Varun Pratap Singh ( Department of Orthodontics and Dentofacial Orthopedics, Dental College, BP Koirala Institute of Health Sciences, Dharan, Nepal. )
Jagannath Sharma ( Department of Orthodontics and Dentofacial Orthopedics, Dental College, BP Koirala Institute of Health Sciences, Dharan, Nepal. )
Shankar Babu ( Department of Pediatric Dentistry, Dental College, BP Koirala Institute of Health Sciences, Dharan, Nepal. )
Rizwanulla ( Department of Periodontics, Dental College, BP Koirala Institute of Health Sciences, Dharan, Nepal. )
Anshul Singla ( Department of Orthodontics and Dentofacial Orthopedics, Dental College, BP Koirala Institute of Health Sciences, Dharan, Nepal. )
For some decades now, bacteria known as probiotics have been added to various foods because of their beneficial effects for human health. The mechanism of action of probiotics is related to their ability to compete with pathogenic microorganisms for adhesion sites, to antagonize these pathogens or to modulate the host\\\'s immune response. The potential application of probiotics includes prevention and treatment of various health conditions and diseases such as gastrointestinal infections, inflammatory bowel disease, lactose intolerance, allergies, urogenital infections, cystic fibrosis, various cancers, reduction of antibiotic side effects, in oral health such as prevention of dental caries, periodontal diseases and oral malodour and many other effects which are under investigation.
The results of many of these clinical investigations suggests that probiotics may be useful in preventing and treating various health conditions and diseases. However, many of these clinical studies require validation so as to apply these results to clinical realm. The role of clinical trials is instrumental in such investigations and in near future the results of such trials will decide the usefulness of probiotics in health and disease. This article strives to summarize the currently available data on the potential benefits of probiotics in health and disease.
Keywords: Bifidobacterium, Immunomodulation, Lactobacilli, Probiotics.
Each day, every human being ingests a large number of living microorganisms, predominantly bacteria. Although these organisms are naturally present in food and water, they can also be deliberately added during the processing of foods such as sausages, cheese, yoghurt and fermented milk products. For several decades now, bacteria called probiotics have been added to some foods because of their beneficial effects for human health.1,2
Endorsed by the Food and Agriculture Organization and the World Health Organization, the definition of probiotics, in 2001,3 describes them as live microorganisms which when administered in adequate amounts confer health benefits on the host. Commonly, most of the species ascribed as having probiotic properties belong to the genera Lactobacillus and Bifidobacterium. These bacteria are generally regarded as safe because they can reside in the human body causing no harm and, on the other hand, they are key microorganisms in milk fermentation and food preservation and used as such from the dawn of mankind.4
Probiotic strains are now widely used to give consumers a health benefit substantiated in a range of randomized clinical trials. The list of disease conditions that may benefit from bacteria includes systemic and infectious diseases such as acute diarrhoea and Crohns disease, cardiovascular disease, urogenital infections, oropharyngeal infections, cancers, food allergies, lactose intolerance, cystic fibrosis, reduction of antibiotic associated side effects, dental and oral disorders-prevention of dental caries, periodontal disease and treatment of oral malodour and this list tends to increase with the advent of more sophisticated research methods utilized in studying the microbe-host interactions.5
Over the years, the scientific interest to discover, asses and analyze species with probiotic properties has intensively grown. This article aims to summarize in the light of currently available literature about probiotics and their role in health and disease.
The role of beneficial bacteria on human health stems from the work of the bacteriologist and Nobel Prize laureate Ilye Metchnikoff in the turn of 20th century. Studying longevity and general health of a Bulgarian population dwelling in the rhodopes mountains and fed basically on dairy products, the scientist introduced the idea that lactic acid bacteria in yogurt may neutralize deleterious effects of gut pathogens thus extending life span. He further contributed to the adoption of the name of the species, lactobacillus bulgaricus, one of the two essential yoghurt starter microorganisms. This also meant the birth of modern dairy industry.4
Mechanism of Action of Probiotics:
The mechanism of action of probiotic microorganisms can be explained by enhancement of the non-specific and specific immune response of the host, production of antimicrobial substances and competition with pathogens for binding sites. Further probiotics show adhesion and colonization (at least transitory) of the human body which may increase their retention time thus facilitating prolonged probiotic activity.5-7
Currently Used Probiotics:
The following microorganisms are commonly used as probiotics:
i) Lactobacillus: acidophilus, sporogenes, plantarum, rhamnosum, delbrueck, reuteri, fermentum, lactus, cellobiosus, brevis. ii) Bifidobacterium: bifidum, infantis, longum, thermophilum, animalis. iii) Streptococcus: lactis, cremoris, alivarius, intermedius. iv) Leuconostoc. v) Pediococcus. vi) Propionibacterium. vii) Bacillus. viii) Enterococcus. ix) E. faecium.
