Glossaire

AAD

Antibiotic-associated diarrhea

Actinobacteria

Phylum or group of anaerobic Gram-positive Eubacteria; they are part of the dominant microbiota in the human colon.

Anaerobic

Qualifies an organism that develops in the absence of oxygen.

Anatomic

Relating to anatomy. Anatomy is a science that studies the body parts of living organisms and how they interact: forms, structures, connections between organs, etc.

Antifungal

Drug prescribed to treat infectious diseases caused by fungi (mycoses)

Atherosclerosis

Artery disease characterized by a loss of elasticity in an artery wall as a result of lipid deposits (patches of atheroma)

Atopic dermatitis

or Allergic eczema. Non contagious skin disease combining cutaneous dryness and itching, whose onset is favored by a predisposition to allergies

Axenic

Lacking microbiota

Bacterial vaginosis

Vaginal infection caused by an imbalance in the bacterial flora of the vagina

Bacteriophage

Virus specifically infecting bacteria

Bacteriotherapy

Treatment of an infectious disease by introducing specific bacteria into the body

Bacteroides

Genus of Gram-negative anaerobic bacteria, belonging to the phylum Bacteroidetes. Bacteroides are found in the digestive tract and mucus membranes and constitute an important part of the gastrointestinal flora.

Bacteroidetes

Phylum composed of three large classes of bacteria that are dominant in the colon, particularly the genera Bacteroides and Porphyromonas.

Bifidobacteria

Non-motile, Gram-positive bacteria belonging to the Bifidobacterium genus present in the intestinal flora

Bifidobacterium

Genus of Gram-positive anaerobic bacteria, belonging to the phylum Actinobacteria

Bile salts

Components coming from cholesterol that play a role in the digestion of fats

Butyrate

Short-chain fatty acid that ensures that the cells of the colonic mucosa function properly

Candidiasis

Infection caused by a fungus belonging to the Candida genus, affecting the skin or mucus membranes in the mouth or genital areas (vagina, etc.)

Carmine

Red dye

Cecum

First section of the large intestine

Celiac disease

Autoimmune digestive disease caused by a gluten intolerance

Childhood

Relating to children

Chlamydia

Bacteria responsible for various acute and chronic genital, ocular, and respiratory infections in humans

Cognitive

Relating to the process of knowing

Colonic mucosa

Layer of cells lining the colon

Colonocyte

Epithelial membrane cell in the colon

Colonoscopy

Exam to explore the colonic mucosa

Corticosteroid

Hormones secreted by the adrenal glands and synthetically produced drugs that have the same effect as these hormones with anti-inflammatory and immunomodulating effects

Cranberry

Red berry.

Cutaneous condition

Skin disease

Cystitis

Inflammation of the bladder, most often caused by a urinary infection

Diabetes mellitus

Chronic disease related to a dysfunction in the production or use of insulin, a hormone that regulates glycemia

Dopamine

Molecule that transmits information between neurons. Dopamine is involved in motor control

Duodenum

First section of the small intestine, located at the exit from the stomach

Dysbiosis

Imbalance in the microbiota associated with harmful consequences for the host. Dysbiosis can result from an excess of detrimental microorganisms and/or a relative lack of microorganisms that are beneficial to the host

Ecosystem

Combination of living organisms and their biological environment.

Enteric

Relating to the intestines

Enterotype

Type of bacterial composition characterizing a microbiota. Currently, 3 enterotypes have been identified in humans.

Enzymatic

Relating to the action of an enzyme, a protein involved in chemical reactions in the organism

Epithelial

Relating to the epithelium

Epithelium

Thin tissue formed by one or more juxtaposed layers of cells. There are two kinds: surface epithelium (skin or mucosa) and glandular epithelium (secretion function)

Escherichia coli

Intestinal Gram-negative bacteria, very common in humans (commensal). However, certain strains (pathogens) can generate disorders (gastroenteritis, urinary infections, etc.)

Faecalibacterium prausnitzii

Primary species of firmicute in the human colon, which produces butyrate, among others. Its volume is reduced in Crohn’s disease.

FGD

Functional gastrointestinal disorder

Firmicutes

Phylum consisting of Gram-positive bacteria including Clostridies and lactobacilli, prevalent in the human colon.

Fructan

Complex carbohydrate composed of fructose polymers. They are produced by microorganisms or plants. There are different categories of fructans, including inulin

Fructooligosaccharide (FOS)

Complex carbohydrate composed of fructose and sucrose. They are the most frequent prebiotics, naturally present in food.

Fructosan

Complex carbohydrate (polysaccharide) composed of fructose polymers

Galactooligosaccharide (GOS)

Complex carbohydrate composed of oligosaccharide and galactose. GOSs are present in breast milk, in particular.

Genus

Taxonomic rank gathering a set of species.

Gonococci

Gram-negative bacteria, causing a sexually transmitted genital infection (gonorrhea)

Gram+/-

Corresponds to a bacterial classification as determined by a staining technique called Gram stain. While Gram-positive bacteria appear violet under the microscope, Gram-negative bacteria appear pink. The staining technique is based on characteristics of the bacteria’s membranes and wall.

Gut core bacteria

The part of the microbiota shared by all or a vast majority of individuals.

Helicobacter pylori

Bacteria present in the stomach that can survive in a highly acidic environment. H. Pylori is involved in the majority of cases of stomach and duodenum ulcers.

Host

Organism (human, animal, etc.) that is home to a virus, parasite, bacteria, etc. Also refers to a person receiving a transplant.

