" Bacterial flora " is the traditional term used to refer to all the microorganisms residing on the body's surfaces—the current scientific term is " microbiota." It is not limited to the gut: we distinguish between the gut, skin, oral, vaginal, and respiratory microbiota, each with its own specific composition and functions. Its balance is key to digestive, immune, and skin health. Discover our probiotics and lactic acid bacteria.
What is bacterial flora?
Bacterial flora refers to the communities of microorganisms (bacteria, yeasts, archaea, viruses) living in symbiosis with the human body. Humans host more than 38,000 billion microorganisms—a number greater than the number of human cells. Each anatomical site has its own distinct flora: the gut flora is dominated by Firmicutes and Bacteroidetes, the skin flora by Staphylococcus and Cutibacterium, the vaginal flora by Lactobacillus, and the oral flora by Streptococcus. These microbiomes communicate and influence one another via the immune system and the bloodstream.
Gut Microbiota: The Cornerstone of Overall Health?
The gut microbiota is the most extensively studied—it is involved in numerous physiological functions.
- Digestion of dietary fiber: production of short-chain fatty acids (butyrate, propionate, acetate) that nourish colonocytes
- Partial synthesis of vitamins K2, B1, B2, B6, B9, and B12
- Regulation of the mucosal and systemic immune systems
- Production of intestinal serotonin (90% of the body’s serotonin)
- Protection against colonization by pathogens (competitive barrier effect)
- See our digestive comfort and prebiotic line
Skin, vaginal, and oral microbiota?
Each flora has its own balance requirements and its own disruptors.
- Skin flora: Staphylococcus epidermidis protects against pathogenic S. aureus — disrupted by repeated use of antiseptic soaps, topical antibiotics, and harsh cosmetics
- Vaginal flora: 90% dominated by lactic acid-producing Lactobacillus (crispatus, jensenii) — maintains a protective acidic pH (3.8–4.5); imbalance = bacterial vaginosis or yeast infection
- Oral flora: more than 700 identified species—its imbalance is linked to dental caries (S. mutans), gingivitis, and periodontitis
- Targeted oral probiotics are available for each type of flora—choose a formula suited to the site of action (vaginal, oral, intestinal)
What factors disrupt the bacterial flora?
Dysbiosis (microflora imbalance) can be caused by many factors.
- Antibiotics: a major and immediate disruption—loss of up to 30% of gut diversity within the first few days; take lactic acid bacteria starting on the first day, spaced 2 to 3 hours apart from antibiotic doses
- Ultra-processed foods: refined sugars and saturated fats promote opportunistic species
- Chronic stress: via the hypothalamic-pituitary axis, increases intestinal permeability and alters motility—promoting dysbiosis
- Tobacco, alcohol, lack of sleep, and a sedentary lifestyle—documented disruptors of microbial diversity
- Repeated use of topical antiseptics on the skin—opt for a mild, moisturizing soap
How can bacterial flora be restored and supported?
Restoring the flora requires targeted strategies depending on the specific flora involved.
- Gut flora: probiotics with identified strains + prebiotics (inulin, FOS) + a diet of 30 servings of plants per week + fermented foods
- Vaginal flora: probiotics containing Lactobacillus crispatus or rhamnosus, taken orally or applied topically—as a supplement to medical treatment if a yeast infection or bacterial vaginosis is confirmed
- Skin flora: pH-balanced (5.5) cosmetics, free of SLS and denatured alcohol, with topical prebiotics (beta-glucans, fructooligosaccharides)
- Post-antibiotic therapy: Saccharomyces boulardii + multi-strain formula — continue for 7 to 14 days after the end of treatment
- Glutamine: supports the integrity of the intestinal epithelial barrier
Bacterial flora and the immune system?
The gut microbiota is one of the main regulators of the immune system.
- 70 to 80% of immune cells reside in the intestinal mucosa—their activation and regulation are constantly dependent on signals sent by the flora
- A diverse microbiota modulates immune tolerance and reduces the risk of inappropriate inflammatory responses
- Bifidobacteria stimulate secretory IgA—the first-line antibodies of the mucous membranes
- Imbalances in the gut microbiota are associated with increased intestinal permeability and a low-grade systemic inflammatory state