B. Yeast and Moulds:
A. cerevisiae, A. niger, A. oryzue, C. Pintolopesii, Sacharomyces boulardii.
Table denotes the probiotics provided in food products throughout the world.8
Indications of Probiotics:
The following are the areas where probiotics may be indicated:
Rotavirus diarrhea, reduction of antibiotic-associated side effects, food allergies and lactose intolerance, atopic eczema, prevention of vaginitis, urogenital infections, irritable bowel syndrome, inflammatory bowel disease, cystic fibrosis, traveller\\\'s diarrhea, enhance oral vaccine administration, H. pylori infection, various cancers, oral and dental conditions such as dental Caries, periodontal diseases and oral malodour.
Prevention of Diseases:
Probiotics may selectively inhibit the growth of pathogenic bacteria. Probiotics like S. faecalis, C. butyricum and B. mesentericus promote the growth of bifidobacterium which selectively inhibits the growth of pathogenic bacteria and also produces glutamine that maintains mucosal integrity and enhances the protection of mucosal barrier.9,14
Effectiveness in Controlling Various Types of Diarrhoea:
Studies have reported effectiveness of probiotics in treating diarrhoea of various nature, especially in traveller\\\'s diarrhoea, antibiotic induced diarrhoea and diarrhoeal diseases in young children caused by rotavirus.11,12
Effects on Mutations and Carcinogens:
Various pathogenic bacterias like E.coli [enterohaemorrhagic E. coli (EHEC) strain, extraintestinal E. coli (ExPEC)] and Clostridium perfringens are mutagenic and associated with the development of colorectal cancers.13,14 Probiotics such as bifidobacteria can selectively inhibit growth of these pathogenic bacterias and develop a favourable microenvironment which modulates the bacterial enzymes. Purified bifidobacteria has cell wall antitumour activities and induces activation of phagocytes to destroy growing tumour cells.13,14
Irritable Bowel Syndrome (IBS):
The etiology of irritable bowel syndrome is not well understood. It is a multifactorial condition making it difficult to treat such patients. Hunter et al15 demonstrated a symptomatic improvement in patients with the use of Enterococcus faecium strain PR88 as oral probiotic. However further studies are needed to justify the role of probiotics in such cases.16
Probiotics and Food Allergies:
Probiotics have shown beneficial effects in patients with food allergies, their effects are due to additive action on immunologic and non-immunologic defense barriers of the gut. Lactobacilli modify the immunomodulatory properties of native food protein. Thus, probiotics influence the immune system by activating the lymphoid cells of the gastrointestinal lymphoid tissue.17-20
Atopic Dermatitis and Probiotics:
Studies have been conducted to assess the role of probiotics in atopic disease. Kirjavainen PV et al reported an alleviation of atopic eczema and subjective symptoms in study population with oral supplementation of viable and heat inactivated probiotic bacteria.21
Probiotics and Vaccine Adjuvants:
Isolauri et al22 observed an increase in rotavirus specific IgM secreting cells when the children were given Lactobacillus GG as an adjuvant to an oral vaccine to rotavirus as compared to placebo on 8th post-vaccination day. LGG also increased IgA and IgM seroconversion when measured in paired sera measured prior to vaccination, and after 30 days of vaccination.22
Probiotics and Urinary Tract Infections:
It has been known that lactobacilli has a preventive effect against urinary tract infection(UTI) in females.23 Studies have shown that a two strain combination of distal urethral isolate L rhamnosus GR-1, selected primarily for its anti gram-negative activities and resistance to spermicide and L fermentum B-54 replaced more recently by RC-14, for anti gram-positive cocci activities and hydrogen peroxide production. Results from various studies indicate that the recurrence rate of UTI can be significantly reduced using one or two capsules vaginally per week for a year with no side effects or yeast infections.23-26
Blood Cholestrol Levels and Probiotics:
Probiotics have been reported to have cholesterol lowering properties in humans.The mechanism of action is that probiotics cause direct assimilation of lipids, convert them into other metabolites and end products, which affects synthesis of cholesterol. Many studies have been conducted but none of the studies had shown statistical significant changes in cholesterol levels.27
Inflammatory Bowel Diseases:
Probiotics by their immunomodulatory and bowel flora manipulating properties, show a promising effect in treatment of chronic inflammatory bowel disease.28 As only a few clinical trials are reported in the current indexed literature further studies are needed to evaluate the true place of probiotics within a treatment regimen for chronic inflammatory bowel disease.
