What is probiotic yogurt? A beginner's guide to L. reuteri and our six strains

All yogurt starts with bacteria. What makes a yogurt probiotic is which bacteria are in it, whether they are still alive when you eat it, and whether those exact strains have been studied in people. This beginner's guide explains what probiotic yogurt is, how it differs from ordinary yogurt, and how Lactobacillus reuteri and our five other strains fit into a simple daily habit.

If you are new to all this, you don't need a science degree to choose well. You need to know three things: what the word "probiotic" actually means, why the strain on the label matters, and how to keep the bacteria alive until they reach your spoon. By the end of this guide you will know all three.

What "probiotic" actually means

Scientists define probiotics as live microorganisms that, when given in adequate amounts, provide a health benefit to the person taking them. That definition comes from a 2001 expert panel of the UN's Food and Agriculture Organization and the World Health Organization, and it was reaffirmed by the International Scientific Association for Probiotics and Prebiotics in 2014.

Three parts of that definition matter when you choose a probiotic yogurt:

• Live. The bacteria need to be alive when you eat them. Heat kills them, which is why probiotic yogurt is eaten cold, not cooked.
• Adequate amounts. A trace is not enough. A long fermentation lets the culture multiply into billions of live bacteria per serving.
• A health benefit. Benefits are studied strain by strain, so the exact strain named on the label matters.

A yogurt that misses any of the three is still yogurt, and it can still be delicious. It just isn't doing the job of a probiotic.

Probiotic yogurt vs regular yogurt

Every yogurt is milk fermented by bacteria. The bacteria eat some of the milk's sugar and turn it into lactic acid, which thickens the milk and gives yogurt its tang. So what separates a probiotic yogurt from a regular one?

• The bacteria used. Many yogurts are made with cultures chosen for texture and flavour. A probiotic one is made with a strain that has been studied for its effects on people.
• Whether they are still alive. Some yogurt products are heat-treated after fermentation to make them last longer on the shelf. That kills the cultures. Live yogurt is kept cold from the moment it is made.
• How many there are. A short fermentation gives a mild yogurt with fewer bacteria. A longer one gives the culture time to multiply.
• What else is in the tub. Many flavoured yogurts add sugar, thickeners and gums. A live, well-made yogurt doesn't need them.

When you read a label, look for a named strain, live cultures, and a short ingredient list.

Why the strain matters more than the brand

Probiotics are named in three parts: genus, species and strain. Take Lactobacillus reuteri LRDR™:

• Lactobacillus is the genus, a large family of lactic acid bacteria.
• reuteri is the species.
• LRDR™ is the strain, one specific line within that species.

Those last letters matter. Research on one strain does not automatically apply to another, even within the same species. Two strains of L. reuteri can behave differently in the gut, the same way two varieties of mango can taste completely different.

That is why every jar of Bacilibloom is made with one named strain that you choose yourself, rather than an unnamed "probiotic blend". You always know exactly which bacteria you are eating, and you can look up the research on that strain.

What is L. reuteri?

L. reuteri is a lactic acid bacterium that lives naturally in the human gut, mouth and breast milk. Dr. William Davis, author of the book Super Gut, argues that many people today carry little or none of it, after decades of antibiotics, processed food and changes in how we live. Restoring it is the idea behind his approach, and L. reuteri is the culture he recommends fermenting into yogurt.

This is the bacterium that started Bacilibloom. We use LRDR™, the strain Dr. Davis uses, sold as MyReuteri™.

What the research on L. reuteri shows

An honest note first: LRDR™ itself has not yet been tested in a published clinical trial. The studies below used other strains of L. reuteri. They explain why the species attracts so much interest, not what LRDR™ is proven to do.

• Bone in older women. In a year-long, double-blind trial in Sweden, 90 women aged 75 to 80 with low bone density took L. reuteri ATCC PTA 6475 or a placebo every day. The probiotic group lost about half as much bone in the shin as the placebo group: 0.83% against 1.85% (Journal of Internal Medicine, 2018).
• Oxytocin and healing. At the Massachusetts Institute of Technology, mice given L. reuteri in their drinking water healed wounds in half the time. The effect worked through oxytocin, the hormone tied to bonding and calm (PLoS One, 2013).
• Skin and fur. The same group found that older mice given the bacterium grew thicker skin and glossier fur, much like younger animals (PLoS One, 2013).

Results in mice do not always carry over to people. Customers who eat L. reuteri yogurt usually describe everyday changes first: smoother digestion, deeper sleep and a lighter mood. Read the full research in our L. reuteri LRDR™ guide.

