Reviewed by Saskia Knight, Nutritionist
Published on February 12 2025
Bifidobacterium is a family of beneficial bacteria that support gut health and plays a critical role in maintaining gut health. Bifidobacterium is one of the most researched types of bacteria within the human body and is found primarily in the colon.
This group of beneficial microbes is one of the first to colonise the human gut during infancy, particularly in breastfed babies, and remains essential throughout life.
Known as a ‘good’ bacterium, Bifidobacterium is celebrated for its ability to promote digestion, support the immune system, and plays a crucial part in maintaining the balance of the gut and reducing the risk of gut dysbiosis, a bacterial imbalance in the gut microbiome.
What is Bifidobacterium?
Bifidobacterium naturally inhabit the gastrointestinal tract, vagina, and mouth. These bacteria are among the most studied probiotics, recognised for their significant role in supporting gut health and overall wellbeing. Due to the health benefits associated with Bifidobacterium, they are classed as probiotics and are present in many different supplements designed to support gut and overall health.
There are many species of Bifidobacterium, including:
- Bifidobacterium longum
- Bifidobacterium bifidum
- Bifidobacterium breve
- Bifidobacterium infantis
- Bifidobacterium animalis
Each species offers distinct benefits, but collectively, they contribute to maintaining a healthy and balanced gut environment.
The benefits of Bifidobacterium
- Supports digestion: Bifidobacterium supports digestion by fermenting complex carbohydrates and dietary fibres that the human body cannot digest.
- Produces short-chain fatty acids (SCFAs): Bifidobacterium boosts the production of short-chain fatty acids by producing acetate, which other microbes feed on, converting it to butyrate. SFCAs have a vast amount of health benefits, from protecting us from chronic disease to supporting immunity, heart health, gut health and even helping to reduce inflammation within the body.
- Protects the gut from pathogenic bacteria: It inhibits harmful bacteria such as Clostridium difficile and Escherichia coli by producing lactic acid, lowering gut pH, and competing for nutrients and space. Bifidobacterium alongside other beneficial bacteria help to regulate and maintain balance of the gut microbiome.
- Supports the immune system: Bifidobacterium helps regulate and calm immune responses, including reducing inflammation and promoting tolerance to non-harmful antigens like food particles.
- Synthesises vitamins: Some species are involved in producing essential vitamins, such as B vitamins and vitamin K.
In short, Bifidobacterium is essential for gut health, and maintaining balanced levels of this microbe is critical for healthy ageing.
What is a healthy level of Bifidobacterium?
The percentage of Bifidobacterium in a healthy adult gut ranges from 3 to 10% of the total gut bacteria, but this can vary depending on age, diet, and health conditions.
- Infants: Up to 60-70% of their gut microbiome consists of Bifidobacterium, particularly Bifidobacterium breve, Bifidobacterium infantis, and Bifidobacterium longum.
- Healthy adults: The abundance of Bifidobacterium decreases and stabilises to around 10%.
- Elderly individuals: Levels often decline with age, dropping to around 5%.
Source - https://www.nature.com/articles/s41522-024-00524-6
What happens if Bifidobacterium levels are too low?
Low levels of Bifidobacterium can have a profound impact on our health, there are several symptoms or conditions that may manifest because of low levels of Bifidobacterium.
Digestive issues
- Reduced ability to break down dietary fibre, leading to an accumulation of undigested food in the gut. Fibre is crucial to the production of short-chain fatty acids that are essential to our health: if the optimal levels of Bifidobacterium are not present to help break down fibre, there will be a decline in SCFAs that are produced.
Weakened immune system
- Greater risk of infections and chronic inflammation, as Bifidobacterium plays a role in modulating immune responses and creating SCFAs which are known to reduce systemic inflammation throughout the body.
Gut dysbiosis
- An imbalance in gut bacteria can lead to the overgrowth of harmful microbes, such as Candida or opportunistic pathogens. Bifidobacterium helps to suppress and inhibit the growth of harmful microbes within the gut. Gut dysbiosis has been linked to many different chronic diseases as seen below.
Chronic diseases
- Low levels of Bifidobacterium are linked to several chronic diseases such as inflammatory bowel diseases (IBD), irritable bowel syndrome (IBS), and metabolic conditions like obesity and type 2 diabetes.
