Probiotics: Difference between revisions
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'''Probiotics''' are [[dietary supplement]]s | '''Probiotics''' are "live microbial [[dietary supplement]]s which beneficially affect the host animal by improving its intestinal microbial balance. Antibiotics and other related compounds are not included in this definition. In humans, [[lactobacillus|lactobacilli]] are commonly used as probiotics, either as single species or in mixed culture with other bacteria. Other genera that have been used are bifidobacteria and streptococci."<ref>{{MeSH}}</ref><ref name="pmid7782892">{{cite journal |author=Gibson GR, Roberfroid MB |title=Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics |journal=J. Nutr. |volume=125 |issue=6 |pages=1401–12 |year=1995 |pmid=7782892 |doi=}}</ref> Lactobacilli 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 [[fermentation (food)|fermented]] dairy foods such as [[yogurt]], but acts as a preservative, by lowering the [[pH]] and creating fewer opportunities for spoilage organisms to grow. | ||
==Proposed mechanism of action== | |||
The rationale for probiotics is that they restore the normal microbes in the gastrointestinal tract that may have been reduced by use of [[antibiotic]]s or other conditions. | |||
There is no published evidence that probiotic supplements are able to replace the body’s natural flora when these have been killed off; indeed bacterial levels in feces disappear within days when supplementation ceases<ref>[http://www.bbc.co.uk/radio4/science/gutreactions.shtml Gut Reactions programme 3]</ref>. It is hoped, however, that probiotics do form beneficial temporary colonies which may assist the body in the same functions as the natural flora, while allowing the natural flora time to recover from depletion. The probiotic strains are then thought to be progressively replaced by a naturally developed gut flora. If the conditions which originally caused damage to the natural gut flora persist, the benefits obtained from probiotic supplements will be short lived. | |||
==Adverse effects== | |||
Priobiotics were associated with increased mortality in a [[randomized controlled trial]] of patients with severe acute [[pancreatitis]].<ref>Besselklnk et al. (2008) Probiotic prophylaxis in predicted severe acute pancreatitis: a randomised, double-blind, placebo-controlled trial. Lancet. {{DOI|10.1016/S0140-6736(08)60207-X}} http://www.thelancet.com/journals/lancet/article/PIIS014067360860207X/abstract?iseop=true</ref> | |||
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==Potential benefits== | ==Potential benefits== | ||
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===Managing Lactose Intolerance=== | ===Managing Lactose Intolerance=== | ||
Because | Because lactobacilli convert [[lactose]] into [[lactic acid]], their ingestion may help lactose intolerant individuals tolerate more lactose than what they would have otherwise.<ref name="Sanders"/> | ||
===Prevention of Colon Cancer=== | ===Prevention of Colon Cancer=== | ||
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===Cholesterol Lowering=== | ===Cholesterol Lowering=== | ||
Animal studies have demonstrated the efficacy of a range of | Animal studies have demonstrated the efficacy of a range of lactobacilli to be able to lower serum [[cholesterol]] levels, presumably by breaking down [[bile]] in the [[gut]], thus inhibiting its reabsorption (which enters the blood as cholesterol).Some, but not all human trials have shown that dairy foods fermented with LAB can produce modest reductions in total and [[LDL]] cholesterol levels in those with normal levels to begin with, however trials in hyperlipidemic subjects are needed.<ref name="Sanders"/> | ||
===Lowering Blood Pressure=== | ===Lowering Blood Pressure=== | ||
