Probiotic Yogurt Consumption Research Articles

Dietary habits in patients with ischemic stroke: a case-control study.

Background and AimsDiet appears to have some role in stroke development. The objective of our study was to describe the dietary habits in patients admitted with acute ischemic stroke and compare selected dietary components with healthy controls. Adherence to healthy diet behaviors was also assessed.MethodsA case-control study of consecutive patients with acute ischemic stroke admitted to the Neurology Department of Hospital del Mar from 2007 to 2010. Patients were matched by age and sex with control subjects. A previously validated nutritional survey was administered to patients and controls. Demographic data, vascular risk factors, caloric intake and dietary nutrients were evaluated. Intention to follow a healthy diet was also assessed in both groups.ResultsA total of 300 acute ischemic stroke patients and 300 controls with evaluation of dietary habits. No differences were observed in vascular risk factors, except smoking habit, diabetes and ischemic heart disease. Stroke patients reported a higher caloric intake: 2444.8(1736.8–3244.5) vs 2208.7(1753.1–2860.7) Kcal, p = 0.001. After adjusting for energy intake, patients had higher intake of proteins (p<0.001; OR 1.02), total cholesterol (p = 0.001; OR 1.04), and breaded foods (p = 0.001; OR 1.94) and lower consumption of probiotic yogurt (p = 0.002; OR 0.88). Compared to patients, control participants indicated greater intention to eat vegetables (p = 0.002; OR 1.5) and whole foods (p = 0.000; OR 2.4) and reduce their intake of salt (p = 0.002; OR 1.7), fat (p = 0.000; OR 3.7) and sweets (p = 0.004; OR 1.7) than patients.ConclusionWe observed different dietary patterns between stroke patients and controls. Stroke patients have a higher caloric intake and are less concerned about maintaining healthy nutritional habits.

Effects of probiotic yogurt consumption on metabolic factors in individuals with nonalcoholic fatty liver disease

The aim of this study was to investigate the effects of probiotic yogurt consumption on some metabolic factors in nonalcoholic fatty liver disease (NAFLD) patients. This double-blind, randomized, controlled clinical trial was conducted on 72 patients with NAFLD (33 males and 39 females) aged 23 to 63 yr. Subjects in the intervention group (n=36) consumed 300g/d of probiotic yogurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and those in the control group (n=36) consumed 300g/d of conventional yogurt for 8 wk. Fasting blood samples, anthropometric measurements, and dietary records (24h/d for 3 d) were collected at baseline and at the end of the trial. Probiotic yogurt consumption resulted in reductions of 4.67, 5.42, 4.1, and 6.92% in serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, and low-density lipoprotein cholesterol, respectively, compared with control group. No significant changes were observed in levels of serum glucose, triglycerides, or high-density lipoprotein cholesterol in either group. Probiotic yogurt consumption improved hepatic enzymes, serum total cholesterol, and low-density lipoprotein cholesterol levels in studied subjects and might be useful in management of NAFLD risk factors.

Randomized Open-Label Pilot Study of the Influence of Probiotics and the Gut Microbiome on Toxic Metal Levels in Tanzanian Pregnant Women and School Children

ABSTRACTExposure to environmental toxins is a 21st century global health problem that is often the result of dietary intake. Although efforts are made to reduce dietary toxin levels, they are often unsuccessful, warranting research into novel methods to reduce host exposure. Food-grade microbes that can be delivered to the gastrointestinal tract and that are capable of sequestering toxins present a safe and cost-effective intervention. We sought to investigate the potential for probiotic-supplemented yogurt to lower heavy metal levels in at-risk populations of pregnant women and in children in Mwanza, Tanzania, and to examine the microbiome in relation to toxin levels. Two populations suspected to have high toxic metal exposures were studied. A group of 44 school-aged children was followed over 25 days, and 60 pregnant women were followed over their last two trimesters until birth. A yogurt containing 1010 CFU Lactobacillus rhamnosus GR-1 per 250 g was administered, while control groups received either whole milk or no intervention. Changes in blood metal levels were assessed, and the gut microbiomes of the children were profiled by analyzing 16S rRNA sequencing via the Ion Torrent platform. The children and pregnant women in the study were found to have elevated blood levels of lead and mercury compared to age- and sex-matched Canadians. Consumption of probiotic yogurt had a protective effect against further increases in mercury (3.2 nmol/liter; P = 0.035) and arsenic (2.3 nmol/liter; P = 0.011) blood levels in the pregnant women, but this trend was not statistically significant in the children. Elevated blood lead was associated with increases in Succinivibrionaceae and Gammaproteobacteria relative abundance levels in stool.