Mental health concerns
- Since Bifidobacterium contributes to the gut-brain axis, low levels may worsen anxiety, depression, or cognitive issues. Gut issues can influence our mood via the gut-brain axis which is a bidirectional communication pathway.
Autoimmune conditions
- Insufficient levels of this bacteria are associated with an increased risk of developing allergies and autoimmune diseases, such as eczema and rheumatoid arthritis.
How to increase Bifidobacterium levels naturally
Consume probiotic-rich foods
Probiotic-rich foods naturally contain Bifidobacterium and can help replenish its levels in the gut. Examples include:
- Live yoghurt: Look for active cultures that include Bifidobacterium species.
- Fermented vegetables: Sauerkraut and kimchi, and pickles (made without vinegar) can provide beneficial microbes.
- Miso and tempeh: Fermented soy products that support gut health.
Focus on prebiotic foods
Prebiotics are non-digestible fibres that feed Bifidobacterium and other beneficial bacteria. Giving healthy bacteria such as Bifidobacterium a food source will help to increase their numbers and support your gut health.
Key sources include:
- Chicory root
- Jerusalem artichokes
- Garlic
- Onions
- Asparagus
- Bananas
- Whole grains, like oats and barley
- Legumes/pulses
- Polyphenol-rich foods like berries, apples, tea, herbs, dark chocolate, and flaxseeds.
Our guide provides a full breakdown on the best foods to eat for gut health.
Consider probiotic supplements
High-quality probiotic supplements often contain strains of Bifidobacterium. Look for products with multiple strains, such as B. longum, B. bifidum, or B. breve.
Breastfeeding for Infants
Breast milk is a natural source of oligosaccharides, which promote the growth of Bifidobacterium in infants. Formula-fed infants may receive added probiotics to support gut health.
Why diversity and balance are key
The key to a healthy gut is diversity and balance, with each bacterial species contributing unique benefits to our overall health. While Bifidobacterium is undeniably important, its dominance should not overshadow other beneficial microbes, such as Lactobacillus, Akkermansia and many more. Key reasons why balance matters include:
- Optimal digestion: A well-balanced microbiome ensures all digestive processes are supported.
- Immunity: Microbial diversity helps prevent both underactive and overactive immune responses.
- Mental wellbeing: A balanced microbiome supports the gut-brain axis and the production of neurotransmitters like serotonin.
- Resistance to pathogens: Diversity creates a competitive environment that limits pathogens and harmful bacteria overgrowths.
What can decrease Bifidobacterium levels?
Several factors can disrupt gut balance and lower the levels of Bifidobacterium and other beneficial bacteria, including:
- Poor diet/Western diet: Diets high in processed foods, sugar, alcohol, and artificial additives with a lack of fibre intake can harm beneficial bacteria.
- Stress: Chronic stress disrupts the gut-brain axis and impacts microbial health.
- Antibiotics: Broad-spectrum antibiotics kill both good and bad bacteria, which destroys the balance of the gut microbiome.
- Ageing: Bifidobacterium levels naturally decline with age, highlighting the importance of maintaining gut health through diet and supplementation. Bifidobacterium makes up as much as 60-70% of the bacteria within our gut at birth and then drops to around 5% in older age.
Why should I test my Bifidobacterium levels?
A well-balanced and diverse gut microbiome is key to good health. When your gut is balanced, you’re unlikely to experience common digestive issues, fatigue, low energy, or irregular bowel movements.
A gut biome test can assess the levels of Bifidobacterium in your gut, along with other beneficial and harmful bacteria that may disturb the overall balance of your gut. Most importantly, a gut microbiome test will provide you with nutritional and supplement recommendations to help address any imbalances identified.
Conclusion
- Bifidobacterium is a ‘good’ bacterium, essential for gut health, immune function, and mental wellbeing.
- Low levels of Bifidobacterium can result in digestive issues, weakened immunity, and chronic health conditions.
- Diet is critical for maintaining healthy levels of Bifidobacterium. Probiotic-rich foods, prebiotic fibres, polyphenols and supplements can support its growth.
- Balance is key to gut health. Promoting microbial diversity ensures optimal digestion, immune regulation, and pathogen resistance.
If you are experiencing symptoms related to your gut health, consider microbiome testing to understand your unique microbial profile. This can guide personalised dietary and lifestyle changes to optimise Bifidobacterium levels and overall gut health.
