Lactic acid bacteria (LAB) are the most common type of microbes used. LAB have been used in the food industry for many years, because they are able to convert sugars (including lactose) and other carbohydrates into lactic acid. This not only provides the characteristic sour taste of fermented dairy foods such as yogurt, but also by lowering the pH may create fewer opportunities for spoilage organisms to grow, hence creating possible health benefits on preventing gastrointestinal infections.. Strains of the genera Lactobacillus and Bifidobacterium, are the most widely used probiotic bacteria.
Probiotic bacterial cultures are intended to assist the body's naturally occurring gut flora, an ecology of microbes, to re-establish themselves. They are sometimes recommended by doctors, and, more frequently, by nutritionists, after a course of antibiotics, or as part of the treatment for gut related candidiasis. Claims are made that probiotics strengthen the immune system to combat allergies, excessive alcohol intake, stress, exposure to toxic substances, and other diseases. In these cases, the bacteria that work well with our bodies (see symbiosis) may decrease in number, an event which allows harmful competitors to thrive, to the detriment of our health.
Maintenance of a healthy gut flora is, however, dependent on many factors, especially the quality of food intake. Including a significant proportion of prebiotic foods in the diet has been demonstrated to support a healthy gut flora and may be another means of achieving the desirable health benefits promised by probiotics.
Henry Tissier, also from the Pasteur Institute, was the first to isolate a Bifidobacterium. He isolated the bacterium from a breast-fed infant and named it Bacillus bifidus communis. This bacterium was later renamed Bifidobacterium bifidum. Tissier showed that bifidobacteria are predominant in the gut flora of breast-fed babies, and he recommended administration of bifidobacteria to infants suffering from diarrhea. The mechanism claimed was that bifidobacteria would displace the proteolytic bacteria that cause the disease.
German professor Alfred Nissle, in 1917 isolated a strain of Escherichia coli from the feces of a First World War soldier who did not develop enterocolitis during a severe outbreak of shigellosis. In those days, antibiotics were not yet discovered, and Nissle used the strain with considerable success in acute cases of infectious intestinal diseases (salmonellosis and shigellosis). Escherichia coli Nissle 1917 is still in use and is one of the few examples of a non-LAB probiotic.
In 1920 Rettger demonstrated that Metchnikoff’s “Bulgarian Bacillus”, later called Lactobacillus bulgaricus, could not live in the human intestine, and the fermented food phenomena petered out. Metchnikoff’s theory was disputable (at this stage), and people doubted his theory of longevity.
After Metchnikoff’s death in 1916, the centre of activity moved to the US. It was reasoned that bacteria originating from the gut were more likely to produce the desired effect in the gut, and in 1935 certain strains of Lactobacillus acidophilus were found to be very active when implanted in the human digestive tract. Trials were carried out using this organism, and encouraging results were obtained especially in the relief of chronic constipation.
The term “probiotics” was first introduced in 1953 by Kollath (see Hamilton-Miller et al 2003). Contrasting antibiotics, probiotics were defined as microbially derived factors that stimulate the growth of other microorganisms. In 1989 Roy Fuller suggested a definition of probiotics which has been widely used: “A live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance”. Fuller’s definition emphasizes the requirement of viability for probiotics and introduces the aspect of a beneficial effect on the host.
In the 1960s the dairy industry began to promote fermented milk products containing Lactobacillus acidophilus. In subsequent decades other Lactobacillus species have been introduced including Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus johnsonii, because they are intestinal species with beneficial properties.
As probiotics are mainly active in the small intestine and prebiotics are only effective in the large intestine, the combination of the two may give a synergistic effect. Appropriate combinations of pre- and probiotics are synbiotics.
Synbiotics have also been defined as metabolites produced by ecoorgan or by synergistic action of prebiotics and probiotics e.g. short chain fatty acids, other fatty acids, amino acids, peptides, polyamines, carbohydrates, vitamins, numerous antioxidants and phytosterols, growth factors, coagulation factors, various signal molecules such as cytokine-like bacteriokines.
