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Ingredient file // Other

Dried Lactobacillus Casei Fermentation Product

A cultured additive with an unproven payoff

This ingredient is made by growing Lactobacillus casei in a nutrient medium and drying the cultured material. Makers add it for bacteria or fermentation substances, but its name gives no live count, and dog studies have not tested this ingredient on its own.

Role in the food Does a job
What it is
A dried material made by culturing Lactobacillus casei in a nutrient medium.
Made from
Lactobacillus casei and nutrient medium
Main job
Microbial fermentation supplement
Typical amount
Not published for this standalone ingredient
Watch for
No guaranteed live count
Not the same as
A verified probiotic dose

Straight answer

Is Dried Lactobacillus Casei Fermentation Product safe for dogs?

Look for a live count, then move on

If this appears near the end of a bag's ingredient list, read the main protein, fat and carbohydrate ingredients first. If the brand sells a probiotic benefit, look for a guaranteed live count on the finished food. Without one, treat this as a minor fermentation ingredient with an unproven payoff.

Why it is in the food
Microbial fermentation supplement

Our read // In our catalog

In 1 of every 11 foods we track

Share of foods that list it

9%

298 of the 3,204 foods with an ingredient list on file, from 26 brands. 293 dry dog food, 4 frozen dog food, 1 freeze-dried dog food.

Each square is 1% of the catalog

Where it sits on the label

Median position 30.5. In the top five of 0 foods, so it is usually a minor ingredient.

Top five List position, heaviest first

Above the salt

2%

Usually listed after the salt, which caps it at roughly 1% of the recipe in 98% of foods.

Price per lb

Foods with it $3.33
All foods $3.25

Median of the cheapest bag price across 181 priced foods, about level with the catalog. The price is the food's, not the ingredient's.

Who leans on it

9%

of the foods that list it are from Horizon. 26 brands use it in total.

What it is

How it is made

Feed ingredient producers grow Lactobacillus casei in a nutrient medium, then dry the cultured material. It is made for use in feed rather than recovered as a leftover from another food process.5,6

  1. 01 // Source Culture and medium Lactobacillus casei is grown in a nutrient medium selected to support fermentation.
  2. 02 // Process Controlled fermentation The culture grows and produces substances in the medium around it.
  3. 03 // Process Drying The cultured material is dried; the ingredient name specifies neither the drying method nor a live count.
  4. 04 // Output Dry fermentation product The dry material reaches the food maker for addition to a recipe or microbial blend.

What is in it

Composition, as fed

1

% protein min

The protein floor for a published feed blend containing this culture. It is not a nutrient source; any value it has is microbial.

Protein, blend (min) 1%7
Fat, blend (min) 1%7
Fiber, blend (max) 30%7
Moisture, soluble blend 7.8%7

These are as-fed label figures for supplier blends of four cultures, one on a rice mill by-product and calcium carbonate carrier. No standalone analysis of the casei product was found; its makeup follows the medium and carrier used.5,7

Why it is in the bag

A microbial add-in, in an amount nobody publishes

  1. Main nutrition
  2. Supporting nutrient
  3. Does a job
  4. Mostly filler

Makers add it for the culture: Lactobacillus casei and the substances its fermentation leaves in the dried material. It is not a nutrient source. Labels list ingredients by weight, and this one usually sits near the end, often below salt, so it is likely too little to change the food's nutrition. Whether it does its microbial job depends on a live count, which the name does not promise.5,6,8

  1. 01

    Adds cultured material

    Fermentation leaves microbial cells and the substances they make in the dried material. The ingredient name identifies the culture used, but does not show which substances remain in a particular batch.5

  2. 02

    Offers a live culture

    Some makers use dried cultures to supply live bacteria. FDA says a viable count must be guaranteed and testable if that is what the product claims to deliver.6

  3. 03

    Ships and doses dry

    Dry culture blends store and mix easily into feed. One supplier sells a blend containing L. casei fermentation product in 50 lb lined bags, on a rice mill by-product carrier.7

How much No recipe percentage is published for this ingredient; a different Lactobacillus fermentation product was tested in dogs at 4 mg per kilogram of body weight.3

Our read // The claims

What the evidence supports

Strong: controlled studies in dogs agree. Some: small or mixed dog data. Thin: mechanism or lab work only. None: nothing, or the evidence points the other way.

