Increase of intestinal Bifidobacterium and suppression of coliform bacteria with short-term yogurt ingestion

Microbial production of lactic acid from food waste: Latest advances, limits, and perspectives

A significant amount of food waste (FW) is produced every year. If it is not disposed of timeously, human health and the ecological environment can be negatively affected. Lactic acid (LA), a high value-added product, can be produced by fermentation from FW as a substrate, realizing the concurrent treatment and recycling of FW, which has attracted increasing research interest. In this paper, the latest advances and deficiencies were presented from the following aspects: microorganisms involved in LA fermentation and the metabolic pathways of Lactobacillus, fermentation conditions, and methods of enhanced biotransformation and LA separation. The limitations of the LA fermentation of FW are mainly associated with low LA concentration and yield, the low purity of L(+)-LA, and the high separation costs. The establishment of biorefineries of FW with lactic acid as the target product is the future development direction, but there are still many research studies to be done.

The effect of yogurt fortified with Lactobacillus acidophilus and Bifidobacterium sp. probiotic in patients with lactose intolerance

This study assessed the effect of probiotic yogurt fortified with Lactobacillus acidophilus and Bifidobacterium sp. in patients with lactose intolerance. Fifty-five patients suffering from lactose intolerance were randomly divided into control group of 28 lactose intolerance patients who received nonprobiotic yogurt (100 ml) and experimental group consisted of 27 lactose intolerance patients who received probiotic yogurt fortified (100 ml) with L. acidophilus and Bifidobacterium sp. Each individual received yogurt for one week. Lactose intolerance was confirmed when the patients received 75 g lactose and were positive after 30 min until 3 hr for lactose intolerance symptoms and by hydrogen breath test (HBT). After intervention, the hydrogen level was lower in experimental group in comparison with the control group. Lactose intolerance symptoms in experimental group were much less than the control group. Our findings revealed that probiotic yogurt fortified with L. acidophilus and Bifidobacterium sp. could safely and effectively decrease lactose intolerance symptoms and HBT, so our probiotic can be recommended as a treatment of choice in lactose intolerance patients.

Microencapsulation of probiotic bacteria using thermo-sensitive sol-gel polymers for powdered infant formula

In this study the application of thermo-sensitive sol-gel polymers in microencapsulation formulation of probiotic bacteria, Bifidobacterium animalis spp lactis, for powdered infant formula (PIF), which is reconstituted at 70 °C, has been assessed. A double-layered microcapsule containing hydroxypropyl methyl cellulose (HPMC) as an inner layer and an outer layer, as the smart coating layer, based on a combination of hydroxypropyl cellulose (HPC) and poloxamer was designed. Generally, this specific microencapsulation provided superior protection against the reconstitution temperature. A high molecular weight of HPC and a greater thickness of the smart coating layer resulted in a delayed release of the bacteria from the microcapsules especially in the PIF composition. However, this was compensated by a high stability of the bacteria at 70 °C. Both the surface texture and particle size distribution of microcapsules have been respectively characterised by scanning electron microscopy and particle size analysis.

Probiotics-containing yogurts suppress Helicobacter pylori load and modify immune response and intestinal microbiota in the Helicobacter pylori-infected children

BACKGROUND

 The benefits of probiotics to the pediatric Helicobacter pylori infection remain uncertain. We tested whether the H. pylori-infected children have an altered gut microflora, and whether probiotics-containing yogurt can restore such change and improve their H. pylori-related immune cascades.

METHODS

We prospectively included 38 children with H. pylori infection confirmed by a positive ¹³C-urea breath test (UBT) and 38 age- and sex-matched noninfected controls. All of them have provided the serum and stool samples before and after 4-week ingestion of probiotics-containing yogurt. The serum samples were tested for the TNF-α, IL-10, IL-6, immunoglobulin (Ig) A, G, E, pepsinogens I and II levels. The stool samples were tested for the colony counts of Bifidobacterium spp. and Escherichia coli. The follow-up UBT indirectly assessed the H. pylori loads after yogurt usage.

