Kefir

Jacob Schor ND FABNO

February 16, 2009

According to genetic data, Genghis Khan, the Mongolian conqueror, has more living descendents than any other man who has ever lived.   Geneticists have found that nearly 8 percent of the men living in the region of the former Mongol empire carry y-chromosomes that are nearly identical. That translates to 0.5 percent of the male population in the world, or roughly 16 million male descendants living.   Assuming that he has a similar number of female descendents, 1 percent of the world’s population are descended from a single person.

What does this have to do with anything?    I’ve been reading about yogurt and kefir for the last several weeks.  Genghis Khan, according to legend, originated yogurt.

The story goes that survivors of a village ransacked and pillaged by Khan’s warriors put sour milk in a gourd intending to poison him.  The milk turned to a kind of custard that Khan and then his other horseman enjoyed. Written records do tell us that Genghis Khan’s armies lived on yogurt.  Not quite the Yoplait yogurt we know today, but something called Kumiss  they made from fermented horse milk.

My interest in yogurt and kefir was triggered by reading an abstract of a 2007 paper that compared extracts made from milk, yogurt and kefir on breast cancer cell growth.  The milk extracts stimulated the cells to grow faster.  Both the yogurt and kefir extracts inhibited growth of the breast cancer cells.  While yogurt was good, the kefir was far better at stopping cancer cell growth.

“After 6 days of culture, extracts of kefir-fermented milk depressed MCF-7 cell growth in a dose-dependent manner, showing 29% inhibition of proliferation at a concentration as low as 0.63%, whereas yogurt extracts began to show dose-dependent antiproliferative effects only at the 2.5% dose. Moreover, at the 2.5% dose, kefir extracts decreased the MCF-7 cell numbers by 56%, while yogurt extracts decreased MCF-7 cell proliferation by only 14%.”

The kefir extracts had four times the inhibitory effect on the breast cancer cells than the yogurt did at one quarter the concentration. 

This should get your attention. Women at high risk for breast cancer or who have breast cancer or who have ever had breast cancer should be eating kefir daily.

So that’s why I am reading about Kefir. 

Kefir is different than yogurt.  They aren’t at all the same except both are made from milk.   While yogurt is made by fermenting milk with acidophilus bacteria, kefir is far more complex a fermentation; it is fermented using a culture of yeast and bacteria living in a symbiotic relationship.

Reading this may soon get boring so for relief, I suggest you play some kefir inspired background music by opening the following link:

http://www.kefir-grains.com/audio/lets-say-kefir.mp3

You are listening to Dominic Anfiteatro, a kefir obsessed Australian who maintains the most comprehensive kefir related website I’ve found on the web: http://users.chariot.net.au/~dna/kefirpage.html#Links

Mr. Anfiteatro also hosts a kefir Yahoo chatroom with 7,500 members: http://groups.yahoo.com/group/Kefir_making/

Kefir originated in the northern slopes of the Caucasus Mountains at least 1,000 years ago. The people in that part of the world consume large amounts of kefir.  They are known for living long, healthy lives with little disease.  Life spans over one hundred years are common in the region and kefir is often given credit for this longevity.

Kefir, “is a viscous, slightly carbonated dairy beverage that contains small quantities of alcohol….”  Besides having an effervescent tang from the yeast, Kefir contains between 0.08% to 2% alcohol. Alcohol content can go as high as 3%, varying with the type of milk and ripening conditions.

Kefir is made by culturing fresh milk with kefir grains. Kefir grains are not cereal grains.  The bacteria and yeast used to culture kefir form small granular lumps that are only called grains because that’s what they look like. It would probably be better to call them kefir granules. Farnsworth describes them as, “a mass of proteins, polysaccharides, mesophilic, homofermentative and heterofermentative lactic acid streptococci, thermophilic and mesophilic lactobacilli, acetic acid bacteria and yeast.”

A clump of these kefir grains (or granules) looks like a white clump of cauliflower made  of gelatin. It’s a fairly complex biological structure composed of protein, amino acids, lipids and soluble-polysaccharides.  The major polysaccharide in the mix is called kefiran.

It is easy to make kefir at home. Milk is mixed with some kefir grains and left at room temperature for about 24 hours. The resulting cultured-milk is strained to separate out and retrieve the kefir grains. The grains are saved and added to more milk to repeat the process. That’s it. 

