July 25, 2024

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The mechanism of Bifidobacterium longum to prevent intestinal diseases

The mechanism of Bifidobacterium longum to prevent intestinal diseases


The mechanism of Bifidobacterium longum to prevent intestinal diseases.  Bifidobacterium longum can effectively improve the immune system and prevent intestinal diseases. 

There is a flora that can improve the body’s immune response and help prevent intestinal diseases. It also has the effect of suppressing allergies, lowering cholesterol and improving skin health. It is-Bifidobacterium longum

Next, I will take you to explore its secrets…



01. What is Bifidobacterium longum?


Definition discovery

Bifidobacterium is isolated from six different ecological niches, three of which are directly related to the intestinal environment of humans and animals. For example: human and animal intestines (cow, rabbit, rat, chicken and insects) and oral cavity, while others are sewage, blood and food, which may also be the result of gastrointestinal contamination.

Bifidobacteria are widely distributed in living organisms that provide their offspring with parental care, such as mammals, birds, and social insects. So far, Bifidobacterium has not been isolated from other animals (such as reptiles and fish). Therefore, the important reason for their ecological distribution may be the direct transmission of bifidobacteria cells to the offspring by the parents/caregivers.

Bifidobacterium longum is a gram-positive coryneform bacterium that naturally exists in the human gastrointestinal tract. It is one of the first bacteria to colonize the intestinal tract when a baby passes through the birth canal. These bacteria are also called probiotics. Bifidobacterium infantis and Bifidobacterium suis are subspecies of Bifidobacterium longum.


Structural metabolism

Bifidobacteria are Gram-positive, anaerobic and branched rod-shaped bacteria. They are also non-motile and non-spore forming.

Bifidobacteria produce hexose metabolism through the phosphoketolase pathway. Fructose-6-phosphate phosphoketolase (F6PPK) is an important part of it.

Bifidobacterium longum fermentes sugar into lactic acid, which helps lower the pH of the intestinal tract. “It has homologues of enzymes that repair oxidative damage, such as NADH oxidase and NADH peroxidase. It also contains proteins and lipids that reverse oxidative damage, such as thiol peroxidase, alkyl hydrogen peroxide reduction Enzyme (ahp C), peptide methionine sulfoxide reductase.”

The Bifidobacterium longum genome encodes various proteins that are specifically used to decompose oligosaccharides. The bacterium exists in the colon for a long time because it can metabolize the host or other poorly absorbed substrates of the intestinal flora.



02.  The potential benefits of Bifidobacterium longum?


1) Enhance immunity

A small study of Bifidobacterium infantis showed that Bifidobacterium infantis can prevent poliovirus. Bifidobacterium infantis improved the immune response of experimental volunteers.


We know that gut health from infancy is related to health-related conditions and disease risk factors in future life. Research has linked changes in the intestinal flora to a variety of diseases, including autoimmune diseases such as celiac disease and type 1 diabetes, metabolic syndrome, allergies, asthma, and inflammatory bowel disease.


Many factors can promote intestinal health. Healthy intestinal flora is one of the factors that support intestinal health, improve immune function and may reduce the risk of certain diseases.


Researchers believe that the protective ability of bifidobacteria against early life diseases is through the production of short-chain fatty acids (SCFA) and lactic acid, through specific immune stimulation and acidification of the intestinal environment.


Bifidobacterium longum also stimulated the immune function of 45 elderly hospitalized patients who had received the flu vaccine. Compared with other well-known strains, Bifidobacterium infantis has a stronger immunomodulatory effect in the blood of elderly patients.


2) Reduce infectious diseases

Experiments have shown that Bifidobacterium longum protects mice from death caused by pneumonia by fine-tuning the inflammatory response and accelerating lung recovery. Bifidobacterium infantis can inhibit rotavirus infection in mice, and oral Bifidobacterium longum can protect mice from intestinal sepsis caused by Pseudomonas aeruginosa, and greatly improve the survival rate of mice infected with Salmonella typhi.


Infants fed with Bifidobacterium longum showed a lower rate of respiratory infections. In 27 elderly subjects who received the flu vaccine, Bifidobacterium longum supplements reduced flu and fever rates.


3) Relieve and treat gastrointestinal infections

Probiotics are often used in combination with antibiotics to reduce the risk of gastrointestinal infections and prevent the death of beneficial bacteria. In addition, some studies have shown that treatment with probiotics containing bifidobacteria can help treat infections like Clostridium difficile by reducing diarrhea.