everal small clinical trials have shown that consumption of milk fermented with various strains of LAB can result in modest reductions in [[blood pressure]]. It is thought that this is due to the [[ACE inhibitor]]-like [[peptides]] produced during fermentation.<ref name="Sanders"/> | everal small clinical trials have shown that consumption of milk fermented with various strains of LAB can result in modest reductions in [[blood pressure]]. It is thought that this is due to the [[ACE inhibitor]]-like [[peptides]] produced during fermentation.<ref name="Sanders"/> | ||
===Improving Immune Function and Preventing Infections=== | ===Improving Immune Function and Preventing Infections=== | ||
Lactobacilli are thought to have several presumably beneficial effects on immune function. They may protect against [[pathogens]] by means of [[competitive inhibition]] (i.e., by competing for growth) and there is evidence to suggest that they may improve immune function by increasing the number of [[IgA]]-producing plasma cells, increasing or improving [[phagocytosis]] as well as increasing the proportion of [[T lymphocytes]] and Natural Killer cells.<ref name="Reid_Jass_Sebulsky">Reid G, Jass J, Sebulsky MT, McCormick JK. Potential uses of probiotics in clinical practice. Clin Microbiol Rev. 2003;16:658-72. PMID 14557292</ref><ref name="Ouwehand_Salminen_Isolauri">Ouwehand AC, Salminen S, Isolauri E. Probiotics: an overview of beneficial effects. Antonie Van Leeuwenhoek. 2002;82:279-89. PMID 12369194</ref> [[Clinical trials]] have demonstrated that probiotics may decrease the incidence of respiratory tract infections<ref>Hatakka K, Savilahti E, Ponka A, Meurman JH, Poussa T, Nase L, Saxelin M, Korpela R. Effect of long term consumption of probiotic milk on infections in children attending day care centres: double blind, randomised trial. BMJ. 2001;322:1327 PMID 11387176</ref> and [[dental caries]] in children<ref>Nase L, Hatakka K, Savilahti E, Saxelin M, Ponka A, Poussa T, Korpela R, Meurman JH. Effect of long-term consumption of a probiotic bacterium, Lactobacillus rhamnosus GG, in milk on dental caries and caries risk in children. Caries Res. 2001;35:412-20. PMID 11799281</ref> LAB foods and supplements have been shown to be effective in the treatment and prevention of acute [[diarrhea]]; decreasing the severity and duration of [[rotavirus]] infections in children as well as travelers diarrhea in adults.<ref name="Reid_Jass_Sebulsky"/><ref name="Ouwehand_Salminen_Isolauri"/> A diet including milk fermented with [[Lactobacillus]] bacteria prevented [[Salmonella]] infection in pigs.<ref>[http://www.nutraingredients.com/news/ng.asp?n=75107&m=1NIE320&c=csjgoiuhudky Probiotics may protect against food poisoning]</ref> Claims are made that probiotics strengthen the [[immune system]]. <ref name="Sanders">Sanders ME. Considerations for use of probiotic bacteria to modulate human health. J Nutr. 2000;130:384S-390S. PMID 10721912</ref> | |||
====Helicobacter pylori==== | ====Helicobacter pylori==== | ||
Probiotics may aid the treatment of ''[[Helicobacter pylori]]'' infections (which cause [[peptic ulcers]]) in adults when used in combination with standard medical treatments.<ref name="pmid14522098">Hamilton-Miller JM. The role of probiotics in the treatment and prevention of Helicobacter pylori infection. Int J Antimicrob Agents. 2003;22:360-366. PMID 14522098</ref> | |||
====Antibiotic-associated diarrhea==== | ====Antibiotic-associated diarrhea==== | ||
A meta-analysis suggested probiotics may reduce antibiotic-associated diarrhea. | A meta-analysis suggested probiotics may reduce antibiotic-associated diarrhea.<ref name="pmid12182746">Cremonini F, Di Caro S, Nista EC, Bartolozzi F, Capelli G, Gasbarrini G, Gasbarrini A. Meta-analysis: the effect of probiotic administration on antibiotic-associated diarrhoea. Aliment Pharmacol Ther. 2002;16:1461-1467 PMID 12182746</ref> A subsequent [[randomized controlled trail]] showed that consumption of a probiotic drink containing ''L casei'', ''L bulgaricus'', and ''S thermophilus'' can reduce the incidence of antibiotic associated diarrhoea and ''C difficile'' associated diarrhoea in elderly patients.<ref name="pmid17604300">{{cite journal |author=Hickson M, D'Souza AL, Muthu N, ''et al'' |title=Use of probiotic Lactobacillus preparation to prevent diarrhoea associated with antibiotics: randomised double blind placebo controlled trial |journal=BMJ |volume=335 |issue=7610 |pages=80 |year=2007 |pmid=17604300 |doi=10.1136/bmj.39231.599815.55}}</ref> | ||
