Glossary - B
Bacillus species of bacteria are widely distributed in the environment mainly in soil. They are spore-forming organisms, which are often considered to be contaminants. As this species of bacteria can become dormant in harsh environments, it is particularly hardy and able to survive extreme conditions. Some species, such as Bacillus coagulans are considered to be beneficial probiotic bacteria, but they do not have as much safety evidence as the Lactobacillus and Bifidobacteria species.
Bacteria are unicellular (single cell) microorganisms belonging to the “prokaryote” kingdom of organisms. They are characterised by their lack of specialised internal organs or any organised nucleus. Bacteria are not visible to the human eye and are able to reproduce asexually, growing and dividing their cells at incredible speed. Bacteria can be pathogenic (bad) or beneficial for human health. Bacteria that are beneficial to human health are referred to as probiotics or friendly bacteria. Commensal bacteria are native to their host, ie. they live in a relationship in which one organism derives food or other benefits from another organism without hurting or helping it.
These are a genus of gram-negative bacteria which makes up a significant proportion of the gastrointestinal bacteria in mammals. They are involved in many important metabolic activities in the human digestive system including helping to break down complex carbohydrates into more simple ones. Bacteroides are beneficial to the host as long as they reside in the gut, although they may cause infections and abscesses if they move to other parts of the body.
The Bacteroidetes group (or phylum) of bacteria is composed of three large classes of gram-negative, non-spore forming, anaerobic, and rod-shaped bacteria. They are widely distributed in the environment, including in soil, sediments, and seawater as well as being found in the guts and on the skin of animals.
The Bacteroidia class is the most well studied and is present in the digestive tract of most mammals, and includes the Bacteroides genus.
Probiotics such as Lactobacillus acidophilus adhere to the epithelial cells that cover the gut wall lining. The good, probiotic bacteria decrease the amount of available space for pathogens (harmful bacteria) to bind, effectively creating a protective barrier against pathogens; resulting in what is known in microbiology as the ‘Barrier Effect’. The Barrier Effects is one key way in which probiotics are thought to be good for immunity.
A genus of gram-positive, non-motile, often branched anaerobic bacteria. They are ubiquitous inhabitants of the gastrointestinal tract, vagina, and mouth of mammals, including humans. Bifidobacteria are one of the major genera of bacteria that make up the gastrointestinal tract microbiota in mammals.
Bifidobacterium (singular) or Bifidobacteria (plural) is a genus, or family, of bacteria generally found in the large intestine. Types, or species, of Bifidobacteria, include bifidum, infantis and breve. Over the age of 60, levels of Bifidobacteria, in particular, are thought to largely deplete in the gut.
Bifidum is a probiotic species belonging to the Bifidobacterium family. Bifidobacterium bifidum will naturally reside in the large intestine. Different strains of Bifidobacterium bifidum will have different properties, for example, Bifidobacterium bifidum Rosell-71 is β-galactosidase positive (β-galactosidase is an enzyme required for the digestion of lactose.) It is particularly resistant to gastric acidity at a pH over 4, which is why it is recommended to take it at mealtimes.
Bifidobacterium breve is a probiotic species believed to have particular benefits in the inhibition of pathogens. Different strains of breve are sourced from different mediums and can have different qualities. The strain Bifidobacterium breve Rosell-70, for example, is a strictly anaerobic, gram-positive rod of human origin. This specific strain is both β-galactosidase positive and a-glucosidase positive.
‘infantis’ is a probiotic species belonging to a family of bacteria called Bifidobacteria. Bifidobacterium infantis can be found in the microbiota of infants, children, and adults, although it is found in higher concentration in infants and is thought to be beneficial for children’s’ wellbeing and immunity. Interestingly, breast-fed infants have shown higher volumes of Bifidobacterium infantis in the faeces than children who were bottled-fed.
As for all probiotics, it is important to look at the specific strain within the infantis species in order to determine its qualities. Bifidobacterium infantis Rosell-33, for example, is an anaerobic, gram-positive rod isolated in pairs or short chains.
Bifidobacterium lactis is a species from the Bifidobacterium genus (family) of probiotics. Bifidobacterium lactis is one of many types of probiotic bacteria in the large intestine that makes up the human microbiota. Different strains of probiotics have been tested for different properties, so as with all probiotics, it is worth being aware of the specific strain.
For example, Bifidobacterium lactis BB-12® has been scientifically researched to help maintain regular bowel movements and is probably the most researched strain of the B. lactis probiotic in the world.
Bifidogenic means to stimulate the growth of Bifidobacteria in the intestines. Prebiotics must be bifidogenic to fulfil their role of feeding the friendly bacteria in the gut and helping them to multiply and colonise.
A biofilm is a collection of microorganisms that have adhered to each other upon a surface. The formation of biofilms can occur on living and non-living surfaces and is often a reactionary response to the microorganisms’ environment. Biofilms are thought to be responsible for most microbial infections in the human body.
A blind trial is an experiment in which the participants do not know certain information about the experiment in which they are participating. This may include such information as to whether they are in the experimental group or the control group.
Bloating is a feeling of tightness and fullness in the abdomen, often causing a visible protrusion of the abdominal region or tummy. Bloating affects both men and women and can be caused by excessive intestinal gas, the menstrual cycle, or overeating. It is also thought to be a symptom of dysbiosis.
Bloating can be a symptom of serious illness such as bowel or ovarian cancer. Anyone with persistent bloating should see their GP. This site does not provide medical diagnosis or treatment.
Blood Lipids is the term used for all the fatty substances found in the blood, including cholesterol and triglycerides. Lipids join with protein in your blood to form lipoproteins which make energy for your body, so they’re important to the cells in your body. There are three types of lipoproteins (also known as cholesterol). High-density lipoprotein (HDL), low-density lipoprotein ( LDL) and very-low-density lipoprotein (VLDL). HDL is sometimes called the “good cholesterol” because it keeps cholesterol from building up in your arteries. LDL can be thought of as the “bad” cholesterol because high LDL levels can increase your risk of heart attack or stroke. It is the balance between the two which is important when monitoring your cholesterol levels.
Broad-Spectrum Antibiotics are antibiotics that work on both gram-positive and gram-negative bacteria. These can, therefore, be used for a variety of bacterial infections.