RESULTS

 The H. pylori-infected children had lower fecal Bifidobacterium spp. count (p = .009), Bifidobacterium spp./E. coli ratio (p = .04), serum IgA titer (p = .04), and pepsinogens I/II ratio (p < .001) than in controls. In the H. pylori-infected children, 4-week yogurt ingestion reduced the IL-6 level (p < .01) and H. pylori loads (p = .046), but elevated the serum IgA and pepsinogen II levels (p < .001). Moreover, yogurt ingestion can improve the childhood fecal Bifidobacterium spp./E. coli ratio (p = .03).

CONCLUSIONS

 The H. pylori-infected children have a lower Bifidobacterium microflora in gut. The probiotics-containing yogurt can offer benefits to restore Bifidobacterium spp./E. coli ratio in children and suppress the H. pylori load with increment of serum IgA but with reduction in IL-6 in H. pylori-infected children.

The therapeutic potential of manipulating gut microbiota in obesity and type 2 diabetes mellitus

Obesity and type 2 diabetes mellitus (T2DM) are attributed to a combination of genetic susceptibility and lifestyle factors. Their increasing prevalence necessitates further studies on modifiable causative factors and novel treatment options. The gut microbiota has emerged as an important contributor to the obesity--and T2DM--epidemic proposed to act by increasing energy harvest from the diet. Although obesity is associated with substantial changes in the composition and metabolic function of the gut microbiota, the pathophysiological processes remain only partly understood. In this review we will describe the development of the adult human microbiome and discuss how the composition of the gut microbiota changes in response to modulating factors. The influence of short-chain fatty acids, bile acids, prebiotics, probiotics, antibiotics and microbial transplantation is discussed from studies using animal and human models. Ultimately, we aim to translate these findings into therapeutic pathways for obesity and T2DM in humans.

Probiotic yogurt effects on intestinal flora of patients with chronic liver disease

BACKGROUND

Patients with chronic liver disease generally have intestinal flora imbalance that is related to the development and worsening of the disease.

OBJECTIVE

The purpose of this study was to evaluate the effects of probiotic yogurt on intestinal flora of patients with chronic liver disease.

METHODS

A randomized controlled trial, pretest-posttest control group design, was used. Patients were randomized to an experimental group (41 patients) or a control group (40 patients). Patients in the experimental group were given probiotic yogurt (one cup each time, three times per day for 14 days) containing Bacillus bifidus, Lactobacillus acidophilus, Lactobacillus bulgaricus, and Streptococcus thermophilus within 2 hours after meals. Levels of fecal flora, symptoms and signs, and laboratory examination indexes were collected.

RESULTS

After intervention, the experimental group had a lower Escherichia coli count and reduced intestinal flora imbalance (p < .05). Comparison of the experimental and control groups after the intervention showed that the former had improved symptoms and signs, including significant improvement in debilitation, food intake, appetite, abdominal distension, and ascitic fluid (p < .05).

CONCLUSION

Probiotic yogurt reduces the levels of intestinal flora imbalance and has an additional therapeutic effect on patients with chronic liver disease.

Genomic insights into bifidobacteria

Since the discovery in 1899 of bifidobacteria as numerically dominant microbes in the feces of breast-fed infants, there have been numerous studies addressing their role in modulating gut microflora as well as their other potential health benefits. Because of this, they are frequently incorporated into foods as probiotic cultures. An understanding of their full interactions with intestinal microbes and the host is needed to scientifically validate any health benefits they may afford. Recently, the genome sequences of nine strains representing four species of Bifidobacterium became available. A comparative genome analysis of these genomes reveals a likely efficient capacity to adapt to their habitats, with B. longum subsp. infantis exhibiting more genomic potential to utilize human milk oligosaccharides, consistent with its habitat in the infant gut. Conversely, B. longum subsp. longum exhibits a higher genomic potential for utilization of plant-derived complex carbohydrates and polyols, consistent with its habitat in an adult gut. An intriguing observation is the loss of much of this genome potential when strains are adapted to pure culture environments, as highlighted by the genomes of B. animalis subsp. lactis strains, which exhibit the least potential for a gut habitat and are believed to have evolved from the B. animalis species during adaptation to dairy fermentation environments.

