Faecalibacterium prausnitzii is a Gram-negative and strictly anaerobic bacterium, one of the most abundant common bacterial species in the colon of healthy humans, accounting for approximately 5% (up to 15%) of the total intestinal microbiome. Faecalibacterium prausnitzii belongs to the phylum Firmicutes and it is a member of the Clostridium leptum complex.
Faecalibacterium prausnitzii is known as one of the most important butyric acid producers in the gastrointestinal tract. Butyric acid plays an important role in gut physiology and has pleiotropic effects on the life cycle of gut cells and numerous beneficial health effects through protection against pathogen invasion, regulation of the immune system, and reduction of cancer progression.
As a major member of the human microbiome, F. prausnitzii is a multi-tool organism. This bacterium has a variety of biological functions, including modulating the immune response, suppressing inflammation, and promoting intestinal barrier integrity.
F. prausnitzii is a bacterium with anti-inflammatory properties, as demonstrated in clinical studies. Several studies have shown that reducing the abundance of F. prausnitzii can reduce gut protection against inflammatory responses. This defense mechanism probably involves the stimulation of active molecules to secrete anti-inflammatory cytokines while simultaneously inhibiting the secretion of pro-inflammatory cytokines.
Strengthening the function of the intestinal barrier
An important element in the development and maturation of the intestine is the establishment of the integrity of the intestinal mucosa, which is not only necessary for the absorption of nutrients but also to prevent the entry of bacteria and food antigens into the underlying tissues. Metabolites released by F. prausnitzii have been shown to reduce the severity of inflammation by improving intestinal barrier function and affecting paracellular permeability, i.e., the permeability of epithelial cells and strengthening of intestinal mucus barrier function.
Metabolites of Faecalibacterium prausnitzii
Although the anti-inflammatory property of Faecalibacterium prausnitzii has been confirmed, the exact active molecules and their mechanism have not been fully elucidated. As a consumer of acetic acid, Faecalibacterium prausnitzii can produce anti-inflammatory molecules such as butyric and salicylic acids. A growing body of literature reports that the main metabolite of Faecalibacterium prausnitzii, butyric acid, plays an important role in its anti-inflammatory activity. Butyric acid is a short-chain fatty acid (SCFA) produced by intestinal microorganisms that ferment dietary fiber. Faecalibacterium prausnitzii is one of the main producers of butyric acid in the intestine. Butyric acid provides energy (5-15% of total calories) to the host and regulates the immune system, protecting the host from pathogens.
Salicylic acid is another metabolic product with anti-inflammatory activity produced by Faecalibacterium prausnitzii. As potent regulators of the inflammatory process, salicylic acid can also block NF-κB activation to inhibit IL-8 production as does butyric.
In addition, F. prausnitzii can secrete other anti-inflammatory substances besides butyric and salicylic acids. Another anti-inflammatory substance produced by F. prausnitzii, called microbial anti-inflammatory molecule (MAM), can inhibit NF-κB activation in vitro and in vivo. In general, MAM could reach the whole body and may play an important role in the regulation of inflammatory processes and anatomical locations outside the gut.
Diseases associated with Faecalibacterium prausnitzii
Research has revealed that the abundance of F. prausnitzii is low in both ulcerative colitis and Crohn's disease patients. A reduction in Faecalibacterium prausnitzii has been reported to be associated with an increase in irritable bowel syndrome (IBS) symptoms. Its reduction has been observed in patients with colon cancer compared to healthy controls.
Other diseases that have been associated with a reduced presence of Faecalibacterium prausnitzii include:
- Diabetes mellitus type 2
- Non-alcoholic fatty liver disease
- Diseases of the nervous system (Alzheimer's disease, Parkinson's disease, multiple sclerosis, depression, bipolar disorder)
The role of Faecalibacterium is being investigated in several other diseases such as chronic heart failure, cardiometabolic diseases, arthritis in children, rheumatoid arthritis, blood pressure, Sjögren's syndrome, celiac disease, psoriasis, attention-deficit/hyperactivity disorder, autism, prostate cancer, chronic pancreatitis, atopic dermatitis. The interesting point in most studies is the occurrence of lower relative abundance in patients compared to healthy controls.
What foods increase levels of Faecalibacterium prausnitzii?
Eating the typical Western diet high in meat, sugar, animal fat, processed foods, and a low-fiber diet reduces F. prausnitzii levels, while a high-fiber, low-meat diet can increase them. Therefore, the abundance of F. prausnitzii can be regulated through the consumption of prebiotics and/or dietary supplements. F. prausnitzii utilizes various fibers such as inulin, arabinoxylans, resistant starch, fructans, and pectins. Treatment with inulin-type fructans and fructooligosaccharides has been shown to increase levels of F. prausnitzii. An increase in F. prausnitzii was also reported with red wine consumption. Thus, increasing the consumption of apples with their skin, kiwifruit, unripe bananas, onion, leek, and garlic can improve the abundance of Faecalibacterium prausnitzii in the gut.
The quantitative determination of Faecalibacterium prausnitzii together with the rest of the EnteroScan® findings enables us to determine the most appropriate, personalized nutritional program of Microbiome Nutrition and Microbiome Therapy that aims to improve the composition and functions of the intestinal microbiome. Through the process of balancing the intestinal microbiome, we can achieve optimal levels of physical and mental health in the human body.