Rebuild the microbiome with lost species – With yogurt from L. reuteri, L. gasseri, B. longum

Updated on August 7, 2026

Recipe: L. reuteri, L. gasseri and B. longum – Make SIBO yogurt yourself

Also suitable for people with lactose intolerance (see notes below).

Ingredients (for approx. 1 liter of yogurt)

• 4 capsules L. reuteri (each 5 billion CFU)
• 1 capsule L. gasseri (each 12 billion CFU)
• 2 capsules B. longum (each 6 billion CFU)
• 1 tbsp inulin (alternatively: GOS or XOS for fructose intolerance)
• 1 liter (organic) whole milk, 3.8% fat, ultra-high temperature treated and homogenized or UHT milk
• (The higher the fat content of the milk, the thicker the yogurt)

Note:

• 1 capsule L. reuteri, at least 5 × 10⁹ (5 billion) CFU (en)/KBE (de)
• CFU stands for colony forming units – in German, kolonie-bildende Einheiten (KBE). This unit indicates how many viable microorganisms are contained in a preparation.

Notes on milk choice and temperature

• Do not use fresh milk. It is not stable enough for the long fermentation times and not sterile.
• Ideal is H-milk (long-life, ultra-high temperature milk): It is sterile and can be used directly.
• The milk should be at room temperature – alternatively, gently warm it in a water bath to 37 °C (99 °F). Avoid higher temperatures: from about 44 °C, the probiotic cultures are damaged or destroyed.

Optimal Fermentation Temperatures for Each Starter Set

Preparation

1. Open the total of 7 capsules and put the powder into a small bowl.
2. Add 1 tbsp of inulin per liter of milk – this serves as a prebiotic and promotes bacterial growth. For people with fructose intolerance, GOS or XOS are suitable alternatives.
3. Add 2 tbsp of milk to the bowl and stir thoroughly to avoid lumps.
4. Stir in the remaining milk and mix well.
5. Pour the mixture into a fermentation-suitable container (e.g., glass)
6. Put into the yogurt maker, set the temperature to 37 °C (98.6 °F), and let ferment for 36 hours.

From the second batch onwards, use 2 tablespoons of yogurt from the previous batch as a starter

You prepare the first batch with the bacteria capsules.

From the second batch onwards, use 2 tablespoons of yogurt from the previous batch as a starter. This also applies if the first batch is still thin or not perfectly firm. Use it as a starter as long as it smells fresh, tastes mildly sour, and shows no signs of spoilage (no mold, no unusual discolorations, no pungent odor).

Per 1 liter of milk:

• 2 tbsp yogurt from the previous batch

• 1 tbsp inulin

• 1 liter UHT milk or ultra-high temperature treated, homogenized whole milk

Here’s how:

1. Put 2 tbsp yogurt from the previous batch into a small bowl.

2. Add 1 tablespoon of inulin and stir smooth with 2 tablespoons of milk until no lumps remain.

3. Stir in the remaining milk and mix well.

4. Pour the mixture into a fermentation-suitable container and place it in the yogurt machine.

5. Let ferment at 37 °C for 36 hours.

Note: Inulin is the food for the cultures. Add 1 tablespoon of inulin per liter of milk for each batch.

If you have questions, we are happy to assist you via email at team@tramunquiero.com or through our contact form.

Why 36 hours?

The choice of this fermentation duration is scientifically based: L. reuteri requires about 3 hours per doubling. In 36 hours, there are 12 doubling cycles – this corresponds to exponential growth and a high concentration of probiotic active germs in the finished product. Additionally, the longer maturation stabilizes the lactic acids and makes the cultures particularly resilient.

!Important to note!

The first batch often does not succeed for many users. However, it should not be discarded. Instead, it is recommended to start a new batch with two tablespoons of the first batch. If this also fails, please check the temperature of your yogurt maker. For devices where the temperature can be set precisely to the degree, the first batch usually succeeds well.

Tips for perfect results

• The first batch is usually still a bit more liquid or grainy. Use 2 tablespoons of the previous batch as a starter for the next round – with each new batch, the consistency improves.
• More fat = thicker consistency: The higher the fat content of the milk, the creamier the yogurt becomes.
• The finished yogurt is shelf-stable in the refrigerator for up to 9 days.