Probiotics and Dental Caries:
Dental caries is a multifactorial disease of bacterial origin that is characterized by acid demineralization of the tooth enamel. To have a beneficial effect in limiting or preventing dental caries, a probiotic must be able to adhere to dental surfaces and integrate into the bacterial communities making up the dental biofilm. It must also compete with and antagonize the cariogenic bacteria and thus prevent their proliferation. Comelli and colleagues reported that of 23 bacterial strains used in the dairy industry, Streptococcus thermophilus and Lactobacillus lactis ssp. lactis were the only ones with the capacity to integrate into a biofilm present on a hydroxyapatite surface and to interfere with development of the cariogenic species Streptococcus sobrinus. More recently, it was demonstrated that isolates of W. cibaria had the capacity to inhibit, both in vitro and in vivo, biofilm formation by S. mutans and to prevent proliferation of this bacterial strain.29-31
Probiotics and Periodontal Diseases:
Periodontal disease is classified into 2 types: gingivitis and periodontitis. Gingivitis is characterized by inflammation limited to the unattached gingiva, whereas periodontitis is a progressive, destructive disease that affects all supporting tissues of the teeth, including the alveolar bone.32 Since the primary etiological factors for the development of periodontal disease are bacteria in supra- and subgingival biofilm, efforts for disease prevention and treatment are mainly focused on pathogen reduction and strengthening of the epithelial barrier, thus contributing to decreased susceptibility to infection. Probiotic bacteria, generally regarded as safe, may favour periodontal health if able to establish themselves in oral biofilm and inhibit pathogen growth and metabolism. Only few clinical studies outlining probiotic effectiveness in periodontal disease have been published.33,34 Therefore, data on probiotics with specific target periodontal structures are mainly from laboratory experiments. Patients with periodontal disease who used chewing gum or lozenges containing probiotics saw their periodontal status improve.
Halitosis, foetor ex ore, or bad breath, is a condition affecting comparatively large section of the population .Bad breath in the oral cavity is mainly ascribed to the production of volatile sulfur compounds (VSC) predominantly by Gram negative anaerobes residing in periodontal pockets and on the tongue dorsum.35 It has been shown that bacteriotherapy can also improve this condition. The replacement of bacteria implicated in halitosis by colonization with probiotic bacterial strains from the indigenous oral microbiota of healthy humans may have potential application as adjuncts for the prevention and treatment of halitosis.35
The authors thank Dr. Shweta, House Surgeon, Department of Orthodontics for her kind help in preparing this manuscript.
1. Bonifait L, Chandad F, Grenier D. Probiotics for Oral Health: Myth or Reality? J Can Den Assoc 2009; 75: 585-90.
2. Parvez S, Malik KA, Ah Kang S, Kim HY. Probiotics and their fermented food products are beneficial for health. J Appl Microbiol 2006; 100: 1171-85.
3. Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food. Cordoba: Argentina, 2001.
4. Fuller R. History and development of probiotics. In: Fuller R, ed. probiotics: the scientific basis. London: Chapman and Hall, 1992; pp 1-7.
5. Reid G, Jass J, Sebulsky MT, McCormick JK. Potential uses of probiotics in clinical practice. Clin Microbiol Rev 2003; 16: 658-72.
6. Gueimonde M, Salminen S. New methods for selecting and evaluating probiotics. Dig Liver Dis 2006; 38(Suppl 2): S242-7.
7. Erickson KL, Hubbard NE. Probiotic immunomodulation in health and disease. J Nutr 2000; 130(2S Suppl): 403S-9S.
8. Caglar E, Kargul B, Tanboga I. Bacteriotherapy and probiotics role on oral health. Oral Dis 2005; 11: 131-7.
9. Seo G, Shimizu K, Sasatsu M , Kono M. Inhibition of growth of some enteropathogenic strain in mixed cultures of streptococcus faecalis and clostridium butyricum. Microbios Letter 1989; 40: 151-60.
10. Lino H, Seo G, Shimizu K, Kono M. Stimulation of bacterial growth of some strain of Bifidobacterium by crude preparation of some strain of bifidobacterium by a crude preparation of metabolites from bacillus mesenteries TO-A. Biome Letter 1993; 48: 73-8.
11. Saavedra JM, Bauman NA, Oung I, Perman JA, Yolken RH. Feeding of Bifidobacterium bifidum and Streptococcus thermophilus to infants in hospital for prevention of diarrhoea and shedding of rotavirus. Lancet 1994; 344: 1046-9.
12. Black FT, Andersen PL, Orskov J, Orskov F, Gaarslev K, Laulund S. Prophylactic efficacy of lactobacilli on traveller\\\'s diarrhea. In: Stiffen Re, ed. Travel Medicine, conference on international travel medicine. Zurich, Switzerland: Springer, 1989; pp 333-5.
