Yogurt and gut function

Yogurt protects against growth retardation in weanling rats fed diets high in phytic acid

The purpose of this study was to determine the effects of adding yogurt to animal diets that were high in phytic acid (PA) and adequate in zinc (38 microg Zn/g). The PA:Zn molar ratio was 60:1. Zinc status was determined by documenting growth and measuring the zinc concentration in bone (tibia) and plasma. For 25 days, six groups (n=6) of Sprague-Dawley weanling rats were fed one of six AIN-76 diets. Half of the diets contained PA. Four of the diets contained yogurt with either active or heat-treated (inactive) cultures added at 25% of the diet. The diets were as follows: (a) AIN, (b) AIN with active yogurt, (c) AIN and inactive yogurt, (d) AIN with PA, (e) AIN with PA plus active yogurt and (f) AIN with PA plus inactive yogurt. Body weight, weight gain and zinc concentration in bone and plasma were measured, and food efficiency ratio was calculated. Rats fed diets with PA and yogurt had normal growth compared to the control group. Growth retardation was evident in the group fed the diet with PA and no yogurt. This group had significantly lower body weight compared to all other groups (P<.05). Rats fed diets with PA, with or without yogurt, had significantly lower zinc concentration in bone and plasma (P<.05). Adding yogurt to diets high in PA resulted in normal growth in weanling rats; however, zinc concentration in bone and plasma was still suboptimal.

Two stomach-originated lactobacillus strains improve Helicobacter pylori infected murine gastritis

AIM: To investigate the potential anti-Helicobacter pylori (H. pylori) and anti-inflammation in vivo effects of two lactobacillus strains from human stomach.

METHODS: Forty H. pylori infected Balb/c mice were randomly divided into 4 groups: proton pump inhibitor and antibiotics triple treated group, Lactobacillus fermenti (L. fermenti) treated group, Lactobacillus acidophilus treated group and normal saline control group. Ten uninfected mice were also included as blank control group. The infection of H. pylori was detected by rapid urease tests, Giemsa staining and bacterial culture. The colonization of H. pylori was assessed in bacterial density score and gastric inflammation was assessed in histological score. The colonization of L. fermenti was performed by fluorescent probe.

RESULTS: Histopathologic evaluation showed significant release of mucosal inflammation in gastric antrum and gastric body in lactobacillus treated groups and triple treated group. H. pylori eradication rate in both lactobacillus treated groups and triple treated group were higher than normal saline control group. Lactobacillus treated groups and triple treated group showed significant decrease of H. pylori bacterial density.

CONCLUSION: Both lactobacillus strains have a significant anti-H. pylori activity; L. fermenti displays more efficient antagonistic activity in vivo against H. pylori infection.

Yoghurt and dairy snacks presented for sale to an Australian consumer: are they becoming less healthy?

OBJECTIVE

To assess the nutrient profile of yoghurts and dairy desserts.

DESIGN

Nutrition information panels and product labels on yoghurts and dairy desserts offered for sale were surveyed in 2005 and 2008 and nutrients analysed by two nutrient profiling systems.

SETTING

A large supermarket in metropolitan Melbourne, Australia.

RESULTS

In total, 248 and 140 dairy snacks (yoghurt, fromage frais or dairy desserts) were surveyed in 2005 and 2008, respectively. Over this time, median packet size rose significantly (P < or = 0.001). In yoghurts, median energy and total fat content also increased while protein decreased (all P < 0.05). The proportion of 'full-fat' products rose from 36 % to 46%. Because of the addition of sugar, most 'reduced-fat' yoghurts had energy content similar to many 'full-fat' yoghurts. Overall, the proportion of yoghurts and dairy desserts that were 'less healthy' (i.e. displaying one or more 'red traffic lights' for high fat, saturated fat, salt and sugar content) rose from 12% in 2005 to 23% in 2008. Only 1-2% could be deemed 'healthy' by the most stringent criterion (displaying four 'green traffic lights'), while 21% (2005) or 28% (2008) were 'healthy' by a nutrient profiling system that included a score for protein. Sucrose, the most common sweetener, was found in levels up to 29 g/100 g. Claims on packaging mainly related to Ca, fat or protein content. Few labels referred to sugar content.

CONCLUSIONS

The deterioration in nutrient quality of yoghurts needs to be redressed.

Consumption of a fermented dairy product containing the probiotic Lactobacillus casei DN-114001 reduces the duration of respiratory infections in the elderly in a randomised controlled trial

Common infectious diseases (CID) of the airways and the gastrointestinal tract are still a considerable cause of morbidity and mortality in elderly. The present study examined the beneficial effect of a dairy product containing the probiotic strain Lactobacillus casei DN-114 001 (fermented product) on the resistance of free-living elderly to CID. The study was multicentric, double blind and controlled, involving 1072 volunteers (median age = 76.0 years) randomised for consumption of either 200 g/d of fermented (n 537) or control (non-fermented) dairy product (n 535) for 3 months, followed by an additional 1 month's follow-up. The results showed that, when considering all CID, the fermented product significantly reduced the average duration per episode of CID (6.5 v. 8 d in control group; P = 0.008) and the cumulative duration of CID (7 v. 8 d in control group; P = 0.009). Reduction in both episode and cumulative durations was also significant for all upper respiratory tract infections (URTI; P < 0.001) and for rhinopharyngitis (P < 0.001). This was accompanied with an increase of L. casei species in stools throughout the fermented product consumption (2-3.8 x 107 equivalents of colony-forming unit/g of stools, P < 0.001). The cumulative number of CID (primary outcome) was not different between groups nor was the CID severity, fever, pathogens' occurrence, medication, immune blood parameters and quality of life. The fermented product was safe and well tolerated. In conclusion, consumption of a fermented dairy product containing the probiotic strain L. casei DN-114 001 in elderly was associated with a decreased duration of CID in comparison with the control group, especially for URTI such as rhinopharyngitis.

