its Practical Application,” Journal of Japanese Society of Nutrition and Food Science 73(4):123–131 (2020) https://www.jstage.jst.go.jp/article/jsnfs/73/4/73_123/_pdf