Effects of probiotic yogurt consumption on inflammatory biomarkers in patients with type 2 diabetes.

Introduction: The role of inflammatory cytokines in diabetes and its complications has been shown in some studies. The purpose of this study was to compare the effect of probiotic and conventional yogurt on inflammatory markers in patients with type 2 diabetes. Methods: Forty-four patients with type 2 diabetes were participated in this randomized, double-blind controlled clinical trial and assigned to two intervention and control groups. The subjects in the intervention group consumed 300 g/d probiotic yogurt and subjects in the control group consumed 300 g/d conventional yogurt for 8 weeks. Anthropometric indices, dietary intakes, and serum levels of glucose, HbA1c, IL-6, TNF-α and hs-CRP were evaluated at the beginning and end of the intervention. Results: For anthropometric indices and dietary intakes, no significant differences were seen within and between groups post intervention (p> 0.05). The consumption of probiotic yogurt caused significant decrease in HbA1c and TNF-α levels (p= 0.032 and p= 0.040, respectively) in the intervention group. Conclusion: It is suggested that probiotic yogurt may be used as an alternative prevention approach and treatment method to control diabetic complications.

Molecular monitoring of fecal microbiota in healthy adults following probiotic yogurt intake

Probiotic consumption is known to influence the composition of intestinal microbiota by significantly increasing the counts of the target probiotic strains. However it is still unknown whether other bacterial indicators of the fecal microbiota are affected. In this study, two culture-independent molecular methods were used to profile the fecal microbiota of healthy human adult subjects: Terminal restriction fragment length polymorphism (T-RFLP) and quantitative PCR (qPCR). The impact of probiotic intake on bacterial community profile as well as effect on the variation of some indicator fecal microbiota species were assessed on fecal DNA samples obtained during the clinical trial of a commercial yogurt. T-RFLP of fecal samples showed no difference in profile variation between placebo or yogurt consumption (Bray–Curtis distance). Quantification by qPCR of some elements of fecal populations and endogenous Bifidobacterium species revealed that beyond the increase in probiotic species (Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus LA-5), the variations observed were largely due to inter-subject variation rather than treatment effect. The molecular profile of the fecal microbiota of healthy adults is not disturbed by commercial probiotic yogurt consumption despite a strong presence of the probiotic strains.

Effect of daily consumption of probiotic yoghurt on insulin resistance in pregnant women: a randomized controlled trial