Characterization of four plasmids harboured in a Lactobacillus brevis strain encoding a novel bacteriocin, brevicin 925A, and construction of a shuttle vector for lactic acid bacteria and Escherichia coli

In this study we isolated over 250 lactic acid bacteria (LAB) candidates from fruit, flowers, vegetables and a fermented food to generate an LAB library. One strain, designated 925A, isolated from kimchi (a traditional Korean fermented dish made from Chinese cabbage) produced a novel type of bacteriocin, brevicin 925A, which is effective against certain LAB, including strains of Lactobacillus, Enterococcus, Streptococcus, Bacillus and Listeria. Strain 925A, identified as Lactobacillus brevis, harboured at least four plasmids and we determined the entire nucleotide sequence of each one. The four plasmids were designated pLB925A01-04, and have molecular sizes of 1815, 3524, 8881 and 65 037 bp, respectively. We obtained bacteriocin non-producing derivatives by treatment of strain 925A with novobiocin. All of these derivatives, which were susceptible to their own antibacterial product, lost the largest plasmid, pLB925A04, suggesting that the genes for bacteriocin biosynthesis (breB and breC) and immunity (breE) are located on pLB925A04. The partial amino acid sequence of purified brevicin 925A and sequence analysis of pLB925A04 showed that breB is the structural gene for brevicin 925A. We constructed a shuttle vector (pLES003, 6134 bp) that can replicate in both Escherichia coli and LAB such as Lactobacillus plantarum, Lb. brevis, Lactobacillus helveticus, Lactobacillus hilgardii and Enterococcus hirae. To determine the function of gene breE, which displays no significant similarity to any other sequences in the blast search database, the gene was inserted into pLES003. A pLB925A04-cured derivative transformed with pLES003 carrying breE acquired immunity to brevicin 925A, suggesting that breE encodes an immunity protein.

Inhibition of 1,2-dimethylhydrazine induced colon genotoxicity in rats by the administration of probiotic curd

Epidemiologic and experimental studies suggest that the probiotic organisms are effective in preventing colon carcinogenesis, which is the major cause of mortality and morbidity in western countries. Keeping this in view, a curd (a common Indian fermented milk product) was prepared by the addition of probiotic cultures Lactobacillus acidophilus, Lactobacillus casei and curd culture Lactococcus lactis biovar. diacetylactis. In present study, we have evaluated the anti tumor effect of probiotic curd by monitoring the DNA damage through comet assay. The rats were allocated to four groups, first group was DMH control group, second group was probiotic curd group in which probiotic curd was given along with DMH (1,2-dimethylhydrazine) injection, third group was normal curd group in which normal curd was given along with DMH injection and fourth group was normal control group. Animals received subcutaneous injection of DMH dissolved in normal saline at a dose rate of 20 mg/kg body weight, once weekly for 15 weeks. The rats were dissected at 40th week of experiment and comet assay was done in colonic cells to assess the DNA damage. A significant reduction in DNA damage (54.7%) was observed in probiotic curd group as compared to DMH control group (88.1%). The probiotic curd was effective to significantly reduce the L:W ratio in comparison to DMH control group and normal curd. The results of present study show the protective effects of probiotic curd against DMH induced genotoxicity in colonic cells.

Highly efficient production of the staphylococcal nuclease reporter in Lactobacillus bulgaricus governed by the promoter of the hlbA gene

Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) genome sequence analysis revealed the presence of two genes that encode histone-like HU proteins (hlbA and hlbB) showing extensive similarity to other bacterial homologues. These genes were found to be extremely conserved among several L. bulgaricus strains. The hlbA gene was shown to be constitutively transcribed from a unique promoter (phlbA) during normal growth, whereas hlbB did not seem to be expressed under usual laboratory conditions. Using a reporter cassette in which the staphylococcal nuclease was fused at its N-terminus to the lactococcal signal peptide Usp45 (SP Usp45), we have demonstrated that phlbA promotes high expression of the reporter in L. bulgaricus, which correlated with an abundant secretion of the mature nuclease in the supernatant fraction. Quantification of the exported enzyme reveals a secretion level approximately threefold higher when the expression of the reporter was under the control of phlbA compared with the lactococcal usp45 promoter. Together, these results indicate that phlbA is suitable for gene expression in L. bulgaricus, that SP Usp45 is functionally recognized and processed by the L. bulgaricus secretion machinery and that the nuclease reporter gene can be used for the identification of exported products in this bacterium.

Gut health immunomodulatory and anti-inflammatory functions of gut enzyme digested high protein micro-nutrient dietary supplement-Enprocal

BACKGROUND

Enprocal is a high-protein micro-nutrient rich formulated supplementary food designed to meet the nutritional needs of the frail elderly and be delivered to them in every day foods. We studied the potential of Enprocal to improve gut and immune health using simple and robust bioassays for gut cell proliferation, intestinal integrity/permeability, immunomodulatory, anti-inflammatory and anti-oxidative activities. Effects of Enprocal were compared with whey protein concentrate 80 (WPC), heat treated skim milk powder, and other commercially available milk derived products.