4) Improve diarrhea and constipation

Irritable bowel syndrome (IBS) is usually characterized by abdominal pain or discomfort, accompanied by changes in the frequency and/or consistency of stool, which may lead to diarrhea and/or constipation.


The clinical practice guidelines for IBS concluded that according to some randomized clinical controlled trials, Bifidobacterium longum can improve the overall symptoms of IBS patients.


Infant Bifidobacterium longum can improve abdominal pain/discomfort, bloating, and difficulty in defecation.

Bifidobacterium longum also reduced the visceral hypersensitivity of IBS mice, and significantly reduced the visceral pain threshold pressure of the first pain behavior and total pain behavior in rats.

The American Academy of Family Physicians pointed out that “probiotics can reduce the incidence of antibiotic-related diarrhea, reduce the duration of all infectious diarrhea and the severity of pain and patient’s bloating.” The beneficial degree of the effect depends on the type and formula used. And the given amount.


5)  Prevent eczema

Many studies have shown that the use of probiotics containing Bifidobacterium strains for mothers and infants during pregnancy and lactation can prevent eczema in infants and children. But when it comes to eczema treatment, the beneficial uses of probiotics are diverse, so more research is needed to determine their benefits. Before giving any supplements to your child, you should perform an intestinal flora test or consult a doctor for advice.


6) Reduce allergies

In patients with cedar pollen allergies, ingestion of yogurt or powder added with Bifidobacterium longum can reduce subjective symptoms and affect blood markers of allergy. Nasal symptoms such as itching, rhinorrhea, blockage and throat symptoms can often be relieved.



Experiments show that the Bifidobacterium strain reduces allergic airway inflammation and food allergy symptoms in mice. Oral Bifidobacterium longum can suppress IgE levels and improve the IgG2a/IgG1 ratio. It also increased Th1 cytokine in mice and decreased Th2 cytokine production. Bifidobacterium longum balanced the Th1/Th2 response and reduced β-lactoglobulin allergic inflammation in mice.


7) Reduce cholesterol

Bifidobacterium longum lowers total cholesterol, especially in patients with moderate hypercholesterolemia. Bifidobacterium longum supplements can significantly reduce the total cholesterol, liver lipid deposition and fat cell size in hypercholesterolemia rats, and positively affect liver and kidney functions.


The rats were fed cholesterol-rich food and supplemented with Bifidobacterium longum, and it was found that triglycerides, low-density lipoprotein cholesterol (LDL-C), ultra-low-density lipoprotein (VLDL) cholesterol and malondialdehyde were significantly reduced .


8) Reduce schizophrenia

Taking Bifidobacterium longum every day can alleviate the feeding behavior of mice with schizophrenia, reduce the plasma corticosterone level and the ratio of kynurenine to tryptophan at rest.


9) Treat anxiety and depression

Bifidobacterium longum can normalize anxiety-like behavior and hippocampal brain-derived neurotrophic factor (BDNF) in mice with infectious colitis.


Taking Bifidobacterium infantis can reverse depression. Long-term administration of Bifidobacterium infantis can protect rats from depressive symptoms caused by stress caused by the separation of the mother.




03. What are the mechanisms of action of Bifidobacterium longum?


At present, the effect of Bifidobacterium longum on the cell level has been studied. These may reflect the mechanism of action of Bifidobacterium longum in the human body.


The following are all supported by research literature.


Inflammatory conditions

● Decreased Th1-related cytokines (T-bet, IL-2, and IFN-γ) and Th17-related cytokines (IL-12p40, RORγt, IL-17A, IL-21, and IL-23) , And added regulatory T cell-related molecules (Foxp3, IL-10, and TGF-β).

● Reduce the expression of IL-1α, IL-1β, IL-6, IL-18 and TNF-α.

● IL-27 is elevated.

● Reduce CD80, CD40, CXCL1, CRP, iNOS and antimicrobial peptides Reg3b and Reg3g.



Infectious conditions

● Increase natural killer (NK) cell activity.

● Increase in serum IgA and decrease in IgG2a production.

● IL-2, IL-12 and IL-18 are elevated.

● Reduce IL-6 and IL-8.

● Decreased TNF-α.

● Both increase and decrease IL-10, and decrease and increase IFN-γ




● Reduced IgE and improved IgG2a/IgG1 ratio.

