Everyday care for a bloated gut

Feeling heavy after meals, or bloated more days than not? Duolac's 위청장쾌 (Wi-Cheong-Jang-Kwae) is a daily probiotic made specifically for a gut that often feels bloated and uncomfortable, from Korea's World-Class Product probiotic brand.

World-Class Product brand, Korea's Ministry of Trade, Industry and Energy (2024).

Rated 4.9 out of 5

Here's what customers on Duolac's Korean store say:

• “If your gut is on the weak side, I really recommend it. It suits me even better than Duolac Gold!”
• “I sit at a desk for long hours and often felt bloated. I've taken it for just over a month and I'm going to keep buying it.”
• “I'm a student who sits and studies for hours. Taking it consistently has helped.”

Rating from Duolac's SmartStore (as of 10 Aug 2023). Reviews from Duolac's Korean store, translated by Gochujar. Individual results may vary.

Tried the rest? This is where people land.

Looking for a probiotic for a gut that often feels bloated? One you can keep in your bag? One made with 100% Korean strains? It's all here, in just two capsules a day.

• When your gut feels bloated
• When big meals and late dinners leave you uncomfortable
• When you don't move much and your gut feels it

Two capsules. Once a day.

A premium probiotic designed around one job: looking after a bloated, sluggish gut.

• 2 probiotic strains, 100% Korean in origin
• Made only with strains on the US FDA GRAS register*
• A science-backed strain formula for a bloated gut
• Patented dual coating (Korea, US, EU, Japan, China) helps cultures reach your gut alive
• Enzyme food from Australia as a sub-ingredient
• A plant-based capsule

*GRAS relates to ingredient safety, not to health benefits.

Made for you if…

• You feel bloated most days
• Big meals and late dinners leave your gut heavy
• You sit for long hours at a desk
• You often eat out or rely on instant food
• Bloating comes with irregular bowel movements
• You want an everyday probiotic you can keep on hand

Specialists, not generalists

Before you choose a probiotic, check who designed it. Duolac has spent 30 years researching one thing: probiotic strains of Korean origin.

Two strains, both from Korea

Chosen with Korean guts in mind.

• Streptococcus thermophilus CBT-ST3, originally isolated from Koreans
• Lactiplantibacillus plantarum CBT-LP3, originally isolated from kimchi (a patented strain)

47 scientists behind every capsule

Duolac doesn't buy in its strains. It develops them itself: sourced from healthy Koreans and traditional Korean fermented foods, safety-verified in human trials with Korean adults, and researched strain by strain with next-generation genome sequencing.

• 107 patents
• 35 human trials
• 124 published papers
• 231 research achievements in total

Cell Biotech figures, as of 2025.

What does “CBT” mean?

Every probiotic strain has a name, just like people do. CBT stands for Cell Biotech, the company behind Duolac, and marks strains Duolac developed itself. When you see CBT, you know where it came from.

Safety you can check for yourself

Probiotics are live cultures, so safety comes first. Duolac uses only strains on the US FDA GRAS (Generally Recognized As Safe) register, and holds more GRAS-listed strains than any other company in the world (as of February 2024).

GRAS is the FDA's safety recognition for food ingredients. It relates to safety, not to health benefits.

Verified at every level

Duolac doesn't just say its probiotics are safe. It shows you the paperwork.

• Strain functionality recognized under Korea's MFDS health functional food standards
• Strains deposited with Germany's DSMZ and the Korean Collection for Type Cultures (KCTC)
• DNA sequence of each strain registered with the US NCBI
• Exported to 55 countries; No.1 Korean probiotic exporter 11 years running (2013–2023)
• World-Class Product brand, Korea's Ministry of Trade, Industry and Energy (2024)

Quality certifications: GMP, CODEX HACCP, ISO 9001, MUI Halal, OK Kosher, BPOM. Halal and kosher apply to specific ingredients or strains.

From strain to your door, all Duolac

No outsourcing, no shortcuts. Duolac runs every step itself, to global standards.

• Strain development and research
• Culturing and isolation
• Patented coating and freeze-drying
• Strain blending
• Finished product manufacturing
• Quality testing
• Delivery and customer service

A formula built for a bloated gut

Cell Biotech's Microbiome Institute used years of strain-analysis data to design this blend specifically for a gut that often feels bloated: 100% lactic acid bacteria, from S. thermophilus CBT-ST3 and L. plantarum CBT-LP3.

Why the blend matters

Each strain has its own home in the gut and its own growth pace, and our gut flora shifts as we age. Duolac designs every product's blend around that, so each strain can do its job.

With enzyme food from Australia

Alongside the probiotics, every capsule includes an enzyme food ingredient (Aspergillus oryzae fermented powder and Aspergillus niger culture, with pineapple and papaya extracts), plus fructooligosaccharides, a prebiotic that feeds good bacteria.

A plant-based capsule

The capsule shell is plant-based (HPMC), so it's easy to feel good about. Just two capsules with a glass of water.

Protected all the way down

A probiotic only helps if it survives the trip. Duolac's patented dual coating wraps each culture in a tough matrix of protein and polysaccharide, shielding it from stomach acid and bile so it reaches your gut alive. It's patented in the EU, US, Korea, China and Japan.

Up to 221× more reach the gut

The coating makes a real difference. In a human study, people taking dual-coated probiotics had up to 221 times more of the strain in their gut (L. rhamnosus CBT-LR5) than those taking uncoated probiotics.

Randomized, double-blind, controlled study of 40 adults over 2 weeks. Source: “Effect of double-coated probiotic formulation on functional constipation in the elderly.” The study used other Duolac strains; individual results may vary.

No fridge? No problem.

Duolac's CBT strains were confirmed to survive from −70°C all the way up to 40°C, so they're happy at room temperature: in your bag, at your desk or on a trip. Under the microscope, the cultures kept multiplying over time.

Tested by the Korea Functional Food Research Institute and Korea Food Research Institute (samples provided by Cell Biotech).

Product

Duolac 위청장쾌 (Wi-Cheong-Jang-Kwae) probiotics

Contents

60 capsules × 500 mg (30-day supply)

Probiotics

1 billion CFU guaranteed per daily serving

Strains

Streptococcus thermophilus CBT-ST3, Lactiplantibacillus plantarum CBT-LP3

Other ingredients

Fructooligosaccharides, corn starch, enzyme food (Aspergillus oryzae fermented powder, Aspergillus niger culture, maltodextrin, pineapple extract, papaya extract), stearic acid. Capsule: HPMC (plant-based), titanium dioxide.

Allergens

Contains milk and soy. Made in a facility that also handles eggs, buckwheat, peanuts, wheat, mackerel, crab, shrimp, peach, tomato, sulfites, walnuts, chicken, squid, shellfish and pine nuts.

How to take

2 capsules once a day, with water

Storage

Room temperature, away from humidity and direct sunlight

Shelf life

2 years from the date of manufacture

Manufacturer

Cell Biotech Co., Ltd., Gimpo, Republic of Korea

Country of origin

South Korea

Q&A

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