Owing to excess body weight and increased secretion of inflammatory cytokines primarily during the third trimester, pregnancy is associated with elevated insulin resistance. To our knowledge, no report is available indicating the effects of probiotic yoghurt consumption on serum insulin levels in pregnant women. This study was designed to determine the effects of daily consumption of probiotic yoghurt on insulin resistance and serum insulin levels of Iranian pregnant women. In this randomized controlled clinical trial, 70 primigravida pregnant women with singleton pregnancy at their third trimester were participated. We randomly assigned participants to consume 200 g per day of conventional (n=33) or the probiotic group (n=37) for 9 weeks. The probiotic yoghurt was a commercially available product prepared with the starter cultures of Streptococcus thermophilus and Lactobacillus bulgaricus, enriched with probiotic culture of two strains of lactobacilli (Lactobacillus acidophilus LA5) and bifidobacteria (Bifidobacterium animalis BB12) with a total of min 1 × 10⁷ colony-forming units. Fasting blood samples were taken at baseline and after 9-week intervention to measure fasting plasma glucose and serum insulin levels. Homeostatic model assessment of insulin resistance (HOMA-IR) was used to calculate insulin resistance score. Although consumption of probiotic yogurt for 9 weeks did not affect serum insulin levels and HOMA-IR score, significant differences were found comparing changes in these variables between probiotic and conventional yogurts (changes from baseline in serum insulin levels: +1.2±1.2 vs +5.0±1.1 μIU/ml, respectively, P=0.02; and in HOMA-IR score: -0.2±0.3 vs 0.7±0.2, respectively, P=0.01). It is concluded that in contrast to conventional yogurt, daily consumption of probiotic yogurt for 9 weeks maintains serum insulin levels and might help pregnant women prevent developing insulin resistance.

Effect of Daily Consumption of Probiotic Yogurt on Oxidative Stress in Pregnant Women: A Randomized Controlled Clinical Trial

Background: Due to the enhanced oxygen requirement of the mitochondria-rich placenta primarily during the third trimester, pregnancy is associated with elevated levels of oxidative stress. This study was designed to determine the effects of daily consumption of probiotic yogurt on oxidative stress among Iranian pregnant women. Methods: This randomized single-blind controlled clinical trial was performed among 70 pregnant women, singleton primigravida, aged 18-30 in their third trimester. Subjects were randomly assigned to two groups to consume 200 g/day of either conventional yogurt (n = 33) or probiotic yogurt (n = 37) for 9 weeks. Fasting blood samples were taken at baseline and after a 9-week intervention to measure oxidative stress parameters. Results: Consumption of probiotic yogurt resulted in increased erythrocyte glutathione reductase (GR) levels as compared to the conventional yogurt (p = 0.01). Despite the significant effect of probiotic yogurt consumption on plasma glutathione (67.9 µmol/l, p = 0.01), erythrocyte glutathione peroxidase (163 mmol/min/ml, p = 0.04) and serum 8-oxo-7,8-dihydroguanine levels (-74.3 ng/ml, p = 0.04), no significant differences were found between the two yogurts in terms of their effects on the mentioned parameters. Conclusion: Consumption of probiotic yogurt among pregnant women resulted in increased levels of erythrocyte GR as compared to the conventional yogurt, but could not affect other indices of oxidative stress.

RETRACTED ARTICLE: Effect of daily consumption of probiotic yoghurt on lipid profiles in pregnant women: a randomized controlled clinical trial

Statement of Retraction We, the Editor and Publisher of The Journal of Maternal-Fetal & Neonatal Medicine, have retracted the following article: Zatollah Asemi, Mansoreh Samimi, Zohreh Tabasi, Parisa Talebian, Zohreh Azarbad, Zahra Hydarzadeh & Ahmad Esmaillzadeh (2012), Effect of daily consumption of probiotic yoghurt on lipid profiles in pregnant women: a randomized controlled clinical trial. The Journal of Maternal-Fetal & Neonatal Medicine, 25:9, 1552-1556, DOI: 10.3109/14767058.2011.640372 Following publication, significant concerns were raised by a third party[1] about the integrity of the data and the reported findings in the article. When approached for an explanation, the authors and their institution have been cooperative in providing some original data and documents. In order to verify the reported findings, the article and the original data provided by the authors were sent for review by an external statistical reviewer. Both the journal editorial team and the external statistical reviewer were unable to confirm the integrity of the trial design and the main outcome of the external review was that the article’s conclusions are unreliable. Therefore, as the editorial team no longer have confidence in the reported conclusions the decision has been made to retract the article. The authors listed in the publication have been informed. The authors do not agree with the retraction. We have been informed in our decision-making by our editorial policies and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ’Retracted’.

