Bifidobacterium infantis 35624: New Insights in IBS Support

Bifidobacterium infantis 35624 has gained attention for its role in managing irritable bowel syndrome (IBS). As a probiotic, it supports gut health by influencing microbiota composition and immune responses. Research suggests that IBS patients often have an imbalance in gut bacteria, making probiotics like B. infantis 35624 a promising area of study.

Morphology And Identification

Bifidobacterium infantis 35624 is a Gram-positive, anaerobic, non-motile bacterium with a distinctive Y-shaped morphology, a hallmark of the Bifidobacterium genus. This branching structure, visible under electron microscopy, results from its unique cell division process. Its thick peptidoglycan cell wall provides structural integrity and resistance to environmental stressors. Unlike many gut bacteria, B. infantis 35624 lacks flagella and instead adheres to intestinal mucosa via specialized surface proteins.

Identification relies on phenotypic and genotypic techniques. Traditional culture methods use anaerobic incubation on selective media like MRS agar with cysteine. Colonies appear convex, white, and smooth, distinguishing them from other gut bacteria. However, molecular techniques such as 16S rRNA sequencing and whole-genome analysis are now the gold standard for confirming strain specificity, differentiating it from closely related species like Bifidobacterium longum and Bifidobacterium breve.

Comparative genomic studies reveal strain-specific markers that contribute to its probiotic properties. B. infantis 35624 possesses an expanded set of carbohydrate metabolism genes, allowing it to utilize a broad range of prebiotic substrates. Unique surface-associated proteins enhance adhesion to intestinal epithelial cells, improving its persistence in the gut. These genetic adaptations set it apart from other Bifidobacterium strains.

Colonization Routes

Successful colonization of Bifidobacterium infantis 35624 depends on its introduction method, gastrointestinal conditions, and interactions with existing microbiota. It is typically consumed via capsules, powders, or functional foods like yogurts. To survive stomach acidity, it employs acid tolerance mechanisms, including stress response gene upregulation and membrane integrity maintenance.

In the small intestine, it encounters bile salts that can disrupt bacterial membranes. However, B. infantis 35624 produces bile salt hydrolase enzymes, reducing bile toxicity and aiding persistence. Adhesion to intestinal epithelial cells is facilitated by surface proteins, allowing it to anchor to the mucosal layer and resist elimination through peristalsis.

Once established, it competes for nutrients in the colon. Its ability to metabolize complex carbohydrates, such as human milk oligosaccharides (HMOs) and plant-derived polysaccharides, gives it a competitive advantage. Unlike probiotic strains that rely on simple sugars, B. infantis 35624 thrives on prebiotic compounds indigestible to the host, ensuring stable integration into the gut microbiome.

Substrate Utilization

Bifidobacterium infantis 35624 metabolizes complex carbohydrates, allowing it to thrive in the gut. Its genome encodes glycosyl hydrolases, transporters, and carbohydrate-modifying enzymes, enabling it to break down HMOs, fructooligosaccharides (FOS), and resistant starches. This metabolic flexibility supports its survival and benefits microbial balance.

Fermentation of these carbohydrates produces short-chain fatty acids (SCFAs), such as acetate and lactate, which help maintain intestinal homeostasis. SCFAs mildly acidify the gut, discouraging pathogenic bacteria while serving as an energy source for colonocytes, reinforcing gut barrier integrity. This strain’s ability to utilize prebiotic compounds enhances its persistence and shapes microbial composition.

Impact On Gut Environment

Bifidobacterium infantis 35624 influences microbial composition, metabolic activity, and intestinal barrier function. It produces SCFAs, which lower gut pH, suppressing the growth of harmful bacteria like Clostridium and Escherichia. By fostering a favorable microbial balance, it supports gut health.

Beyond pH modulation, it affects nutrient availability. Its carbohydrate metabolism generates substrates that support cross-feeding interactions with other beneficial bacteria. Acetate produced by B. infantis 35624 can be utilized by butyrate-producing microbes like Faecalibacterium prausnitzii, which contribute to gut barrier integrity and anti-inflammatory effects. These cooperative metabolic networks enhance microbial diversity, often diminished in individuals with gut imbalances.

IBS-Related Observations

Research shows IBS patients often have lower levels of beneficial bacteria, including Bifidobacterium species, and higher levels of pro-inflammatory microbes. This imbalance contributes to IBS symptoms such as bloating, diarrhea, constipation, and abdominal pain. Bifidobacterium infantis 35624 has been studied for its ability to restore microbial balance and alleviate symptoms.

Clinical trials have shown promising results. A randomized, placebo-controlled study in Gastroenterology found that daily supplementation significantly reduced abdominal discomfort, bloating, and irregular bowel movements. These improvements occurred without notable adverse effects, highlighting its safety. By enhancing gut barrier function and modulating fermentation byproducts, B. infantis 35624 may help reduce gas production and intestinal hypersensitivity, common contributors to IBS discomfort.