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The Science Behind Bifidobacterium Lactis BL-04

One of the active ingredients in Bionaze™

Your Guide To Bifidobacterium Lactis BL-04

We all know how our immune system works. This network of cells protects us from diseases and infections. It does this by regulating our body’s reactions to disease-causing microorganisms.

But did you know that the population of bacteria in your gut can affect your immune system?

Though further studies are needed, growing evidence shows that our microbiome (the bacteria population in our body) interacts with our immune system. As such, they can influence our body’s immune responses. When your microbiome is disturbed, it triggers a chain of reactions that can compromise your body’s immunity.

To address this, scientists are looking into the potential of probiotics. Also dubbed as the “good bacteria”, probiotics are living microorganisms beneficial to your body. It restores balance to your microbiome which helps boost your immune system.

Among the thousands of probiotic strains, studies show that Bifidobacterium lactis Bl-04 is the best for this purpose. Learn more about the best probiotics according to science here.


BL-04 in the stomach

Read The Scientific Studies Read Studies Done On The BL-04 Probiotic Strain

What is Bifidobacterium Lactis BL-04?

Bifidobacterium lactis Bl-04 is a bacteria strain typically found in the intestines of healthy humans. This anaerobic, rod-shaped bacterium has been the subject of various studies in recent years. Experts believe that this strain has great potential in terms of:

  • improving immune function
  • regulating gastrointestinal processes
  • reducing the side effects of antibiotics

Aside from being naturally found in our body, it’s also present in some of the foods we eat. Because of this, it’s generally regarded to be safe for consumption. There are also no harmful bodily reactions associated with this strain.

Resistance to Stomach Acid

Unknown to many, your stomach acid wipes out more than half of the bacteria that enter your body. This includes both the harmful and beneficial ones. But studies show that Bifidobacterium lactis Bl-04 is highly resistant to stomach acid.

This means that, unlike other probiotic strains, more of them can reach your gut. Now, think of probiotics as your body’s soldiers. If more of them are present, they can easily defeat the bad bacteria and colonize your gut.

Interaction With the Intestinal Tract

Various studies have demonstrated that Bl-04 is strongly adhesive to the intestinal tract. Why is this important?

Research shows that a probiotics’ ability to stick to the intestinal tract may prolong the time it can live in the intestine. It also brings them in close contact with the intestinal immune cells. This allows for a better chance of regulating the body’s immune response.

Health Benefits of Bl-04

Like other probiotic strains, Bl-04 benefits our body in specific ways. Because its main function is to regulate our immune responses, taking probiotics with the Bl-04 strain can bring about the following health benefits:

Reduce Allergies

A 2009 study sought to investigate whether probiotics can help reduce seasonal allergies. Randomly selected children with confirmed birch pollen allergy were given a probiotic combination of L. acidophilus and Bifidobacterium lactis Bl-04. The probiotics were given 4 months before the start of the birch pollen season.

The study yielded very promising results. During allergy season, only very few of those kids reported runny nose and nasal blockage. Watery eyes, a common allergy symptom, was also significantly reduced.

Further inspection also showed that there is a lesser incidence of eosinophil infiltration. The presence of eosinophils usually indicates the presence of infections and allergic diseases. The noticeable lack of eosinophils shows reduced allergy symptoms in the study subjects.

Better Tolerance for Vaccines

Vaccines are undoubtedly very helpful in protecting us against certain diseases. But some types of vaccines can be harmful to those with compromised immune systems.

This is why a study was conducted to evaluate if B. lactis Bl-04 can affect a healthy response to vaccination. The study administered an oral cholera vaccine to 83 volunteers. Some of them were also given seven different probiotic strains including Bl-04 for 21 days.

Those who received a probiotic treatment showed significant changes in antibody concentrations. In particular, subjects who received Bifidobacterium lactis Bl-04 and Lactobacillus acidophilus La-14 showed increased IgG. Immunoglobulin G (IgG) is the most common type of antibody found in our blood. These results suggest that some probiotic strains can enhance our body’s tolerance for vaccines.

Bifidobacterium lactis  for Immunity, Hay Fever and Allergies

Growing evidence shows that our bodies resident microbiome interacts with our immune system and may even influence immune responses; and Bifidobacteria strains, specifically BL-04™ appear to be one of the best probiotics for this purpose.

Summaries From Recent Studies Done On Bl-04

In a randomised, double blind, placebo-controlled study, 115 participants were administered with ‘rhinovirus’ i.e. given the cold virus. The group was also given the strain Bifidobacterium lactis BL-04 28 days before and during the rhinovirus challenge. Results showed a reduced incidence of respiratory tract infection as well as ‘viral shedding’, i.e. the replication / spread of the virus, in the probiotic group compared to placebo.

A human study evaluated the ability of B. lactis BL-04 to encourage a healthy immune reaction in response to a vaccination. Human volunteers were orally vaccinated against cholera, and then given either a placebo or one of seven different probiotic strains including B. lactis BL-04 for a period of 21 days. Via blood serum and saliva testing, significant changes in immunoglobulin serum concentrations were found in 6 out of the 7 probiotic supplementation groups, whereas no changes were observed in the control group. Those in the BL-04 group showed increased IgG in an early response to the vaccine (Paineau et al. 2008).