Probiotic yogurt consumption may improve gastrointestinal symptoms, productivity, and nutritional intake of people living with human immunodeficiency virus in Mwanza, Tanzania

The gut-associated lymphoid tissue is a major site of human immunodeficiency virus (HIV) activity and significantly influences disease prognosis. Reducing immune activation due to gastroenteritis may thus help slow disease progression. Probiotic microorganisms have considerable immunomodulatory effects at the level of the gut-associated lymphoid tissue. A probiotic yogurt initiative was thus established in Mwanza, Tanzania, to improve gastrointestinal (GI) integrity and reduce the incidence and severity of opportunistic infections among people with HIV. The research objective was to retrospectively evaluate the effects of yogurt supplemented with Lactobacillus rhamnosus as an adjunct to the diet of people living with HIV on systemic and GI symptoms, daily routine activities, and nutritional intake. Eighty-five people with HIV consuming probiotic yogurt and 86 controls were interviewed. Demographics and HIV disease stage were comparable between groups. Probiotic yogurt consumers reported an ability to work a median of 2 hours more daily (P = .01), experienced a lower fever incidence (P = .01), and were more likely to achieve daily nutrient requirements for vitamin A, several B complex vitamins, and calcium (P = .02). Antiretroviral users experienced less drug-induced stomach pain (P = .02) and a lower overall impact of GI symptoms on routine activities (P = .03). The results of this study need be further substantiated because of limits imposed by the observational, retrospective study design; however, results suggest that yogurt supplemented with L rhamnosus may effectively alleviate GI symptoms and improve productivity, nutritional intake, and tolerance to antiretroviral treatment among people with HIV in Mwanza.

Probiotic yogurt improves antioxidant status in type 2 diabetic patients

ObjectiveOxidative stress plays a major role in the pathogenesis and progression of diabetes. Among various functional foods with an antioxidant effect, probiotic foods have been reported to repress oxidative stress. The objective of this clinical trial was to assess the effects of probiotic and conventional yogurt on blood glucose and antioxidant status in type 2 diabetic patients. MethodsSixty-four patients with type 2 diabetes mellitus, 30 to 60 y old, were assigned to two groups in this randomized, double-blind, controlled clinical trial. The patients in the intervention group consumed 300 g/d of probiotic yogurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and those in the control group consumed 300 g/d of conventional yogurt for 6 wk. Fasting blood samples, 24-h dietary recalls, and anthropometric measurements were collected at the baseline and at the end of the trial. ResultsProbiotic yogurt significantly decreased fasting blood glucose (P < 0.01) and hemoglobin A1c (P < 0.05) and increased erythrocyte superoxide dismutase and glutathione peroxidase activities and total antioxidant status (P < 0.05) compared with the control group. In addition, the serum malondialdehyde concentration significantly decreased compared with the baseline value in both groups (P < 0.05). No significant changes from baseline were shown in insulin concentration and erythrocyte catalase activity within either group (P > 0.05). ConclusionThe consumption of probiotic yogurt improved fasting blood glucose and antioxidant status in type 2 diabetic patients. These results suggest that probiotic yogurt is a promising agent for diabetes management.

Effect of probiotic yogurt containing Lactobacillus acidophilus and Bifidobacterium lactis on lipid profile in individuals with type 2 diabetes mellitus

The purpose of this study was to investigate the effects of probiotic and conventional yogurt on the lipid profile in type 2 diabetic people. In a randomized double-blind controlled trial, 60 people (23 males and 37 females) with type 2 diabetes and low-density lipoprotein cholesterol (LDL-C) greater than 2.6 mmol/L were assigned to 2 groups. Participants consumed daily 300g of probiotic yogurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 or 300g of conventional yogurt for 6 wk. Fasting blood samples, anthropometric measurements and 3-d, 24-h dietary recalls were collected at the baseline and at the end of the trial. Probiotic yogurt consumption caused a 4.54% decrease in total cholesterol and a 7.45% decrease in LDL-C compared with the control group. No significant changes from baseline were shown in triglyceride and high-density lipoprotein cholesterol (HDL-C) in the probiotic group. The total cholesterol:HDL-C ratio and LDL-C:HDL-C ratio as atherogenic indices significantly decreased in the probiotic group compared with the control group. Probiotic yogurt improved total cholesterol and LDL-C concentrations in type 2 diabetic people and may contribute to the improvement of cardiovascular disease risk factors.