<ref name="pmid12182746">Cremonini F, Di Caro S, Nista EC, Bartolozzi F, Capelli G, Gasbarrini G, Gasbarrini A. Meta-analysis: the effect of probiotic administration on antibiotic-associated diarrhoea. Aliment Pharmacol Ther. 2002;16:1461-1467 PMID 12182746</ref> A subsequent [[randomized controlled trail]] showed that consumption of a probiotic drink containing ''L casei'', ''L bulgaricus'', and ''S thermophilus'' can reduce the incidence of antibiotic associated diarrhoea and ''C difficile'' associated diarrhoea in elderly patients.<ref name="pmid17604300">{{cite journal |author=Hickson M, D'Souza AL, Muthu N, ''et al'' |title=Use of probiotic Lactobacillus preparation to prevent diarrhoea associated with antibiotics: randomised double blind placebo controlled trial |journal=BMJ |volume=335 |issue=7610 |pages=80 |year=2007 |pmid=17604300 |doi=10.1136/bmj.39231.599815.55}}</ref> | |||
===Reducing Inflammation=== | ===Reducing Inflammation=== | ||
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===Irritable Bowel Syndrome and Colitis=== | ===Irritable Bowel Syndrome and Colitis=== | ||
B. infantis 35624, sold as Align, was found to improve some symptoms of irritable bowel syndrome in women | B. infantis 35624, sold as Align, was found to improve some symptoms of [[irritable bowel syndrome]] (IBS) in women.<ref>{{cite web | ||
|title=Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome | |title=Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome | ||
|author=Whorwell PJ, Altringer L, Morel J, Bond Y, Charbonneau D, O'Mahony L, Kiely B, Shanahan F, Quigley EM. | |author=Whorwell PJ, Altringer L, Morel J, Bond Y, Charbonneau D, O'Mahony L, Kiely B, Shanahan F, Quigley EM. | ||
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== Criticism == | == Criticism == | ||
Some | Some researchers are skeptical of some of the claims made for probiotics. Their reasons include the following considerations<ref>{{cite web | ||
|title="Probiotics." Encyclopedia of Alternative Medicine, eNotes.com. | |title="Probiotics." Encyclopedia of Alternative Medicine, eNotes.com. | ||
|first=Thomas | |first=Thomas | ||
Revision as of 02:04, 19 February 2008
Probiotics are "live microbial dietary supplements which beneficially affect the host animal by improving its intestinal microbial balance. Antibiotics and other related compounds are not included in this definition. In humans, lactobacilli are commonly used as probiotics, either as single species or in mixed culture with other bacteria. Other genera that have been used are bifidobacteria and streptococci."[1][2] Lactobacilli 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 acts as a preservative, by lowering the pH and creating fewer opportunities for spoilage organisms to grow.
Proposed mechanism of action
The rationale for probiotics is that they restore the normal microbes in the gastrointestinal tract that may have been reduced by use of antibiotics or other conditions.
There is no published evidence that probiotic supplements are able to replace the body’s natural flora when these have been killed off; indeed bacterial levels in feces disappear within days when supplementation ceases[3]. It is hoped, however, that probiotics do form beneficial temporary colonies which may assist the body in the same functions as the natural flora, while allowing the natural flora time to recover from depletion. The probiotic strains are then thought to be progressively replaced by a naturally developed gut flora. If the conditions which originally caused damage to the natural gut flora persist, the benefits obtained from probiotic supplements will be short lived.
