Bifidobacteria are among the key representatives of the normal gut microbiota, playing a crucial role in maintaining overall health. They colonize the intestines from the first days of life and participate in numerous processes that support digestion, strengthen the immune system, and contribute to the synthesis of essential vitamins.
However, with age and under the influence of various factors, their numbers decrease, leading to an imbalance in the microbiota and an increased risk of developing various diseases. Understanding the distribution of bifidobacteria in the intestines, their functions, and the factors that affect their levels helps maintain microbiome balance and prevent potential health issues.
Composition of the Microbiome and Distribution of Bifidobacteria
Different sections of the intestine have unique microbiota compositions when in a healthy state:
- The small intestine contains significantly fewer bacteria (10³–10⁴ CFU/mL) due to rapid food transit and exposure to bile. Lactobacilli, enterococci, and streptococci dominate here, along with small amounts of bifidobacteria. If bacterial levels in the small intestine become excessively high, it can lead to small intestinal bacterial overgrowth (SIBO).
- The large intestine is the main site of microbiota concentration (10¹¹–10¹² CFU/mL), including bifidobacteria, bacteroides, certain species of clostridia (Clostridium butyricum), as well as beneficial strains of Escherichia coli, such as E. coli Nissle 1917, which participate in vitamin K synthesis and immune balance.
- The rectum also contains a rich microbiome (10¹⁰–10¹¹ CFU/mL), including bifidobacteria, E. coli, non-pathogenic enterobacteria, and various anaerobic bacteria that finalize food breakdown. The balance between these microorganisms is essential for maintaining gut health.
Read more about the microbiome in the article: Microbiome: The Invisible Ecosystem Within and Around Us.
Bifidobacteria Deficiency: Impact on Health and the Probiotic Dilemma
Bifidobacteria are most actively present in the large intestine, where their proportion in infants can reach up to 90% of the gut microbiota. However, in adults, this percentage declines to 3-10%, giving way to other bacterial species. Research suggests that the reduction in bifidobacteria is associated with aging and may contribute to a weakened immune system, which is considered one of the markers of aging.
Despite their critical role in gut health, bifidobacteria are less common in probiotic supplements. This is because they are more difficult to cultivate, reproduce more slowly, and are therefore more expensive to produce on an industrial scale. However, bifidobacteria store well in capsules and powders, meaning their preservation does not pose a significant challenge.
Lactobacilli dominate probiotic supplements because they multiply quickly, withstand acidic environments, and are cheaper to produce. They are also more commonly found in yogurts and starters for homemade fermented dairy products. Additionally, most yogurt makers are not designed to provide the optimal conditions needed for growing bifidobacteria.
It is essential to carefully examine the composition of probiotics and starter cultures: even when bifidobacteria are listed, their actual quantity may be minimal compared to lactobacilli.
Characteristics of Bifidobacteria
Now, let’s take a closer look at the unique characteristics of bifidobacteria. These are anaerobic microorganisms, meaning they cannot survive in the presence of oxygen. They play a crucial role in fermenting carbohydrates, converting them into short-chain fatty acids (SCFAs), which serve as an energy source for intestinal cells and contribute to the restoration of the intestinal mucosa.
Additionally, bifidobacteria strengthen the intestinal barrier, preventing toxins and pathogenic microorganisms from entering the bloodstream. By creating an acidic environment, they inhibit the growth of harmful bacteria, maintaining microbiota balance and reducing the risk of inflammation.
Functions of Bifidobacteria
Bifidobacteria perform several important functions in the body:
- Maintain acid-base balance, creating an unfavorable environment for pathogens.
- Strengthen the intestinal barrier, reducing the risk of inflammation.
- Stimulate peristalsis, helping to prevent constipation.
- Regulate immune responses, reducing inflammatory reactions.
- Participate in the synthesis of B vitamins (B1, B2, B6, B12) and vitamin K, essential for metabolism and blood formation.