Effects of Daily Consumption of Probiotic Yoghurt on Inflammatory Factors in Pregnant Women: A Randomized Controlled Trial

Previous studies have shown that inflammatory factors increases in pregnancy and is associated with several complications of pregnancy. The aim of this study was to assess effects of daily consumption of probiotic yoghurt on inflammatory factors in pregnant women. In a randomized clinical trial, seventy primigravid (the first pregnancy) and singleton pregnant women aged 18-30 years were assigned to two groups. Subjects consumed daily 200 g probiotic yoghurt containing Lactobacillus acidophilus La5 and Bifidobacterium animalis BB12 (10(7) CFU g(-1) for each) or 200 g conventional yoghurt for 9 weeks. Fasting blood samples were collected at baseline (28 weeks of gestation) and after intervention (37 weeks of gestation). Inflammatory factors, hs-CRP and TNF-alpha, were measured by Enzyme-linked Immunosorbent Assay (ELISA). Independent t-test was used to compare the two groups after intervention and paired-sample t-test compared variables before and after treatment. The results showed that the probiotic yogurt brought about a decrease in the serum hs-CRP level, from 10.44 +/- 1.56 to 7.44 +/- 1.03 microg mL(-1) (p = 0.041). There was no significant change in the conventional yogurt group in the serum hs-CRP level (12.55 +/- 1.57 to 14.51 +/- 1.62 microg mL(-1), p = 0.202). The probiotic yogurt had no effect on TNF-alpha (from 73.75 +/- 6.59 to 77.91 +/- 5.61 pg mL(-1), p = 0.633). Serum TNF-alpha did not change in the conventional yogurt group (p = 0.134). In conclusion probiotic yogurt significantly decreased hs-CRP in pregnant women but had no effect on TNF-alpha.

Macrophages of the mucosa-associated lymphoid tissue (MALT) as key elements of the immune response to vitamin D binding protein-macrophage activating factor

Macrophages are key elements of the immune response and vitamin D binding protein-macrophage activating factor (DBP-MAF, also known as GcMAF) has been successfully used in treatment of immunodeficiency (J Med Virol 81:16-26, 2009). Here we report the effects of DBP-MAF on the immune system of HIV/AIDS patients as well as the effects of an original probiotic preparation, putatively containing DBP-MAF. Eight HIV/AIDS patients were treated with 100 ng/week DBP-MAF (from www.gcmaf.eu) i.v. for 15 weeks. During treatment, patients did not assume antiretroviral drugs. Blood monocyte count rose in six patients, indicating a response to DBP-MAF consistent with the effects of DBP-MAF described in Immunol Cell Biol 76:237-44, 1998. Individual response appeared to be associated with vitamin D receptor (VDR) gene polymorphisms ( BsmI and FokI ). Within the time frame of administration, however, no significant increase in CD4 cell count or decrease in viral load was observed. Therefore, searching for an alternative approach, we tested an original milk-derivative (MAF 3 14®) that contains microorganisms introduced in order to maximize natural DBP-MAF production. We hypothesized that natural DBP-MAF, once ingested, activated the Mucosa-Associated Lymphoid Tissue (MALT) widely diffused in the walls of the entire gastrointestinal tract. In fact, enzymes of certain strains of microorganisms contained in yogurt and kefir are able to convert milk Gc-protein into active DBP-MAF and it is known that kefir modulates the immune response in mice, increasing the phagocytic activity (i.e. activating) of peritoneal and pulmonary macrophages (Immunobiology 211:149-56, 2006). It is also known that probiotic yogurt consumption is associated with an increase of CD4 count among people living with HIV/AIDS (J Clin Gastroenterol 44:e201-5, 2010). Thus, members of the research team consumed 125 ml/day of MAF 3 14® for three weeks. Participants did not assume any drug or supplement and did not modify their usual diet and lifestyle. Blood analyses were performed two weeks before beginning consumption, and after three week consumption. After three week consumption, CD4 count dramatically increased in those of us who started with low CD4 count (subject # 1, before consumption CD4: 372; CD8: 206. After consumption: CD4: 609; CD8: 448), or abnormal CD4/CD8 ratio (subject # 2, before consumption: CD4: 857; CD8: 794. After consumption: CD4: 1279; CD8: 640). Also these effects appeared to be associated with VDR gene polymorphisms.