 

The optimum ratio of grain to milk is reported to be between 1:30 and 1:50.  This procedure can be repeated indefinitely as kefir grains appear to last forever.  Strained kefir can be consumed fresh or refrigerated for later use, or allowed to ‘ripen’ further at room temperature.  The same kefir granules can apparently be used to ferment a wide range of liquids beside milk including fruit juices.

The fermentation process though is fairly complex: “Fermentation of the milk by the inoculum proceeds for approximately 24 hours, during which time homofermentative lactic acid streptococci grow rapidly, initially causing a drop in the pH.  This low pH favours the growth of lactobacilli, but causes the streptococci numbers to decline.  The presence of yeasts in the mixture, together with fermentation temperature encourages the growth of aroma-producing heterfermentative streptococci.  As fermentation proceeds, growth of lactic acid bacteria is favoured over growth of yeasts and acetic acid bacteria.” (Farnsworth and Koroleva)

Lucky for you, all this occurs on its own.   All you have to do is be patient while it happens.  What I find especially interesting is that the microbiological profile of the finished product is different from the grains; you can’t use the finished kefir to inoculate your next batch.  You need to use kefir grains.

In John Le Carre’s  book, Our Game,  he describes the Caucasus as taking up an area of land about the size of Scotland but containing 40 different spoken languages.   This image of cultural overcrowding seems appropriate for the diverse microbiologic overcrowding in these kefir granules.

Though not as well studied as yogurt there are some interesting scientific papers published on kefir. A paper published in December 2008 reported that kefiran, that principle polysaccharide in the kefir grains, could be used to prevent allergic asthmatic responses, at least in mice.   This paper was preceded by a similar report in 2007 showing that kefiran had both an anti-allergy and an anti inflammatory effect on bronchial asthma.   Both these studies used mice to test the effect.  Yogurt has already been tested in humans, actually asthmatic children, and does not produce noticeable improvement.   A 1997 paper reported that eating yogurt decreased eosinophil counts, a blood marker of allergic reactions but it failed to produce a decrease in asthma symptom intensity.   In other words yogurt seems like it helps asthma a little but not enough to actually notice.  Kefir, though not yet proven to help, certainly might.

The first reports of anti-tumor effect from kefir were published in 1982.   Shimoni et al showed that something in kefir inhibited the growth of liver cancer and sarcoma tumors in mice.  Incubating the cancer cells with the kefir extracts had little effect. It appears that action was due to immune stimulation.   In addition to the breast cancer study already mentioned, there are several other published papers suggesting that kefir may be useful at hindering growth of breast cancer cells.  

Unfortunately no human trials are apparent yet.  It’s not clear why kefir would inhibit cancer cell growth.  A paper on yogurt, not kefir, suggests that the anticancer effect, at least in yogurt, comes not from the bacteria but from components of the milk that are modified by the bacteria.

The microbes that create kefir will grow in other liquids beside milk. Testing kefir made from soymilk against kefir made from cow milk found that the soy version had a greater effect at inhibiting tumor growth.   Perhaps we should make kefir from foods that have anticancer effects and in doing so increase their potency.  What would a pomegranate-soy-green tea- raspberry kefir beverage taste like? 

Researchers who tested to see if kefir might help reduce mucositis in patients being treated for colon cancer were disappointed.  Kefir produced no more benefit for this than gargling with salt water.  

The kefir microbes produce chemicals that kill off other bacteria that might cause spoilage or act as disease causing pathogens in the milk. A recent paper tells us kefir kills Helicobacter pylori, the microbe blamed for gastric ulcers.

In our modern world we have grown very fearful of microbes and expend great effort at trying to kill them, sanitizing our food, our homes, our bodies and our environment.  The Hygiene Theory of autoimmune disease blames this sterile world for the recent increase in autoimmune diseases.  We’ve been too successful at reducing exposure to other life forms that it is making it difficult for our own health.  It seems our immune systems need to be exposed to a wide variety of other life forms in order to learn how to function.    In cutting ourselves off from microbial exposure, we have lost some of the magic that the world has to offer us.  Yogurt and especially kefir may be one of those magical ways we can bring ourselves back in contact with our world and bring some degree of balance to the way our bodies function.

Special thanks to Denver acupuncturist, M. K. Christian who provided me with my first kefir grains.

