Introduction
Probiotics are live microorganisms (bacteria or yeasts of the intestinal commensal flora) that, ingested in adequate amounts, are beneficial for human health or physiology.
Some authors include probiotics within the broader concept of functional foods, which would be those foods that contain ingredients (which may or may not be nutrients) that affect one or some functions of the organism selectively and for the benefit of health, or that they have physiological or psychological effects beyond the nutritional effects.
Although they have been extensively studied, the mechanism of action of probiotics is still not known in detail, which can also vary substantially between the different probiotics and also depending on the characteristics of the host.
The competitiveness with intestinal pathogens for adhesion to intestinal epithelium or for luminal nutrients, the production and secretion of antimicrobial substances that inhibit or lyse pathogens (bacteriocins) and, fundamentally, a great variety of actions on the response of innate immunity and acquired intestinal, seem the main actions of these microorganisms.
The clinical applications studied have been mainly some digestive diseases of an infectious or immunoinflammatory nature.
Sakara Chocolate Probiotic Organic Supplement for Digestion & Immune Health 30ct
Studies that have evaluated the effects of probiotics on the general state or well-being in healthy individuals are scarce and have variable results, so their consumption is not justified in a systematic way with the aim of "improving the general state".
Mechanism of action
The intestinal commensal flora has as main functions:
- the prevention of intestinal colonization by opportunistic microorganisms or pathogens (competing for adhesion sites and for nutrients).
- act as a source of energy for the colonocytes (through the fermentation of carbohydrates and the consequent formation of short chain fatty acids).
- stimulate and regulate the intestinal immune response.
The intestinal mucosa is the largest surface of the human body exposed to the outside, and the gastrointestinal tract is the organ richest in immune cells. The loss of balance between the proportion of "beneficial" and "harmful" bacteria of the gut microbiota leads to a predisposition to the development of infections and / or immunoinflammatory diseases. The symbiosis between the bacterial flora can be optimized through pharmacological or nutritional intervention on the intestinal microbes ecosystem using probiotics. Probiotics produce immunological benefits by activating local macrophages and increasing the production of secretory immunoglobulin A as local as systemic, modulating the cytokine profile and inducing the decrease of the response to food antigens.
Other non-immunological benefits that probiotics can provide are the digestion of food competing with pathogens for nutrients, altering the pH of the environment to create an unfavorable environment for pathogens and increase the function of intestinal barrier.
It must be said, however, that not all probiotic microorganisms induce the same type of effects or with the same intensity on the immune response or on the microorganisms present in the intestinal lumen. In addition, the effects of different probiotics can vary depending on the host (remember that the commensal flora is established after 2 years of age - varying according to various factors such as the type of lactation - and, since then, it varies greatly little in each individual) and the characteristics of their disease.
At the moment, the detailed mechanism of action for each of the probiotics is unknown. For this reason, along with the variability of the characteristics of the host to which it is administered (babies, children, adults or old) and their health status (healthy, infectious, immunoinflammatory, neoplastic diseases), it is difficult to assess which is the probiotic most suitable for each situation.
General recommendations on the use of probiotics
Different studies with probiotics suggest that these would have a series of potential health benefits, but the effects described can only be attributed to the strains analyzed in each study and can not be generalized to the entire species or the entire group of probiotics.
Therefore, to use a probiotic for a specific indication, the health effects of each specific strain present in the commercialized probiotic product must be documented. Studies that document the efficacy of specific strains at a certain dose do not constitute sufficient evidence to support health effects at a lower dose.