  1. Brands say

    It improves a dog's gut microbiome

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    A 90-dog study found changes in fecal bacteria after a live, three-strain blend containing L. casei. It did not isolate this species or test this dried fermentation ingredient in kibble, so the finding is indirect at best.1

  2. Brands say

    It strengthens a dog's immune defenses

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    The same 90-dog blend study found higher blood IgG and fecal IgA. Those are immune markers from a different, live three-strain product, not fewer infections, and the study cannot assign the changes to this ingredient.1

  3. Brands say

    It stops diarrhea in dogs

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    A placebo-controlled trial tested a live ten-strain blend containing L. casei in 60 dogs. Stools formed after 3.5 days with the blend and 4.8 with placebo, but the difference was not statistically significant.2

  4. Owners say

    Its name guarantees live bacteria in kibble

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    FDA warns that a dry microbial product may lack the viable bacteria it claims. A specially encapsulated L. casei powder retained live cells after 12 months on its own; foods fortified with it were measured for 6 months.4,6

Straight answers

What owners ask

  1. Q01

    Is it just filler?

    No

    It is added as a fermentation ingredient, not as a main source of food energy. Its intended job is microbial, although the ingredient line alone does not prove that a useful live dose reaches your dog.5,6

  2. Q02

    Does drying kill the bacteria?

    Not always

    A specially encapsulated L. casei powder kept live cells during storage. That result does not tell you what survives processing and storage in your dog's food. Check the finished food for a guaranteed live count.4,6

  3. Q03

    Will it treat my dog's diarrhea?

    No proof

    The controlled trial tested a live blend, not this ingredient alone, and found no statistically significant improvement over placebo. An ingredient listing is not evidence of a treatment dose.2

Who uses it

Brands, best sellers and the company it keeps

Top brands, by foods that list it

  1. Horizon 26 / 27
  2. Nature's Logic 24 / 32
  3. Acana 23 / 23
  4. Earthborn Holistic 23 / 28
  5. Bil-Jac 21 / 32
  6. Merrick 18 / 107
  7. Annamaet 17 / 20
  8. Wysong 17 / 20
  9. Solid Gold 15 / 46
  10. Holistic Select 15 / 16

Foods that list it / all the brand's recipes we track.

Plus 16 more brands.

Usually listed with, share of the foods that list it

  1. Mixed Tocopherols 61%
  2. Chicken Fat 48%
  3. Chicken Meal 42%
  4. Flaxseed 42%
  5. Peas 37%
  6. Chicken 33%
  7. Brown Rice 28%
  8. Natural Flavor 26%
  9. Oatmeal 26%
  10. Turkey Meal 22%
  11. Sweet Potatoes 16%
  12. Dried Beet Pulp 16%

On the shelf

Foods that list Dried Lactobacillus Casei Fermentation Product

298 foods in our catalog list it. These 60 list it highest on the label.

