XBrain’s Probiotic capsules contain eight live strains of beneficial probiotic bacteria, which naturally colonise the human gastro-intestinal tract. Probiotics were defined by a FAO/WHO joint committee as live micro-organisms which, when taken in adequate amounts, confer a health benefit to the host. Each healthy person has around 100 trillion symbiotic bacteria in their bodies. However, this ‘gut flora’, can be upset through several ways, which can lead to negative health outcomes. One of the main ways in which people lose their beneficial microflora is through antibiotic treatment, especially wide spectrum antibiotics, which are increasingly being used given the incidence of resistant bacteria. Antibiotics don’t discriminate between pathogenic and beneficial bacteria, and destroy both types. Other possible causes of a gut flora imbalance include diarrhoea, colonic hydrotherapy, or even foreign travel and exposure to unfamiliar microbes and foods.
To be considered a probiotic the bacterial strain must be naturally found in the gastro-intestinal tract and must have beneficial actions. It must also be bile and acid resistant, and be able to adhere to the intestinal lining. Probiotics must also be given in sufficient amounts, usually in the order of 108 colony forming units (CFU) daily, although the exact effective amount varies depending on the strain.
The importance of the ‘friendly bacteria’ living in our intestines was first investigated over a hundred years ago by Elie Metchnikoff, a pioneer of research into the immune system and Nobel prize winner. Metchnikoff correlated the unusually long lives of Bulgarian peasants with their heavy consumption of fermented milk containing the bacterium Lactobacillus bulgaricus. His theory of ‘intestinal auto-intoxication’ suggested that aging is caused by proteolytic bacteria in the intestines, which produce toxins such as phenols, indols, and ammonia. Probiotics limit the numbers of these harmful microbes, by producing acetic and lactic acid, which lowers the pH of the intestines, and by competing with them for nutrients and adhesion sites in the gut lining.
Although Metchnikoff’s theory was largely ignored by the medical community for most of the century after his death, there is now a renewed interest in probiotics, with many clinical trials and studies into their benefits underway. Probiotics are natural and generally safe, since they merely aim to replace the bacteria that normally grow in a healthy digestive tract. There is increasing agreement that an imbalance in the gut flora might be a contributing factor to the increasing incidence of gastro-intestinal disorders such as irritable bowel syndrome, or inflammatory bowel disease, as well as the rising incidence of allergies. It is thought that children raised in modern clean environments, and fed on pasteurised foods, don’t develop the full and complex intestinal flora, which is necessary to train their immune system to fight disease, but not react to harmless substances.
One of the best characterised function of the beneficial gut microflora is protection against infection with pathogenic bacteria. The acidic environment they create in the intestines, through production of lactic and acetic acids is inhospitable to many infectious bacteria. Well established gut flora also prevents the growth of pathogenic bacteria by outcompeting them for nutrients and adhesion sites in the intestinal lining. Some strains have also been shown to secrete anti-microbial chemicals. It is not surprising that antibiotic treatment puts patients at risk of the so-called ‘antibiotic-associated-diarrhoea’ (AAD). The antibiotics kill off the beneficial gut flora, and the intestines become susceptible to being colonised by pathogenic bacteria like Clostridium difficile.
However, the benefits of probiotics extend beyond protection from harmful micro-organisms. Since they are lactic bacteria, capable of digesting lactose, they provide relief in lactose intolerant people. The acidic environment they create might protect against colon cancer, which is associated with a high pH. Certain strains have been shown to have anti-oxidative and anti-inflammatory capabilities, and to help people with Crohn’s disease and inflammatory bowel disease. They also interact through the mucosal intestinal lining, to which they adhere, and modulate its properties. Imbalances in the bacterial gut flora have been linked to persistent diseases such as irritable bowel syndrome.
Xbrain’s Probiotic preparation contains from 108 to 109 colony forming units of eight probiotic strains from the Bifidobacterium, Lactobacillus and Streptococcus strains naturally found in the human digestive system, in each non-GMO cellulose capsule. The combination of B. longum, B. infantis, B. breve, L. acidophilus, L. bulgaricus, L. casei, L. rhamnosus, and S. thermophilus is carefully selected for the health benefits these strains confer.
Bifidobacterium. longum B.
longum is a rod shaped bacterium, and is one of the earliest of the beneficial bacteria strains to colonise the infant digestive system. Since it is an anaerobe, a bacterium which doesn’t need oxygen, and in fact is killed by oxygen, it is found in the colon. As people age, its numbers in the gut flora decrease, and it is a minority species in adults. Despite this, it does seem to play an important part in maintaining health. Other than the usual functions of the beneficial bacteria, it appears have very specialised properties which help protect against some of the most common modern diseases.
The first of these appears to be its anti-oxidative properties. The biological reactions of normal metabolism generate reactive oxygen metabolites and free radicals. These are very unstable, and will react with many other molecules, for example they can oxidise phospholipids in cell membranes, damage proteins, and react with the nucleic bases in DNA, causing mutations. Reactive oxygen metabolites are therefore very dangerous, and the body has many mechanisms to neutralise them. When the number of free radicals exceeds the body’s capacity to deal with them, the body goes into oxidative stress, which is thought to contribute to many of the modern chronic diseases like cancer, cardio-vascular disease, atherosclerosis and arthritis.