Probiotic Yogurt Consumption is Associated With an Increase of CD4 Count Among People Living With HIV/AIDS

To evaluate the long term effect of yogurt supplemented with Lactobacillus rhamnosus Fiti on the immune function (CD4 count) of people living with HIV/AIDS. Gastrointestinal infections and the leakage of microbial products from the gut have a profound impact on the deterioration of the immune system among people living with HIV/AIDS. Among persons not infected with the virus, probiotics can prevent gastrointestinal infections and restore an effective gut barrier, suggesting they might have a beneficial effect on the immune function of people living with HIV/AIDS. We carried out an observational retrospective study over a period of 3 years, with longitudinal comparison of the CD4 count within participants (n=68) before and during probiotic yogurt consumption, and compared with a control group of participants not consuming the yogurt (n=82). Among the yogurt consumers before use and the nonconsumers, an average increase in CD4 count was seen of 0.13 cells/μL/day (95% CI; 0.07-0.20, P=<0.001). After commencing consumption, yogurt consumers experienced an additional increase of 0.28 cells/μL/day (95% CI; 0.10-0.46, P=0.003). When adjusting for length of time using antiretroviral medication, the additional increase explained by yogurt consumption remained 0.17 cells/μL/day (95% CI; 0.01-0.34, P=0.04). Treatment with antiretroviral medication was associated with an increase of 0.27 cells/μL/day (95% CI; 0.17-0.38, P=<0.001). The introduction of probiotic yogurt, made by local women in a low-income community in Tanzania, was significantly associated with an increase in CD4 count among consumers living with HIV.

No causal link between obesity and probiotics

1that probiotics increase the risk of obesity. The impact of probiotics in farm animals has been shown to include: an increase in size and weight but not in fat mass 2,3 ; a reduction in fat mass in farm animals that are gaining weight 4,5 ; or no impact on growth 6 . In the livestock industry, probiotics are used to promote growth and lean mass, not adiposity. These observations are consistent with weight gain resulting from improved gut function and resistance to infection rather than from a metabolic imbalance that causes obesity. No human study cited by Raoult showed a statistically significant increase in weight gain for subjects who were given probiot ics compared to those who were given a placebo 7,8 . In spite of the widespread use of probiotics in modern and traditional diets, there is no evidence that the consumption of probiotics leads to weight gain in healthy people. Most probiotics are delivered as dairy products, and in the USA, where levels of obesity are high, consumption of probiotic yogurt (4 kg per person per year) is substantially lower than that in countries such as France, Finland and Japan, where obesity rates are low. The data showing an association between obesity and both a reduction in the levels of Gram-negative bacteria and an increase in the levels of Firmicutes in the gut are mainly based on statistical correlations that cannot distinguish between cause and consequence. Furthemore, these data have been partly con tradicted by numerous other studies, includ ing that of Turnbaugh et al. 9 , which revealed a higher proportion of Actinobacteria and a lower proportion of Bacteroidetes among obese subjects but no significant difference in Firmicute levels. In other studies, comparisons of microbiota using real-time PCR revealed a higher Bacteroidetes/Firmicutes ratio among overweight and obese subjects than among lean ones 10 . At least one study has shown a resultant decrease in body weight and fat mass in obese individuals taking prebiotics 11 . The consumption of probiotics does not lead to any sustained compositional change in the gut microbiota, and there is no suggestion from a multitude of human studies that weight gain is a side effect of probiotic consumption. Probiotic-induced weight gain in ill or undernourished sub jects, which might result from improved gut function, is not an adverse outcome. Unfortunately, Raoult confuses probiotics (live microbes) and prebiotics (selectively fermented substrates for beneficial colonizing microbes) and is inaccurate with regard to the microbio logical identity of different probiotics. Strains of the Bifidobacterium genus, commonly used as probiotics and indicted by Raoult as contributors to increased levels of Firmicutes, are in fact members of the phylum Actinobacteria. Furthermore, there are important strain-to-strain