RESULTS

Enprocal (undigested) and digested (Enprocal D) selectively enhanced cell proliferation in normal human intestinal epithelial cells (FHs74-Int) and showed no cytotoxicity. In a dose dependent manner Enprocal induced cell death in Caco-2 cells (human colon adencarcinoma epithelial cells). Digested Enprocal (Enprocal D: gut enzyme cocktail treated) maintained the intestinal integrity in transepithelial resistance (TEER) assay, increased the permeability of horseradish peroxidase (HRP) and did not induce oxidative stress to the gut epithelial cells. Enprocal D upregulated the surface expression of co-stimulatory (CD40, CD86, CD80), MHC I and MHC II molecules on PMA differentiated THP-1 macrophages in coculture transwell model, and inhibited the monocyte/lymphocyte (THP-1/Jurkat E6-1 cells)-epithelial cell adhesion. In cytokine secretion analyses, Enprocal D down-regulated the secretion of proinflammatory cytokines (IL-1beta and TNF-alpha) and up-regulated IFN-gamma, IL-2 and IL-10.

CONCLUSION

Our results indicate that Enprocal creates neither oxidative injury nor cytotoxicity, stimulates normal gut cell proliferation, up regulates immune cell activation markers and may aid in the production of antibodies. Furthermore, through downregulation of proinflammatory cytokines, Enprocal appears to be beneficial in reducing the effects of chronic gut inflammatory diseases such as inflammatory bowel disease (IBD). Stimulation of normal human fetal intestinal cell proliferation without cell cytotoxicity indicates it may also be given as infant food particularly for premature babies.

Pediococcus pentosaceus NB-17 for probiotic use

The plant-derived Pediococcus pentosaceus NB-17 was isolated from Japanese traditional vegetable pickles. The production of cytokines from mouse spleen cells co-cultivated with heat-killed bacteria was investigated in vitro. The bacteria significantly induced secretion levels of interferon (IFN)-gamma and interleukin (IL)-12 p70, and suppressed IL-4 productions in ovalbumin (OVA) sensitized mouse spleen cells. Therefore, the bacteria could effectively stimulate immune activities and showed allergic inhibitory effects. Further study on acid tolerance was performed under simulated gastric conditions and NB-17 showed resistance to simulated gastric acidity at pH 3.0 and pH 2.5. Moreover, after oral administration of the intact cells to rats, bacterial colonies derived from feces were analyzed by random amplification polymorphic DNA (RAPD). It was confirmed that the administered strain NB-17 remained alive in feces. These results suggest the possibility to use the P. pentosaceus NB-17 as functional foods.

The effect of long-term lactobacilli (lactic acid bacteria) enteral treatment on the central nervous system of growing rats

The aim of this study was to explore the relationship between consumption of large doses of lactic acid bacteria (LAB) and the behaviour and brain morphobiochemistry of normal growing rats. Four groups of rats were treated with LAB cultures twice daily for 6 months. The control group received 1 ml of saline per treatment, while two experimental groups received 1 ml of living bacteria (Lactobacillus plantarum and Lactobacillus fermentum, respectively) and the remaining group received a heat-treated (inactivated) L. fermentum culture. After 2 and 6 months of treatment, respectively, eight animals from each group were sacrificed, and specimens were taken for further analyses. The behaviour of the rats was evaluated five times in an open-field test at monthly intervals throughout the study. Lactobacilli treatment for 2 months induced changes in the motoric behaviour of the rats. The concentration of the astrocytesoluble and filament glial fibrillary acidic protein (GFAP) decreased in the posterior part of the hemispheres, including the thalamus, hippocampus and cortex of the rats treated with L. fermentum. A greater decrease in filament GFAP (up to 50%) was shown in the group receiving the live form of L. fermentum. In contrast, the GFAP in the live L. plantarum-treated group increased, showing elevated levels of the soluble and filament forms of GFAP in the posterior part of the hemispheres. A 60-66% decrease in the amount of the astrocyte-specific Ca-binding protein S-100b was shown in the posterior parts of the hemispheres and in the hindbrain of rats given LAB for 2 months. Prolonged feeding with LAB for 4 months up to full adulthood led to a further decrease in astrocyte reaction, reflected as an additional decrease in the amount of soluble GFAP and locomotor activity in all experimental groups. The changes in filament GFAP and S-100b appeared to disappear after prolonged feeding (total of 6 months) with LAB. In summary, LAB dietary treatment affected the ontogenetic development of the astrocytes, with the highest intensity observed in the early stages of rat development. It can be postulated that LAB treatment may play a preventive role in neurological diseases by decreasing astrocyte reaction and, consequently, lowering locomotor activity.

Probiotic yogurt for the treatment of minimal hepatic encephalopathy

OBJECTIVES

Minimal hepatic encephalopathy (MHE), the preclinical stage of overt hepatic encephalopathy (OHE), is a significant condition affecting up to 60% of cirrhotics. All MHE therapies modify gut microflora, but consensus regarding MHE treatment and long-term adherence studies is lacking. The aim was to determine the effect of probiotic supplementation in the form of a food item, probiotic yogurt, on MHE reversal and adherence.

METHODS

Nonalcoholic MHE cirrhotics (defined by a standard psychometric battery) were randomized with unblinded allocation to receive probiotic yogurt (with proven culture stability) or no treatment (no Rx) for 60 days in a 2:1 ratio. Quality of life (short form [SF]-36), adherence, venous ammonia, model of end-stage liver disease (MELD) scores, and inflammatory markers (tumor necrosis factor [TNF]-alpha, interleukin [IL]-6) were also measured. Outcomes were MHE reversal using blinded scoring, OHE development, and adherence.