Use of probiotics in the prevention and treatment of diseases
A. Diarrhea.
Treatment of acute diarrhea
Acute infectious gastroenteritis is the most frequent cause of acute diarrhea, constituting an especially important problem in children due to its frequency and associated morbidity. Although it may be of viral or bacterial etiology, in the pediatric age the most common cause is rotavirus infection and its treatment is limited, until now, rehydration. In this context, the administration of Lactobacillus rhamnosus strain GG has been shown in multiple controlled studies to be useful in the treatment of pediatric gastroenteritis, significantly reducing the duration of diarrhea; In addition, the effect of this lactobacillus is greater when the etiologic agent of the condition is rotavirus. Some meta-analyzes confirm the usefulness of probiotics in this situation, reducing the clinical symptoms in 24 hours. The usefulness of probiotics in the treatment of gastroenteritis in adults has been less studied. However, some probiotics such as Enterococcus faecium SF 68 have also been shown to be effective in reducing the duration of diarrhea in several controlled studies.
Prevention of acute diarrhea
For the prevention of diarrhea in adults and pediatrics there is only evidence that Lactobacillus GG , Lactobacillus casei DN-114001 and Saccharomyces Boulard are effective in some specific situation.
Diarrhea associated with antibiotics
The diarrhea associated with the use of antibiotics (AAD) appears in approximately 20% of the individuals who consume these drugs. It is believed that DAA is due to the alteration of the intestinal microbiota by the action of the drug, so that the proliferation of pathogens is favored and the capacity of fermentation of the colon is reduced.
Several studies have shown that the use of different probiotics ( Saccharomyces boulardii or Lactobacillus rhamnosus ) associated with the administration of antibiotics reduces the incidence or duration of AAD secondary to erythromycin, clindamycin or ampicillin, among others.
Recently, the efficacy of Lactobacillus casei DN-114 001 in hospitalized adults for the prevention of diarrhea associated with antibiotics and Clostridium difficile diarrhea has been demonstrated.
Traveler's diarrhea
About half of individuals who travel to high-risk areas have acute diarrhea. The etiological agents are scattered, but the most common are Escherichia coli, Salmonella spp, Shigella spp and Campylobacter spp . Although it usually self-limiting in a few days, it is associated with high morbidity. The efficacy shown by the administration of probiotics in the prevention of this condition has been very heterogeneous in the different controlled studies carried out so far, so its use can not be recommended with the available data.
Radiation-induced diarrhea
Studies conducted to establish the efficacy of VSL # 3 , a preparation containing Lactobacillus casei, Lactobacillus acidophillus, Lactobacillus plantarum, Lactobacillus delbrueckii, Lactobacillus bulagricus, Bifidobacterium longum, Bifidobacterium brevis, Binfantis, Saccharomyces thermophilus (450x109), are inadequate and do not allow to define with certainty its efficacy in the treatment of radiation-induced diarrhea.
B. Eradication of Helicobacter pylori
There are several strains of lactobacilli and bifidobacteria, as well as Bacillus clausii , which seem to reduce the effects of antibiotic therapy and improve adherence of patients. There are several strains that demonstrate efficacy in reducing side effects, but do not alter the eradication rate. It is suggested that if anti- Helicobacter pylori antibiotic regimens are supplemented with some probiotics it would also be effective in increasing eradication rates. Therefore, certain probiotics could be useful as adjuvant therapy with antibiotics for the eradication of Helicobacter pylori .
C. Inflammatory bowel disease
Inflammatory bowel disease (IBD) groups different entities (Crohn's disease, ulcerative colitis and indeterminate colitis) characterized by the current exaggerated and self-perpetuating inflammatory response of the intestinal wall, in genetically susceptible subjects, in response to the flora itself. intestinal commensal.
In addition, different alterations have been described in the intestinal microbiota of patients with IBD, such as dysbiosis (loss of balance between beneficial and harmful bacterial species), the predominance of clostridia, or changes in the proportion of bacteria adhered to the intestinal epithelium. For these reasons, the administration of probiotics is an attractive therapeutic strategy.
We must distinguish three different situations in the use of probiotics in IBD.
In pouchitis (inflammation of the ileoanal reservoir mucosa -which is constructed in patients with ulcerative colitis undergoing proctocolectomy due to lack of response to intensive medical treatment- very similar to ulcerative colitis itself), this is where there is more evidence on the efficacy of probiotics. A cocktail of different lactobacilli, bifidobacteria and streptococci ( VSL # 3 ), has shown clearly effective both in primary and secondary prevention. Therefore, the use of probiotics in patients with chronic or recurrent pouchitis and as primary prevention can be recommended.