Consumption recommendation:

Enjoy about half a cup (approx. 125 ml) of the yogurt daily – preferably regularly, ideally at breakfast or as a snack in between. This allows the contained microbes to develop optimally and sustainably support your microbiome.

Storage of the Bacterial Capsules

Store the bacterial capsules in a cool, dry place. Ideally, keep them in the refrigerator.

The resealable plastic pouch protects the capsules from moisture, making it ideal for refrigerated storage.

For more information, please refer to the FAQs in the product description or the Frequently Asked Questions (FAQ) section in the footer of our online shop.

How to Ferment L. reuteri in Juice:

Probiotic Juice as an Alternative to L. reuteri Yogurt

L. reuteri does not necessarily have to be fermented in milk.

Fruit juices can also provide a plant-based fermentation medium for probiotic bacteria.

Scientific research shows that L. reuteri can be used in different fruit juices, including apple juice, orange juice, pineapple juice, and mango juice.

This opens up an interesting alternative to our classic L. reuteri yogurt, especially for anyone interested in dairy-free probiotic fermentation.

Is Probiotic Juice the Same as Kombucha?

No.

Although both beverages are produced through fermentation, L. reuteri fermented juice is not kombucha.

Kombucha is traditionally fermented using a mixed culture of bacteria and yeasts.

With probiotic L. reuteri juice, L. reuteri is deliberately added as the bacterial starter culture.

The basic principle, however, is similar:

microorganisms metabolize components of the juice and transform the original product during fermentation.

Can L. reuteri Metabolize the Sugar in Fruit Juice?

L. reuteri belongs to the group of lactic acid bacteria and can metabolize carbohydrates.

Fruit juice naturally contains sugars that can serve as substrates for bacterial metabolism during fermentation.

Research into the fermentation of fruit juices with lactic acid bacteria shows that this principle works in practice.

During fermentation, organic acids and other metabolites can be produced, changing the taste, aroma, and composition of the original juice.

Which Fruit Juices Have Been Studied with L. reuteri?

Apple Juice

Apple juice is particularly interesting for fermentation with L. reuteri.

In one scientific study, apple juice was fermented with L. reuteri and analyzed after 0, 6, 12, 18, 24, and 30 hours.

Under the conditions investigated, the optimal fermentation time was approximately 18 hours.

The fermentation affected, among other things, the composition of aroma compounds, organic acids, and polyphenols in the apple juice.

Another study also demonstrated that L. reuteri can remain viable in apple juice.

Orange Juice

Orange juice has also been investigated as a medium for L. reuteri.

Research demonstrated that L. reuteri can remain viable in orange juice, making it another potentially interesting basis for probiotic beverages.

Pineapple Juice

The same applies to pineapple juice.

L. reuteri has also been shown to remain viable in pineapple juice.

Mango Juice

The targeted fermentation of mango juice with L. reuteri has also been scientifically investigated.

During fermentation, researchers observed changes in the sugar content and metabolic profile of the juice.

These findings provide further evidence that fruit juice can serve as a fermentation medium for L. reuteri.

Why Fermentation Time Matters

If you already prepare our L. reuteri yogurt, you know how important a constant temperature and the correct fermentation time are.

The same basic principles apply to juice, although the optimal conditions can differ from those used for yogurt.

This is illustrated particularly well by the apple juice study.

Researchers analyzed L. reuteri fermented apple juice after 0, 6, 12, 18, 24, and 30 hours.

Under the conditions investigated, approximately 18 hours provided the optimal fermentation time.

This illustrates an important principle:

Longer fermentation does not automatically mean better fermentation.

The optimal fermentation time depends on the bacteria, fermentation medium, temperature, pH, and other conditions.

Different L. reuteri cultures can also behave somewhat differently, so the approximately 18-hour fermentation period should be regarded as a scientifically investigated starting point rather than a guaranteed optimum under every possible condition.

How to Make L. reuteri Fermented Apple Juice

The following recipe translates the available scientific findings on L. reuteri and fruit juice fermentation into a simple method for experimenting at home.

Ingredients and Equipment for 1 Liter

• 1 liter (approximately 34 fl oz) of 100% pasteurized apple juice

• 1 capsule L. reuteri containing 5 billion CFU

• A clean fermentation vessel with sufficient headspace

• A fermentation airlock

• A yogurt maker or another device capable of maintaining approximately 37°C / 99°F

Choosing the Right Apple Juice

Use 100% pasteurized apple juice without preservatives.