Culture Sources:

http://www.gemcultures.com/

http://www.fermentedtreasures.com/index.html

Dom’s website instruction will tell you just about everything you’ll ever need to know about making kefir and fermenting pretty much anything edible with kefir

http://users.chariot.net.au/~dna/Makekefir.html#usual_method_for_kefir

References:

Am J Hum Genet. 2003 Mar;72(3):717-21. Epub 2003 Jan 17.

    The genetic legacy of the Mongols.

    Zerjal T, Xue Y, Bertorelle G, Wells RS, Bao W, Zhu S, Qamar R, Ayub Q, Mohyuddin A, Fu S, Li P, Yuldasheva N, Ruzibakiev R, Xu J, Shu Q, Du R, Yang H, Hurles ME, Robinson E, Gerelsaikhan T, Dashnyam B, Mehdi SQ, Tyler-Smith C.

    Department of Biochemistry, University of Oxford, Oxford, United Kingdom.

    We have identified a Y-chromosomal lineage with several unusual features. It was found in 16 populations throughout a large region of Asia, stretching from the Pacific to the Caspian Sea, and was present at high frequency: approximately 8% of the men in this region carry it, and it thus makes up approximately 0.5% of the world total. The pattern of variation within the lineage suggested that it originated in Mongolia approximately 1,000 years ago. Such a rapid spread cannot have occurred by chance; it must have been a result of selection. The lineage is carried by likely male-line descendants of Genghis Khan, and we therefore propose that it has spread by a novel form of social selection resulting from their behavior.

J Med Food. 2007 Sep;10(3):416-22. 

    Kefir extracts suppress in vitro proliferation of estrogen-dependent human breast cancer cells but not normal mammary epithelial cells.

    Chen C, Chan HM, Kubow S.

    School of Dietetics and Human Nutrition, Macdonald Campus of McGill University, Ste-Anne-de-Bellevue, Quebec, Canada.

    Anti-tumorigenic effects have been demonstrated in animal studies from the intake of kefir, a traditional fermented milk product believed to originate from the Caucasian mountains of Russia. In the present study, the antiproliferative effects of extracts of kefir, yogurt, and pasteurized cow's milk on human mammary cancer cells (MCF-7) and normal human mammary epithelial cells (HMECs) was investigated at doses of 0.31%, 0.63%, 1.25%, 2.5%, 5%, and 10% (vol/vol). After 6 days of culture, extracts of kefir-fermented milk depressed MCF-7 cell growth in a dose-dependent manner, showing 29% inhibition of proliferation at a concentration as low as 0.63%, whereas yogurt extracts began to show dose-dependent antiproliferative effects only at the 2.5% dose. Moreover, at the 2.5% dose, kefir extracts decreased the MCF-7 cell numbers by 56%, while yogurt extracts decreased MCF-7 cell proliferation by only 14%. No antiproliferative effects of kefir extracts were observed in the HMECs, while the yogurt extracts exerted antiproliferative effects on HMECs at the 5% and 10% doses. Unfermented milk extracts stimulated proliferation of MCF-7 cells and HMECs at concentrations above 0.31%. Peptide content and capillary electrophoresis analyses showed that kefir-mediated milk fermentation led to an increase in peptide concentrations and a change in peptide profiles relative to milk or yogurt. The present findings suggest that kefir extracts contain constituents that specifically inhibit the growth of human breast cancer cells, which might eventually be useful in the prevention or treatment of breast cancer.

Farnsworth ER. Kefir- a complex probiotic. Food Science and Technology Bulletin 2(1) 1-17 2005

Arch Pharm Res. 2008 Dec;31(12):1590-6. Epub 2008 Dec 20.

    Inhibitory effect of kefiran on ovalbumin-induced lung inflammation in a murine model of asthma.

    Kwon OK, Ahn KS, Lee MY, Kim SY, Park BY, Kim MK, Lee IY, Oh SR, Lee HK.

    Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806, Korea.

    Kefiran is a major component of kefir which is a microbial symbiont mixture that produces jelly-like grains. This study aimed to evaluate the therapeutic availability of kefiran on the ovalbumin-induced asthma mouse model in which airway inflammation and airway hyper-responsiveness were found in the lung. BALB/c mice sensitized and challenged to ovalbumin were treated intra-gastrically with kefiran 1 hour before the ovalbumin challenge. Kefiran significantly suppressed ovalbumin-induced airway hyper-responsiveness (AHR) to inhaled methacholine. Administration of kefiran significantly inhibited the release of both eosinophils and other inflammatory cells into bronchoalveolar lavage (BAL) fluid and lung tissue which was measured by Diff-Quik. Interleukin-4 (IL-4) and interleukin-5 (IL-5) were also reduced to normal levels after administration of kefiran in BAL fluid. Histological studies demonstrate that kefiran substantially inhibited ovalbumin-induced eosinophilia in lung tissue by H&E staining and goblet cell hyperplasia in the airway by PAS staining. Taken above data, kefiran may be useful for the treatment of inflammation of lung tissue and airway hyper-responsiveness in a murine model and may have therapeutic potential for the treatment of allergic bronchial asthma.