13. Sekine K, Watanabe SE, Ohta J, Toida T, Kawashima TT, Hashimoto Y. Induction and activation of tumoricidal cells in vitro and (in vivo by the bacterial cell wall of B infants). Bifidobacteria Microflora 1994; 13: 54-77.
14. Kotsinas A, Spandidos D, Romanowski P, Wyllie A. Relative expression of wild type and activated ki-ras2 oncogene on colorectal carcinomas. Int J Oncol 1993; 3: 841-5.
15. Hunter JO, Lee AJ, King TS. Enterococcus faecium strain PR88 - an effective probiotic. Gut 1996; 38 (Suppl 1): A62.
16. Niedzielin K, Kordecki H, Kosik R. New possibility in the treatment of irritable bowel syndrome: probiotics as a modification of the microflora of the colon. Gastroenterol 1998; 114: A402.
17. Loskutova IE. Effectiveness of using maluitka and Malysh adapted propronic acidophilus mixtures in the combined treatment of congenital hypertrophy. Vopr Pitan 1985; 17- 20.
18. Trapp CL, Chang CC, Halpern GM, Keen CL, Gerschwin ME. The influence of chronic yogurt consumption on population of young and elderly adults. Int J Imunother 1993; 9: 53-64.
19. Yasui H, Nagaoka N, Mike A, Hayakawa K, Ohwaki M. Detections of bifidobacterium strains that induce large quantities of IgA. Microb Ecol Health Dis 1992; 5: 155-62.
20. Sutas Y, Hurme M, Isolauri. Down-regulation of anti-Co3 antibody induced IL-4 production by bovine caseins hydrolysed with LGG derived enzymes. Scand J Immunol 1996; 98: 216-24.
21. Kirjavainem PV, Salminen SJ, Isolauri E. Probiotic bacteria in the management of atropic disease: underscoring the importance of viability. J Pediatr Gastroenterol Nutr 2003; 36: 223-7.
22. Isolauri E, Joensuu J, Suomalainen H, Luomala M, Vesikari T. Improved immunogenecity of oral Dx RRV reassortant rotavirus vaccine by Lactobacillus casei GG. Vaccine 1995; 13: 310-2.
23. Bruce AW, Chadwick P, Hassan A, van Cott GF. Recurrent urthritis in women. Can Med Assoc J 1973; 108: 973.
24. Reid G, Charbonneau D, Erb J, Kochanowski B, Beuerman D, Poehner R, et al. Oral use of Lactobacillus rhamnosus GR-1 and L. Fermentum RC-14 significantly alters vaginal flora: randomised placebo controlled trial in 64 healthy women. FEMS Immunol Med Microbiol 2003; 35: 131-4.
25. Reid G, Bruce AW, Fraser N, Heinemann C, Owen J, Henning B. Oral probiotics can resolve urogenital infections. FEMS Immunol Med Microbiol 2001; 30: 49-52.
26. Reid G, Bruce AW, Taylor M. Instillation of Lactobacillus and stimulation of indigenous organisms to prevent recurrence of urinary tract infections. Microecol Therapy 1995; 23: 32-45.
27. Mann GV, Spoery A. Studies of a surfactant and cholesteremia in the maassai. Am J Clin Nut 1974; 23: 464-9.
28. Schultz M, Sartor RB. Probiotics and inflammatory bowel disease. Am J Gastroenterol 2000; (1 Suppl): S19-21.
29. Selwitz RH, Ismail AI, Pitts NB. Dental caries. Lancet 2007; 69: 51-9.
30. Comelli EM, Guggenheim B, Stingele F, Neeser JR. Selection of dairy bacterial strains as probiotics for oral health. Eur J Oral Sci 2002; 110: 218-24.
31. Kang MS, Chung J, Kim SM, Yang KH, Oh JS. Effect of Weissella cibaria isolates on the formation of Streptococcus mutans biofilm. Caries Res 2006; 40: 418-25.
32. Houle MA, Grenier D. Maladies parodontales : connaissances actuelles.Current concepts in periodontal diseases. Méd Mal Infect 2003; 33: 331-40.
33. Riccia DN, Bizzini F, Perilli MG, Polimeni A, Trinchieri V, Amicosante G, etal. Anti-inflammatory effects of Lactobacillus brevis (CD2) on periodontal disease. Oral Dis 2007; 13: 376-85.
34. Shimazaki Y, Shirota T, Uchida K, Yonimoto K, Kiyohara Y, Lida M et al. Intake of dairy products and periodontal disease: the Hisayama Study. J Periodontol 2008; 79: 131-7.
35. Scully C, Greenman J. Halitosis (breath odor). Periodontol 2000 2008; 48: 66-75.