Answers Pet Food Detailed Mighty Raw Chicken Frozen Dog FoodAnswers Pet FoodAnswers Pet Food Detailed Mighty Raw Chicken Frozen Dog FoodFrozen // No. 9 on the labelAnswers Pet Food Detailed Mighty Raw Turkey Frozen Dog FoodAnswers Pet FoodAnswers Pet Food Detailed Mighty Raw Turkey Frozen Dog FoodFrozen // No. 10 on the labelCanidae Pure Grain-Free Real Wild Boar & Garbanzo Bean Recipe Dry Dog FoodCanidaeCanidae Pure Grain-Free Real Wild Boar & Garbanzo Bean Recipe Dry Dog FoodDry // No. 16 on the labelWellness Core Six Free-Range Lamb Grain-Free Dry Dog FoodWellnessWellness Core Six Free-Range Lamb Grain-Free Dry Dog FoodDry // No. 17 on the labelWellness Core Six Cage-Free Duck Grain-Free Dry Dog FoodWellnessWellness Core Six Cage-Free Duck Grain-Free Dry Dog FoodDry // No. 17 on the labelCanidae Pure Grain-Free Real Lamb, Goat & Venison Meals Recipe Dry Dog FoodCanidaeCanidae Pure Grain-Free Real Lamb, Goat & Venison Meals Recipe Dry Dog FoodDry // No. 17 on the labelEarthborn Holistic Venture Turkey Meal & Pumpkin Grain-Free Dry Dog FoodEarthborn HolisticEarthborn Holistic Venture Turkey Meal & Pumpkin Grain-Free Dry Dog FoodDry // No. 18 on the labelWhole Earth Farms Grain-Free Recipe Healthy Weight Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Recipe Healthy Weight Dry Dog FoodDry // No. 19 on the labelCanidae All Life Stages Large Breed Formula Turkey Meal & Brown Rice Dry Dog FoodCanidaeCanidae All Life Stages Large Breed Formula Turkey Meal & Brown Rice Dry Dog FoodDry // No. 19 on the labelBil-Jac Senior Dry Dog FoodBil-JacBil-Jac Senior Dry Dog FoodDry // No. 20 on the labelBil-Jac Senior Select Formula Dry Dog FoodBil-JacBil-Jac Senior Select Formula Dry Dog FoodDry // No. 20 on the labelWysong Fundamentals Dry Dog FoodWysongWysong Fundamentals Dry Dog FoodDry // No. 21 on the label
Show 48 more
Answers Pet Food Detailed Mighty Raw Pork Frozen Dog FoodAnswers Pet FoodAnswers Pet Food Detailed Mighty Raw Pork Frozen Dog FoodFrozen // No. 10 on the labelAnswers Pet Food Detailed Mighty Raw Beef Frozen Dog FoodAnswers Pet FoodAnswers Pet Food Detailed Mighty Raw Beef Frozen Dog FoodFrozen // No. 10 on the labelCanidae Pure Grain-Free Real Duck & Sweet Potato Recipe Dry Dog FoodCanidaeCanidae Pure Grain-Free Real Duck & Sweet Potato Recipe Dry Dog FoodDry // No. 17 on the labelWellness Core Six Small Breed Sustainably-Sourced Salmon Dry Dog FoodWellnessWellness Core Six Small Breed Sustainably-Sourced Salmon Dry Dog FoodDry // No. 18 on the labelWellness Core Six Sustainably-Sourced Salmon Grain-Free Dry Dog FoodWellnessWellness Core Six Sustainably-Sourced Salmon Grain-Free Dry Dog FoodDry // No. 18 on the labelCanidae Pure Grain-Free Healthy Weight Real Chicken & Pea Recipe Dry Dog FoodCanidaeCanidae Pure Grain-Free Healthy Weight Real Chicken & Pea Recipe Dry Dog FoodDry // No. 18 on the labelCanidae Pure Grain-Free Real Lamb & Pea Recipe Dry Dog FoodCanidaeCanidae Pure Grain-Free Real Lamb & Pea Recipe Dry Dog FoodDry // No. 19 on the labelCanidae Pure Grain-Free Small Breed Real Chicken, Potato & Whole Egg Recipe Dry Dog FoodCanidaeCanidae Pure Grain-Free Small Breed Real Chicken, Potato & Whole Egg Recipe Dry Dog FoodDry // No. 20 on the labelCanidae Pure Puppy Grain-Free Real Chicken, Lentil & Whole Egg Recipe Dry Dog FoodCanidaeCanidae Pure Puppy Grain-Free Real Chicken, Lentil & Whole Egg Recipe Dry Dog FoodDry // No. 20 on the labelBil-Jac Large Breed Dry Dog FoodBil-JacBil-Jac Large Breed Dry Dog FoodDry // No. 21 on the labelWhole Earth Farms Grain-Free Small Breed Recipe with Chicken & Turkey Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Small Breed Recipe with Chicken & Turkey Dry Dog FoodDry // No. 21 on the labelBil-Jac Large Breed Adult Dry Dog FoodBil-JacBil-Jac Large Breed Adult Dry Dog FoodDry // No. 21 on the labelBil-Jac Picky No More Medium & Large Breed Dry Dog FoodBil-JacBil-Jac Picky No More Medium & Large Breed Dry Dog FoodDry // No. 22 on the labelBil-Jac Sensitive Solutions Healthy Weight Support Dry Dog FoodBil-JacBil-Jac Sensitive Solutions Healthy Weight Support Dry Dog FoodDry // No. 22 on the labelBil-Jac Adult Dry Dog FoodBil-JacBil-Jac Adult Dry Dog FoodDry // No. 22 on the labelBil-Jac Puppy Dry Dog FoodBil-JacBil-Jac Puppy Dry Dog FoodDry // No. 22 on the labelBil-Jac Small Breed Dry Dog FoodBil-JacBil-Jac Small Breed Dry Dog FoodDry // No. 22 on the labelWhole Earth Farms Grain-Free Small Breed Recipe with Salmon & Whitefish Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Small Breed Recipe with Salmon & Whitefish Dry Dog FoodDry // No. 22 