Immunobiology. 2007;212(8):647-54. Epub 2007 Jul 10.

    Anti-inflammatory and anti-allergic effects of kefir in a mouse asthma model.

    Lee MY, Ahn KS, Kwon OK, Kim MJ, Kim MK, Lee IY, Oh SR, Lee HK.

    Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, Yusung, Daejeon 305-600, Korea.

    Kefir is a microbial symbiont mixture that produces jelly-like grains. As a widely used neutraceutical, however, the therapeutic applicability of kefir is not certain. In order to investigate the pharmacological effects of kefir, we used a mouse asthma model, in which airway inflammation and airway remodeling was produced by ovalbumin sensitization and challenge. BALB/c mice sensitized and challenged to ovalbumin, were treated with kefir (50mg/kg administered by intra-gastric mode) 1h before the ovalbumin challenge. Kefir significantly suppressed ovalbumin-induced airway hyper-responsiveness (AHR) to inhaled methacholine. Intra-gastric administration of kefir significantly inhibited the increase in the total inflammatory cell count induced by ovalbumin, and the eosinophil count in bronchoalveolar lavage fluid (BALF). Type 2 helper T cell (Th2) cytokines, such as interleukin-4 and interleukin-13, and total immunoglobulin E (Ig E) levels, were also reduced to normal levels in bronchoalveolar lavage fluid. Histological studies demonstrate that kefir substantially inhibited ovalbumin-induced eosinophilia in lung tissue and mucus hyper-secretion by goblet cells in the airway. Kefir displayed anti-inflammatory and anti-allergic effects in a mouse asthma model and may possess new therapeutic potential for the treatment of allergic bronchial asthma.

Pediatr Res. 2007 Aug;62(2):215-20.Click here to read    

    A randomized prospective double blind controlled trial on effects of long-term consumption of fermented milk containing Lactobacillus casei in pre-school children with allergic asthma and/or rhinitis.

    Giovannini M, Agostoni C, Riva E, Salvini F, Ruscitto A, Zuccotti GV, Radaelli G; Felicita Study Group.

    Department of Pediatrics, San Paolo Hospital, University of Milan, Via A di Rudinì 8, I-20142 Milan, Italy.

    To examine whether long-term consumption of fermented milk containing a specific Lactobacillus casei may improve the health status of preschool children suffering from allergic asthma and/or rhinitis a randomized, prospective, double blind, controlled trial was conducted in 187 children 2-5 y of age. The children received for 12 mo either fermented milk (100 mL) containing Lactobacillus casei (10(8) cfu/mL) or placebo. The time free from and the number of episodes of asthma/rhinitis after starting intervention were the outcome measures. The number of fever or diarrhea episodes and the change in serum immunoglobulin were further assessed. No statistical difference between intervention and control group occurred in asthmatic children. In children with rhinitis, the annual number of rhinitis episodes was lower in the intervention group, mean difference (95% CI), -1.6 (-3.15 to -0.05); the mean duration of an episode of diarrhea was lower in the intervention group, mean difference -0.81 (-1.52 to -0.10) days. While long-term consumption of fermented milk containing Lactobacillus casei may improve the health status of children with allergic rhinitis no effect was found in asthmatic children.

Ann Allergy Asthma Immunol. 1997 Sep;79(3):229-33.   

    Immune and clinical impact of Lactobacillus acidophilus on asthma.

    Wheeler JG, Shema SJ, Bogle ML, Shirrell MA, Burks AW, Pittler A, Helm RM.

    Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, USA.