Cholesterol-Lowering Effect of Probiotic Yogurt in Comparison with Ordinary Yogurt in Mildly to Moderately Hypercholesterolemic Subjects

Background and Aims: Hypercholesterolemia is the most important risk factor for cardiovascular diseases. In this study, we compared the effect of consuming probiotic yogurt with that of ordinary yogurt on serum cholesterol level in mildly to moderately hypercholesterolemic subjects. Methods: This randomized and crossover trial included 14 healthy subjects with serum total cholesterol 5.17–7.76 mmol/l. They did not consume yogurt for a 2-week prestudy period and added 300 g/day of milk to their diet. After this period, they were randomly allocated to 2 groups to receive either 300 g of ordinary yogurt or probiotic yogurt (fermented with a starter composed of Lactobacillus acidophilus and Bifidobacterium lactis in addition to bacteria in ordinary yogurt) for 6 weeks as a substitution for milk. After a 4-week washout period, the crossover was made and the study lasted for another 6 weeks. Blood lipid tests were done at the beginning and at the end of each period. Results: Consumption of probiotic yogurt in comparison with ordinary yogurt caused a significant decrease in serum total cholesterol (p < 0.05). Comparison of other blood lipid indices did not show any significant differences between these 2 periods. Conclusion: Yogurt containing two probiotic bacteria strains, L. acidophilus and B. lactis, had a cholesterol-lowering effect in hypercholesterolemic subjects.

Reduction of salivary mutans streptococci in orthodontic patients during daily consumption of yoghurt containing probiotic bacteria

Previous studies have suggested that probiotic supplements in dairy products may affect the oral microbial ecology, but the effect in orthodontic patients has not previously been reported. The aim of the present study was to examine whether short-term consumption of fruit yogurt containing probiotic bifidobacteria would affect the levels of salivary mutans streptococci and lactobacilli in patients with fixed orthodontic appliances. A double-blind, randomized crossover study was performed and 24 healthy adolescents (12-16 years) undergoing orthodontic treatment were followed over four periods. During periods 2 and 4 (2 weeks each), the subjects ingested 200 g fruit yogurt containing Bifidobacterium animalis subsp. lactis DN-173010 (2 x 10(8) colony forming units/g) once daily or a control yogurt without viable bacteria. Periods 1 and 3 were run-in and wash-out periods of 1 and 6 weeks, respectively. Salivary mutans streptococci and lactobacilli were enumerated with chair-side kits before and after the yogurt consumption periods. Pre- and post-treatment values within each regimen were compared with a two-tailed marginal homogeneity test for categorical data. A statistically significant reduction of salivary mutans streptococci was recorded after probiotic yogurt consumption (P < 0.05), which was in contrast to the control yogurt. No significant alterations of the salivary lactobacilli counts were observed. Short-term daily consumption of fruit yogurt containing Bifidobacterium animalis subsp. lactis DN-173010 may reduce the levels of mutans streptococci in saliva during orthodontic treatment with fixed appliances.