A deficiency of bifidobacteria can lead to microbiota imbalance, digestive disorders, and weakened immune protection, increasing the risk of inflammatory and autoimmune diseases.
Causes of Decreased Bifidobacteria Levels
The number of bifidobacteria can decrease due to various factors:
- Antibiotics. Not all antibiotics affect the microbiome in the same way. Some destroy both pathogenic and beneficial bacteria, while others may even promote the growth of bifidobacteria by suppressing their competitors.
- Ozone and other oxygen-based therapies. Since bifidobacteria are anaerobic, excessive oxygen exposure and ozone therapy can inhibit their growth.
- Low-fiber diet. A lack of dietary fiber and excessive sugar intake can lead to a decline in bifidobacteria populations.
- Chronic stress. Prolonged stress affects hormonal balance, which in turn impacts gut microbiota composition.
- Aging. As people age, both the overall level and diversity of bifidobacteria decline.
- Infections and inflammation. Some pathogenic microorganisms can outcompete beneficial bifidobacteria, disrupting microbiota balance.
- High temperatures. Fever, prolonged hyperthermia, or heat-processed food can reduce bifidobacteria populations, as they do not form spores and are sensitive to overheating.
- Exposure to toxins and heavy metals. Environmental pollutants can have a destructive impact on the microbiome.
- Prebiotic deficiency. A lack of soluble dietary fibers, which serve as food for bifidobacteria, reduces their numbers.
- Food additives and preservatives. Artificial colourants, preservatives, flavor enhancers, and other chemical additives found in ultra-processed foods can suppress bifidobacteria growth, altering microbiota composition and reducing its diversity.
The Link Between Bifidobacteria Deficiency and Diseases
A lack of bifidobacteria can have significant effects on overall health. Studies confirm a connection between low bifidobacteria levels and the development of various conditions:
- Irritable Bowel Syndrome (IBS). Microbiota imbalance is associated with inflammation and altered intestinal motility.
- Metabolic Syndrome. Bifidobacteria deficiency has been linked to obesity, insulin resistance, and type 2 diabetes.
- Autoimmune Diseases. Changes in the microbiome may contribute to the development of rheumatoid arthritis, Crohn’s disease, and other immune disorders.
- Allergies and Atopic Conditions. Low bifidobacteria levels increase the body’s sensitivity to potential allergens.
- Neurological Disorders. Gut microbiota imbalance affects the gut-brain axis and may be associated with autism, ADHD, and Parkinson’s disease.
- Infectious Diseases. A weakened microbiome compromises immune defenses, making the body more susceptible to viral infections, including COVID-19.
How to Increase Bifidobacteria in the Gut?
Several strategies can help maintain a high level of bifidobacteria in the gut. The key factors are proper nutrition and the intake of essential nutrients, while certain probiotics and medications (only under medical supervision) may also be beneficial.
Supplements That Promote Bifidobacteria Growth
Certain vitamins and minerals create a favorable environment for beneficial bacteria:
- Vitamins D, K2, B6, B12, C – support intestinal barrier health and promote bifidobacteria population growth.
- Zinc, magnesium, and moderate amounts of iron – improve conditions for beneficial bacteria, supporting their growth.
- Lactoferrin – regulates the microbiome and stimulates bifidobacteria activity.
- Prebiotics (inulin, FOS, GOS, resistant starch) – serve as food for bifidobacteria, encouraging their proliferation.
Probiotics Containing Bifidobacteria
Introducing live bifidobacteria strains into the body helps restore microbiota balance and maintain stability:
- B. bifidum – one of the earliest colonizing strains, supports immunity, strengthens the gut lining, reduces inflammation, and aids in dairy digestion.
- B. breve – balances microbiota, protects against pathogens, improves metabolism, and is beneficial for allergies.
- B. infantis – breaks down oligosaccharides, reduces inflammation, and is useful for autism, IBS, and inflammatory bowel diseases.
- B. lactis – enhances calcium and iron absorption, strengthens the gut barrier, improves motility, and helps with constipation.