    BACKGROUND: Animal and human studies have suggested that yogurt containing live active bacteria leads to improved immune and clinical responses. Specific benefits of yogurt containing L. acidophilus on allergic asthma have been hypothesized but not studied. METHODS: In a crossover double-blinded design, the effect of live active yogurt (225 g twice daily) with or without L. acidophilus was studied in 15 adult patients with moderate asthma. Immune and clinical parameters were measured before and after the two 1-month crossover phases. RESULTS: No significant changes were noted in peripheral cell counts, IgE, IL-2, or IL-4 when comparing the two diets to each other. Concanvalin A-stimulated lymphocytes from patients who consumed yogurt containing L. acidophilus produced borderline elevated interferon gamma levels (P = .054). No differences were noted in mean daily peak flows or changes in spirometric values. Quality of life indices were unchanged when comparing the two groups. CONCLUSIONS: Yogurt containing L. acidophilus generated trends in the increase in interferon gamma and decreased eosinophilia; however, we were unable to detect changes in clinical parameters in asthma patients in association with these modest immune changes.

Jpn J Med Sci Biol. 1982 Apr;35(2):75-80.   

    Antitumor activity in mice of orally administered polysaccharide from Kefir grain.

    Shiomi M, Sasaki K, Murofushi M, Aibara K.

    The antitumor activity of a water-soluble polysaccharide (KGF-C), isolated from the Kefir grain, was studied in the mice subcutaneously inoculated with Ehrlich carcinoma (EC) or Sarcoma 180 (S-180). The growth of EC and S-180 solid tumor was inhibited by 40-59% and 21-81%, respectively, by oral administration of KGF-C as compared with the unadministered mice. The tumor growth was similarly inhibited by intraperitoneal administration. The mechanism of the antitumor activity of KGF-C was considered to be host-mediated because of the lack of direct in vitro effect on tumor cells.

Jpn J Med Sci Biol. 1982 Apr;35(2):75-80.   

    Antitumor activity in mice of orally administered polysaccharide from Kefir grain.

    Shiomi M, Sasaki K, Murofushi M, Aibara K.

    The antitumor activity of a water-soluble polysaccharide (KGF-C), isolated from the Kefir grain, was studied in the mice subcutaneously inoculated with Ehrlich carcinoma (EC) or Sarcoma 180 (S-180). The growth of EC and S-180 solid tumor was inhibited by 40-59% and 21-81%, respectively, by oral administration of KGF-C as compared with the unadministered mice. The tumor growth was similarly inhibited by intraperitoneal administration. The mechanism of the antitumor activity of KGF-C was considered to be host-mediated because of the lack of direct in vitro effect on tumor cells.

J Med Food. 2007 Sep;10(3):416-22.Click here to read    

    Kefir extracts suppress in vitro proliferation of estrogen-dependent human breast cancer cells but not normal mammary epithelial cells.

    Chen C, Chan HM, Kubow S.

    School of Dietetics and Human Nutrition, Macdonald Campus of McGill University, Ste-Anne-de-Bellevue, Quebec, Canada.

    Anti-tumorigenic effects have been demonstrated in animal studies from the intake of kefir, a traditional fermented milk product believed to originate from the Caucasian mountains of Russia. In the present study, the antiproliferative effects of extracts of kefir, yogurt, and pasteurized cow's milk on human mammary cancer cells (MCF-7) and normal human mammary epithelial cells (HMECs) was investigated at doses of 0.31%, 0.63%, 1.25%, 2.5%, 5%, and 10% (vol/vol). After 6 days of culture, extracts of kefir-fermented milk depressed MCF-7 cell growth in a dose-dependent manner, showing 29% inhibition of proliferation at a concentration as low as 0.63%, whereas yogurt extracts began to show dose-dependent antiproliferative effects only at the 2.5% dose. Moreover, at the 2.5% dose, kefir extracts decreased the MCF-7 cell numbers by 56%, while yogurt extracts decreased MCF-7 cell proliferation by only 14%. No antiproliferative effects of kefir extracts were observed in the HMECs, while the yogurt extracts exerted antiproliferative effects on HMECs at the 5% and 10% doses. Unfermented milk extracts stimulated proliferation of MCF-7 cells and HMECs at concentrations above 0.31%. Peptide content and capillary electrophoresis analyses showed that kefir-mediated milk fermentation led to an increase in peptide concentrations and a change in peptide profiles relative to milk or yogurt. The present findings suggest that kefir extracts contain constituents that specifically inhibit the growth of human breast cancer cells, which might eventually be useful in the prevention or treatment of breast cancer.

J Dairy Sci. 2007 Apr;90(4):1920-8.Click here to read    

    Study of immune cells involved in the antitumor effect of kefir in a murine breast cancer model.

    de Moreno de Leblanc A, Matar C, Farnworth E, Perdigón G.