One of the reactions that contributes to oxidative stress is the peroxidation of linoleic acid, which creates lipid hydroperoxides that rapidly decompose into free radicals. B. longum was found to inhibit this reaction. It is also able to scavenge free radicals and neutralise them, decreasing the oxidative stress on the body.
Bifidobacterium longum was also found to have a beneficial effect on serum cholesterol levels. Despite its bad reputation, cholesterol is, in fact, essential for life, it is a constituent of cell plasma membranes and a precursor of steroid hormones, bile acids and vitamin D. It can be synthesised by human cells, but is also absorbed from the diet, and transported in the bloodstream bound to low density lipoprotein (LDL) and high density lipoprotein (HDL) molecules. It is when the levels of cholesterol, and LDL transporters become too high, through a failure of regulation, that it becomes harmful to health, leading to atherosclerosis. A high ratio of LDL to HDL in the blood serum, and high serum levels of cholesterol are directly associated with the disease, in which fat and cholesterol build up in the wall of arteries forming plaques, which block the arteries and interfere with blood flow.
In several studies, consuming B. longum over a period of weeks was found to lead to a drop in serum cholesterol and LDL levels, and an increase in HDL. Unlike most bacteria, B. longum incorporates cholesterol into its membranes, removing it from the intestines, so it cannot be re-adsorbed into the blood. It also binds bile, which cannot be re-adsorbed, forcing the body to synthesise more bile salts, which uses up cholesterol.
As its name suggests Bifidobacterium Infantis is one of the main beneficial bacteria passed to a baby by its mother, and a major component of the infant’s gut fauna. Apart from protecting its host from pathogenic bacteria it appears to have significant activity as an anti-inflammatory agent.
Inflammation is the body’s natural response to injury or an infection and plays an important part in fighting pathogenic microorganisms and initiating the healing. It is mediated by immune cells such as granulocytes and is tightly controlled by complex signaling cascades of molecules such as the interleukins and cytokines, which both propagate, and inhibit the response. However, chronic inflammation can be maladaptive and is a feature of many diseases such as psoriasis, Crohn's disease, ulcerative colitis and even chronic fatigue syndrome. A chronic state of inflammation is also found in obese people. Chronic inflammation puts a stress on the organism, even when it does not present as a specific disease. Microbial imbalance has been suggesting as a possible explanation of the increasing rates of inflammatory diseases in modern Western populations.
Data from clinical trials showing that probiotic B. infantis has significant benefits in fighting inflammation is accumulating. In one study the probiotic resulted in a significant increase in the anti-inflammatory cytokine, Interleukin-10, while plasma levels of TNF-alpha, IL-6 and C-reactive protein, a major marker of inflammation were significantly reduced. These changes were not seen in the patients given a placebo.
There is also a wealth of anecdotal evidence that B. infantis is useful in combatting the symptoms of irritable bowel syndrome. IBS is a not-very well understood debilitating disease, characterised by abdominal pain, bloating, diarrhoea or constipation. Although its cause has not been identified it is thought that it might be due in part to changes in the peristaltic movements, microscopic inflammation, and intestine hypersensitivity. In a published British study a dose of 108 colony forming units (CFU) taken over a period of four weeks, was able to significantly decrease abdominal pain and other IBS symptoms, compared to a placebo.
Bifidobacterium breve contains unique enzymatic pathways which allow it to digest oligosccharides. The byproducts of its metabolism include acetic and lactic acid, which decreases the pH of the colon. This makes it inhospitable to pathogenic bacteria, enhancing B. breve’s antimicrobial properties. It might even play a role in preventing colon cancer, since a high pH is thought to contribute to neoplasmic changes in the colon.
The strain has been found to be effective, when takes with Lactobacillus acidophilus, in the prevention of rotavirus infections in children (stomach flu). It also prevents traveller’s diarrhoea, which is caused by exposure to new pathogens, for which the body hadn’t developed immunity.
A pilot study showed that it is effective in treating childhood constipation, although further work is required for this to be accepted by the medical community.
Lactobacillus acidophilus is one of the most commonly used probiotic strains. It is taken to treat conditions as diverse as diarrhoea, ulcers, lactose intolerance, as an anti-oxidant and to help lower cholesterol.
The antibacterial properties of L. acidophilus are the best documented. A meta analysis of a number of randomized controlled trials concluded that, in combination with Lactobacillus casei, it significantly lowered the risk of developing diarrhoea caused by Clostridium difficile.
The species name of C. difficile comes from the Greek word for “difficult”, it is a minor component of the gut flora. However, when the beneficial bacteria are wiped up by antibiotic treatment, it can rapidly multiply causing serious, and occasionally life-threatening, diarrhoea. A number of studies have concluded that taking probiotic supplement with L. acidophilus and L. casei during antibiotic treatment, can help protect against C. difficile.
Lactobacillus acidophilus has also been shown to be effective at treating diarrhoea caused by rotavirus (commonly known as stomach flu) in children. It has also been shown to be effective as a supplementary treatment for Heliobacter pylori infections, which cause stomach ulcers.
