**4. Effects of probiotics on human health**

Probiotics have the potential for contributing greatly to human and animal health via a wide range of applications. Historically, probiotics have been used in food for humans and animals without any side effects, while providing for the balance of intestinal flora (Holzapfel & Wood, 1998). The health-promoting effects of probiotics have been widely explored and include stabilization of the indigenous microbial population, boosting of the immune system, inhibition of the growth of pathogenic organisms, prevention of diarrhea from various causes, alleviation of lactose intolerance, increased nutritional value of foods, reduction of serum cholesterol levels, antimutagenicity and anticarcinogenicity, reduction of the risk of inflammatory bowel conditions, improvement of digestion of proteins and fats, synthesis of vitamins, and detoxification and protection from toxins (Klaenhammer, 1998; Perdigon et al., 2002; Gaudana et al., 2010).

Highlights in Probiotic Research 253

through immuneregulation, particularly through establishing and maintaining a balance between pro-and anti-inammatory cytokines (Isolauri et al., 2001). TNF-a and IL-6 are proinammatory cytokines, which are produced by the host in response to bacterial colonisation or invasion and hence are central to the host defense mechanism against pathogens (Solis-Pereyra et al., 1997). Though lipopolysaccharide of Gram-negative bacteria is known to stimulate their production, Miettinen et al. (1996) have reported an increase in IL-6 and TNF-a production in human PBMC exposed to lactobacilli and thereby suggested the use of probiotics as vaccine vectors and for the purpose of stimulating non-specic immunity. Kailasapathy & Chin (2000) proved that the synthesis of cytokines is increased as

Ziarno et al. (2007) studied cholesterol assimilation by commercial starter cultures, reporting *L. acidophilus* monocultures to assimilate cholesterol by 49-55%. In another study involving hypercholesterolemic mice, the probiotic potential of *L. plantarum* PHO4 was established by Nguygen et al. (2007). The mice were fed with 107 CFU per day over two weeks. These mice had 7 to 10% lesser serum cholesterol and triglycerides than the control mice deprived of the

Many probiotic species have been identified to be effective in children suffering from rotaviral diarrhea (Saavedra, 2000). Longdet et al. (2011) investigated the probiotic efficacy of *L. casei* isolated from human breast milk in the prevention of shigellosis in albino rats infected with clinical strains of *Shigella dysenteriae*. The results showed that the experimental rats infected with *S. dysenteriae* but not treated suffered from shigellosis, while the test groups infected and treated with the *L. casei* showed no sign of the disease as well as no

Senol et al. (2011a) investigated the protective effect of a probiotic mixture of 13 different bacteria and a-tocopherol on 98% ethanol-induced gastric mucosal injury. Levels of gastric mucosal pro-and anti-inammatory cytokines, malondialdehyde, and secretory immunglobulin A were measured. Results showed that probiotic pretreatment signicantly suppressed the ethanol-induced increase of gastric mucosal interleukin-4 levels. Pretreatment with either probiotic or a–tocopherol inhibited the ethanol-induced increase of mucosal malondialdehyde concentration. Probiotic pretreatment enhanced the gastric mucosal secretory immunoglobulin A concentration. The researchers indicated that the probitic mixture and a-tocopherol reduced ethanol-induced gastric mucosal lipid peroxidation, suggesting that these probiotics may be benecial for helping heal gastric lesions induced by lower ethanol concentration. In another study, the role of a probiotic mixture, including 13 different bacteria, in the prevention of aspirin-induced gastric mucosal injury was investigated. Pretreatment with the probiotic mixture reduced aspirininduced gastric damage and exerted a tendency toward downregulation of proinflammatory cytokines elicited by aspirin. Researchers also found that the probiotic mixture increased sIgA production approximately 7.5-fold in the stomach, and significantly reduced the malondialdehyde increase in the gastric mucosa elicited by aspirin. Additionally, pretreatment with the probiotic mixture alleviated aspirin-induced reduction

the probiotics adhere to the intestinal epithelium.

probiotic feed.

clinical effect on the liver.