● Increase in IgA.

● Th1 cytokine increases and Th2 cytokine production decreases.

● Reduce IL-4 and IL-5.

● Increase IL-10, IL-12 and TGF-β.

● Increase or decrease of IFN-γ.

● Suppress MDC and TARC.

● CD4 + CD25 + Foxp3 + Treg cells increase.



Celiac disease

● Reduce TNF-α.

● NFκB increases.

● IL-10 is elevated.

● Decreased CD3+ T, CD4+ and CD4+ / Foxp3+ cells and increased CD8+ T.

● Increased MIP-1β.



The following specifically takes Bifidobacterium longum BB536 as an example to elaborate on the effects of Bifidobacterium longum on alleviating allergic infection, regulating metabolism, and regulating immunity.


Bifidobacterium longum BB536 works synergistically with the intestinal microbiota to improve gastrointestinal health, regulate host immune homeostasis, and relieve allergic diseases and infections.

The mechanism of  Bifidobacterium longum to prevent intestinal diseases

Wong C B, et al., Journal of Functional Foods, 2019


Bifidobacterium longum BB536 regulates intestinal metabolism through crosstalk with human intestinal microbiota.

The mechanism of  Bifidobacterium longum to prevent intestinal diseases

Wong C B, et al., Journal of Functional Foods, 2019

(A) BB536 regulates biotin biosynthesis by promoting the production of precursor pimelic acid, and enables Bacteroides caccae to further metabolize it into biotin, thereby promoting the host intestinal homeostasis.

(B) BB536 affects the metabolic activity of symbiotic butyric acid producing bacteria (such as Eubacterium rectum) through a cross-feeding mechanism. The acetate produced by BB536 during carbohydrate fermentation is used as a substrate to maintain the growth of Eu. rectale and stimulate the production of butyrate.



The immunomodulatory effect of Bifidobacterium longum BB536

The mechanism of  Bifidobacterium longum to prevent intestinal diseases

Wong C B, et al., Journal of Functional Foods, 2019

(A) The fluctuation of the intestinal microbiota, especially the overdose of Bacteroides fragilis, helps to interfere with host immunity and develop allergic diseases. In an allergic reaction, an allergen is absorbed by dendritic cells, presented to naive T cells (Th0), and then transformed into helper T cell type 2 (Th2). Th2 cells secrete interleukin-4 and interleukin-5, which then stimulate memory B cells to convert into an allergen-specific humoral response, mainly by the production of immunoglobulin E (IgE) antibodies. These IgE antibodies attach to mast cells and basophils, making them susceptible to subsequent exposure and the development of allergic symptoms.

(B) BB536 regulates immune homeostasis in host-microbe interactions and alleviates allergic diseases through indirect and direct mechanisms.

(I) BB536 corrects the prevalence of Bacteroides fragilis, thereby restoring the balance of Th1/Th2, reducing allergic symptoms, and promoting the stability of the intestinal microbiota.

(Ii) BB536 directly affects antigen-induced IgE-mediated Th2 tilt immune balance through its bacterial components.




04.  How to take Bifidobacterium longum?


1. Dosage and characteristics

Before using bifidobacteria, consult a doctor. If you have some chronic diseases, you may not be able to use bifidobacteria.

Bifidobacteria come in the form of capsules, tablets, powders and chewable tablets. Do not use different formulas at the same time without medical advice.

In the following situations, you need to consult whether the product can be used safely:

● Milk allergy or lactose intolerance

● While taking antibiotics

● During pregnant women or breastfeeding


How to judge the quality of probiotics?

Probiotics are labeled according to colony forming units (CFU). This indicates the density or strength of live bacteria. The higher the number of CFU in probiotics, it means that it has a greater impact on the growth of beneficial bacteria in the intestinal flora. Many products on the market now use the number of CFU as a kind of live bacteria identification.

Some researchers believe that there are fewer studies on the specific dose of CFU and may not be important. It is more important to find a high-quality product that has been properly processed and stored, so that you can get a product that contains a lot of live bacteria.

Products that are not properly prepared and stored may cause bacteria to die, resulting in ineffectiveness or waste. To prevent this from happening, some companies have packaged their products.


What kind of conditions does the beneficial bacteria meet?

1) It must not be toxic or pathogenic.

2) It must retain features that have been proven to be beneficial to the host (the person who uses it).