Probiotics, immunomodulation, and health benefits

Probiotics are defined as live microorganisms that, when administered in adequate amount, confer a health benefit on the host. Amongst the many benefits associated with the consumption of probiotics, modulation of the immune system has received the most attention. Several animal and human studies have provided unequivocal evidence that specific strains of probiotics are able to stimulate as well as regulate several aspects of natural and acquired immune responses. There is also evidence that intake of probiotics is effective in the prevention and/or management of acute gastroenteritis and rotavirus diarrhoea, antibiotic-associated diarrhoea and intestinal inflammatory disorders such as Crohn's disease and pouchitis, and paediatric atopic disorders. The efficacy of probiotics against bacterial infections and immunological disorders such as adult asthma, cancers, diabetes, and arthritis in humans remains to be proven. Also, major gaps exist in our knowledge about the mechanisms by which probiotics modulate immune function. Optimum dose, frequency and duration of treatment required for different conditions in different population groups also remains to be determined. Different probiotic strains vary in their ability to modulate the immune system and therefore efficacy of each strain needs to be carefully demonstrated through rigorously designed (randomised, double-blind, placebo-controlled) studies. This chapter provides an over view of the immunomodulatory effects of probiotics in health and disease, and discusses possible mechanisms through which probiotics mediate their disparate effects.

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.

Increased probiotic yogurt or resistant starch intake does not affect isoflavone bioavailability in subjects consuming a high soy diet

OBJECTIVE

Probiotics and prebiotics that affect gut microflora balance and its associated enzyme activity may contribute to interindividual variation in isoflavone absorption after soy intake, possibly enhancing isoflavone bioavailability. This study examined the effects of the consumption of bioactive yogurt (a probiotic) or resistant starch (a known prebiotic) in combination with high soy intake on soy isoflavone bioavailability.

METHODS

Using a crossover design, chronic soy consumption was compared with soy plus probiotic yogurt or resistant starch in older male and postmenopausal females (n = 31). Isoflavone bioavailability was assessed at the beginning and end of each 5-wk dietary period by sampling plasma and urine after a standardized soy meal.

RESULTS

Chronic soy intake did not significantly affect plasma or urinary isoflavones after the soy meal and there were no significant effects of probiotic or resistant starch treatment. However, there were trends for increased circulating plasma daidzein and genistein after the probiotic treatment and for increased plasma daidzein and genistein 24 h after soy intake with resistant starch treatment. Neither treatment induced or increased equol production, although there was a trend for increased plasma equol in "equol-positive" subjects (n = 12) after probiotic treatment.

CONCLUSION

The weak or absence of effects of probiotic yogurt or resistant starch supplement to a chronic soy diet suggests that gut microflora were not modified in a manner that significantly affected isoflavone bioavailability or metabolism.

Increasing ursodeoxycholic acid in the enterohepatic circulation of pigs through the administration of living bacteria

We investigated the feasibility of increasing ursodeoxycholic acid (UDCA) in the enterohepatic circulation of pigs by administering living bacteria capable of epimerising endogenous amidated chenodeoxycholic acid (CDCA) to UDCA. We first demonstrated that combining Bifidobacterium animalis DN-173 010, as a bile salt-hydrolysing bacterium, and Clostridium absonum ATCC 27555, as a CDCA to UDCA epimerising bacterium, led to the efficient epimerisation of glyco- and tauro-CDCA in vitro, with respective UDCA yields of 55·8 (se 2·8) and 36·6 (se 1·5)%. This strain combination was then administered to hypercholesterolaemic pigs over a 3-week period, as two daily preprandial doses of either viable (six experimental pigs) or heat-inactivated bacteria (six controls). The main effects of treatment were on unconjugated bile acids (P=0·035) and UDCA (P<0·0001) absorbed into the portal vein, which increased 1·6–1·7- and 3·5–7·5-fold, respectively, under administration of living compared with inactivated bacteria. In bile, UDCA did not increase significantly, but the increase in biliary lithocholic acid with time in the controls was not observed in the experimental pigs (P=0·007), and the same trend was observed in faeces. All other variables (biliary lipid equilibrium, plasma lipid levels and partition of cholesterol between the different lipoprotein classes) remained unaffected by treatment throughout the duration of the experiment. In conclusion, it is feasible to increase the bioavailability of UDCA to the intestine and the liver by administering active bacteria. This may represent an interesting new probiotic activity, provided that in future it could be expressed by a safe food micro-organism.