Adverse effects
Priobiotics were associated with increased mortality in a randomized controlled trial of patients with severe acute pancreatitis.[4]
Potential benefits
Experiments into the benefits of probiotic therapies suggest a range of potentially beneficial medicinal uses for probiotics. For many of the potential benefits, research is limited and only preliminary results are available.
Managing Lactose Intolerance
Because lactobacilli convert lactose into lactic acid, their ingestion may help lactose intolerant individuals tolerate more lactose than what they would have otherwise.[5]
Prevention of Colon Cancer
In laboratory investigations, LAB have demonstrated anti-mutagenic effects thought to be due to their ability to bind with heterocyclic amines; carcinogenic substances formed in cooked meat.[6] Animal studies have demonstrated that LAB can protect against colon cancer in rodents, though human data is limited and conflicting.[7] Most human trials have found that LAB may exert anti-carcinogenic effects by decreasing the activity of an enzyme called ß-glucuronidase[7] (which can generate carcinogens in the digestive system). Lower rates of colon cancer among higher consumers of fermented dairy products have been observed in some population studies.[5]
Cholesterol Lowering
Animal studies have demonstrated the efficacy of a range of lactobacilli to be able to lower serum cholesterol levels, presumably by breaking down bile in the gut, thus inhibiting its reabsorption (which enters the blood as cholesterol).Some, but not all human trials have shown that dairy foods fermented with LAB can produce modest reductions in total and LDL cholesterol levels in those with normal levels to begin with, however trials in hyperlipidemic subjects are needed.[5]
Lowering Blood Pressure
everal small clinical trials have shown that consumption of milk fermented with various strains of LAB can result in modest reductions in blood pressure. It is thought that this is due to the ACE inhibitor-like peptides produced during fermentation.[5]
Improving Immune Function and Preventing Infections
Lactobacilli are thought to have several presumably beneficial effects on immune function. They may protect against pathogens by means of competitive inhibition (i.e., by competing for growth) and there is evidence to suggest that they may improve immune function by increasing the number of IgA-producing plasma cells, increasing or improving phagocytosis as well as increasing the proportion of T lymphocytes and Natural Killer cells.[8][9] Clinical trials have demonstrated that probiotics may decrease the incidence of respiratory tract infections[10] and dental caries in children[11] LAB foods and supplements have been shown to be effective in the treatment and prevention of acute diarrhea; decreasing the severity and duration of rotavirus infections in children as well as travelers diarrhea in adults.[8][9] A diet including milk fermented with Lactobacillus bacteria prevented Salmonella infection in pigs.[12] Claims are made that probiotics strengthen the immune system. [5]
Helicobacter pylori
Probiotics may aid the treatment of Helicobacter pylori infections (which cause peptic ulcers) in adults when used in combination with standard medical treatments.[13]
Antibiotic-associated diarrhea
A meta-analysis suggested probiotics may reduce antibiotic-associated diarrhea.[14] A subsequent randomized controlled trail showed that consumption of a probiotic drink containing L casei, L bulgaricus, and S thermophilus can reduce the incidence of antibiotic associated diarrhoea and C difficile associated diarrhoea in elderly patients.[15]
Reducing Inflammation
LAB foods and supplements have been found to modulate inflammatory and hypersensitivity responses, an observation thought to be at least in part due to the regulation of cytokine function.[8] Clinical studies suggest that they can prevent reoccurrences of inflammatory bowel disease in adults,[8] as well as improve milk allergies[16] and decrease the risk of atopic eczema in children.[17]
Improving Mineral Absorption
It is hypothesized that probiotic lactobacilli may help correct malabsorption of trace minerals, found particularly in those with diets high in phytate content from whole grains, nuts, and legumes.[18]
Prevents Harmful Bacterial Growth Under Stress
In a study done to see the effects of stress on intestinal flora, rats that were fed probiotics had little occurrence of harmful bacteria latched onto their intestines compared to rats that were fed sterile water.[19]
Irritable Bowel Syndrome and Colitis
B. infantis 35624, sold as Align, was found to improve some symptoms of irritable bowel syndrome (IBS) in women.[20] Another probiotic bacterium, Lactobacillus plantarum 299V, was also found to be effective in reducing IBS symptoms. [21] Additionally, a probiotic formulation, VSL3, was found to be effective in treating ulcerative colitis [22] Bifidobacterium animalis DN-173 010 may help. [23]
Synbiotics
It is also possible to increase and maintain a healthy bacterial gut flora by increasing the amounts of prebiotics in the diet such as inulin, raw oats, and unrefined wheat .Template:Fact
As probiotics are mainly active in the small intestine and prebiotics are only effective in the large intestine [24], 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.
