Probiotique Complément Alimentaire

Probiotics are living microorganisms, mainly found in the gut and other parts of the body. Increasingly popular, probiotics are now widely used as food supplements due to their numerous benefits.

We offer an in-depth exploration of probiotics, including the essential criteria to consider when purchasing a quality probiotic supplement.

What is a probiotic?

Probiotics are living microorganisms, mainly bacteria, which, when consumed in adequate amounts, provide benefits to the person consuming them.

These beneficial microorganisms are naturally present in our body, particularly in strategic locations. They primarily reside in the intestine, especially in the colon, where they form a significant part of the gut microbiota (also called "intestinal flora"), a complex ecosystem of bacteria, fungi, and other microorganisms.

The most commonly studied and used probiotic strains in food supplements include:

• Lactobacillus, with well-known strains like Lactobacillus acidophilus and Lactobacillus rhamnosus.
• Bifidobacterium, such as Bifidobacterium bifidum and Bifidobacterium longum.
  

These strains are primarily found in the small intestine and colon.

What are the different types of probiotics and where are they found?

Probiotics include different families of microorganisms naturally present in our body or derived from certain fermented food sources. Here are the main types of probiotics classified by their origin and location.

The gut microbiota (intestinal flora)

The gut microbiota, often called intestinal flora, is a complex set of microorganisms that reside in the human gastrointestinal tract. Composed of bacteria, viruses, fungi, and yeasts, it plays a role in the body.

1. What is the gut microbiota?

The gut microbiota is a living ecosystem that includes billions of microorganisms. It is estimated that there are approximately 100 trillion bacteria in our gut. These microorganisms are organized into diverse communities and bacterial strains, whose diversity can vary from person to person.

2. Where is the gut microbiota located?

The gut microbiota primarily resides in the colon and small intestine, although it is also present in other regions of the digestive tract. It is found throughout the digestive tract, but its concentration is highest in the colon.

3. Role of the small intestine and colon

The small intestine and colon are two key parts of the digestive system. These two organs provide a natural habitat for probiotics, which offer many benefits to the body.

• The small intestine

The small intestine is a central organ of the digestive system, located between the stomach and the colon. Several meters long (approximately 5 to 7 meters in adults), it is divided into three segments: the duodenum, the jejunum, and the ileum. It is in this environment that most enzymatic digestion and nutrient absorption of proteins, carbohydrates, lipids, vitamins, and minerals take place.

Certain probiotic strains are naturally found in the small intestine, particularly in the jejunum and ileum areas. Among the most frequently detected genera in this region are Lactobacillus, including strains such as Lactobacillus acidophilus and Lactobacillus rhamnosus.

Although the small intestine contains a lower bacterial density than the colon, it constitutes an important transient habitat for specific bacteria capable of surviving in an environment rich in digestive enzymes, bile acids, and nutrients undergoing assimilation.

• The colon

The colon, also known as the large intestine, is the last part of the digestive system, located after the small intestine. It measures approximately 1.5 meters and is divided into several segments: ascending, transverse, descending, and sigmoid colon. Its inner wall harbors an extremely dense and varied microbial flora, making the colon one of the richest areas in microorganisms in the entire human body.

The main purpose of the colon is to finalize food digestion by absorbing remaining water and electrolytes, to temporarily store food residues before their elimination (in the form of stool), and to maintain an environment conducive to microbial life. It is in this section that unabsorbed matter from the small intestine is transformed into stool, while maintaining the body's water balance.

The conditions prevailing in the colon are:

• a more neutral pH,
  
• a slower transit time,
• an anaerobic environment.

These conditions make it an ideal habitat for many beneficial bacteria. Among them, large quantities of Bifidobacterium are found, such as Bifidobacterium bifidum or Bifidobacterium longum. Strains of Lactobacillus, such as Lactobacillus plantarum or Lactobacillus reuteri, are also present, although generally in smaller proportions than in the small intestine.

These microorganisms concentrate particularly in the distal sections of the colon, such as the descending colon and the sigmoid colon.

4. The composition of the gut microbiota: diversity and balance

The gut microbiota is a complex ecosystem consisting of several trillions of microorganisms, mostly bacteria. Its composition naturally varies among individuals, influenced by factors such as diet, age, lifestyle, and medical history. Despite this variability, certain major bacterial families systematically dominate the human gut flora, notably:

• Firmicutes
• Bacteroidetes
• Actinobacteria

These families include a wide variety of bacteria with complementary functions. Among the most studied are the genera Lactobacillus (associated with the Firmicutes family) and Bifidobacterium (belonging to Actinobacteria), which are naturally found in different regions of the digestive system.

5. Factors influencing the gut microbiota

Many factors influence the composition of the gut microbiota, and its balance can be altered by:

• Antibiotics: Excessive or incorrect use of antibiotics can disrupt the balance of the microbiota by reducing bacterial diversity.
• Stress: Long-term stress can affect the balance of the intestinal flora.
• Diet: An unbalanced diet (too much sugar, too little fiber) can disrupt the balance of the microbiota.

This can lead to an excess of pathogenic bacteria.

How to maintain a healthy gut microbiota?

To preserve a balanced and health-promoting microbiota, here are some recommendations:

• Include fermented foods in your diet: yogurt, kefir, sauerkraut, tempeh, etc.
• Limit the use of antibiotics to strictly necessary cases and under medical supervision.
• Manage stress through relaxation techniques such as meditation or physical exercise.