IBDs

Inflammatory bowel disease

Immune response

A body’s defense reaction involving immune cells

Immunomodulator

Molecular component that activates or slows down immune reactions (modulation)

insulin resistance

Body’s resistance to hypoglycemic action (reduction of glucose levels in the blood) by insulin

Intestinal tract

All the organs that make up the intestines

Intestine

(or bowel) Part of the digestive tract composed of the duodenum, jejunum, ileum, cecum, colon, and rectum.

inulin

Fructan obtained from chicory roots or artichokes. It is a prebiotic.

Lactobacilli

Genus of Gram-positive bacteria involved in the fermentation of carbohydrates and their transformation into lactic acid. Lactobacilli are important organisms in the intestinal flora

Lipopolysaccharide

Component composed of lipids and carbohydrates

Mesenteric

Relating to the mesentery

Mesentery

The mesentery is a membrane formed by the fold of the peritoneum (the membrane covering the abdominal cavity and its organs), connecting the jejunum and ileum (sections of the small intestine) to the posterior wall of the abdomen. It contains nerves and blood vessels

Metabolic

Relating to the metabolism

Metabolism

Set of chemical reactions that transform matter and energy, at the cellular level, inside the body

Metabolite

Product formed by the process of transforming an organic body (metabolism) within a cell, tissue, or the blood.
Also defines a product that enters the metabolic process

Metabolome

All of the intermediary or final metabolites in the microbiota.

Metagenomics

Procedure aiming at studying the genetic content of a sample taken from a complex environment (like the intestine)

Metaproteomics

Procedure aiming at studying the protein content of a sample taken from a complex environment (like the intestine)

Metatranscriptomics

Procedure aiming at studying the RNA content of a sample taken from a complex environment (like the intestine).

Microbiota

All microorganisms (bacteria, yeasts, fungi, virus) living in a specific environment

Mucus

Viscous secretion produced by the cells of the mucus membranes It has a protective function

Nonsteroidal anti-inflammatory drug (NSAID)

Anti-inflammatory drug used to counteract inflammation, fever, and pain.

Norovirus

Virus frequently responsible for gastroenteritis and diarrhea in developed countries

Oligosaccharide

Carbohydrate composed of a set of one to a dozen simple carbohydrate molecules (monosaccharides)

Parenteral

Relating to the intravenous, intramuscular, or subcutaneous administration of a drug

Pathobiont

All of the bacteria that can cause diseases

Pathogen

Which can cause a disease

Perennial

Which can occur at any point during the year (no seasonal influence, for example)

Phylogenetics

The study of existing connections between related species. Through it, it is possible to retrace the primary evolutionary stages of organisms from a common ancestor and therefore to more precisely classify the relationships between living beings

Phylum

Second taxonomic rank which gathers several genera and species.

Polyp

Pedunculated tumor (long structure), most often benign, that develops in body cavities lined with mucus membranes (intestine, esophagus, bladder, nose, etc.)

Polysaccharide

High molecular weight carbohydrate composed of numerous simple carbohydrate molecules (monosaccharides or simple sugars)

Prebiotic

Non-digestible fibers in the diet that selectively stimulate the growth of beneficial colon bacteria in the host’s microbiota.

Prevotella

Genus of Gram-negative bacteria belonging to the phylum Bacteroidetes

Probiotic

Living microorganisms that, when administered in sufficient quantity, have beneficial effects on the health of the host

Prophylactic

Things that preserve health against the appearance, worsening, or expansion of diseases

Resilience

Capacity of an ecosystem or species to resume normal development or function after experiencing trauma. When the microbiota is disturbed by antibiotics, it has a tendency (most often) to regain its equilibrium after a while.

Rotavirus

Virus that can cause gastroenteritis

Ruminococcus

Genus of Gram-positive anaerobic bacteria belonging to the phylum Firmicutes

Salmonella

Bacteria that can cause food poisoning responsible for gastroenteritis

Short-chain fatty acid

Short-chain fatty acids (SCFAs) are products from the fermentation of dietary fiber that is not absorbed or digested by the body. This fermentation is done by anaerobic bacteria in the microbiota present in the colon. SFCAs are composed of a maximum of six carbon atoms and are involved in energetic metabolism.

Steatosis

Fat overloadin the cells

Steroid therapy

Corticosteroid-based therapy

Stools

(or feces or excrement) Residue of digestion excreted via defecation following digestive transit

Strain

Taxonomic rank below species.

Streptomycin

Aminoglycoside-class antibiotic

Symbiotic

Relating to symbiosis (an interdependent relationship between two organisms that cannot live without one another and that benefit from one another)

Taxonomy

Science of classifying living organisms to describe them and group them into entities called taxons (families, genera, species, etc.) in order to be able to name and classify them.

TNFα inhibitor

Also known as tumor necrosis factor inhibitor. Medication with an anti-inflammatory action prescribed for the treatment of some chronic inflammatory diseases (IBDs, inflammatory polyarthritis, etc.)

Topical steroid

Corticosteroid used to treat skin diseases

Tract

Defines both a set of organs making up a system (ex: digestive tract) and a set of fibers (connective or nerve) located on the surface or within an organ

Trophic

Relating to the growth of organs, of living tissues, of an individual

Ulcerative colitis

Inflammatory disease of the rectum and colon(an IBD)

Villi

All of the “hair-shaped” small protrusions that line the surface of mucus membranes (ex: the intestine) and give it a hairy appearance

Yeast

Microscopic fungus made up of a single cell (unicellular). Some yeasts are involved in food fermentation and are used in cooking (brewer’s yeast, etc.). Some are used for therapeutic purposes (Saccharomyces boulardii). Others can even cause diseases (ex. Candidiasis caused by Candida albicans)