RESULTS

Twenty-five patients (17 yogurt, 8 no Rx; 84% Child class A) were enrolled. A significantly higher percentage of yogurt patients reversed MHE compared to no Rx patients (71%vs 0%, P= 0.003, intention-to-treat). Yogurt patients demonstrated a significant improvement in number connection test-A (NCT-A), block design test (BDT), and digit symbol test (DST) compared to baseline/no Rx group. Twenty-five percent of no Rx versus 0% of yogurt patients developed OHE during the trial. Eighty-eight percent of yogurt patients were adherent. No adverse effects or change in covariates were observed. All patients who completed the yogurt arm were agreeable to continue yogurt for 6 months if needed.

CONCLUSIONS

This trial demonstrated a significant rate of MHE reversal and excellent adherence in cirrhotics after probiotic yogurt supplementation with potential for long-term adherence.

Recommendations for probiotic use--2008

Recommendations for the clinical use of probiotics were published after a Yale University Workshop in 2005. A similar workshop was held in 2007, and the recommendations were updated and extended into other areas. The recommendations are graded into an "A," "B," "C" or no category based on the expert's opinion and review by the workshop participants. An "A" recommendation is made for acute childhood diarrhea, prevention of antibiotic-associated diarrhea, preventing and maintaining remission in pouchitis, and in an immune response for the treatment and prevention of atopic eczema associated with cow's milk allergy. The group maintained several "B" recommendations in other areas of treating inflammatory bowel disease and irritable bowel syndrome. Although there are significant studies in the "B" group, most "B" recommendations did not reach an "A" level because of some negative studies or a limited number of studies. Many reports in the "C" recommendations were significant but fell short of receiving stronger ratings because of the size of reported patient studies, and also the factors that limited categories to the "B" rating.

Lactobacillus fermentum ACA-DC 179 displays probiotic potential in vitro and protects against trinitrobenzene sulfonic acid (TNBS)-induced colitis and Salmonella infection in murine models

Lactobacillus fermentum ACA-DC 179, Lactobacillus plantarum ACA-DC 287 and Streptococcus macedonicus ACA-DC 198 were studied for their probiotic potential. Firstly, strains were screened for antimicrobial activity towards a broad range of target strains, including lactic acid bacteria, food spoilage and pathogenic bacteria. L. fermentum ACA-DC 179 was active against five streptococci, including the two pathogenic strains Streptococcus oralis LMG 14532T and Streptococcus pneumoniae LMG 14545T. S. macedonicus ACA-DC 198 was active against the majority of the strains tested, including not only lactic acid bacteria but also many food spoilage or pathogenic species. The three potential probiotic strains were found to survive variably at pH 2.5 and were unaffected by bile salts. Only S. macedonicus ACA-DC 198 exhibited bile salt hydrolase activity, while none of the strains was haemolytic. Moreover, strains exhibited variable susceptibility towards commonly used antibiotics. L. plantarum ACA-DC 287 and S. macedonicus ACA-DC 198 induced the secretion of the pro-inflammatory cytokines IL-12, IFN-gamma and TNF-alpha by human peripheral blood mononuclear cells. Also elevated levels of the anti-inflammatory IL-10 were observed with L. fermentum ACA-DC 179. This strain consequently was found to significantly reduce colitis in a TNBS-induced colitis mouse model. Furthermore, L. fermentum ACA-DC 179 was successfully applied in an experimental Salmonella-infection mouse model. To conclude, strain L. fermentum ACA-DC 179 possesses desirable probiotic properties, such as antimicrobial activity and immunomodulation in vitro, which were confirmed in vivo by the use of animal models.

Effects of milk fermented by Lactobacillus gasseri SBT2055 on adipocyte size in rats

Despite adequate scientific evidence of the potential benefits of probiotics to human health or disease prevention, their contribution to the growth of adipose tissue remains to be established. Four-week-old male Sprague-Dawley rats were fed a diet containing skim milk (control diet) or skim milk fermented by Lactobacillus gasseri SBT2055 (LGSP diet) for 4 weeks. Their body weight gain, adipose tissue weight, adipocyte size distribution profile, blood and hepatic lipids, and serum leptin, glucose and adiponectin levels were determined. There was a significant reduction in average adipocyte size in mesenteric white adipose tissue (P = 0.004). Moreover, the rats fed the LGSP diet displayed greater numbers of small adipocytes from mesenteric and retroperitoneal adipose tissues than did those on the control diet. Whereas adiponectin concentrations did not differ between the groups, serum leptin concentrations were decreased to 32 % in the LGSP diet group compared with the control group. Concentrations of serum glucose and lipids, and liver lipids, except for the liver TAG level, were similar in the two groups. These results indicate a possible role for a fermented milk product in the regulation of adipose tissue growth.

Effects of yogurt and bifidobacteria supplementation on the colonic microbiota in lactose-intolerant subjects

AIMS

Colonic metabolism of lactose may play a role in lactose intolerance. We investigated whether a 2-week supplementation of Bifidobacterium longum (in capsules) and a yogurt enriched with Bifidobacterium animalis could modify the composition and metabolic activities of the colonic microbiota in 11 Chinese lactose-intolerant subjects.