Anderson & Gilliland (1999) conducted two controlled clinical studies to test effects of yoghurt on heart-related health. They reported an average reduction of serum cholesterol by 2.9% with regular consumption of yoghurt containing *L. acidophilus* and a 6-10% decrease in cardiac complications due to hypercholesterolemia. A study by Ouwehand et al. (2002) found that a multi-strain probiotic mixture composed of *L. reuteri, L. rhamnosus* and *Propionibacterium freudenreichii* proved effective in both increasing the number of bowel movements and decreasing mucin secretion in elderly subjects. The probiotic mixture was more effective than *L. reuteri* alone, although unfortunately it is difcult to draw conclusions about mixtures versus individual probiotics, since only one component of the mixture was tested and its dose was over 10 times lower than the total bacterial dose in the mixture. Agarwal & Bhasin (2002) have reported that the strain *L. casei* DN-114001 reduced diarrhoeal morbidity by 40% in children.

Isolauri *et al.* (1999) found significant improvement when a supplement of either *L. rhamnosus* or *B. lactis was given* to children from 4 to 6 years of age who had atopic eczema. Another study involving pregnant women and newborns suggested that consumption of probiotic *L. rhamnosus* GG reduced the rate of newborns having atopic dermatitis (Kalliomaki et al., 2001). In an Australian study, 178 newborns of women with allergies who received either *L. acidophilus* LAVRI-A1 or placebo daily for the first 6 months of life showed no difference in atopic dermatitiS. However, at 12 months, the rate of sensitization was significantly higher in the probiotic group. These results suggested that the probiotic treatment had increased the risk of subsequent cow's milk sensitization (Taylor et al., 2007).

Can (2003) used an experimental animal model to study the effects of a probiotic mixture and *L*. GG on immune responses in allergy. The OVA specific IgE levels of the study groups which were administred probiotics and reference strain were found lower than the skim milk fed groups. A double-blind, randomized, placebo controlled trial study was conducted by Abrahamsson et al. (2007) on 188 subjects with allergic disease, in which the mothers received *L. reuteri* ATCC 55730 daily from gestational week 36 until delivery, and their babies continued with the probiotic until 12 months. Probiotic supplemented babies showed less IgE-associated eczema during the second year. Several probiotic effects are mediated through immuneregulation, particularly through establishing and maintaining a balance between pro-and anti-inammatory cytokines (Isolauri et al., 2001). TNF-a and IL-6 are proinammatory cytokines, which are produced by the host in response to bacterial colonisation or invasion and hence are central to the host defense mechanism against pathogens (Solis-Pereyra et al., 1997). Though lipopolysaccharide of Gram-negative bacteria is known to stimulate their production, Miettinen et al. (1996) have reported an increase in IL-6 and TNF-a production in human PBMC exposed to lactobacilli and thereby suggested the use of probiotics as vaccine vectors and for the purpose of stimulating non-specic immunity. Kailasapathy & Chin (2000) proved that the synthesis of cytokines is increased as the probiotics adhere to the intestinal epithelium.

252 Lactic Acid Bacteria – R & D for Food, Health and Livestock Purposes

**4. Effects of probiotics on human health** 

Perdigon et al., 2002; Gaudana et al., 2010).

diarrhoeal morbidity by 40% in children.

Probiotics have the potential for contributing greatly to human and animal health via a wide range of applications. Historically, probiotics have been used in food for humans and animals without any side effects, while providing for the balance of intestinal flora (Holzapfel & Wood, 1998). The health-promoting effects of probiotics have been widely explored and include stabilization of the indigenous microbial population, boosting of the immune system, inhibition of the growth of pathogenic organisms, prevention of diarrhea from various causes, alleviation of lactose intolerance, increased nutritional value of foods, reduction of serum cholesterol levels, antimutagenicity and anticarcinogenicity, reduction of the risk of inflammatory bowel conditions, improvement of digestion of proteins and fats, synthesis of vitamins, and detoxification and protection from toxins (Klaenhammer, 1998;

