Bifidobacteria: The Key to a Healthy Microbiome and Strong Immunity

Bifidobacteria are one of the key representatives of the normal gut microbiota, playing an important 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 synthesize essential vitamins.

However, with age and under the influence of various factors, their numbers decrease, leading to microbial imbalance and increasing the risk of various diseases. Understanding the distribution of bifidobacteria in the gut, their functions, and the factors that affect their levels helps maintain microbiome balance and prevent potential health problems.

Microbiome Composition and Distribution of Bifidobacteria

Different sections of the intestine have a unique composition when the microbiota is healthy:

• The small intestine contains significantly fewer bacteria (10³–10⁴ CFU/ml) due to rapid food transit and the action of bile. It is dominated by lactobacilli, enterococci, streptococci, and also contains small amounts of bifidobacteria. If bacterial levels in the small intestine become excessively high, this can lead to small intestinal bacterial overgrowth (SIBO).
• The large intestine is the primary site of microbiota concentration (10¹¹–10¹² CFU/ml), including bifidobacteria, bacteroides, certain types of clostridia (Clostridium butyricum), as well as beneficial strains of E. coli, such as E. coli Nissle 1917, which are involved in vitamin K synthesis and immune balance maintenance.
• The rectum contains a rich microbiome (10¹⁰–10¹¹ CFU/ml), including bifidobacteria, E. coli, non-pathogenic enterobacteria, and various anaerobic bacteria that complete the food breakdown process. The balance among these microorganisms is important for maintaining intestinal health.

Read more about the microbiome in the article: Microbiome: The Invisible Ecosystem Within and Around Us.

Bifidobacteria Deficiency: Health Impact and the Probiotic Problem

Bifidobacteria are most active in the colon, where in infants they can make up 90% of the total gut microbiota. However, in adults, this proportion drops to 3–10%, giving way to other bacterial species. Research shows that a reduction in bifidobacteria is associated with age-related changes, which may weaken the immune system and is considered one of the signs of aging.

Despite the important role of bifidobacteria in gut health, they are less commonly found in probiotic supplements. This is because they are more difficult to cultivate, reproduce more slowly, and are therefore more expensive to produce industrially. However, bifidobacteria are well preserved in capsules and powders, so storage does not pose much difficulty.

Lactobacilli dominate probiotic supplements because they multiply quickly, are acid-resistant, and are cheaper to produce. They are more commonly found in yogurts and starters for homemade fermented dairy products. Moreover, almost all yogurt makers lack the proper settings for cultivating bifidobacteria.

It is important to carefully check the composition of probiotics and starters: even if bifidobacteria are listed, their quantity may be minimal compared to lactobacilli.

Features of Bifidobacteria

Let’s now look at the features of bifidobacteria. Bifidobacteria are anaerobic microorganisms, which means contact with oxygen is harmful to them. They are involved in the fermentation of carbohydrates, turning them into short-chain fatty acids (SCFAs), which serve as an energy source for intestinal cells and help restore the intestinal mucosa.

In addition, bifidobacteria strengthen the intestinal barrier, preventing the penetration of toxins and pathogenic microorganisms into the bloodstream. By creating an acidic environment, they suppress the growth of harmful bacteria, maintain microbiota balance, and reduce the risk of inflammation.

Functions of Bifidobacteria

Bifidobacteria perform several important functions in the body:

• Maintain acid-base balance, creating unfavorable conditions for pathogens.
• Strengthen the intestinal barrier, reducing the risk of inflammation and increased mucosal permeability.
• Stimulate peristalsis, helping to prevent constipation and supporting normal food movement through the intestines.
• Regulate immune processes, stimulating immune cell activity and reducing inflammatory responses.
• Participate in the fermentation of complex carbohydrates, contributing to the formation of short-chain fatty acids that support the intestinal lining and overall microbiota balance.
• Synthesize B vitamins (B1, B2, B6, B9) and vitamin K, which are essential for metabolism, the nervous system, and blood clotting.
• Improve the absorption of iron, calcium, and magnesium, by creating optimal pH conditions in the intestines for better uptake.