Impact of consumption of probiotic lactobacilli-containing yogurt on microbial composition in human feces

An in vivo study was carried out to determine the effect of consuming probiotic lactobacilli-containing yogurt on the composition of microbiota in the human gut. Fifteen healthy adults ingested a daily serving of one of three commercial yogurts (two of the products contained a probiotic lactobacilli strain) for 20 days. Fecal samples at defined time points before, during, and after the period of yogurt ingestion were collected and analyzed. The fecal population of lactobacilli was determined by a culture-based method and subsequent colony PCR for the identification of species. Six predominant bacterial groups in the fecal samples were quantitatively determined based on a sequence-specific SSU rRNA cleavage method coupled with a suite of oligonucleotide probes, which was optimized for the target-specific detection of bacterial groups inhabiting human feces. In the ingestion period, one probiotic strain was detected in the feces of all five subjects who consumed the yogurt containing the strain, while the other strain was detected in three of another five subjects. The population levels of the two major groups ( Bacteroides and Prevotella, and the Clostridium coccoides– Eubacterium rectale group) in the fecal samples tended to change in response to the ingestion but the change did not seem to be dependent on the product-specific property of each yogurt. These results suggest that the human fecal bacterial community could be altered by ingesting yogurt, although whether probiotic lactobacilli are present or absent in the yogurt does not seem to be a factor in this change.

Diversity and temporal stability of fecal bacterial populations in elderly subjects consuming galacto-oligosaccharide containing probiotic yoghurt

Denaturing gradient gel electrophoresis was applied to study the effect of 3-week consumption of probiotic yoghurt containing galacto-oligosaccharides (GOS) on intra-individual diversity and temporal stability of predominant bacterial, bifidobacterial, Lactobacillus-group, and Erec-group Eubacterium rectale– Clostridium coccoides fecal populations of elderly subjects. Diversity and temporal stability of the selected bacterial groups of elderly subjects were compared with those obtained from younger adults in our previous studies. In the present study, GOS-yoghurt consumption did not significantly affect diversity or temporal stability of the selected bacterial groups. On average, the Erec-group and the predominant bacterial and bifidobacterial populations remained almost stable, and the Lactobacillus-group was unstable in elderly subjects. No differences were found between elderly and younger adults in temporal stability of studied bacterial populations. However, the difference in diversity of predominant bacterial population and Erec-group bacteria was significantly higher in elderly subjects of this study as compared with younger adults from our previous studies.

Probiotic, as well as conventional yogurt, can enhance the stimulated production of proinflammatory cytokines

Lactic acid bacteria have been shown to stimulate the secretion of cytokines by lymphocytes and monocytes in a strain-dependent manner. Therefore, in this study, the effect of a daily intake of probiotic yogurt on cytokine production in young healthy women was compared with that of a conventional product. For 2 weeks each, subjects consumed 100 g, then 200 g of either a probiotic or a conventional, commercially available yogurt, both containing Lactobacillus bulgaricus and Streptococcus thermophilus with additional Lactobacillus casei DN 114 001 in the probiotic product. Cytokine production in blood culture following stimulation with phytohaemmaglutinin and lipopolysaccharide was measured using Cytometric Bead Array and enzyme-linked immunosorbent assay. Stimulated production of tumour necrosis factor-alpha increased significantly following consumption of conventional or probiotic yogurt (+63% and +24% compared with baseline, respectively, P < 0.001). There was also a significantly higher production of interleukin (IL)-1beta in the conventional (+40%, P = 0.006) and of interferon gamma in the probiotic group (+108%, P < 0.05). IL-10 decreased following consumption of the probiotic product, but increased significantly after intake cessation (+129%, P < 0.001). No significant differences in cytokine responses between the conventional and the probiotic yogurt were observed. Both conventional and probiotic yogurt enhanced the stimulated production of pro-inflammatory cytokines.