Our six strains at a glance

L. reuteri is where most of our customers start, but every Bacilibloom yogurt can be fermented with any one of these six:

• L. reuteri LRDR™, the Love Maker, for sleep, mood and skin.
• B. subtilis HU58™, the Digestive Helper, for digestion after meals. A spore former that survives stomach acid well.
• B. longum BB536, the Gut Guardian, for immunity and a settled stomach. In a trial in Malaysian preschool children, sore throats lasted 46% shorter than with a placebo.
• L. gasseri BNR17™, the Belly Burner, for weight and women's health. Studied for visceral fat in Korean adults.
• B. infantis EVC001, the Guardian Infant, for a sensitive gut. Studied in breastfed babies.
• L. casei Shirota, the Mood Lifter, for regularity. In fermented milk since 1935.

Not sure which to pick? Our guide to choosing a strain walks you through all six.

How we make our probiotic yogurt

We make every jar to order in small batches. Here is what goes into it:

1. A2 milk. All four of our recipes are made with A2 milk, from cows that produce only the A2 type of beta-casein protein.
2. Your strain. Each L. reuteri batch starts with a MyReuteri™ LRDR™ capsule as the live culture. The other five strains are fermented the same way.
3. 36 hours. We ferment slowly for 36 hours, far longer than most yogurt. A long ferment gives the culture time to multiply, so every serving carries billions of live bacteria.
4. Nothing else. No added sugar, gums, thickeners or preservatives.

Each new L. reuteri batch is started from the previous one, which keeps the culture strong and the quality consistent.

How to eat probiotic yogurt

The best way to eat it is simple: cold, often, and with food you enjoy.

• Eat it cold. Straight from the fridge, with fruit, granola or honey, or stirred into overnight oats. Cooking kills the live cultures.
• Eat it regularly. Probiotics work quietly in the background, and the effects build up over time rather than overnight. A small serving every day beats a big bowl once a week.
• Pair it with fibre. Fruit, oats, nuts and seeds contain fibre, which is what the bacteria in your gut feed on.
• Keep it simple. A spoonful after dinner counts. So does a bowl at breakfast.

How to store it

• Keep it in the chiller section of your fridge, not the door.
• It keeps for 4 weeks. Don't freeze it.
• Use a clean, dry spoon every time.
• Liquid on top is whey, a natural part of yogurt. Stir it back in.

Is probiotic yogurt right for you?

Most adults can enjoy live yogurt as part of a normal diet. Our yogurt is not suitable for children. If you are pregnant, breastfeeding, have a weakened immune system or a medical condition, check with your doctor first.

Frequently asked questions

Is all yogurt probiotic?

No. All yogurt is made with bacteria, but not every yogurt contains live, named strains that have been studied in people. Some yogurts are heat-treated after fermentation, which kills the cultures.

What is the best probiotic yogurt for beginners?

There is no single best one for everyone, because each strain is studied for different goals. L. reuteri LRDR™ is the strain most of our customers first come to us for. A 100g jar is an easy way to try it, then you can choose a strain for your own goal from there.

How much probiotic yogurt should I eat?

There is no official daily amount. Many people have one serving a day, around 100g to 150g, and keep it up as a habit.

Can I cook with probiotic yogurt?

You can, and it tastes great in curries and marinades, but cooking kills the live bacteria. For the probiotic benefit, eat at least some of it cold.

Can I change strains?

Yes. You choose your strain every time you order, so you can start with one and switch later.

Why does Bacilibloom ferment for 36 hours?

A longer ferment gives the culture more time to multiply. Dr. Davis describes a long ferment for L. reuteri, and we follow the same method.

Try your first jar

A good first order is L. reuteri LRDR™ in a 100g jar. Move up to 450g or 900g once it becomes a daily habit. We deliver across Kuala Lumpur and the Klang Valley, or you can pick up at Mukha Cafe, TTDI.

Sources

• Hill C et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology, 2014. PubMed
• Nilsson AG et al. Lactobacillus reuteri reduces bone loss in older women with low bone mineral density. Journal of Internal Medicine, 2018. PubMed
• Poutahidis T et al. Microbial symbionts accelerate wound healing via the neuropeptide hormone oxytocin. PLoS One, 2013. PubMed
• Levkovich T et al. Probiotic bacteria induce a 'glow of health'. PLoS One, 2013. PubMed

This guide is general information, not medical advice.