Types
The most common form for probiotics are dairy products and probiotic fortified foods. However, tablets and capsules containing the bacteria in freeze dried form are also available.
Some common probiotics include various species of the genera Bifidobacterium and Lactobacillus such as:
There is currently only one species of yeast used as a probiotic:
Some commonly used bacteria in products, but without probiotic effect (yogurt bacteria):
Some other bacteria mentioned in probiotic products:
- Bacillus coagulans
- Lactobacillus bifidus - became new genus Bifidobacterium [1]
- Lactobacillus caucasicus, a fantasy name, as no species with this name exists.
Some fermented products containing similar (often not proven to have a probiotic or health effect) lactic acid bacteria include:
Criticism
Some researchers are skeptical of some of the claims made for probiotics. Their reasons include the following considerations[25]:
- The studies done in support of probiotics are mostly anecdotal or heavily reliant on test-tube experimentation rather than on clinical trials in human subjects
- The basic concept of probiotics is based on a misunderstanding of the role of microflora in the human digestive tract.
- It is difficult to see how bacteria taken by mouth can survive the process of human digestion (though research shows that they do, in fact, survive [26])
References
- ↑ Anonymous (2024), Probiotics (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Gibson GR, Roberfroid MB (1995). "Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics". J. Nutr. 125 (6): 1401–12. PMID 7782892. [e]
- ↑ Gut Reactions programme 3
- ↑ Besselklnk et al. (2008) Probiotic prophylaxis in predicted severe acute pancreatitis: a randomised, double-blind, placebo-controlled trial. Lancet. Template:DOI http://www.thelancet.com/journals/lancet/article/PIIS014067360860207X/abstract?iseop=true
- ↑ 5.0 5.1 5.2 5.3 5.4 Sanders ME. Considerations for use of probiotic bacteria to modulate human health. J Nutr. 2000;130:384S-390S. PMID 10721912
- ↑ Wollowski I, Rechkemmer G, Pool-Zobel BL. Protective role of probiotics and prebiotics in colon cancer. Am J Clin Nutr. 2001;73:451S-455S. PMID 11157356
- ↑ 7.0 7.1 Brady LJ, Gallaher DD, Busta FF. The role of probiotic cultures in the prevention of colon cancer. J Nutr. 2000;130:410S-414S. PMID 10721916
- ↑ 8.0 8.1 8.2 8.3 Reid G, Jass J, Sebulsky MT, McCormick JK. Potential uses of probiotics in clinical practice. Clin Microbiol Rev. 2003;16:658-72. PMID 14557292
- ↑ 9.0 9.1 Ouwehand AC, Salminen S, Isolauri E. Probiotics: an overview of beneficial effects. Antonie Van Leeuwenhoek. 2002;82:279-89. PMID 12369194
- ↑ Hatakka K, Savilahti E, Ponka A, Meurman JH, Poussa T, Nase L, Saxelin M, Korpela R. Effect of long term consumption of probiotic milk on infections in children attending day care centres: double blind, randomised trial. BMJ. 2001;322:1327 PMID 11387176