Analysis of treatment effects on the microbial ecology of the human intestine

A large number of studies have investigated gastrointestinal microbiota and changes in the gastrointestinal community. However, a concern in these studies is how best to assess changes in gastrointestinal community structure. This paper presents two different human trials where the fecal terminal restriction fragment length polymorphism data sets were analyzed to search for treatment effects. Principle components analysis and cluster analysis based on grouped data are compared with analysis of data by subject using distance coefficients. Comparison with baseline within an individual before grouping by treatment provided a clearer indication of treatment effects than did an evaluation of data grouped before analysis. In addition, a large within-subject sample size and multiple baseline samples are necessary to accurately analyze treatment effects.

Inhibitory effect of yoghurt and soya yoghurt containing bifidobacteria on the proliferation of Ehrlich ascites tumour cells in vitro and in vivo in a mouse tumour model

The effect of yoghurt and soya yoghurt containing Bifidobacterium lactis Bb-12 or B. longum Bb-46 on Ehrlich ascites tumour cell proliferation was investigated in vitro and in vivo. Tumour cells were incubated with B. lactis Bb-12 or B. longum Bb-46 cultivated in de Mann Rogosa Sharpe (MRS) broth medium, or with their centrifuged supernatant fractions or sediments, for 2 h at 37 degrees C. Treatment resulted in the inhibition of tumour cell proliferation by 85.42 (SD 0.78) and 85.10 (SD 1.28) % by intact micro-organisms, 77.61 (SD 0.29) and 71.43 (SD 1.75) % by their supernatant fractions, but only 4.00 (SD 0.19) and 9.09 (SD 1.24) % by the two sedimented bacteria, respectively. The incubation of tumour cells with yoghurt and soya yoghurt containing Bb-12 for 2 h resulted in 83.01 (SD 0.11) and 88.23 (SD 0.06) % inhibition, respectively, while it was 83.82 (SD 0.24) and 86.36 (SD 0.06) %, respectively for the same products containing Bb-46. Corresponding values for plain yoghurt and soya milk (without bifidobacteria) were 32.81 (SD 0.14) and 5.55 (SD 0.12) %, respectively. The differences between yoghurt or soya yoghurt containing Bb-12 or Bb-46 and plain yoghurt, soya milk or control treatments were statistically significant (n 3; P<0.05). Female Swiss albino mice were injected intraperitoneally with the same tumour cells. The lifespan of mice fed diets supplemented with yoghurt or soya yoghurt containing Bb-12 or Bb-46 was prolonged by 16, 23, 34 and 39 %, respectively compared with that of the positive control group (n 6; P<0.05). The lifespan of groups fed plain yoghurt or soya milk was prolonged by 15 and 8 %, respectively. Prolongation of lifespan was positively correlated with faeces bifidobacterial count in the groups fed yoghurt or soya yoghurt containing bifidobacteria (r 0.917; P<0.05).

Effects of dietary yoghurt on immunological and clinical parameters of rhinopathic patients

OBJECTIVES

To examine the immunological and clinical influence of 4 months' feeding with either yoghurt or partially skimmed milk or nothing, on 20 volunteers.

SUBJECTS

Thirteen subjects had a demonstrated allergic rhinopathy and seven were healthy subjects and participated as controls.

RESEARCH DESIGN

Either a group of seven or a group of six rhinopathic patients were fed either 450 g yoghurt or 450 g partially skimmed milk, respectively, for 4 months between March and October 1999. All subjects maintained their usual diet throughout the study. Peripheral blood mononuclear cells (PBMC) were isolated before and after the experimental period and cultured for periods of 40 and 64 h. Proliferation index assay and release of IFNgamma and IL-4 without and with PHA stimulation were assessed. Allergic rhinopathy was evaluated before and after the 4 months period by performing the nasal functionality tests (Active Anterior Rhinomanometry, Acoustic Rhinometry), the prick test, the nasal specific provocation test (NPT), the dosage of specific IgE blood levels, the evaluation of the symptomatological score and the nasal mucociliary transport test.