Anderson & Gilliland (1999) conducted two controlled clinical studies to test effects of yoghurt on heart-related health. They reported an average reduction of serum cholesterol by 2.9% with regular consumption of yoghurt containing *L. acidophilus* and a 6-10% decrease in cardiac complications due to hypercholesterolemia. A study by Ouwehand et al. (2002) found that a multi-strain probiotic mixture composed of *L. reuteri, L. rhamnosus* and *Propionibacterium freudenreichii* proved effective in both increasing the number of bowel movements and decreasing mucin secretion in elderly subjects. The probiotic mixture was more effective than *L. reuteri* alone, although unfortunately it is difcult to draw conclusions about mixtures versus individual probiotics, since only one component of the mixture was tested and its dose was over 10 times lower than the total bacterial dose in the mixture. Agarwal & Bhasin (2002) have reported that the strain *L. casei* DN-114001 reduced

Isolauri *et al.* (1999) found significant improvement when a supplement of either *L. rhamnosus* or *B. lactis was given* to children from 4 to 6 years of age who had atopic eczema. Another study involving pregnant women and newborns suggested that consumption of probiotic *L. rhamnosus* GG reduced the rate of newborns having atopic dermatitis (Kalliomaki et al., 2001). In an Australian study, 178 newborns of women with allergies who received either *L. acidophilus* LAVRI-A1 or placebo daily for the first 6 months of life showed no difference in atopic dermatitiS. However, at 12 months, the rate of sensitization was significantly higher in the probiotic group. These results suggested that the probiotic treatment had increased the risk of subsequent cow's milk sensitization (Taylor et al., 2007). Can (2003) used an experimental animal model to study the effects of a probiotic mixture and *L*. GG on immune responses in allergy. The OVA specific IgE levels of the study groups which were administred probiotics and reference strain were found lower than the skim milk fed groups. A double-blind, randomized, placebo controlled trial study was conducted by Abrahamsson et al. (2007) on 188 subjects with allergic disease, in which the mothers received *L. reuteri* ATCC 55730 daily from gestational week 36 until delivery, and their babies continued with the probiotic until 12 months. Probiotic supplemented babies showed less IgE-associated eczema during the second year. Several probiotic effects are mediated Ziarno et al. (2007) studied cholesterol assimilation by commercial starter cultures, reporting *L. acidophilus* monocultures to assimilate cholesterol by 49-55%. In another study involving hypercholesterolemic mice, the probiotic potential of *L. plantarum* PHO4 was established by Nguygen et al. (2007). The mice were fed with 107 CFU per day over two weeks. These mice had 7 to 10% lesser serum cholesterol and triglycerides than the control mice deprived of the probiotic feed.

Many probiotic species have been identified to be effective in children suffering from rotaviral diarrhea (Saavedra, 2000). Longdet et al. (2011) investigated the probiotic efficacy of *L. casei* isolated from human breast milk in the prevention of shigellosis in albino rats infected with clinical strains of *Shigella dysenteriae*. The results showed that the experimental rats infected with *S. dysenteriae* but not treated suffered from shigellosis, while the test groups infected and treated with the *L. casei* showed no sign of the disease as well as no clinical effect on the liver.

Senol et al. (2011a) investigated the protective effect of a probiotic mixture of 13 different bacteria and a-tocopherol on 98% ethanol-induced gastric mucosal injury. Levels of gastric mucosal pro-and anti-inammatory cytokines, malondialdehyde, and secretory immunglobulin A were measured. Results showed that probiotic pretreatment signicantly suppressed the ethanol-induced increase of gastric mucosal interleukin-4 levels. Pretreatment with either probiotic or a–tocopherol inhibited the ethanol-induced increase of mucosal malondialdehyde concentration. Probiotic pretreatment enhanced the gastric mucosal secretory immunoglobulin A concentration. The researchers indicated that the probitic mixture and a-tocopherol reduced ethanol-induced gastric mucosal lipid peroxidation, suggesting that these probiotics may be benecial for helping heal gastric lesions induced by lower ethanol concentration. In another study, the role of a probiotic mixture, including 13 different bacteria, in the prevention of aspirin-induced gastric mucosal injury was investigated. Pretreatment with the probiotic mixture reduced aspirininduced gastric damage and exerted a tendency toward downregulation of proinflammatory cytokines elicited by aspirin. Researchers also found that the probiotic mixture increased sIgA production approximately 7.5-fold in the stomach, and significantly reduced the malondialdehyde increase in the gastric mucosa elicited by aspirin. Additionally, pretreatment with the probiotic mixture alleviated aspirin-induced reduction of mast cell count in the gastric mucosa. Probiotic mixture pretreatment attenuates the aspirin-induced gastric lesions by reducing the lipid peroxidation, enhancing mucosal sIgA production, and stabilizing mucosal mast cell degranulation into the gastric mucosa (Senol et al., 2011b).