METHODS AND RESULTS

The numbers of total cells, total bacteria and the Eubacterium rectale/Clostridium coccoides group in faeces as measured with fluorescent in situ hybridization and the faecal beta-galactosidase activity increased significantly during supplementation. The number of Bifidobacterium showed a tendency to increase during and after supplementation. With PCR-denaturing gradient gel electrophoresis, in subjects in which B. animalis and B. longum were not detected before supplementation, both strains were present in faeces during supplementation, but disappeared after supplementation. The degree of lactose digestion in the small intestine and the oro-caecal transit time were not different before and after supplementation, whereas symptom scores after lactose challenge decreased after supplementation.

CONCLUSIONS

The results suggest that supplementation modifies the amount and metabolic activities of the colonic microbiota and alleviates symptoms in lactose-intolerant subjects. The changes in the colonic microbiota might be among the factors modified by the supplementation which lead to the alleviation of lactose intolerance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides evidence for the possibility of managing lactose intolerance with dietary lactose (yogurt) and probiotics via modulating the colonic microbiota.

["Fast track" colorectal surgery]

Many factors have effect on the enhanced recovery after colon surgery. Not only the technical skill but the perioperative events needed to be optimized by the pre- and postoperative issues. Articles were obtained with search for keywords in Medline electronic database and evidences have been ranked according to the recommendation of the Oxford Evidence-Based Medicine Centre. Multicentric, randomised studies have proved that preoperative bowel emptying could not decrease the number of anastomotic insufficiency and wound infection rate; the use of abdominal drains is not necessary in every case; the proper, early oral intake is safe and well tolerated in colo-rectal surgery, and with laparoscopic surgery the same results can be achieved as with open ones. The evidences found even are not used completely. The advantage of laparoscopic surgery can be improved with fast track methods. To use correctly the affecting factors it is essential to know the current literature.

The genus Lactobacillus--a genomic basis for understanding its diversity

The genus Lactobacillus is a diverse group that includes many species used in food production and preservation. Some lactobacilli are considered probiotic, conferring health benefits upon the host. The heterogeneity of this genus poses challenges and opportunities when characterizing or exploiting individual strains. To date, 10 Lactobacillus genome sequences have been published, and at least 11 more sequencing projects are ongoing. These studies will dramatically improve one's understanding of metabolic processes, bioprocessing capabilities and potential roles in health and well-being of the Lactobacilli. This review describes the current status of Lactobacillus genome sequence projects, highlights the major findings and summarizes functional genomics or comparative genomics studies. The genomic basis for the unusual diversity of this genus is discussed, and the potential for comparative genomics to rigorously extend phylogenetic analysis of the Lactobacilli is described.

Acute Calcium Assimilation from Fresh or Pasteurized Yoghurt Depending on the Lactose Digestibility Status

OBJECTIVE

The major aim of this trial was to evaluate the potential interaction of fresh or pasteurized yoghurt intake with lactose intolerance on calcium assimilation by means of the stable isotope 43Ca as a tracer.

METHODS

Forty volunteers (age: 32 +/- 7 years) participated in this parallel simple blind study (20 of them with moderate lactose intolerance). The protocol included the intake of a test meal consisting on 43Ca-labelled fresh or pasteurized yoghurt. Volunteers, in whom the calcium status was assessed, collected the 24-h urine before and after the test meal to measure the stable isotope output. The intake-related 43Ca enrichment in urine was measured by isotopic rate mass spectrometry.

RESULTS

In lactose tolerant and intolerant volunteers taken together, the fresh yoghurt consumption resulted in a statistically higher circulating calcium levels (p = 0.028) and urinary 43Ca output (p = 0.017) than after the pasteurized yoghurt intake. The lactose maldigestion status resulted in higher urinary 43Ca excretion (p = 0.013) after the fermented milk consumption, regardless of the nature of ingested product (p = 0.887).

CONCLUSIONS

This novel and non-aggressive protocol allowed the in vivo comparison of calcium utilization from two different dairy sources, revealing a higher acute calcium assimilation from fresh as compared to the pasteurized yoghurt, in both lactose digesting and maldigesting subjects.

Isolation and characterization of a Lactobacillus fermentum temperate bacteriophage from Chinese yogurt

AIMS

The aim of this study was to investigate the properties of temperate bacteriophage of Lactobacillus fermentum, based on its morphology, restriction patterns, protein profile and the impact on the growth of host strain.

METHODS AND RESULTS

With Mitomycin C, seven temperate phages were induced from Lactobacilli derived from Chinese yogurt. The temperate phages induced belong to the most common Bradley's group B, having hexagonal head and long, noncontractile tail. They were furthermore confirmed to be the same bacteriophage by identical restriction patterns. SDS-PAGE profile showed that the phage studied had one major structure protein about 31.9 kDa. The presence of the prophage influenced the cell shape and colony size of its lysogenic strain.

CONCLUSIONS

The phage obtained had similar, but not complete identical properties with other L. fermentum phages reported. It influenced the growth behaviour of its lysogenic strain.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides some information about bacteriophages occurring in the Chinese yoghurt manufacture and contributes to our knowledge on the bacteriophage diversity in the dairy industry.

Dairy consumption and related nutrient intake in African-American adults and children in the United States: continuing survey of food intakes by individuals 1994-1996, 1998, and the National Health And Nutrition Examination Survey 1999-2000

OBJECTIVE

To establish the first baseline of dairy and related nutrient intake in African Americans, an at-risk population of public health concern in the United States. To document dairy consumption in African Americans by age and sex during 1994-1998 and 1999-2000 and compare it with concomitant dairy, calcium, and related nutrient intakes in non-African-American adults and children.

