This glossary helps you understand key terms related to the gut microbiome, fermentation, and nutrition. Whether you're a parent, an athlete, or simply curious about your gut health, you'll find clear, evidence-based definitions here.
A
Lactic acid
A molecule produced during lactic fermentation, a natural process in which bacteria convert sugars into acid. In fermented foods like kefir or yogurt, lactic acid contributes to preservation, gives the characteristic tangy taste, and creates an environment that supports beneficial gut bacteria. In athletes, lactic acid is also produced by muscles during intense exercise.
Gut-brain axis
A bidirectional communication system between the digestive system and the brain, primarily via the vagus nerve. This axis explains why the state of your microbiome influences your mood, stress, and sleep — and vice versa. Research from INRAE and Inserm has shown that 95% of serotonin (the “feel-good” hormone) is produced in the gut. This is what’s referred to as the “gut feeling.”
→ Read also: The incredible power of the microbiome on stress and mental health
B
Gut biodiversity
The variety of microbial species present in the gut. The greater the biodiversity, the more resilient the microbiome is and the better it can perform its functions: digestion, immunity, and protection against pathogens. A diet rich in fiber, fermented foods, and plant-based ingredients supports this diversity. Conversely, an ultra-processed diet tends to reduce it.
C
Plant-based calcium
Calcium sourced from non-animal foods: almonds, sesame seeds, kale, broccoli, figs, and calcium-rich mineral waters. Calcium is essential for bone growth in children and for maintaining bone density in adults and athletes. A minimiil shot provides plant-based calcium, contributing to daily recommended intake without relying on dairy.
CFU (Colony Forming Units)
A unit of measurement indicating the number of live, active bacteria in a probiotic product. The higher the CFU count, the more microorganisms are capable of colonizing the gut. A minimiil shot contains 10 billion CFU, a dosage considered effective by scientific literature (World Gastroenterology Organisation, 2017).
D
Dysbiosis
An imbalance in the gut microbiome characterized by reduced bacterial diversity or an overgrowth of potentially harmful bacteria. Dysbiosis can manifest as bloating, chronic fatigue, digestive issues, weakened immunity, or inflammation. Common causes include ultra-processed diets, chronic stress, antibiotic use, and lack of fiber. Restoring balance involves consuming probiotics and prebiotics.
E
Digestive enzymes
Proteins produced by the body (saliva, stomach, pancreas, intestines) that break down food into absorbable nutrients. The main ones are amylase (carbohydrates), lipase (fats), and protease (proteins). Fermented foods support digestion because fermentation pre-digests certain nutrients and naturally produces additional enzymes.
F
Fermentation
A natural biological process in which microorganisms (bacteria, yeasts) transform organic compounds — mainly sugars — into other substances such as lactic acid, alcohol, or CO₂. In food, fermentation enriches products with probiotics, improves digestibility, and increases the bioavailability of certain nutrients. Kefir, yogurt, sauerkraut, kimchi, and kombucha are traditional fermented foods.
→ Read also: Fermented foods: what are they?
Prebiotic fibers
Non-digestible dietary fibers that serve as food for beneficial gut bacteria. The most well-known are inulin (chicory, agave, Jerusalem artichoke), fructo-oligosaccharides (FOS), and galacto-oligosaccharides (GOS). Unlike probiotics, which introduce live bacteria, prebiotics feed those already present in your gut. minimiil contains agave inulin, a recognized prebiotic.
Soluble vs. insoluble fiber
Soluble fiber (oats, legumes, fruits) dissolves in water and forms a gel that slows digestion, feeds the microbiome, and helps regulate cholesterol. Insoluble fiber (whole grains, vegetables, fruit skins) does not dissolve and helps speed up intestinal transit. Adults need 25–30 g of fiber per day (ANSES), ideally a mix of both types.
→ Read also: Soluble vs insoluble fiber: what’s the difference?
Gut flora
An outdated term for the gut microbiome. The word “flora” incorrectly suggested that gut microorganisms were plants. The modern scientific term is “microbiome,” which better reflects the diversity of organisms present: bacteria, archaea, fungi, viruses, and protozoa.
G
Gut health
A widely used term referring to the overall health of the digestive system, particularly the balance of the gut microbiome. Gut health goes beyond digestion: it influences immunity (70% of the immune system resides in the gut, according to the French Society of Immunology), energy, mood, sleep quality, and athletic recovery. It’s the philosophy at the core of minimiil: a daily ritual to nourish your gut.
I
Gut immunity
The gut houses around 70% of the body’s immune cells. The microbiome acts as a barrier: it prevents pathogens from colonizing the gut, stimulates antibody production, and regulates inflammation. A balanced microbiome strengthens natural defenses — a key factor for growing children, adults, and athletes exposed to physical stress.
Low-grade chronic inflammation
A persistent but subtle inflammatory state, often linked to microbiome imbalance (dysbiosis), ultra-processed diets, or chronic stress. Unlike acute inflammation (redness, pain), it is silent but contributes to fatigue, joint pain, and many chronic diseases. Fermented foods and a fiber-rich diet help reduce it.
→ Read also: Reducing inflammation: what your diet can really change
Inulin
A prebiotic fiber naturally found in chicory, agave, artichokes, and Jerusalem artichokes. Inulin selectively feeds bifidobacteria and lactobacilli, two families of beneficial gut bacteria. It also promotes calcium and magnesium absorption. minimiil uses organic agave inulin to provide a natural prebiotic effect.