Highlights in Probiotic Research 255

Başyiğit Klç, G., Klç, B., Kuleaşan, H. & Karahan, A.G. (2010). Effect of Probiotics and αtocopherol applications on microbial flora of rat gastrointestinal tract, *Journal of Animal* 

Başyiğit Klç, G. & Karahan, A.G. (2010). Identification of lactic acid bacteria isolated from the fecal samples of healthy humans and patients with dyspepsia and determination of their pH, bile and antibiotic tolerance properties, *Journal of Molecular Microbiology and* 

Başyiğit Klç, G., Kuleaşan, H. & Çakmak, V.F. (2011a). Determination of probiotic properties of *L. plantarum* strains isolated from the human fecal samples, *Proceedings of Novel Approches in Food Industry, International Food Congress*, 26-29 May 2011, Çeşme-

Başyiğit Klç, G., Kuleaşan, H., Akpnar, D., Çakmak, V.F. (2011b). Characterization of technological properties of human originated probiotic *L. plantarum* strains, *Proceedings of International Scientific Conference on Probiotics and Prebiotics-IPC*, Slovakia, pp. 14. Başyiğit Klç, G. (2012) (unpublished data). Determination of probiotic and technological properties of some *Lactobacillus plantarum* strains, TUBITAK 109 O 623, Ongoing Project. Blanquet, S., Marol-Bonnin, S., Beyssac, E., Pompon, D., Renaud, M. & Alric, M. (2001). The "biodrug" concept: an innovative approach to therapy, *Trends in Biotechnology* 19(10):

Bude-Ugarte, M., Guglielmotti, D., Giraffa, G., Reinheimer, J.A. & Hynes, E. (2006). Non starter lactobacilli isolated from soft and semi hard Argentinean cheeses: genetic characterization and resistance to biological barriers, *Journal of Food Protection* 69: 2983-

Can, R. (2003). The effects of probiotics on allergy, *PhD Thesis*, Süleyman Demirel University, Medicinal Faculty, Departmant of Microbiology, Isparta, Turkey, p. 75

Candela, M., Seibold, G., Vitali, B., Lachenmaier, S., Eikmanns, B.J. & Brigidi, P. (2005) Realtime PCR quantification of bacterial adhesion to Caco-2 cells: competition between

Capela, P., Hay, T.K.C. & Shah, N.P. (2006). Effect of cryoproyectants, prebiotics and microencapsulation on survival of probiotic organisms in yoghurt and freeze-dried

Carr, F.J., Chill, D. & Maida, N. (2002). The lactic acid bacteria: a literature survey, *Critical* 

Champagne, C.P., Lacroix C. & Sodini-Gallot, I. (1994). Immobilized cell technology for the

Chandramouli, V., Kalasapathy, K., Peiris, P. & Jones, M. (2004). An improved method of microencapsulation and its evaluation to protect *Lactobacillus* spp. in simulated gastric

Charteris, W.P., Kelly, P.M., Morelli, L. & Collins, J.K. (1998). Development and application of an *in vitro* methodology to determinate the transit tolerance of potentially probiotic *Lactobacillus* and *Bidobacterium* species in the upper human gastrointestinal tract,

Clementi, F. & Aquilanti, L. (2011). Recent investigations and updated criteria for the assessment of antibiotic resistance in food lactic acid bacteria, *Anaerobe* 17: 394-398.

bifidobacteria and enteropathogens, *Research in Microbiology* 156(8): 887-895.

yoghurt, *Food Reseach International* 39: 203-211.

dairy industry, *Critical Reviews in Biotechnology* 14: 109-134.

conditions, *Journal of Microbiological Methods* 56: 27-35.

*Reviews on Microbiology* 28: 281-370.

*Journal of Applied Microbiology* 84: 759-768.

*and Veterinary Advances* 9(14): 1972-1977.

*Biotechnology* 18: 220-229.

İzmir, Turkey, pp. 56.

393–400.

2991.

(unpublished).