    Départment de Chimie-Biochimie, Université de Moncton, Moncton, New Brunswick, Canada E1A 3E9.

    Administration of kefir and a kefir cell-free fraction (KF) to mice injected with breast tumor cells produced, locally in the mammary gland, different profiles of cells secreting cytokines. Here, the immune cell populations in mammary glands affected by the cyclic consumption of kefir or KF for 2 or 7 d were evaluated using a breast tumor model. Apoptosis was also assayed as another mechanism involved in tumor growth delay. The rate development of tumor cells, IgA(+) cells, and CD4+ and CD8+ T lymphocytes was monitored in mammary gland tissues. The number of Bcl-2(+) cells in the mammary gland was compared with the apoptosis observed in the tumor. Two-day cyclical administration of both products delayed tumor growth and increased the number of IgA(+) cells in the mammary gland. Changes in the balance between CD4+ and CD8+ cells in the mammary gland were observed in mice from the group fed KF cyclically for 2 d, such that the number of CD4+ cells increased when the number of CD8+ cells remained constant. Mice that received 2-d cyclic administration of KF showed significant increases in the number of apoptotic cells and decreases in Bcl-2(+) cells in the mammary gland, compared with the tumor control group. The present study allows a better understanding of the mechanisms (immune and nonimmune) involved in the antitumor effect observed in mice administered kefir or KF. The importance of nonmicrobial components released during milk fermentation to obtain the beneficial antitumor effects is also reported.

Cytokine. 2006 Apr;34(1-2):1-8. Epub 2006 May 12.Click here to read    

    Study of cytokines involved in the prevention of a murine experimental breast cancer by kefir.

    de Moreno de LeBlanc A, Matar C, Farnworth E, Perdigon G.

    Départment de Chimie-Biochimie, Université de Moncton, Moncton, NB, Canada E1A 3E9.

    Previous studies have shown that compounds released during milk fermentation by Lactobacillus helveticus are implicated in the antitumour effect of this product. Here the effects of the consumption, during 2 or 7 days, of kefir or kefir cell-free fraction (KF) on the systemic and local immune responses in mammary glands and tumours using a murine hormone-dependent breast cancer model were studied. In the tumour control group, mice did not receive these products. At the end of the feeding period, mice were injected subcutaneously with tumour cells in the mammary gland. Four days post-injection, they received kefir or KF on a cyclical basis. Rate of tumour development, cytokines in serum; mammary gland tissue, and tumour isolated cells were monitored. Two-day cyclical administration of both products delayed tumour growth. Both kefir and KF increased IL-10 in serum and decreased IL-6(+) cells (cytokine involved in oestrogen synthesis) in mammary glands. Two-day cyclical administration of KF increased IL-10(+) cells in mammary glands and in tumours and decreased IL-6(+) cells in tumour. This study demonstrated the modulatory capacity of KF on the immune response in mammary glands and tumours and the importance of the administration period to obtain this effect.

Nutr Cancer. 1997;28(1):93-9.   

    Antiproliferative effect of fermented milk on the growth of a human breast cancer cell line.

    Biffi A, Coradini D, Larsen R, Riva L, Di Fronzo G.

    Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy.

    In vivo and in vitro studies have shown an antitumor activity of Lactobacilli in colon cancer, and some epidemiologic studies have indicated a reduced risk of breast cancer in women who consume fermented milk products. We studied the direct effect of milk fermented by five bacteria strains (Bifidobacterium infantis, Bifidobacterium bifidum, Bifidobacterium animalis, Lactobacillus acidophilus, and Lactobacillus paracasei) on the growth of the MCF7 breast cancer cell line. Our results showed a growth inhibition induced by all fermented milks, even though B. infantis and L. acidophilus were the most effective (85% inhibition after 9 days). The antiproliferative effect was not related to the presence of bacteria in fermented milk, and neither whole milk (crude or ultrahigh temperature sterlizied) nor its main fractions (lactalbumin or beta-lactoglobulin fraction) affected cell growth. Our findings suggest the presence of an ex novo soluble compound produced by lactic acid bacteria during milk fermentation or the microbial transformation of some milk components in a biologically active form. Although the mechanism of the antitumor activity is not clear, the present study suggests the potentiality offered by fermented milk as producers of compounds with antiproliferative activity useful in the prevention and therapy of solid tumors like breast cancer.