K
Kefir
A traditional fermented drink rich in live probiotics. Original kefir is made from kefir grains (a symbiotic culture of bacteria and yeasts) grown in milk or sweetened water. minimiil offers almond kefir: a plant-based fermented drink made from almond milk, combining the benefits of traditional kefir with a 100% plant-based, lactose-free formula suitable for the whole family.
Almond kefir
A plant-based variation of traditional kefir, obtained by fermenting almond milk with probiotic cultures. Almond kefir combines the beneficial fats and nutrients of almonds with live probiotics from fermentation. It is the base of the minimiil recipe: a 60 ml fermented almond kefir shot, enriched with blackcurrant, blueberry, and basil, delivering 10 billion probiotics per serving.
L
Lacto-fermentation
A type of fermentation carried out by lactic acid bacteria (Lactobacillus, Leuconostoc, Pediococcus), which convert sugars into lactic acid. This process is used to produce sauerkraut, kimchi, pickles, yogurt, and kefir. Lacto-fermentation is one of the oldest food preservation methods and one of the most beneficial for the microbiome.
→ Read also: Lacto-fermentation: the future of food is already in your kitchen
Lactose
A sugar naturally found in cow’s milk and dairy products. Its digestion requires lactase, an enzyme that many adults produce in insufficient amounts (it is estimated that 65–70% of the global population becomes lactose intolerant after childhood, according to the NIH). Plant-based fermented drinks like minimiil are naturally lactose-free and therefore suitable for intolerant individuals.
M
Microbiome
The collection of genes carried by the microorganisms of the microbiota. While “microbiota” refers to the organisms themselves, “microbiome” refers to their collective genetic material. The human microbiome contains approximately 3.3 million genes — about 150 times more than the human genome. This genetic richness allows the microbiome to perform functions our own cells cannot, such as synthesizing certain vitamins (K, B12).
Gut microbiota
An ecosystem of 100 trillion microorganisms (bacteria, viruses, fungi, archaea) living in the human digestive tract, primarily in the colon. It weighs between 1 and 2 kg in adults. It performs essential functions: digesting fiber, producing vitamins (K, B12, B9), regulating the immune system, protecting against pathogens, and communicating with the brain via the gut-brain axis. Each person has a unique microbiota, comparable to a fingerprint.
→ Read also: The importance of the gut microbiome: why it matters and how to support it
Intestinal mucus
A protective layer lining the inner wall of the intestine. It acts as a physical barrier between microbiome bacteria and intestinal cells while allowing nutrient absorption. Some beneficial bacteria (such as Akkermansia muciniphila) feed on mucus and contribute to its renewal. A fiber- and polyphenol-rich diet supports the quality of this protective layer.
P
Intestinal permeability (leaky gut)
An abnormal increase in the permeability of the intestinal wall, allowing unwanted molecules (toxins, bacterial fragments) to pass into the bloodstream. This phenomenon, often referred to as “leaky gut,” is associated with chronic inflammation, certain food intolerances, and fatigue. Maintaining a diverse microbiome and a healthy gut lining helps prevent this condition.
Postbiotics
Beneficial substances produced by probiotics during fermentation: short-chain fatty acids (butyrate, propionate, acetate), vitamins, enzymes, and antimicrobial peptides. Postbiotics are considered one of the key mechanisms through which fermented foods exert their health benefits, even after live bacteria have been digested.
Prebiotics
Non-digestible food compounds — mainly fibers — that selectively stimulate the growth and activity of beneficial microbiome bacteria. The most studied include inulin, FOS, and GOS. They are found in garlic, onions, leeks, artichokes, bananas, and chicory. Not to be confused with probiotics: prebiotics feed bacteria, probiotics are bacteria.
Probiotics
According to the World Health Organization (WHO, 2001), probiotics are “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.” The most studied strains belong to the Lactobacillus and Bifidobacterium genera. They are naturally found in fermented foods (kefir, yogurt, sauerkraut, miso) or as supplements. minimiil delivers probiotics through the natural fermentation of almond milk — the bacteria develop directly in the drink, rather than being added afterward.
→ Read also: Which probiotic should you choose: food or supplements?
R
Athletic recovery and the microbiome
Intense physical activity causes oxidative stress and temporary inflammation, which affect the gut microbiome. Recent studies (Clark & Mach, Journal of the International Society of Sports Nutrition, 2016) show that athletes with a diverse microbiome recover faster, absorb nutrients better, and experience fewer respiratory infections. Probiotics and fermented foods help support the microbiome during intensive training periods.
→ Read also: Microbiome and sport: the gut as a hidden performance driver
S
Probiotic strains
Specific varieties of probiotic bacteria, identified by their genus, species, and strain (e.g., Lactobacillus rhamnosus GG). Each strain has different properties: some strengthen immunity, others improve digestion or reduce inflammation. This is why not all probiotics are equal — strain and dosage (CFU) determine effectiveness.
Synbiotics
Products combining probiotics (live bacteria) and prebiotics (fibers that feed them) in the same formulation. The idea is that prebiotics enhance the survival and effectiveness of probiotics by providing a growth substrate. minimiil is naturally synbiotic: almond kefir provides live probiotics, and agave inulin provides prebiotics.
V
Vitamin D
A fat-soluble vitamin essential for calcium absorption, bone health, and proper immune function. Vitamin D is mainly synthesized by the skin through sunlight exposure (UVB), but deficiencies are common — ANSES estimates that 80% of people in France lack sufficient vitamin D in winter. Growing children and athletes have increased needs. Each minimiil shot is enriched with vitamin D to help meet daily requirements.