In a test comparing the anti-oxidative properties of 34 strains of bacteria, L. acidophillus exhibited among the highest values for activity against the ascorbic and linoleic acid oxidation. When tested, in a probiotic preparation in rats subjected to doxorubicin-induced oxidative stress, it decreased the level of reactive oxygen molecules, and increased the plasma concentration of glutathionine, an anti-oxidant. The study showed that probiotic Lactobacillus acidophilus has anti-oxidant activity and can protect against diseases such as cancer and cardio-vascular disease.
L. bulgaricus is the lactic bacterium in yogurt that Elie Metchnikoff thought was responsible for the longevity of Bulgarian peasants. Like other lactic bacteria in the group it acidifies the intestine, through its production of lactic and acetic acid, making it inhospitable for harmful micro-organisms. Its ability to digest lactose might help in those who are intolerant to dairy.
L. casei complements the growth of L. acidophilus and is often used in combination with it. It was shown to be able to inhibit the growth of H. pylori, responsible for gastric ulcers, in vivo. It has also shown to be effective, in combination with L. acidophilus, in preventing antibiotic-associated diahhroea and Clostridium difficile infections.
At one time L. rhamnosus was thought be be a strain of L. casei, however, sequencing of its genome revealed it to be a separate species. Its DNA sequence revealed the presence of genes for pili and pili-assembly-proteins, which indicate that the bacteria are able to adhere to the cells lining the intestinal mucosa. L. rhamnosus produces molecules which signal to the cells of the gut lining, resulting in decreased permeability, which can be helpful in alleviating the symptoms of irritable bowel syndrome.
In randomised trials it was found to be effective in treating acute diarrhoea in children and in adults, and in decreasing the risk of traveller’s diarrhoea.
A study published in the Proceedings of the National Academy of Sciences, USA, in 2011, also suggested that probiotic Lactobacillus rhamnosis might result in better psychological health through decreasing anxiety. It has long been known, that gastrointestinal disorders, which are now thought to be at least partially caused by disruptions in the intestinal microflora balance, are accompanied by anxiety and depression. The USA study showed that the link between beneficial bacteria and psychological health might be mediated through GABA, the main inhibitory neurotransmitter in the central nervous system. It was found that mice fed with a probiotic strain of L. rhamnosus show different levels of GABA receptor mRNA in different regions of the brain, with increased expression of the GABAB1b gene in cortical regions and a reduction in its expression in the hippocampus and amygdala.
The L. rhamnosus fed mice had lower levels corticosterone in the blood, and exhibited less stress and depression-related behaviour.
Although the genus Streptococcus contains several pathogenic species, S. thermopiles is not harmful, having diverged from the pathogenic strains around 3000 years ago. Genome sequencing shows that it has lost the genes responsible for virulence, and instead acquired genes which allow it to metabolise lactose. It is therefore considered to be a lactic bacteria and is used extensively in the dairy industry and yogurt production, in a synbiotic relationship with L. bulgaricus.
S. thermopiles is able to synthesise folic acid, a water soluble, essential B vitamin. Folic acid is essential for DNA synthesis and repair, the production of healthy red blood cells, and for rapid cell division and growth. Folic deficiency in pregnant women, can lead to neural tube defects in the babies.
The probiotic properties of Bifidobacteria:
The Probiotic properties of Lactobacillus:
Health benefits of taking probiotics:
Probiotic Therapy for Irritable Bowel Syndrome:
Oral Administration of the Probiotic Bifidobacterium Infantis 35624 to Humans Induces Immunoregulatory Responses In Vivo:
Bifidobacterium infantis 35624 modulates host inflammatory processes beyond the gut:
Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve:
Role of Lactobacillus in the prevention of Clostridium difficile-associated diarrhea: a meta analysis of randomized controlled trials:
Bifidobacterium longum image taken with an electron microscope. Source Julie 6301. Used under the CC-SA-3.0 licence. You are free to share, copy and redistribute the material in any medium or format, and, adapt-remix, transform, an build upon the material, for any purpose, even commercially, under the following terms: Attribution: You must give appropriate credit, and indicate if changes were made. http://commons.wikimedia.org/wiki/File:Bifidobacterium_longum_en_microscopie_électronique.jpg
Lactobacillus acidophilus, gram stained. Source: Bob Blaylock. Used under the CC-SA-3.0 licence. You are free to share, copy and redistribute the material in any medium or format, and, adapt-remix, transform, an build upon the material, for any purpose, even commercially, under the following terms: Attribution: You must give appropriate credit, and indicate if changes were made. http://en.wikipedia.org/wiki/File:20101212_200110_LactobacillusAcidophilus.jpg
Lactobacillus casei. Source: A doubt. Used under the CC-SA-3.0 licence. You are free to share, copy and redistribute the material in any medium or format, and, adapt-remix, transform, an build upon the material, for any purpose, even commercially, under the following terms: Attribution: You must give appropriate credit, and indicate if changes were made. http://commons.wikimedia.org/wiki/File:Lactobacillus_casei_1.jpg