Always check the ingredient list before purchasing the juice.

In particular, it should not contain potassium sorbate or sodium benzoate.

Dr. William Davis specifically recommends using juice without preservatives for juice fermentation and explicitly mentions avoiding potassium sorbate and sodium benzoate.

This makes microbiological sense:

preservatives are added to foods precisely because they inhibit the growth of microorganisms.

During fermentation, however, we want the opposite, we want the added bacteria to remain metabolically active and multiply.

Step 1: Prepare the Apple Juice

Open a fresh container of pasteurized apple juice and pour 1 liter into a thoroughly cleaned fermentation vessel.

Leave sufficient empty space at the top of the vessel.

Step 2: Add the L. reuteri

Open 1 L. reuteri capsule containing 5 billion CFU and add the entire contents to 1 liter of apple juice.

Mix thoroughly to distribute the starter culture throughout the juice.

This provides an initial concentration of approximately 5 million CFU per milliliter of apple juice.

Step 3: Use a Fermentation Airlock

Never ferment the juice in an airtight, completely sealed container.

Gas can be produced during fermentation, potentially creating substantial pressure inside a sealed vessel.

Use a fermentation airlock that allows fermentation gases to escape while helping to protect the ferment from contamination from the surrounding environment.

This principle is also familiar from other fermentation methods, including kombucha and other fermented beverages.

Step 4: Ferment at Approximately 37°C / 99°F

L. reuteri is typically cultivated at approximately body temperature.

As a practical starting point, maintain the apple juice at approximately 37°C / 99°F throughout fermentation.

Keeping the temperature as stable as possible is important.

Step 5: Ferment for Approximately 18 Hours

As a starting point for apple juice, ferment for approximately 18 hours.

This recommendation is based on scientific research in which apple juice fermented with L. reuteri was analyzed after 0, 6, 12, 18, 24, and 30 hours.

Under the conditions investigated, approximately 18 hours was identified as the optimal fermentation time.

However, 18 hours should not be considered a universally guaranteed optimum for every L. reuteri culture.

Fermentation involves living microorganisms, and results can vary depending on the bacterial culture, juice, starting bacterial count, pH, and fermentation conditions.

Step 6: Stop the Fermentation by Refrigerating

Once fermentation is complete, place the juice directly in the refrigerator.

The substantial reduction in temperature greatly slows bacterial metabolic activity and therefore further fermentation.

Keep the finished probiotic juice refrigerated.

Do You Need Inulin or Acacia Fiber?

Not necessarily.

Unlike milk, fruit juice already contains substantial amounts of naturally occurring sugars that can serve as substrates for bacterial metabolism.

Research on fruit juice fermentation with L. reuteri demonstrates that fermentation can occur without adding the inulin commonly used in our L. reuteri yogurt preparation.

Whether adding prebiotic fibers such as inulin or acacia fiber could further improve fermentation for a particular L. reuteri culture is a separate question and requires further investigation.

Why Can Fermentation Results Vary?

L. reuteri is a living microorganism.

How successfully fermentation proceeds depends on several factors, including temperature, fermentation time, initial bacterial concentration, pH, and the composition of the juice.

Different L. reuteri cultures can also vary in their metabolic characteristics.

Scientific research nevertheless demonstrates the fundamental principle that fruit juices can provide a suitable medium for L. reuteri and that L. reuteri can remain viable or actively ferment fruit juice under appropriate conditions.

L. reuteri Juice or L. reuteri Yogurt?

Our L. reuteri yogurt remains the established preparation method covered by our existing fermentation instructions.

Juice fermentation offers an additional and exciting option, particularly for people interested in plant-based or dairy-free fermentation.

Research increasingly demonstrates that L. reuteri is not limited to yogurt-like fermentation, fruit juices such as apple juice can also be used as a fermentation medium for L. reuteri.

This makes probiotic juice an interesting new way to explore L. reuteri fermentation.

Tolerance note:

Fermented fruit juice may be less well tolerated than L. reuteri yogurt, particularly by people who are sensitive to fructose, fruit acids, fermented foods, or FODMAPs.

Fermentation does not necessarily remove all of the naturally occurring sugar from the juice.

If you are trying probiotic juice for the first time, start with a small amount and assess your individual tolerance.