RESULTS

No significant change of the proliferation index was noted among the three groups. Cultured PBMC of the group fed with yoghurt released more IFNgamma and less IL-4. Cytokine plasma levels were at and remained at basal levels. Prick test, specific serum IgEs and NPT remained immodified. Muco-ciliary transport time (MCTt) and symptomatological score showed a definitive improvement after yoghurt feeding.

CONCLUSION

Yoghurt feeding appears to improve or prevent allergic recurrences in rhinopatic patients.

Impact of supplement with Lactobacillus- and Bifidobacterium-containing yogurt on triple therapy for Helicobacter pylori eradication

AIM

To test whether supplements of Lactobacillus- and Bifidobacterium-containing yogurt (AB-Yogurt) affect the success of Helicobacter pylori eradication.

METHODS

One hundred and sixty H. pylori-infected patients were randomized into a triple-plus-yogurt group or a triple-only group, receiving 1 week of triple therapy with and without supplements of AB-Yogurt, respectively. In the triple-plus-yogurt group, AB-Yogurt was continued for 4 weeks after triple therapy. Eight weeks later, patients were assessed for the success of H. pylori eradication. The stool samples of 22 randomly selected patients, 11 from each group, were provided on enrolment, at the first week and at the fifth week for evaluation of the percentage of Bifidobacterium in anaerobes.

RESULTS

By intention-to-treat analysis, the triple-plus-yogurt group had a higher H. pylori eradication rate than the triple-only group (91% vs. 78%, P < 0.05). The per protocol H. pylori eradication rates were similar for both groups (93.5% vs. 89%, P = N.S.). Only patients supplemented with AB-Yogurt showed restoration of the percentage of Bifidobacterium in the anaerobes of stools at the fifth week to the level in the stools on enrolment.

CONCLUSIONS

Supplement with AB-Yogurt can improve the intention-to-treat eradication rates of H. pylori, and can restore the depletion of Bifidobacterium in stools after triple therapy.

Interrelationships between dairy product intake, microflora metabolism, faecal properties and plasmid dissemination in gnotobiotic mice

We previously described the effects of intake of dairy products on plasmid dissemination in the digestive tract of gnotobiotic mice associated with human faecal flora (HFF) and found that yoghurt, heat-treated yoghurt (HTY) and milk reduced population levels of transconjugants compared with findings in mice fed a standard mouse diet. In the case of lactose intake, transconjugants were not detected. The aim of the present study was to assess the possible interrelationships between these observations and other variables (bacterial ecology, pH, moisture, enzyme activities, short-chain fatty acid (SCFA) contents, lactic acid contents). Much of the interest of the present comparison lies in the fact that the animals were homogeneous in terms of age, gender, food and intestinal microflora, owing to the gnotobiotic mouse model maintained in sterile isolators. We observed no variation in SCFA and lactic acid contents or in the population levels of strictly anaerobic strains of Bacteroides and Bifidobacterium, and of the facultative anaerobic recipient Escherichia coli PG1 strain. The main modifications were the reduction of population levels of transconjugants in mice receiving yoghurt, HTY and milk, and concomitantly an increase of beta-galactosidase and a decrease of beta-glucosidase activities, compared with control mice fed a standard diet. Total inhibition of plasmid transfer was observed in HFF mice consuming lactose, and concomitantly the two enzyme activities (beta-glucosidase and beta-galactosidase) were increased, compared with the findings in control mice fed a standard diet. In axenic mice consuming lactose, plasmid transfer occurred, beta-galactosidase was not detected and beta-glucosidase was decreased. It is therefore proposed that these two enzyme activities influence plasmid transfer and persistence of transconjugants in the digestive tract of HFF associated mice. When both activities were increased there was a total inhibition of plasmid transfer (case of lactose intake). When beta-galactosidase increased and beta-glucosidase decreased (case of yoghurt, HTY and milk), plasmid transfer occurred at a lower efficiency than in the control group, resulting in lower population levels of transconjugants.