- B. longum – influences serotonin and GABA levels, reduces anxiety, supports digestive health, and is beneficial for stress and IBS.
Medications (Only Under Medical Supervision!)
Some medications may indirectly support bifidobacteria by suppressing their competitors:
- Low-dose doxycycline (under study). It inhibits pathogenic bacteria, which may promote bifidobacteria growth.
- Ivermectin (under study). It may influence microbiota balance, creating favorable conditions for bifidobacteria proliferation.
What Reduces Bifidobacteria Levels?
Despite all efforts to maintain a healthy microbiome, several factors can negatively affect bifidobacteria populations, including:
- Broad-spectrum antibiotics – suppress not only harmful bacteria but also beneficial ones.
- Nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen) – can disrupt microbiota balance.
- Proton pump inhibitors (e.g., omeprazole) – alter gut pH, negatively impacting microbiota composition.
- Excess iron – may promote the growth of pathogenic bacteria, outcompeting bifidobacteria.
Why Don’t Probiotics with Bifidobacteria Always Work?
At first glance, taking a probiotic seems like the easiest solution for restoring beneficial bacteria in the microbiome. However, it’s not that simple—knowing how to cultivate bifidobacteria and which starters to use is essential.
Why not just take a probiotic? I doubt their effectiveness because bifidobacteria require 36-48 hours to grow, which is roughly the same time it takes for food to pass through the intestines. This may explain why probiotics with bifidobacteria often fail to show noticeable effects. Additionally, most probiotics contain freeze-dried bacteria, and even if they revive in the gut, they require the right conditions to multiply. Without a proper environment, bifidobacteria struggle to establish a stable colony.
Moreover, bifidobacteria do not form spores, meaning their survival entirely depends on external conditions. This is why making yogurt using bifidobacteria-based starters is the most reliable way to ensure a consistent supply of live bacteria to the gut. However, for their successful colonization, it is not enough just to consume yogurt—creating a favorable intestinal environment is equally important. Soluble fibers, FOS, GOS, and resistant starch serve as nourishment for bifidobacteria, while avoiding antimicrobial substances (such as excessive preservatives or artificial additives in food) helps maintain their population.
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Preparation of Yogurt with a High Content of Bifidobacteria
Choosing the Right Milk and Starter Culture:
- It is best to use cow milk, goat milk, or plant-based milk with added prebiotics, including coconut cream.
- The starter culture must contain Bifidobacterium (e.g., B. lactis, B. bifidum, B. breve, B. longum, B. infantis).
- Minimize oxygen exposure by using an airtight lid and a narrow-necked container.
Preparation Steps:
- Heat the milk to approximately 85°C (until it begins to boil), then cool it down to at least 38°C.
- Optimal temperature range: 34-38°C.
- Add the starter culture and mix thoroughly, but avoid excessive aeration.
- Pour the mixture into sterilized containers and seal with lids.
Fermentation and Storage Conditions:
- Yogurt should be incubated in a warm environment (yogurt maker, thermos, or oven with minimal heat).
- Keep it at 34-38°C (93-100°F) for 36-48 hours, as bifidobacteria multiply slowly.
- After fermentation, refrigerate for 6 hours, then store at 4°C (39°F) and consume within 5-7 days.
- To preserve the maximum number of bifidobacteria, avoid overheating the yogurt. At temperatures above 40°C (104°F), bifidobacteria start to die.
Conclusion
Bifidobacteria are a key component of a healthy gut, playing a crucial role in digestion, immune function, and vitamin synthesis. While they colonize the intestine from birth, their levels tend to decline with age and exposure to various external factors, affecting microbiome balance and overall health.
Maintaining optimal bifidobacteria levels can be achieved through a diet rich in prebiotics and probiotics, a healthy lifestyle, stress reduction, and avoiding factors that negatively impact gut flora.
Understanding the role of bifidobacteria and the best ways to support their growth reduces the risk of inflammatory, metabolic, and autoimmune diseases, promoting gut and overall health.