DESIGN

Duplicate and single 24-hour recalls were analyzed to determine dietary intake during the Continuing Survey of Food Intakes by Individuals 1994-1996, 1998 (CSFII), and the National Health and Nutrition Examination Survey 1999-2000 (NHANES), respectively.

SUBJECTS

African Americans and non-African Americans of all ages who participated in CSFII 1994-1996, 1998, and in NHANES 1999-2000; both surveys are a stratified random sample of the total civilian, noninstitutionalized US population.

STATISTICAL ANALYSIS

Dairy food and nutrient intake per day were quantified according to age, sex, and ethnicity/race from CSFII 1994-1996, 1998, and NHANES 1999-2000. For NHANES, mean intakes from 1-day food records were sample-weighted, and standard errors estimated by the Taylor linearization method of SUDAAN (version 9.0, 2004, RTI International, Research Triangle Park, NC). Usual daily intakes of calcium, magnesium, and phosphorus were based on 2-day intake data from CSFII 1994-1996, 1998, and calculated using Software for Intake Distribution from Iowa State University. The percentage of individuals categorized as not meeting the Estimated Average Requirement for magnesium and phosphorus were calculated in the same way.

RESULTS

CSFII 1994-1996, 1998, and NHANES 1999-2000 data both show that African Americans in all age groups consume fewer mean servings per day of total dairy, milk, cheese, and yogurt than non-African Americans, and have lower mean intakes of calcium, magnesium, and phosphorus. Significant differences were seen for men and women.

CONCLUSIONS

In this analysis, young African-American women did not meet Dietary Reference Intakes for phosphorus, and all African Americans did not meet Dietary Reference Intakes for calcium and magnesium. African Americans in all age groups did not meet dairy recommendations from the 2005 US Dietary Guidelines and the 2004 National Medical Association Consensus Report on the role of dairy and dairy nutrients in the diet of African Americans.

In vitro growth control of selected pathogens by Lactobacillus acidophilus- and Lactobacillus casei-fermented milk

AIMS

Food-borne pathogen inhibition was tested in the presence of a mixture of Lactobacillus acidophilus and Lactobacillus casei during fermentation under controlled pH conditions.

METHODS AND RESULTS

The growth of Escherichia coli O157:H7, Salmonella serotype Typhimurium, Staphylococcus aureus, Listeria innocua, Enterococcus faecium and Enterococcus faecalis was evaluated for 48 h at 37 degrees C. In the presence of the lactic acid bacteria (LAB), an increase of the generation time was observed for all the gram-positive bacteria evaluated. Staphylococcus aureus was the most sensitive strain showing an increase of the generation time by 210%. However, for all the gram-negative bacteria evaluated, no inhibition occurred after 8 h of fermentation. The soluble portion of Lact. acidophilus- and Lact. casei-fermented milk was recuperated and tested for its antimicrobial activity. Listeria innocua and Staph. aureus were the most sensitive to the presence of fermented milk supernatant showing an inhibition of 85.9% and 84.7%, respectively. This soluble fraction was neutralized to eliminate the antimicrobial effect of the organic acids produced; the most sensitive strains were L. innocua and E. coli O157:H7 showing an inhibition of 65.9% and 61.9%, respectively. Finally, the soluble fraction was neutralized and irradiated at 45 kGy using a (60)Co source to eliminate the possible antimicrobial effect of both organic acids and bacteriocin-like substances. Enterococcus faecalis, E. coli O157:H7 and Staph. aureus were the most affected bacteria by this fraction, showing 39.1, 32 and 31.2% inhibition, respectively.

CONCLUSIONS

The results obtained in this study suggest the implication of both organic acids and bacteriocin-like inhibitory substances in the antimicrobial activity observed in the soluble fraction of the probiotic preparation.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study revealed the antimicrobial mechanisms of action of Lact. acidophilus- and Lact. casei-fermented milk used to prevent antibiotic-associated diarrhoea.

Fermented infant formulae without live bacteria

Infant and follow-on (or "follow-up") formulae fermented with lactic acid-producing bacteria during the production process contain no viable bacteria in the final product due to their inactivation by heat or other means. In this article the ESPGHAN Committee on Nutrition reviews published information on their clinical evaluation. In a systematic literature review, 2 randomized clinical trials including 933 infants were identified as meeting our predefined inclusion criteria. Our analysis reveals that only limited published data are available on the effects of fermented infant formulae. There are indications from 2 studies that some fermented infant formulae may reduce the occurrence or severity of infectious diarrhea in infants. It is recommended that the effects of fermented infant formulae on infectious diarrhea and other relevant outcomes should be assessed in further randomized controlled trials according to current scientific standards. The available data do not allow general conclusions to be drawn on the use and effects of fermented formulae for infants.

Yoghurt containing galacto-oligosaccharides, prunes and linseed reduces the severity of mild constipation in elderly subjects

OBJECTIVE

Constipation is a common problem in the elderly. Dietary fibre is recommended for its treatment. The aim was to examine whether yoghurt containing galacto-oligosaccharides (GOS), prunes and linseed relieve constipation in elderly subjects.

DESIGN

A randomized, double-blinded, cross-over study.

SETTING

Free-living subjects.

SUBJECTS

A group of 43 elderly subjects with self-reported constipation (mean age 76 years, range 61-92 years, 32 females, 11 males).