3) Each unit must contain a sufficient number of live microorganisms.

4) It must be able to grow and survive the manufacturing process, and be able to be transported through the stomach and small intestine.

5) During storage and use, it must remain alive.


If you need to start supplementing, please try to slowly and gradually increase. The dosage range is very wide, too high a dosage may cause stomach upset.


● Usual adult dietary supplements:

Bifidobacterium-Lactobacillus oral capsule: Take 1 capsule per day.

Bifidobacterium-lactobacillus oral tablets, chewable: chew 1 tablet per day.


2. How to Obtain

Eat foods rich in beneficial bacteria every day. Dr. Rahal once said: “Fermented foods and beverages, such as sauerkraut, kimchi, kefir, kombucha, yogurt and artificially cultivated vegetables, are all excellent sources of live probiotics and active probiotics.”

* Kefir is a fermented dairy product that can be mixed between yogurt and milk, and can be used as a good choice for breakfast.If you want to take supplements, remember that there are many different types of probiotic strains, and each type has a slightly different effect. When looking for bifidobacteria, look for the full name, including genus, species, and strain.

For example, in “Bifidobacterium adolescentis. 22L”, “Bifidobacterium” represents the genus Bifidobacterium, the species is adolescentis, and the strain is 22L.

It is very important to choose the right type of live bacteria in the right ratio.

Take special care when lyophilizing probiotic supplements. You can choose, but “they degrade rapidly when exposed to moisture, so they may not be stable for a long time.”


3. How to store

Probiotics are sensitive to light, heat and moisture. High-quality probiotics should be kept in dark glass bottles to prevent bacterial death. Most types of probiotics need to be refrigerated. Follow the manufacturer’s instructions as much as possible for optimal storage.




05. Common problem


1) What should I avoid while taking bifidobacteria?

Do not mix oral powder with hot liquid or food.


2) What should I do if I miss taking it?

Skip the missed time and use the next dose at the regular time. Do not take two doses at once.


3) What should I do if I overdose?

Consult a doctor and seek emergency medical attention.


4) Possible side effects?

Seek medical attention if you have signs of an allergic reaction:

Hives; difficulty breathing; swelling of the face, lips, tongue or throat.

Common side effects may include: stomach bloating or discomfort. Other side effects may also occur.


5) Do I have to take it?

Not necessarily. First determine whether the body lacks probiotics, especially bifidobacteria. Combining the health benefits of Bifidobacterium longum and the health of each person, you can take it when the intestinal flora is tested and find that Bifidobacterium (especially Bifidobacterium longum) is lacking, or as directed by your doctor. In this way, certain symptoms can be improved in a more targeted manner, so as to achieve better results.




Appendix: Historical Evolution of Bifidobacterium

Since 1900, Henry Tissier discovered bifidobacteria in the feces of newborn babies. Tissier called him Gram-positive curved and bifurcated (split, X-shaped or Y-shaped) rod-shaped cells. Fidobacterium. Nowadays, the original isolate of Tissier is called Bifidobacterium bifidum.

Soon after, as a Nobel laureate, a colleague of the Tissier Institute, Elie Metchnikoff, added Tissier’s bacillus to his research on vitality and longevity. Although early reports on fermented milk have implicitly stated the health benefits of fermented milk, Mechnikov is the first to use it as a scientific basis.

According to Mechnikov’s theory, from the analysis of the impact of the intake of Lactobacillus content on health and longevity, yogurt is currently the most beneficial food, and other foods such as yogurt and pure milk are also contained. Mechnikov’s remarks have led to an increase in public demand for kefir products for 20 years. Mechnikov not only proposed and continued the theory-that the intestinal microbiota can not only control the results of intestinal pathogen infections, but also regulate natural chronic toxemia, which plays an important role in reducing aging and mortality. effect.

Although the outbreak of the First World War and the death of Mechnikov at the age of 71, people’s interest in bacterial therapy was greatly reduced. However, research on the use of lactic acid bacteria in the diet has continued for a century and is still popular today. A large number of bifidobacteria and the fermentation/acidification properties of bifidobacteria are found in healthy breast-fed babies, which implies that bifidobacteria have great benefits for human nutrition and gastrointestinal health.

Now, with the gradual expansion of research, bifidobacteria have not only evaluated the beneficial effects of humans through the consumption of probiotic cultures, but also evaluated livestock and other animals.




(source:internet, reference only)

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