A deficiency in bifidobacteria can lead to microbiota imbalance, impaired digestion, reduced immune defense, and increased permeability of the intestinal wall. This raises the risk of inflammatory, autoimmune, and allergic diseases, and can worsen the condition of the skin, hair, and nails.

Causes of Reduced Bifidobacteria Levels

The number of bifidobacteria can decrease under the influence of various factors:

• Antibiotics. Not all antibiotics affect the microbiome equally. Some kill both harmful and beneficial bacteria, while others may even promote the growth of bifidobacteria by suppressing their competitors.
• Ozone and other oxygen therapies. Since bifidobacteria are anaerobic, excess oxygen and ozone can inhibit their growth.
• Low-fiber diet. A lack of dietary fiber and excess sugar can lead to reduced bifidobacteria populations.
• Chronic stress. Prolonged nervous tension affects hormonal balance, which in turn impacts the composition of the gut microbiota.
• Age-related changes. As we age, both the overall level and diversity of bifidobacteria decline.
• Infections and inflammation. Some pathogenic microorganisms can displace beneficial bifidobacteria, disrupting microbiota balance.
• High temperatures. Fever, prolonged hyperthermia, or thermal processing of food can reduce bifidobacteria populations, as they do not form spores and are sensitive to overheating.
• Exposure to toxins and heavy metals. Pollutants have a destructive effect on the microbiota.
• Prebiotic deficiency. A lack of soluble dietary fibers, which serve as food for bifidobacteria, reduces their population.
• Food additives and preservatives. Colorants, preservatives, flavor enhancers, and other chemical additives in ultra-processed foods can suppress the growth of bifidobacteria, alter microbiota composition, and reduce its diversity.

Connection Between Bifidobacteria Deficiency and Diseases

A lack of bifidobacteria can affect overall health. Studies confirm the link between reduced levels of these bacteria and the development of several conditions:

• Irritable Bowel Syndrome (IBS). Microbiota imbalance is accompanied by inflammation and altered intestinal motility.
• Metabolic syndrome. A deficiency of bifidobacteria is associated with 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 levels of bifidobacteria increase the body’s sensitivity to potential allergens.
• Neurological disorders. Microbiota imbalance affects the “gut-brain” axis and may be linked to autism, ADHD, and Parkinson’s disease.
• Infectious diseases. A weakened microbiome impairs the body’s defenses, making it more susceptible to viral infections, including COVID-19.

How to Increase Bifidobacteria in the Gut?

There are several ways to maintain a high level of bifidobacteria in the gut. The most important are proper nutrition and intake of essential micronutrients, along with the use of certain probiotics and medications (only as prescribed by a doctor).

Supplements That Support the Growth of Bifidobacteria

Certain vitamins and micronutrients create a favorable environment for the growth of beneficial microbiota:

• Vitamins D, K2, B6, B12, C – support the intestinal barrier and promote the growth of bifidobacteria populations.
• Zinc, magnesium, moderate amounts of iron – improve the environment for beneficial bacteria and support their growth.
• Lactoferrin – regulates the microbiome and stimulates bifidobacteria activity.
• Prebiotics (inulin, FOS, GOS, resistant starch) – serve as food for bifidobacteria, encouraging their reproduction.

Probiotics Containing Bifidobacteria

The intake of live bifidobacteria cultures helps restore microbiota balance and maintain its stability:

• B. bifidum – one of the first colonizing strains, supports immunity, mucosal health, reduces inflammation, and aids in digesting dairy products.
• B. breve – balances microbiota, protects against pathogens, improves metabolism, and is helpful in allergic conditions.
• B. infantis – breaks down oligosaccharides, reduces inflammation, useful in autism, IBS, and inflammatory bowel diseases.
• B. lactis – promotes calcium and iron absorption, strengthens the intestinal barrier, improves peristalsis, helps with constipation.
• B. longum – influences serotonin and GABA levels, reduces anxiety, supports gastrointestinal function, beneficial for stress and IBS.