INTERVENTIONS

The study consisted of a 2-week baseline period and 2, 3-week dietary interventions, with a 2-week wash-out period between the interventions. During the interventions, the subjects ingested, in random order, 260 g/day of either control yoghurt or test yoghurt containing GOS (12 g/day), prunes (12 g/day) and linseed (6 g/day). The use of laxatives was controlled and only allowed after 2 days without defecation.

RESULTS

Defecation frequency was 5.7 times/week during the baseline period. During the test yoghurt period, defecation frequency was higher (8.0 vs 7.1 times/week, P=0.011), defecation was easier (on the scale 0-3, 1.3 vs 1.5, P=0.010), and there was a tendency towards softer stools (on the scale 0-3, 2.1 vs 2.2, P=0.059) compared with the control yoghurt period. The subjects felt that the test yoghurt relieved constipation more effectively than the control yoghurt (P=0.005). The sum of gastrointestinal symptoms did not differ between the interventions. The use of laxatives remained constant throughout the study.

CONCLUSIONS

Daily intake of yoghurt containing GOS, prunes and linseed reduced the severity of constipation in elderly subjects with mild constipation.

SPONSORSHIP

Valio Ltd, R&D.

Saccharomyces boulardii inhibits inflammatory bowel disease by trapping T cells in mesenteric lymph nodes

BACKGROUND & AIMS

Saccharomyces boulardii is a nonpathogenic yeast used for treatment of diarrhea. We used a mice model of inflammatory bowel disease (IBD) to analyze the effects of S boulardii on inflammation.

METHODS

Lymphocyte-transferred SCID mice, displaying IBD, were fed daily with S boulardii. Weight loss and inflammatory status of the colon were monitored. Nuclear factor-kappaB activity was assessed in the colon. The CD4(+) T-cell production of interferon (IFN) gamma was evaluated by enzyme-linked immunosorbent assay, and a comprehensive reverse-transcription polymerase chain reaction (RT-PCR) analysis for both colon and mesenteric lymph nodes was performed. Finally, we analyzed cell migration mechanisms in vitro and in vivo.

RESULTS

S boulardii treatment inhibits IBD. S boulardii induces an accumulation of IFN-gamma-producing T-helper 1 cells within the mesenteric lymph nodes correlated with a diminution of CD4(+) T-cell number and IFN-gamma production by CD4+ T cells within the colon. The influence of S boulardii treatment on cell accumulation in mesenteric lymph nodes was also observed in normal BALB/c mice and involves modifications of lymph node endothelial cell adhesiveness by a yeast secretion product.

CONCLUSIONS

S boulardii has a unique action on inflammation by a specific alteration of the migratory behavior of T cells, which accumulate in mesenteric lymph nodes. Therefore, S boulardii treatment limits the infiltration of T-helper 1 cells in the inflammed colon and the amplification of inflammation induced by proinflammatory cytokines production. These results suggest that S boulardii administration may have a beneficial effect in the treatment of IBD.

Induction of heavy-metal-transporting CPX-type ATPases during acid adaptation in Lactobacillus bulgaricus

Lactobacillus bulgaricus is a lactic acid bacteria (LAB) that, through the production of lactic acid, gradually acidifies its environment during growth. In the course of this process, L. bulgaricus acquires an improved tolerance to acidity. A survey of the recently established genome sequence shows that this bacterium possesses few of the pH control functions that have been described in other LAB and raises the question of what other mechanisms could be involved in its adaptation to the decreasing environmental pH. In some bacteria other than LAB, ion transport systems have been implicated in acid adaptation. We therefore studied the expression of this type of transport system during acid adaptation in L. bulgaricus by reverse transcription and real-time quantitative PCR and mapped transcription start sites. Intriguingly, the most significantly induced were three ATPases carrying the CPX signature of heavy-metal transporters. Protein homology and the presence of a conserved sequence motif in the promoter regions of the genes encoding these proteins strongly suggest that they are involved in copper homeostasis. Induction of this system is thought to assist in avoiding indirect damage that could result from medium acidification.

Survival of yogurt bacteria in the human gut

Whether Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus can be recovered after passage through the human gut was tested by feeding 20 healthy volunteers commercial yogurt. Yogurt bacteria were found in human feces, suggesting that they can survive transit in the gastrointestinal tract.

The complete genome sequence of Lactobacillus bulgaricus reveals extensive and ongoing reductive evolution

Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) is a representative of the group of lactic acid-producing bacteria, mainly known for its worldwide application in yogurt production. The genome sequence of this bacterium has been determined and shows the signs of ongoing specialization, with a substantial number of pseudogenes and incomplete metabolic pathways and relatively few regulatory functions. Several unique features of the L. bulgaricus genome support the hypothesis that the genome is in a phase of rapid evolution. (i) Exceptionally high numbers of rRNA and tRNA genes with regard to genome size may indicate that the L. bulgaricus genome has known a recent phase of important size reduction, in agreement with the observed high frequency of gene inactivation and elimination; (ii) a much higher GC content at codon position 3 than expected on the basis of the overall GC content suggests that the composition of the genome is evolving toward a higher GC content; and (iii) the presence of a 47.5-kbp inverted repeat in the replication termination region, an extremely rare feature in bacterial genomes, may be interpreted as a transient stage in genome evolution. The results indicate the adaptation of L. bulgaricus from a plant-associated habitat to the stable protein and lactose-rich milk environment through the loss of superfluous functions and protocooperation with Streptococcus thermophilus.