In ulcerative colitis, the efficacy of the probiotic strain of Escherichia coli Nissle 1917 was equivalent to that of mesalazine in maintaining the remission of ulcerative colitis. There are no adequate studies to ensure that other probiotic preparations are effective in ulcerative colitis.
In Crohn's disease, the results obtained have been mostly negative. A recent Cochrane systematic review has concluded that there is no evidence to suggest that probiotics are beneficial for the maintenance of remission in Crohn's disease.
D. Irritable bowel syndrome
Several studies have shown therapeutic efficacy of probiotics ( Bifidobacterium infantis, Bifidobacterium animalis and VSL # 3 ) compared to placebo in improving the main symptoms of people with irritable bowel syndrome. Published studies have shown a reduction in abdominal distension and flatulence as a result of treatment with probiotics and some strains appear to improve pain ( Bifidobacterium Infantis 35624 ).
Lactobacillus reuteri can improve colic symptoms during the first week of treatment, as demonstrated in a recent trial with 90 infants fed by breastfeeding with intestinal colic.
A very recent systematic review with meta-analysis of 19 controlled studies with almost 1,700 patients shows a favorable effect of probiotics (especially of mixtures and bifidobacteria, not so much of lactobacilli) on irritable bowel symptoms. However, the heterogeneity of the studies in terms of species, strains and doses, as well as the existence of an evident publication bias (in favor of those with positive results) limit the value of these conclusions.
and. Lactose malabsorption
An important proportion of the adult population (variable depending mainly on ethnicity) presents intolerance to lactose (diarrhea, flatulence, colic pain), which excludes milk from the diet. It is known that inpidus who intolerant milk often tolerate yogurt. This is due, among other causes, to the fact that this food contains probiotics (lactobacilli) that contain lactases that are released when the bile secretions lyse the bacterial wall. In addition, the slower intestinal transit of yogurt in relation to milk also favors the first mechanism. This simple probiotic effect is easily applicable not only in individuals with primary malabsorption of lactose, but also in other situations where there may be an acquired deficit of lactases either transient (for example, acute gastroenteritis in children) or chronic (for example, bowel syndrome). short).
Streptococcus thermophilus and Lactobacillus delbrueckii subsp . Bulgaricus improve digestion of lactose and reduce the symptoms related to intolerance. This has been confirmed in a series of controlled studies with individuals who consumed yogurt with live cultures.
E. Necrotizant enterocolitis
Some clinical trials have shown that probiotic supplementation reduces the risk of necrotizing enterocolitis in preterm infants less than 33 weeks gestation with a reduced risk of death in the group treated with probiotics.
Other indications
Allergy
Some strains of specific probiotics have shown efficacy for the treatment of atopic eczema.
Vaginitis and vaginosis
LGG, Lactobacillus reuteri and Lactobacillus acidophilus have been evaluated in this indication with promising results.
Probiotics in a healthy population
There are studies that have evaluated the effect of the consumption of probiotics in the maintenance of health. Lactobacillus reuteri ATCC 55730 has been shown to reduce sick leave , reduce crying in children with infant colic, and episodes of fever and diarrhea in children going to day care. The Lactobacillus casei DN114-001 and LGG increase the resistance to diseases in children in the nursery. A combination of probiotics ( Bifidobacterium longum, Bifidobacterium bifidum, Lactobacillus gasseri ) administered to healthy adults has shown a reduction in the duration of colds but not in their incidence. The mechanism of this effect is due to the stimulation of the immunological function and the direct inhibition of some pathogens. These results suggest that probiotics could be incorporated into the diet of a healthy population to maintain health, although these recommendations are dietary and not clinical recommendations.