on the labelWhole Earth Farms Grain-Free Recipe Healthy Puppy Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Recipe Healthy Puppy Dry Dog FoodDry // No. 22 on the labelI and Love and You Naked Essentials Puppy Grain-Free with Chicken + Lentils Dry Dog FoodI and Love and YouI and Love and You Naked Essentials Puppy Grain-Free with Chicken + Lentils Dry Dog FoodDry // No. 22 on the labelBil-Jac Large Breed Puppy Dry Dog FoodBil-JacBil-Jac Large Breed Puppy Dry Dog FoodDry // No. 22 on the labelBil-Jac Reduced Fat Formula Dry Dog FoodBil-JacBil-Jac Reduced Fat Formula Dry Dog FoodDry // No. 22 on the labelBil-Jac Small Breed Adult Dry Dog FoodBil-JacBil-Jac Small Breed Adult Dry Dog FoodDry // No. 22 on the labelBil-Jac Adult Select Formula Dry Dog FoodBil-JacBil-Jac Adult Select Formula Dry Dog FoodDry // No. 22 on the labelBil-Jac Picky No More Medium Breed Dry Dog FoodBil-JacBil-Jac Picky No More Medium Breed Dry Dog FoodDry // No. 22 on the labelBil-Jac Picky No More Small Breed Dry Dog FoodBil-JacBil-Jac Picky No More Small Breed Dry Dog FoodDry // No. 22 on the labelBil-Jac Puppy Select Formula Dry Dog FoodBil-JacBil-Jac Puppy Select Formula Dry Dog FoodDry // No. 22 on the labelWhole Earth Farms Puppy Recipe Dry Dog FoodWhole Earth FarmsWhole Earth Farms Puppy Recipe Dry Dog FoodDry // No. 23 on the labelWhole Earth Farms Grain-Free Small Breed Recipe with Pork, Beef & Lamb Poultry-Free Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Small Breed Recipe with Pork, Beef & Lamb Poultry-Free Dry Dog FoodDry // No. 23 on the labelWhole Earth Farms Grain-Free Recipe with Salmon & Whitefish Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Recipe with Salmon & Whitefish Dry Dog FoodDry // No. 23 on the labelWhole Earth Farms Grain-Free Recipe with Chicken & Turkey Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Recipe with Chicken & Turkey Dry Dog FoodDry // No. 23 on the labelHorizon Amicus Grain-Free All Life Stages Lamb Formula Dry Dog FoodHorizonHorizon Amicus Grain-Free All Life Stages Lamb Formula Dry Dog FoodDry // No. 23 on the labelHorizon Amicus Grain-Free All Life Stages Salmon Formula Dry Dog FoodHorizonHorizon Amicus Grain-Free All Life Stages Salmon Formula Dry Dog FoodDry // No. 23 on the labelHorizon Pulsar Grain-Free Salmon Formula Dry Dog FoodHorizonHorizon Pulsar Grain-Free Salmon Formula Dry Dog FoodDry // No. 23 on the labelEagle Pack Large & Giant Breed Adult Dry Dog FoodEagle PackEagle Pack Large & Giant Breed Adult Dry Dog FoodDry // No. 23 on the labelBil-Jac Small Breed Puppy Dry Dog FoodBil-JacBil-Jac Small Breed Puppy Dry Dog FoodDry // No. 23 on the labelBil-Jac Sensitive Solutions Skin & Stomach Support Dry Dog FoodBil-JacBil-Jac Sensitive Solutions Skin & Stomach Support Dry Dog FoodDry // No. 24 on the labelBil-Jac 30/20 Performance - Bil-Jac Dry Dog FoodBil-JacBil-Jac 30/20 Performance - Bil-Jac Dry Dog FoodDry // No. 24 on the labelWhole Earth Farms Adult Recipe Dry Dog FoodWhole Earth FarmsWhole Earth Farms Adult Recipe Dry Dog FoodDry // No. 24 on the labelHorizon Amicus Grain-Free All Life Stages Chicken Formula Dry Dog FoodHorizonHorizon Amicus Grain-Free All Life Stages Chicken Formula Dry Dog FoodDry // No. 24 on the labelBil-Jac Sensitive Solutions Dry Dog FoodBil-JacBil-Jac Sensitive Solutions Dry Dog FoodDry // No. 24 on the labelNature’s Logic Original Pure Naturals Sardine Recipe Dry Dog FoodNature's LogicNature’s Logic Original Pure Naturals Sardine Recipe Dry Dog FoodDry // No. 25 on the labelWysong Epigen 90 Starch-Free Dry Dog FoodWysongWysong Epigen 90 Starch-Free Dry Dog FoodDry // No. 25 on the labelWhole Earth Farms Grain-Free Recipe with Turkey & Duck Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Recipe with Turkey & Duck Dry Dog FoodDry // No. 25 on the labelWhole Earth Farms Grain-Free Recipe with Pork, Beef & Lamb Poultry-Free Dry Dog FoodWhole Earth FarmsWhole Earth Farms Grain-Free Recipe with Pork, Beef & Lamb Poultry-Free Dry Dog FoodDry // No. 25 on the labelSolid Gold Barking at the Moon High Protein Beef, Egg & Pea Recipe Dry Dog FoodSolid GoldSolid Gold Barking at the Moon High Protein Beef, Egg & Pea Recipe Dry Dog FoodDry // No. 25 on the labelNature’s Logic Distinction Canine Sardine Recipe Dry Dog FoodNature's LogicNature’s Logic Distinction Canine Sardine Recipe Dry Dog FoodDry // No. 25 on the labelMerrick Full Source with Healthy Grains Raw-Coated Kibble with Salmon & Whitefish Dry Dog FoodMerrickMerrick Full Source with Healthy Grains Raw-Coated Kibble with Salmon & Whitefish Dry Dog FoodDry // No. 25 on the label