Yoghurt accelerates the recovery of defence mechanisms against Streptococcus pneumoniae in protein-malnourished mice

Experiments studied the effect of yoghurt on the recovery of defence mechanisms against Streptococcus pneumoniae respiratory infection in malnourished mice. Weaned mice were malnourished with a protein-free diet (PFD) for 21 d. Malnourished mice were made replete with a balanced diet (BD), yoghurt, or the BD with supplemental yoghurt (BD + Y) for 7, 14 or 21 d. The normal control (NC) group was fed the BD whereas malnourished control (MC) mice consumed only the PFD. Mice were challenged with pneumococci at the end of each dietary treatment. MC mice showed increased susceptibility to pneumococcal infection. Blood leucocytes, phagocyte activity and serum and bronco-alveolar anti-pneumococcal IgG and IgA were significantly lower in the MC than in the NC group. Repletion of malnourished mice with the BD for 21 d was necessary to obtain a response to infection similar to that of NC mice; however, administration of the BD + Y for 14 d was enough to normalise the immune defence mechanisms. Histological examination of MC lungs showed progressive loss of alveolar architecture. Lung injuries were significantly less pronounced in NC mice. Mice treated with the BD + Y for 14 d showed histological signs similar to the NC group. The present study showed that administration of yoghurt to malnourished mice induced an early recovery of the immunological parameters studied. Despite the uncertainties about the mechanisms involved and about the human relevance of the effects observed in animal models, the present study provides a strong rationale for the hypothesis that yoghurt consumption by malnourished hosts will accelerate the recovery of the immune mechanisms involved in the protection against respiratory infections.

Effects of a nutritional intervention with yogurt on lymphocyte subsets and cytokine production capacity in anorexia nervosa patients

BACKGROUND

The benefits of probiotic therapy in immunocompromised subjects still need strong scientific evidences.

AIM OF THE STUDY

To assess the effects of yogurt on certain immunological parameters in anorexia nervosa (AN) patients during refeeding.

METHODS

A parallel 10-week nutritional intervention with yogurt was conducted on a group of patients with AN and on a group of healthy adolescents (HA). In total, 16 AN patients and 16 HA consumed 375 g/d of yogurt containing L. bulgaricus and S. thermophilus (groups AN-y and HA-y, respectively). The control groups for AN patients (n = 14) and healthy subjects (n = 19) consumed 400 ml/d of semi-skimmed milk (groups AN-c and HA-c, respectively). Blood lymphocyte subsets were assessed by flow cytometry and the in vitro production of IL-2, IFN-gamma, IL-1, IL-6 and TNF-alpha by PHA-stimulated PBMC was measured by ELISA.

RESULTS

A significant combined effect of time and nutritional intervention was found for the CD8+ subset and IFN-gamma production, both in HA and AN patients. The CD8+ subset showed a significant increase after 10 weeks in HA-c and AN-c. As a consequence, the CD4+/CD8+ ratio was significantly lower in AN-c than in AN-y after treatment. A significant increase in IFN-gamma production was found after yogurt intake in AN-y, while it decreased significantly in AN-c.

CONCLUSION

The findings suggest that the inclusion of yogurt in the refeeding therapy of AN patients may exert positive effects on the immunological markers related to the nutritional status of these patients, such as the CD4+/CD8+ ratio and the production of IFN-gamma by lymphocytes.

Management and treatment of lactose malabsorption

Lactose malabsorption is a very common condition characterized by intestinal lactase deficiency. Primary lactose malabsorption is an inherited deficit present in the majority of the world’s population, while secondary hypolactasia can be the consequence of an intestinal disease. The presence of malabsorbed lactose in the colonic lumen causes gastrointestinal symptoms. The condition is known as lactose intolerance. In patients with lactase nonpersistence, treatment should be considered exclusively if intolerance symptoms are present. In the absence of guidelines, the common therapeutic approach tends to exclude milk and dairy products from the diet. However, this strategy may have serious nutritional disadvantages. Several studies have been carried out to find alternative approaches, such as exogenous β-galactosidase, yogurt and probiotics for their bacterial lactase activity, pharmacological and non pharmacological strategies that can prolong contact time between enzyme and substrate delaying gastrointestinal transit time, and chronic lactose ingestion to enhance colonic adaptation. In this review the usefulness of these approaches is discussed and a therapeutic management with a flow chart is proposed.

The addition of milk or yogurt to a plant-based diet increases zinc bioavailability but does not affect iron bioavailability in women

The addition of milk and milk-based products to the diets of individuals subsisting on plant-based diets was reported to have positive effects on nutritional status and functional outcomes such as growth, morbidity, and cognition. We examined the effect of the addition of milk or yogurt on the bioavailability of zinc and iron from a plant-based rural diet. The subjects were 48 Mexican women (30.9 +/- 5.7 y) who habitually consumed a plant-based diet. The women were assigned to 1 of 3 groups: 1) the typical rural Mexican diet, 2) that diet with milk added, or 3) that diet with yogurt for 13 d. Zinc absorption was measured after extrinsically labeling meals with (67)Zn and an i.v. dose of (70)Zn; iron absorption was measured by extrinsically labeling meals with (58)Fe and a reference oral dose of (57)Fe. Including milk and yogurt in the diet increased zinc absorption by 50 and 68%, respectively (P < 0.05). The 3 groups did not differ in the percentage iron absorption. The total amount of zinc absorbed was increased (P < 0.05) by 70% when milk was added to the meal and 78% when yogurt was added. The total amount of iron absorbed did not differ among the groups. The addition of milk and yogurt to a plant-based diet high in phytate increases zinc bioavailability without affecting iron bioavailability.