|Proven probiotic strains. Source:|
|Strain||Brandname||Producer||Proven effect in humans|
|Bifidobacterium animalis subsp. lactis BB-12||Chr. Hansen||Immune stimulation, improves phagocytic activity, alleviates atopic eczema, prevents diarrhoea in children and traveller's diarrhoea|
|Bifidobacterium breve Yakult||Bifiene||Yakult|
|Bifidobacterium infantis 35624||Align||Procter & Gamble|
|Bifidobacterium lactis HN019 (DR10)||Howaru Bifido||Danisco||Immune stimulation|
|Bifidobacterium longum BB536||Morinaga Milk Industry||positive effects against allergies|
|Escherichia coli M-17||ProBactrix||BioBalance||Combats pouchitis, irritable bowel syndrome, ulcerative colitis, crohn's disease, celiac disease, IBD, and C. difficile infections, as well as diarrhea caused by antibiotics, chemotherapy, and travel.|
|Escherichia coli Nissle 1917||Mutaflor||Ardeypharm||Immune stimulation|
|Lactobacillus acidophilus LA-5||Chr. Hansen|
|Lactobacillus acidophilus NCFM||Danisco||reduces symptoms of lactose intolerance, prevents bacterial overgrowth in small intestine|
|Lactobacillus casei DN114-001 (Lactobacillus casei Immunitas(s)/Defensis)||Actimel/DanActive||Danone||Diarrhea and allergy reduction, immune stimulation, reduction of duration of winter infections, H. pylori eradication, antibiotic associated diarrhea & C. difficile infections (see Actimel)|
|Lactobacillus casei CRL431||Chr. Hansen|
|Lactobacillus casei F19||Cultura||Arla Foods||Improves digestive health, immune stimulation, reduces antibiotic-associated diarrhoea, induces satiety, metabolizes body fat, reduces weight gain|
|Lactobacillus casei Shirota||Yakult||Yakult||Maintenance of gut flora, immune modulation, bowel habits and constipation (see Yakult)|
|Lactobacillus paracasei St11 (or NCC2461)||Lactobacillus fortis||Nestlé||Designed for children|
|Lactobacillus johnsonii La1 (= Lactobacillus LC1)||Nestlé||Immune stimulation, active against Helicobacter pylori|
|Lactococcus lactis L1A||Norrmejerier||Immune stimulation, improves digestive health, reduces antibiotic-associated diarrhoea|
|Lactobacillus plantarum 299V||GoodBelly / ProViva/ TuZen||NextFoods Probi Ferring||IBS, used post-operative, immune stimulation|
|Lactobacillus reuteri ATTC 55730 (Lactobacillus reuteri SD2112)||BioGaia Biologics||Immune stimulation, against diarrhoea|
|Lactobacillus rhamnosus ATCC 53013 (discovered by Gorbach & Goldin(=LGG))||Vifit and others||Valio||Immune stimulation, alleviates atopic eczema, prevents diarrhoea in children and many other types of diarrhoea|
|Lactobacillus rhamnosus LB21||Verum||Norrmejerier||Immune stimulation, improves digestive health, reduces antibiotic-associated diarrhoea|
|Lactobacillus salivarius UCC118||positive effects with intestinal ulcers and inflammation|
|Saccharomyces cerevisiae (boulardii) lyo||DiarSafe and others||Wren Laboratories and others||against antibiotic-associated diarrhoea and Clostridium difficile infections; to treat acute diarrhoea in adults & children...|
| tested as mixture:|
Lactobacillus rhamnosus GR-1 & Lactobacillus reuteri RC-14
|Bion Flore Intime Jarrow Fem-Dophilus||Chr. Hansen||Oral ingestion results in vaginal colonisation and prevention of vaginitis|
| tested as mixture:|
mixture of 8 strains of Streptococcus thermophilus & four Lactobacillus spp & three Bifidobacterium spp strains
|VSL#3||Sigma-Tau Pharmaceuticals, Inc.||positive effects with intestinal ulcers and inflammation|
| tested as mixture:|
Lactobacillus acidophilus CUL60 & Bifidobacterium bifidum CUL 20
|reduction of Cl. difficile in faeces|
| tested as mixture:|
Lactobacillus helveticus R0052 & Lactobacillus rhamnosus R0011
|A'Biotica and others||Institut Rosell||prevents diarrhoea in children, prevents upset stomachs for patients on antibiotics., active against Helicobacter pylori|
Some commonly used bacteria in products, but without probiotic effect (yoghurt bacteria):
Some other bacteria mentioned in probiotic products:
Some fermented products containing similar lactic acid bacteria include:
A 2007 clinical study at Imperial College London showed that preventive consumption of a commercially available probiotic drink containing L casei DN-114001, L bulgaricus, and S thermophilus can reduce the incidence of antibiotic-associated diarrhea and C difficile-associated diarrhea.
In a double-blind, placebo-controlled therapeutic study on the effects of a probiotic cocktail on pancreatitis at University Medical Center Utrecht (UMC), 24 out of 296 patients died between 2004 and 2007, with more deaths among those receiving the probiotic cocktail directly in the intestine. According to the spokesman of UMC, it is likely that some of these deaths would not have occurred without the probiotics, although other therapeutic trials conducted on probiotics were more positively conclusive