- ↑ Nase L, Hatakka K, Savilahti E, Saxelin M, Ponka A, Poussa T, Korpela R, Meurman JH. Effect of long-term consumption of a probiotic bacterium, Lactobacillus rhamnosus GG, in milk on dental caries and caries risk in children. Caries Res. 2001;35:412-20. PMID 11799281
- ↑ Probiotics may protect against food poisoning
- ↑ Hamilton-Miller JM. The role of probiotics in the treatment and prevention of Helicobacter pylori infection. Int J Antimicrob Agents. 2003;22:360-366. PMID 14522098
- ↑ Cremonini F, Di Caro S, Nista EC, Bartolozzi F, Capelli G, Gasbarrini G, Gasbarrini A. Meta-analysis: the effect of probiotic administration on antibiotic-associated diarrhoea. Aliment Pharmacol Ther. 2002;16:1461-1467 PMID 12182746
- ↑ Hickson M, D'Souza AL, Muthu N, et al (2007). "Use of probiotic Lactobacillus preparation to prevent diarrhoea associated with antibiotics: randomised double blind placebo controlled trial". BMJ 335 (7610): 80. DOI:10.1136/bmj.39231.599815.55. PMID 17604300. Research Blogging.
- ↑ Kirjavainen PV, Salminen SJ, Isolauri E Probiotic bacteria in the management of atopic disease: underscoring the importance of viability. J Pediatr Gastroenterol Nutr. 2003;36:223-227 PMID 12548058
- ↑ Kalliomaki M, Salminen S, Poussa T, Arvilommi H, Isolauri E. Probiotics and prevention of atopic disease: 4-year follow-up of a randomised placebo-controlled trial. Lancet. 2003;361:1869-1871. PMID 12788576
- ↑ Famularo G, De Simone C, Pandey V, Sahu AR, Minisola G. Probiotic lactobacilli: an innovative tool to correct the malabsorption syndrome of vegetarians? Med Hypotheses. 2005;65(6):1132-5. PMID 16095846
- ↑ Hitti, Miranda (April 25, 2006). Probiotics May Help Stressed Gut. WebMD. Retrieved on 2006-10-24.
- ↑ Whorwell PJ, Altringer L, Morel J, Bond Y, Charbonneau D, O'Mahony L, Kiely B, Shanahan F, Quigley EM. (July, 2006). Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome. Am J Gastroenterol.. Retrieved on 2006-12-6.
- ↑ Niedzielin K, Kordecki H, Birkenfeld B (2001). "A controlled, double-blind, randomized study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome". Eur J Gastroenterol Hepatol 13 (10): 1143–7. PMID.
- ↑ Kerr, Martha (May 21, 2003). Probiotics Significantly Reduce Symptoms of IBS, Ulcerative Colitis. Retrieved on 2006-12-6.
- ↑ Guyonnet D, Chassany O, Ducrotte P, et al (2007). "Effect of a fermented milk containing Bifidobacterium animalis DN-173 010 on the health-related quality of life and symptoms in irritable bowel syndrome in adults in primary care: a multicentre, randomized, double-blind, controlled trial". Aliment. Pharmacol. Ther. 26 (3): 475-86. DOI:10.1111/j.1365-2036.2007.03362.x. PMID 17635382. Research Blogging.
- ↑ Glenn R. Gibson and Marcel B. Roberfroid ; Dietary Modulation of the Human Colonic Microbiota: Introducing the Concept of Prebiotics. Journal of Nutrition Vol. 125 No. 6 June 1995, pp. 1401-1412.
- ↑ Gale, Thomas (2006). "Probiotics." Encyclopedia of Alternative Medicine, eNotes.com.. Retrieved on 2007-29-1.
- ↑ "Survival of Yogurt Bacteria in the Human Gut" Marina Elli et al. Appl Environ Microbiol 2006 July; 72(7): 5113–5117