Medications (only as prescribed by a doctor!)

Some medications may indirectly support bifidobacteria by suppressing their competitors:

• Low-dose doxycycline (under study) – suppresses the growth of pathogenic bacteria, which may promote an increase in bifidobacteria populations.
• Ivermectin (under study) – may influence the microbiota balance, creating conditions for bifidobacteria growth.

What Reduces Bifidobacteria Levels?

Despite all efforts to maintain a healthy microbiome, there are factors that can negatively affect the number of bifidobacteria. These include:

• Broad-spectrum antibiotics – suppress both harmful and beneficial bacteria.
• Non-steroidal anti-inflammatory drugs (NSAIDs, e.g., ibuprofen) – can disrupt microbiota balance.
• Proton pump inhibitors (e.g., omeprazole) – alter intestinal pH, negatively impacting microbiota composition.
• Excess iron – may promote the growth of pathogenic bacteria, displacing bifidobacteria.

Why Don’t Bifidobacteria Probiotics Always Work?

This may seem like the most obvious solution when it comes to adding beneficial bacteria to the microbiome. But it’s not that simple — it’s important to know how to properly grow bifidobacteria and which starters to use.

Why not just take a probiotic? I doubt their effectiveness, since bifidobacteria require 36–48 hours to grow, which roughly matches the time food takes to pass through the intestines. This may be why bifidobacteria probiotics rarely yield noticeable results. Moreover, most probiotics contain bacteria in dried form, and even if they revive in the gut, they need the right environment to multiply. Without it, bifidobacteria simply do not establish or form a stable colony.

Additionally, bifidobacteria do not form spores, which means their survival depends entirely on environmental conditions. Therefore, making yogurt with a bifido-starter is the most reliable way to deliver live bacteria to the gut. But for their successful growth and colonization, it is not enough to just consume yogurt — it’s also essential to create the right environment for bifidobacteria to thrive. Soluble fibers, FOS, GOS, and resistant starch provide nutrition for bifidobacteria, while avoiding antimicrobial substances (such as excessive preservatives or food colorings) helps preserve their population.

Making Yogurt with a High Bifidobacteria Content

Choosing the Right Milk and Starter:

• Ideally, use cow’s milk, goat’s milk, or plant-based milk enriched with prebiotics, including coconut cream.
• Starters should contain Bifidobacterium (e.g., B. lactis, B. bifidum, B. breve, B. longum, B. infantis).
• Try to minimize oxygen exposure to the milk by using a tight-fitting lid and a container with a narrow neck.

Preparation Steps:

• Heat the milk to about 85°C (until it begins to boil), then cool it down to at least 38°C.
• Optimal range: 34–38°C.
• Add the starter culture and mix thoroughly, but avoid aerating the mixture.
• Pour into sterile containers and seal with lids.

Fermentation and Storage Conditions:

• Incubate the yogurt in a warm environment (yogurt maker, thermos, or oven on low heat).
• Keep at 34–38°C for 36–48 hours, as bifidobacteria grow slowly.
• After fermentation, refrigerate for 6 hours, then store at 4°C and consume within 5–7 days.
• To preserve the maximum number of bifidobacteria, avoid overheating the yogurt. At temperatures above 40°C, bifidobacteria begin to die.

Conclusion

Bifidobacteria are an essential part of a healthy gut, supporting optimal digestion, immune function, and the synthesis of vital vitamins. They are present from birth, but their levels may decline with age and under the influence of various factors, affecting microbiome balance and overall health.

Maintaining an optimal level of bifidobacteria is possible through a proper diet enriched with prebiotics and probiotics, along with a healthy lifestyle, reduced stress, and avoidance of factors that negatively impact the microbiota.

Understanding the role of bifidobacteria and how to support them helps reduce the risk of inflammatory, metabolic, and autoimmune diseases, while preserving the health of the gut and the entire body.