Sources

What we read

Checked October 1, 2026.

  1. 1 Oral Administration of Compound Probiotics Improved Canine Feed Intake, Weight Gain, Immunity and Intestinal Microbiota Frontiers in Immunology, 2019 // Journal
  2. 2 A Randomized Double Blinded Placebo-Controlled Clinical Trial of a Probiotic or Metronidazole for Acute Canine Diarrhea Frontiers in Veterinary Science, 2019 // Journal
  3. 3 Effects of a Lactobacillus fermentation product on the fecal characteristics, fecal microbial populations, immune function, and stress markers of adult dogs Journal of Animal Science, 2023 // Journal
  4. 4 Delivery of probiotic bacteria in long life ambient stable foods using a powdered food ingredient British Food Journal, 2013 // Journal
  5. 5 Official Names and Definitions of Feed Ingredients AAFCO, 2025 // Regulator
  6. 6 CPG Sec. 689.100 Direct-Fed Microbial Products U.S. Food and Drug Administration, 1995 // Government
  7. 7 Specifications PrimaLac, n.d. // Industry
  8. 8 21 CFR 501.4 Animal food; designation of ingredients Legal Information Institute, Cornell Law School (U.S. Code of Federal Regulations), 2026 // Regulator
An ingredient on its own tells you very little. What matters is how much of it there is and where it sits in the list. That is why we weigh the top five rather than reacting to any single name further down. Back to the wiki

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