Last update
4/6/2026
Reviewed By
Overview
SCIENTIFIC SCORE
Questionable
Based on 2 Researches
6.5
USERS' SCORE
Good
Based on 2 Reviews
8.5
Supplement Facts
Serving Size: One (1) Tablet
Amount Per Serving
%DV
Calories
0
Total Carbohydrate
<1 g
<1%+
Total Sugars
0 g
**
Incl. 0 g Added Sugars
0%+
Xylitol
<1 g
**
Lactobacillus rhamnosus GG
53 mg (10 billion CFUs)
**
Top Medical Research Studies
8
We looked into how GCL1815, a type of lactic acid bacterium, might aid in preventing the common cold. In our randomized, double-blind study with 200 participants, we found that those who took GCL1815 capsules for eight weeks had significantly lower symptoms of colds, like fatigue and nasal congestion, compared to those on placebo. We also observed key immune responses related to dendritic cell activation that were notably more enhanced in participants taking GCL1815. This suggests that GCL1815 is promising in boosting the body’s defenses against the cold.
Read More
5
We conducted a pilot study to explore the effects of heat-sterilized Lactobacillus crispatus strain KT-11 on immune function in healthy adults. Over four weeks, 22 participants took either KT-11 or a placebo. We observed that those taking KT-11 had higher counts of certain immune cells and reported fewer cold-like symptoms, particularly fatigue. However, there were no significant increases in antibodies related to SARS-CoV-2. This indicates potential benefits of KT-11 for immune activity, suggesting further studies on its effectiveness are warranted.
Read More
Most Useful Reviews
9
No colds experienced
8 people found this helpful
In my opinion, this is a very good probiotic. I've been taking it for over five years. It comes in a blister pack and doesn't require refrigeration. It must be keeping me healthy – I haven't had so much as a cold in that time.
Read More
7.5
Stronger immune system
2 people found this helpful
Great buy. I really like this product and have noticed a stronger immune system. My entire family of five caught a cold last month, but I did not – I like to think it’s all thanks to my probiotics.
Read More
Medical Researches
SCIENTIFIC SCORE
Questionable
Based on 2 Researches
6.5
- All Researches
8
We looked into how GCL1815, a type of lactic acid bacterium, might aid in preventing the common cold. In our randomized, double-blind study with 200 participants, we found that those who took GCL1815 capsules for eight weeks had significantly lower symptoms of colds, like fatigue and nasal congestion, compared to those on placebo. We also observed key immune responses related to dendritic cell activation that were notably more enhanced in participants taking GCL1815. This suggests that GCL1815 is promising in boosting the body’s defenses against the cold.
Read More
5
We conducted a pilot study to explore the effects of heat-sterilized Lactobacillus crispatus strain KT-11 on immune function in healthy adults. Over four weeks, 22 participants took either KT-11 or a placebo. We observed that those taking KT-11 had higher counts of certain immune cells and reported fewer cold-like symptoms, particularly fatigue. However, there were no significant increases in antibodies related to SARS-CoV-2. This indicates potential benefits of KT-11 for immune activity, suggesting further studies on its effectiveness are warranted.
Read More
User Reviews
USERS' SCORE
Good
Based on 2 Reviews
8.5
- All Reviews
- Positive Reviews
- Negative Reviews
9
No colds experienced
8 people found this helpful
In my opinion, this is a very good probiotic. I've been taking it for over five years. It comes in a blister pack and doesn't require refrigeration. It must be keeping me healthy – I haven't had so much as a cold in that time.
Read More
7.5
Stronger immune system
2 people found this helpful
Great buy. I really like this product and have noticed a stronger immune system. My entire family of five caught a cold last month, but I did not – I like to think it’s all thanks to my probiotics.
Read More
Frequently Asked Questions
No FAQs are available for this product and symptom.
References
- Watanabe I, Suzuki N, Takara T. Supplementation with heat-sterilized Lactobacillus crispatus strain KT-11 stimulates the T cell-related immune function of healthy Japanese adults: A pilot randomized, placebo-controlled, double-blind, parallel-group study. Nutr Res. 2025;134:99. 10.1016/j.nutres.2024.12.004
- Wada H, Mawatari T, Saito Y, Azuma N, Iwama Y. Induces Two Types of Dendritic Cell Activation and Effectively Suppresses Onset of the Common Cold: A Randomized, Double-Blind, Placebo-Controlled Trial. Nutrients. 2024;17. 10.3390/nu17010101