In another randomised trial, 47 children with hay fever triggered by birch tree pollen were given a probiotic containing a combination of Lactobacillus acidophilusNCFM® and Bifidobacterium lactis BL-04 or placebo. Those taking the two strain combination were found to have a significantly reduced presence of eosinophils (a type of white blood cell which is involved in controlling allergies) in the nose area, compared to the placebo group. Additionally, the participants reported that those on the two-strain probiotic had reduced symptoms of nasal congestion and discharge, compared to those in the placebo group (Ouewhand AC et al, 2009).


BL-04 is mostly found in the large intestines of mammals including humans. Experts are generally interested in its potential for improving gastrointestinal function, immunity and enhancing the side effects of antibiotics.

A recent study has proven its effect on people who are infected with the “rhinovirus” more commonly known as the cold virus. These people were given the BL-04 probiotic strain for about two months. They exhibited reduced respiratory tract infection and the spreading of virus was effectively contained.

A clinical trial also revealed that BL-04 can be used to treat nasal allergies. Children with hay fever caused by a birch tree pollen were administered with a dose of BL-04 and Lactobacillus Acidophilus. Results indicated that their eosinophils in the nose area are reduced. Eosinophils are white blood cells that control allergies. They have also shown lesser incidence of nasal congestion and discharge.

Doubts as to whether its safe for human consumption have already been addressed by several previous studies. It’s even present in several types of foods we consume daily. The European Food Safety Authority even added it to the Qualified Presumption of Safety list. The EU also hasn’t detected any acquired antibiotic resistance from consuming this probiotic strain.

In a recent double-blind, randomised, placebo-controlled study in Australia, 465 healthy participants who exercised regularly were selected. The aim of the study was to determine whether probiotics would help to support immune function in these subjects, as significant exercise can put a strain on the immune system causing an increased risk of colds and respiratory infections. The subjects were divided into three groups: Group 1 were given the probiotic strain B. lactis BL-04 alone; Group 2 were given a combination of L. acidophilus NCFM® & B. lactis BL-07, and Group 3 were given a placebo. Over the 5 months of the trial, it was found that Group 1 displayed a 27% lower incidence of upper respiratory infections. Those in Group 2 also showed a decreased incidence of infection, though results were not as strong as in group 1; however, both groups displayed improved immunity compared to the placebo group which had no impact on infection risk reduction (West NP et al, 2014).

Decreases Side Effects of Antibiotics

We all know that antibiotics kill disease-causing bacteria. But what most people don’t know is that it also wipes out the beneficial ones. This is why a prolonged antibiotic treatment can wreak havoc to your body’s microbial population (microbiome).

This is where probiotics enter the picture. It helps replenish the lost good bacteria and restores balance to your gut microbiota.

A randomized trial found that the probiotic strain B. lactis Bl-04 is especially effective in reducing the side effects of antibiotics. The study focused on people undergoing antibiotic treatments. While taking antibiotics, they were also given probiotics formulated with five strains including Bl-04.

Results showed that the probiotic formulation significantly reduced the overall disturbance in the gut’s microbiome. A higher level of Bifidobacteria was also noted in the participants even two weeks after the treatment ended.

Where to Buy Bl-04

The Bifidobacterium lactis Bl-04 strain had been present in human foods for decades. It is commonly added to fermented dairy products such as cheese and yogurt. It can also be found in some commercial fermented milk brands.

Aside from foods, B. lactis Bl-04 is also commonly taken as a probiotic supplement. Most of the time, it’s mixed with other types of probiotic strains.

One probiotic supplement containing the Bl-04 strain is Bionaze. Formulated with Bl-04 and BLIS K12, Bionaze is especially targeted for nose, ear, throat, and mouth issues. This oral probiotic comes in a lozenge form to further enhance its effectivity.

How Often Should You Take Bl-04 Probiotics?

If you want to achieve its maximum benefits, probiotics should be taken on a regular basis.

Think of your body as a garden. If you don’t trim the weeds regularly, time will come that it will choke out the plants and kill them. This is also what happens in your gut microbiome.

If you don’t replenish the lost good bacteria regularly, the bad ones can take over. This is the last thing you’d want to happen as this can weaken your immune system and cause various types of diseases.

Bl-04 Side Effects

The European Food Safety Authority has added B. lactis Bl-04 to its Qualified Presumption of Safety List. This is after they detected no acquired antibiotic resistance in the strain. No harmful side effects have also been scientifically proven to be associated with Bl-04. But for safety purposes, you should always consult with your doctor before taking any probiotic supplement.

Junecia Ponio Author Image

About The Author

is a professional writer based in the Philippines. Her commitment to communicating factual content in when writing is unmatched. She works hard to cross check reputable sources to ensure her work uses accurate facts.

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