Table with the main indications, degree of efficacy and clinical significance of the use of probiotics
Indication Effectiveness Interest in clinical practice
- Intolerance / lactose malabsorption Demonstrated Allow consumption of lactic (main source of dietary calcium)
- Demonstrated in controlled studies Facilitate adherence to antibiotic treatment when this is determinant of efficacy or in patients with multiple drug allergies. Reduced mobility by Clostridum difficile
- Diarrhea associated with antibiotics
- Acute gastroenteritis Demonstrated in controlled studies Prevention and early treatment in risk groups (immunocompromised children, neoplastic patients, elderly)
- Ulcerative colitis Initial data (controlled studies) Alternative to drugs with a worse safety profile
- Reservoritis Demonstrated in controlled studies Control of chronic or recurrent pouchitis
- Traveler's diarrhea Insufficient data Alternative to the indiscriminate use of antibiotics
- Irritable bowel syndrome Initial data (heterogeneous results) Decrease the symptoms of irritable bowel syndrome
- Vaginitis Insufficient data
- Radiation diarrhea Insufficient data
- Atopic eczema Demonstrated in controlled studies Prevention and treatment
Security
The ingestion of a high number of viable microorganisms makes it necessary to investigate their safety. From a theoretical point of view, being microorganisms that normally form part of our commensal flora, they could hardly cause infectious problems.
Although some isolated cases of translocation in immunocompromised patients and of lactobacillus bacteremia in ulcerative colitis have been described, the safety profile of the most commonly used probiotics in the context of controlled studies should be considered good. The use of probiotics in sick people is restricted to strains and indications with proven efficacy.
Table of products containing probiotics, available in the market
Pharmaceutical specialties with probiotics
- Tradename Composition of probiotics Description Observations
- Ultralevura ® Saccharomyces boulardii (1x109) Capsules Administer in cold liquids
- Casenfilus ® Lactobacillus acidophillus (1x109) Envelopes EFP
- Bifidobacterium bifidum (1x109)
- Infloran ® Lactobacillus acidophillus (1x109) Bifidobacterium bifidum (1x106) Capsules EFP
- Lacteol by Dr Bouchard ® Lactobacillus acidophillus (1x1010) Capsules or envelopes EFP
- Lacteol by Dr Bouchard ® Lactobacillus acidophillus (6x106) Tablets EFP
- Lactofilus® Lactobacillus acidophillus (120x106) Powder EFP
- Salvacolon® Bacillus subtilis Liquid EFP
Food supplements with probiotics
- Tradename Composition of probiotics Description Observations
- Casenbiotic ® Lactobacillus reuteri (1x108) Chewable pills Store at <25ºC
- Reuteri ® Lactobacillus reuteri (20x106) Liquid Store at 2-8ºC
- Administer with liquids
- Protransitus ® Lactobacillus plantarum (3x109) Capsules EFP
- Rotargemine ® Lactobacillus acidophillus, Bifidobacterium bifidum, Lactobacillus bulgaricus, Streptococcus thermophilus (3.5x109) Liquid Contains probiotics, vitamins and lactose
- Enterum ® Bacillus coagulans (2x109) Liquid or tablets Contains prebiotics and lactoferrin
- VSL # 3 ® Lactobacillus casei, Lactobacillus acidophillus, Lactobacillus plantarum, Lactobacillus delbrueckii, Lactobacillus bulgaricus, Bifidobacterium longu, Bifidobacterium brevis, Bifidobacterium infantis, Saccharomyces thermophilus (450x109) Tablets or envelopes Store at 2-8ºC. It contains lactose and soy.
Oral rehydration solutions with probiotics
Tradename Composition of probiotics Description Observations
- Bioralsuero baby ® Lactobacillus reuteri (100x106) Envelopes Store at <25ºC
- Bioralsuero ® Bioralsuero orange Lactobacillus reuteri (100x106) Bricks Store at <25ºC
- Bioralsuerotravel ® Lactobacillus reuteri (100x106) Envelopes EFP
Other preparations
Tradename Composition of probiotics
- Activia ® Lactobacterium animalis DN173010
- Actimel ® Lactobacillus casei DN-114 001
- LC1 ® Lactobacillus johnsonii LaI