Faecalibacterium prausnitzii is one of the most abundant and significant bacteria in the human large intestine. In a healthy individual, it can constitute over 5% of the total bacterial population in stool, making it a dominant member of the gut’s microbial community. This bacterium lives commensally, meaning it coexists with its host while providing several benefits. Its prevalence is often viewed as an indicator of a balanced gut, and understanding its levels can offer insights into intestinal health.
Understanding Faecalibacterium prausnitzii’s Role in Your Gut
The primary contribution of F. prausnitzii to gut health is its production of butyrate, a short-chain fatty acid (SCFA). Butyrate is the main energy source for colonocytes, the cells lining the colon, helping them function and maintain the integrity of the gut wall. This function helps prevent increased intestinal permeability, or “leaky gut,” where unwanted substances can pass from the intestine into the bloodstream. By keeping the intestinal barrier strong, F. prausnitzii contains bacteria within the gut.
Beyond fueling colon cells, the butyrate produced by F. prausnitzii has anti-inflammatory properties. It can block inflammatory pathways to calm immune responses in the gut. The bacterium also produces other anti-inflammatory compounds, including salicylic acid and a protein known as Microbial Anti-inflammatory Molecule (MAM). These substances work to modulate the local immune system and reduce inflammation.
This bacterium also plays a role in the broader gut environment through cross-feeding. F. prausnitzii consumes acetate, an SCFA produced by other beneficial bacteria like Bifidobacterium, and uses it to generate more butyrate. This metabolic cooperation helps create a stable microbial community. Through its fermentation of dietary fibers, it converts otherwise unusable material into beneficial compounds.
What Low Faecalibacterium prausnitzii Means for Your Health
A reduced presence of F. prausnitzii is a consistent finding in individuals with chronic health issues centered around inflammation. Low levels are strongly associated with inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis. In patients with Crohn’s disease, a lower abundance has been linked to a higher risk of disease recurrence after surgery. This suggests its anti-inflammatory and barrier-protective functions are diminished.
The implications of depleted F. prausnitzii extend beyond the gut, with reductions noted in people with irritable bowel syndrome (IBS), certain cancers, and type 2 diabetes. This connection often relates to the loss of butyrate production and its impact on gut barrier function. A less protected gut barrier can allow inflammatory molecules to enter the circulation, contributing to low-grade inflammation throughout the body.
It is important to view low F. prausnitzii as a marker of gut dysbiosis—an imbalance in the microbial community—rather than the sole cause of a disease. Its depletion often occurs alongside an increase in pro-inflammatory bacteria. This reduction signifies a shift in the gut environment from a balanced state to one more susceptible to inflammation and dysfunction.
Factors That Can Deplete Faecalibacterium prausnitzii
Several factors related to diet and lifestyle can negatively impact the abundance of F. prausnitzii. A primary driver is a diet low in dietary fiber, which this bacterium uses as its main fuel source. The Western diet, high in processed foods, sugar, and animal fat while lacking fiber-rich plants, creates an inhospitable environment for F. prausnitzii.
The use of broad-spectrum antibiotics is another major factor. These medications do not distinguish between harmful and beneficial bacteria, leading to a disruption of the gut microbiome. The oxygen-sensitive nature of F. prausnitzii makes it particularly vulnerable, and its populations may struggle to recover after treatment.
Chronic inflammation, such as that in IBD, creates a gut environment that is unfavorable for F. prausnitzii. This bacterium also thrives within a specific pH range, and conditions that alter the colon’s acidity can inhibit its growth. Chronic stress and smoking have also been identified as contributors to its reduction.
Strategies to Support Faecalibacterium prausnitzii Growth
Encouraging the growth of F. prausnitzii largely revolves around dietary choices that provide it with fuel. The most effective strategy is to increase the consumption of various dietary fibers, which act as prebiotics. This bacterium readily ferments fibers like inulin, fructooligosaccharides (FOS), and resistant starches found in many plant foods.
Incorporating a wide variety of plant-based foods is beneficial. Good sources of the fibers and polyphenols that support F. prausnitzii include:
- Onions, garlic, leeks, and asparagus
- Chicory root and whole grains
- Unripe bananas
- Apples (with the skin), berries, and kiwifruit
- Legumes such as beans, lentils, and chickpeas
Direct probiotic supplements containing F. prausnitzii are not widely available due to its extreme sensitivity to oxygen. However, consuming probiotics with Bifidobacterium strains may offer indirect support, as they produce compounds F. prausnitzii can use. Additionally, managing stress, exercising regularly, and avoiding unnecessary antibiotic use can help protect its populations.