The best sources of probiotics and prebiotic fibers

In addition to food supplements, there are many natural food sources of probiotics and prebiotic fibers. Here is an overview of the best sources of these elements.

1. The best sources of probiotics

Probiotics are mainly found in fermented foods, which are produced by the fermentation of beneficial bacteria. These foods directly provide living microorganisms that can colonize the intestine. Here are some of the main food sources containing probiotics:

• Yogurt: Yogurt is one of the most popular and widely consumed sources of probiotics. It is made from fermented milk, usually with strains of Lactobacillus and Streptococcus thermophilus. These strains are able to survive in the gut and provide many benefits.
• Kefir: Kefir is a fermented milk-based drink, but it contains a wider variety of probiotic bacteria and yeasts. It is often considered to have more beneficial effects than yogurt due to its microbial diversity. It can also be made from water (water kefir) for those who prefer to avoid dairy products.
• Sauerkraut: Sauerkraut is fermented cabbage that contains lactic acid bacteria such as Lactobacillus plantarum. It is essential that the sauerkraut is unpasteurized, as pasteurization kills beneficial bacteria.
• Kimchi: Kimchi is a Korean specialty, a dish of fermented vegetables (often cabbage) spiced with ingredients like garlic and ginger. Like sauerkraut, it is rich in lactic acid bacteria, but also in vitamins. Kimchi is an excellent probiotic food to diversify bacterial strains in the gut.
• Miso: Miso is a fermented soybean paste, typically used in Japanese soups. It contains lactic acid bacteria, but also yeasts and other microorganisms. It is an excellent way to incorporate probiotics into a vegan diet.
• Tempeh: Tempeh is a fermented soybean paste, originating from Indonesia. It is rich in protein, and its fermentation produces strains of bacteria and yeasts. Tempeh is also an excellent vegetarian alternative to meat.

2. The best sources of prebiotic fibers

Prebiotic fibers are types of dietary fibers that resist digestion in the stomach and reach the colon, thus feeding good bacteria. Here are some of the best sources of prebiotic fibers:

• Legumes and beans: Lentils, chickpeas, beans, and other legumes are rich in soluble fiber and resistant starch.
• Garlic, onion, asparagus: They contain inulin, a prebiotic fiber.

Quality criteria for a probiotic food supplement

When choosing a probiotic food supplement, it is crucial to consider several criteria to ensure its effectiveness and safety. Here are the elements to consider when purchasing quality probiotics:

1. Specific strains and diversity

The choice of probiotic strains is fundamental. Each strain has distinct effects, and some are better suited to particular needs. Mixtures of strains can offer a wider spectrum of effects, providing many benefits.

2. Number of colony-forming units (CFU)

The number of CFUs (colony-forming units) is an important indicator of a probiotic's potency. It represents the number of live bacteria contained in each dose of the supplement. For a probiotic to be effective, it must contain a sufficient concentration of live bacteria. Generally, a quality probiotic supplement should contain at least 1 billion CFUs per dose, but some products may contain up to several billion.

3. Stability and preservation

The stability of probiotics is a key factor in ensuring their effectiveness. Probiotic bacteria are living organisms that can lose viability over time if not properly stored. Moreover, some strains are more sensitive to heat, humidity, and light.

It is therefore essential to check the recommended storage conditions on the product packaging. For example, some probiotics require refrigeration, while others are stable enough to be stored at room temperature. Also, check the expiration date, as the CFU count in the supplement may decrease over time, affecting its effectiveness.

4. Formulation and absence of additives

The product formulation is another essential criterion. Opt for probiotics that do not contain unnecessary fillers or additives, such as artificial colors or preservatives, which could interfere with the benefits of the supplement. It is preferable to choose products formulated with natural excipients.

5. Labels and certifications

To guarantee the effectiveness of a probiotic food supplement, the presence of reliable labels and certifications is an essential indicator of quality. These mentions reflect compliance with strict manufacturing standards, the stability of the strains used, and their traceability. They also make it possible to identify products that have undergone rigorous selection.

Among the products available on the market, some supplements highlight formulations associated with specific references, such as SynbÆctive®, DRcaps®, or Neuflor®. Many reputable brands also use identifiable strains, such as Lactobacillus reuteri LRC®, Bifidobacterium lactis BB-12®, Lactobacillus acidophilus LA-5®, or Lactobacillus rhamnosus LGG®.

Opting for a product mentioning this type of reference can be a useful benchmark for choosing a probiotic supplement that meets criteria of quality, stability, and reliability.

Usage recommendations

• Consult a healthcare professional: Before starting any supplement, it is advisable to discuss it with a doctor or nutritionist, especially if you have pre-existing medical conditions.
• Follow manufacturer's instructions: Respect recommended doses and storage conditions.

Conclusion

More and more people are turning to probiotic supplements to incorporate them into their dietary routine. These living microorganisms are naturally present in several areas of the human body, particularly in the small intestine and colon, where they coexist with a wide diversity of bacteria.

For effective use, it is essential to choose quality products containing clearly identified strains at precise concentrations, and ideally associated with recognized labels. These criteria ensure that the product complies with expected standards for traceability and stability.

Source

Shah, A. B., Baiseitova, A., Zahoor, M., Ahmad, I., Ikram, M., Bakhsh, A., Shah, M. A., Ali, I., Idress, M., Ullah, R., Nasr, F. A., & Al-Zharani, M. (2024). Probiotic significance of Lactobacillus strains: a comprehensive review on health impacts, research gaps, and future prospects. Gut Microbes, 16(1), DOI: https://doi.org/10.1080/19490976.2024.2431643