Nutr Cancer. 2002;44(2):183-7.   

    Antitumor activity of milk kefir and soy milk kefir in tumor-bearing mice.

    Liu JR, Wang SY, Lin YY, Lin CW.

    Laboratory of Chemistry and Technology of Animal Science, Department of Animal Science, National Taiwan University, Taipei, Taiwan, Republic of China. jerryliu@seed.net.tw

    The effects of oral administration of milk and soy milk kefirs on tumor growth in tumor-bearing mice and the mucosal immunoglobulin A response in mice were studied. Oral administration of milk and soy milk kefirs to mice inoculated with sarcoma 180 tumor cells resulted in 64.8% and 70.9% inhibition of tumor growth, respectively, compared with controls. In addition, oral administration of the two kefir types induced apoptotic tumor cell lysis. Total immunoglobulin A levels for tissue extracts from the wall of the small intestine were also significantly higher for mice fed a milk kefir or a soy milk kefir regimen for 30 days. These results suggest that milk and soy milk kefirs may be considered among the more promising food components in terms of cancer prevention and enhancement of mucosal resistance to gastrointestinal infection.

Invest New Drugs. 2008 Dec;26(6):567-72. Epub 2008 Sep 2.Click here to read    

    Effect of oral administration of kefir on serum proinflammatory cytokines on 5-FU induced oral mucositis in patients with colorectal cancer.

    Topuz E, Derin D, Can G, Kürklü E, Cinar S, Aykan F, Cevikba? A, Di?çi R, Durna Z, Sakar B, Saglam S, Tanyeri H, Deniz G, Gürer U, Ta? F, Guney N, Aydiner A.

    Onkoloji Enstitüsü, Istanbul Universitesi, Istanbul, Turkey.

    In order to investigate the effect of kefir consumption on mucositis induced by 5-FU based chemotherapy (CT), we monitored the systemic immune response by measurement of the serum proinflammatory cytokine levels and we evaluated the anti-microbial effect of kefir with an agar diffusion method. Forty patients with colorectal cancer were included in this randomized prospective study. On the first 5 days of each CT cycle, the study group received oral lavage with kefir and then swallowed 250 ml of kefir while control group received oral lavage with 0.09% NaCl twice a day. Before and after every cycle of CT, the oral mucosa was assessed. Serum proinflammatory cytokine levels were evaluated before the initiation and after the third and the sixth cycle. Kefir was administered in 99 out of 205 courses. Mucositis developed in 27.3% of the courses given with kefir administration and in 21.7% of the courses given with 0.9% NaCl oral rinses. The difference between the two groups was not statistically significant (p > 0.05). When we compared the serum proinflammatory cytokine levels of the two groups at the baseline and following the third and the sixth cycles, we again found no statistically significant difference (p > 0.05). Kefir consumption at the mentioned doses made no statistically significant effect on serum proinflammatory cytokine levels and on the incidence of mucositis development in cancer patients. Under in vitro conditions, kefir inhibits only Staphylococcus epidermidis.

   

J Appl Microbiol. 2002;93(6):1083-8.Click here to read    

    Folk yoghurt kills Helicobacter pylori.

    Oh Y, Osato MS, Han X, Bennett G, Hong WK.

    Department of Head & Neck/Thoracic Medical Oncology, MD Anderson Cancer Center, Houston, TX 77030, USA. ywoh@mdanderson.edu

    AIMS: To evaluate a traditional yoghurt used as folk medicine for its ability to kill Helicobacter pylori in vitro. METHODS AND RESULTS: Micro-organisms from the yoghurt were identified and tested in different food substrates for their effects on H. pylori in a co-culture well system. Two yeasts and several strains of lactobacilli were isolated from the yoghurt, and both the yeast and the lactobacilli independently showed cidal activity against H. pylori. The microbes from the original yoghurt also retained their cidal effect when grown in corn meal and soy milk. CONCLUSIONS: The yeast and lactobacilli found in this yoghurt form a hardy symbiotic culture. The organisms secrete soluble factors capable of killing H. pylori, and these factors may include some organic by-products of fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: These yoghurt-derived food preparations could become simple and inexpensive therapies to suppress H. pylori infections in endemic countries.


Ask the Doctor:

Submit your question here.

_____________________?

Newsletter:
Enter your email address and recieve Free newsletters from our clinic.   You will receive a confirmation email that you will need to open and click on the appropriate link.