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Bugs in Our Guts—Not All Bacteria Are Bad
How Probiotics Keep Us Healthy

(Released September 2006)

  by Leila Kiani  


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allergens: Substances that cause the immunity system to trigger and fight against itself. In normal cases, and in the majority, this happens when foreign bodies such as bacteria enter our body. However, innocent and harmless bodies (proteins) such as pollen, peanuts, milk, penicillin etc. may not be recognized by our immune system and keep thinking of them as harmful foreign bodies. On the other hand, wasps and other insects produce allergens as a self defense.

antibody secretory IgA: A dimeric molecule comprised of two IgA monomers joined by a J polypeptide chain and a glycopeptide secretory component. This is the principal molecule of mucosal immunity.

apoptosis: One of the main types of programmed cell death (PCD). As such, it is a process of deliberate life relinquishment by an unwanted cell in a multicellular organism.

atopic eczema: Atopic dermatitis, also called atopic eczema, is a skin disorder that usually manifests itself as dry, itchy skin and/or a red, scaly rash. The term "atopic" refers to an allergic or immunologic reaction; "dermatitis" and "eczema" both mean inflammation of the skin. Atopic dermatitis is common, affecting 10 to 20 percent of the population in the U.S. It most often affects infants and small children, although it also strikes teenagers and adults. It may be the first sign that a person will go on to develop other atopic conditions such as hay fever or asthma.

bacteremia: The presence of bacteria in the blood.

binding site: A region on a protein to which specific ligands bind. This ability of proteins to bind specific ligands forms the basis for the wide variety of functions that a protein carries out.

butyric acid: Butanoic acid, or normal butyric acid, is a carboxylic acid with structural formula CH3CH2CH2-COOH. It is notably found in rancid butter, parmesan cheese, or vomit and has an unpleasant odor and acrid taste, with a sweetish aftertaste (similar to ether). Butyric acid can be detected by mammals with good scent detection abilities (e.g. dogs) at 10 ppb, while humans can detect it in concentrations above 10 ppm.

casein: A white, tasteless, odorless protein precipitated from milk by rennin. It is the basis of cheese and is used to make plastics, adhesives, paints, and foods.

colony-forming units: In Microbiology, colony-forming unit (CFU) is a measure of viable bacterial numbers. Unlike in direct microscopic counts where all cells, dead and living, are counted, the cfu measures viable cells. A sample is spread or poured on a surface of an agar plate, left to incubate, and the number of colonies formed are counted. CFU number is not an exact measure of numbers of viable cells, as a colony-forming unit may contain more cells.

cytokines: Any of several regulatory proteins, such as interleukins and lymphokines, that are released by cells of the immune system and act as intercellular mediators in the generation of an immune response.

Deconjugating: don't undergo conjugation.

Deoxyribonucleic acid (DNA) : A nucleic acid - usually in the form of a double helix - that contains the genetic instructions monitoring the biological development of all cellular forms of life, and many viruses. DNA is a long polymer of nucleotides (a polynucleotide) and encodes the sequence of the amino acid residues in proteins using the genetic code. DNA is thought to date back to between approximately 3.5 to 4.6 billion years ago.

EFSA: The European Food Safety Authority (EFSA) is the keystone of European Union (EU) risk assessment regarding food and feed safety. In close collaboration with national authorities and in open consultation with its stakeholders, EFSA provides independent scientific advice and clear communication on existing and emerging risks.

endocarditis: The thin serous membrane, composed of endothelial tissue, that lines the interior of the heart.

Enzymes: Catalysts and increase the speed of a chemical reaction without themselves undergoing any permanent chemical change. They are neither used up in the reaction nor do they appear as reaction products.

epithelial cells: Epithelium is a tissue composed of a layer of cells. Epithelium can be found lining internal (e.g. endothelium, which lines the inside of blood vessels) or external (e.g. skin, cornea) free surfaces of the body.

flora: The bacteria and other microorganisms that normally inhabit a bodily organ or part

fungemia: The presence of fungi in the blood.

gamma amino butyric acid (GABA) : An inhibitory neurotransmitter found in the nervous systems of widely divergent species. It is the chief inhibitory neurotransmitter in the vertebrate central nervous system.

genera: A taxonomic category ranking below a family and above a species and generally consisting of a group of species exhibiting similar characteristics. In taxonomic nomenclature the genus name is used, either alone or followed by a Latin adjective or epithet, to form the name of a species.

gluconate: salt of gluconic acid that forms from the oxidation of glucose and other sugars.

GRAS: Generally Recognized as Safe (GRAS) is a United States of America Food and Drug Administration (FDA: designation that a chemical or substance (including certain pesticides) added to food is considered safe by experts, and so is exempted from the usual Federal Food, Drug, and Cosmetic Act (FFDCA) food additive tolerance requirements.

immunoglobulins: Any of a group of large glycoproteins that are secreted by plasma cells and that function as antibodies in the immune response by binding with specific antigens. There are five classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM.

immunoreaction: The reaction resulting from the recognition and binding of an antigen by its specific antibody or by a previously sensitized lymphocyte.

interferon: Any of a group of glycoproteins that are produced by different cell types in response to various stimuli, such as exposure to a virus, bacterium, parasite, or other antigen, and that prevent viral replication in newly infected cells and, in some cases, modulate specific cellular functions.

lactic acid: A syrupy, water-soluble liquid, C3H6O3, produced in muscles as a result of anaerobic glucose metabolism, and present in sour milk, molasses, various fruits, and wines. A synthetic form of the compound is used in foods and beverages as a flavoring and preservative, in dyeing and textile printing, and in pharmaceuticals.

lymphocytes: Any of the nearly colorless cells found in the blood, lymph, and lymphoid tissues, constituting approximately 25 percent of white blood cells and including B cells, which function in humoral immunity, and T cells, which function in cellular immunity.

lyophilized: To freeze-dry (blood plasma or other biological substances).

macrophages: White blood cells, more specifically phagocytes, acting in the nonspecific defense or (nonspecific immunity) as well as the specific defense (or cell-mediated immunity) system of vertebrate animals. Their role is to phagocytize (engulf and then digest) cellular debris and pathogens either as stationary or mobile cells.

mucosa: A membrane lining all body passages that communicate with the air, such as the respiratory and alimentary tracts, and having cells and associated glands that secrete mucus

mutagens: Chemical or physical agents that increase the frequency of mutations. Essentially all mutagens show some specificity for the type of mutations produced.

nitrosamines: Carcinogenic chemical compounds of the chemical structure R2N-N=O. Nitrosamines are produced from nitrites and amines. Their formation can occur only under certain conditions, including strongly acidic conditions such as that of the human stomach.

oxalate (also ethanedioate) : A salt or ester of oxalic acid. The oxalate ion is (COO)22- and is oxalic acid without the two hydrogen ions. Consumption of oxalates (for example, the grazing of animals on oxalate-containing plants such as greasewood) may result in kidney disease or even death due to oxalate poisoning.

proteolytic: The hydrolytic breakdown of proteins into simpler, soluble substances such as peptides and amino acids, as occurs during digestion.

qualified presumption of safety (QPS): An approach to regulating microorganisms in food and animal feed that takes account of Europe's regulatory practices. QPS recognizes and give weight to prior knowledge in assessment.