Prebiotics, probiotics, and dietary fiber in gastrointestinal disease

The association between carbohydrate quality index and headache severity, disability and duration among women with migraine a cross-sectional study

BACKGROUND & AIM

This study aimed to examine the association between Carbohydrate Quality Index (CQI) and headache severity, disability and duration among women with migraine.

MATERIALS & METHODS

In this cross-sectional study, 266 women (aged 18-45 years) were enrolled using a 147-item food frequency questionnaire (FFQ). CQI was defined by four criteria: fiber intake, dietary glycemic index (DGI), whole grains/total grains ratio and solid carbohydrates/total carbohydrates ratio. Anthropometric measurements, visual analogue scale (VAS), migraine disability assessment (MIDAS), and headache duration were assessed for all participants.

RESULTS

Participants with a high adherence to CQI had lower odds of moderate pain (OR = 0.45; 95% CI = 0.21-0.94; P = 0.03) and severe pain (OR = 0.39; 95% CI = 0.18-0.82; P = 0.01) compared to those with a low adherence to CQI. After controlling for potential confounders, individuals with the greatest adherence to CQI showed a 78% reduced prevalence in severe pains and a 63% decreased occurrence in moderate pains compared to those with the lowest adherence (OR = 0.22; 95% CI = 0.09-0.55; P = 0.01 and OR = 0.37; 95% CI = 0.16-0.84; P = 0.01, respectively). Moreover, Subjects with higher adherence to CQI had lower odds of headache duration (OR = 0.54; 95% CI= 0.31-0.96; P = 0.03). The significant association remained (P < 0.05) even after confounding variables (OR = 0.59; 95 % CI = 0.35-1.002; P = 0.05). Despite adjusting for confounding valuables, there was no significant association between the CQI and MIDAS scores (P > 0.05).

CONCLUSION

Higher adherence to CQI was associated with lower severity and duration in patients with migraine. Further studies are needed to confirm these results.

Association of dietary fiber intake with epileptic seizures in U.S. adults: A Population-base study of 13,277 participants

OBJECTIVE

Epilepsy, a neurological disorder, is identified by the presence of recurrent seizures. We aimed to detect dietary fiber intake and its association with epilepsy prevalence in U.S. adults.

METHODS

This cross-sectional study obtained data from the 2013-2018 National Health and Nutrition Examination Survey database. Univariate and multivariate logistic regression models were employed to estimate the association between dietary fiber intake and epilepsy prevalence. The restricted cubic spline (RCS) model was also applied to investigate the dose-response relationships between dietary fiber intake and epileptic seizure events(ESEs).

RESULTS

Our final sample included 13,277 NHANES participants, with the average prevalence of ESEs being 1.09 % (145/13277). After adjusting for all confounding factors, the third quartile of dietary fiber intake levels remained significantly associated with a decreased risk of ESEs[odds ratios (OR) 0.54,95 % confidence interval (CI) 0.33-0.88, P = 0.014)] compared to the first quartile. Higher fiber intake indicated a stable negative association with ESEs in the multivariate logistic regression analysis, weighted generalized additive model. A nonlinear dose-response relationship was observed between dietary fiber intake levels and decreased ESEs risk (P for overall=0.017, P for nonlinear=0.155). Interaction tests showed no significant effect of demographic and disease status on the association between dietary fiber intake and ESEs.

CONCLUSION

In this cross-sectional study, people with a high dietary fiber intake were at a reduced risk of ESEs. However, further prospective studies are needed to investigate the effect of dietary fiber intake in epilepsy events and to determine causality.

Effects of hazelnut soluble dietary fiber on lipid-lowering and gut microbiota in high-fat-diet-fed rats

Hazelnut is one of the most popular nuts in the world, rich in nutrients and various active substances. In this study, soluble dietary fiber (SDF) was extracted from hazelnut kernels, and its physicochemical properties and absorbability were explored. Hazelnut-SDF exhibited ideal water-holding, oil-holding and swelling capacity, and glucose, cholesterol and cholate absorbing ability. Scanning electron microscopy and fourier transform infrared spectroscopy showed that hazelnut-SDF had typical polysaccharide structure of functional groups. The main monosaccharides were identified as arabinose, rhamnose, xylose, ribose, glucuronic acid, mannose and glucose by gas chromatography-mass spectrometry. In high-fat diet rats, hazelnut-SDF could improve serum lipid parameters, inhibit lipid accumulation in liver and adipocytes, and regulate the expression level of liver lipid synthesis-related genes. It also could adjust intestinal short chain fatty acids, promote the composition and structure of intestinal microbiota, and significantly balance the abundance of Alloprevotella, Fusicatenibacter, Lactobacillus, Roseburia, Ruminococcaceae_UCG-005, Ruminococcaceae_UCG-014 and Clostridiales. The results concluded that oral administration of hazelnut-SDF could alleviate hyperlipidemia and obesity, and might serve as a potential functional food ingredient.

Interaction between β-glucans and gut microbiota: a comprehensive review

Gut microbiota (GMB) in humans plays a crucial role in health and diseases. Diet can regulate the composition and function of GMB which are associated with different human diseases. Dietary fibers can induce different health benefits through stimulation of beneficial GMB. β-glucans (BGs) as dietary fibers have gained much interest due to their various functional properties. They can have therapeutic roles on gut health based on modulation of GMB, intestinal fermentation, production of different metabolites, and so on. There is an increasing interest in food industries in commercial application of BG as a bioactive substance into food formulations. The aim of this review is considering the metabolizing of BGs by GMB, effects of BGs on the variation of GMB population, influence of BGs on the gut infections, prebiotic effects of BGs in the gut, in vivo and in vitro fermentation of BGs and effects of processing on BG fermentability.

The association between dietary fiber intake and severe headaches or migraine in US adults

Background

The data on the effect of dietary fiber on severe headaches or migraine are limited. Therefore, this study aimed to investigate the association between dietary fiber intake and the prevalence of severe headaches or migraine.

Methods

We conducted a cross-sectional study involving 12,710 participants, all data collected from NHANES 1999-2004. A multivariable logistic regression model was used to analyze the relationship between dietary fiber intake (as an independent variable) and severe headaches or migraine (as outcome variable). We also performed sensitivity analyses, including multiple sensitivity analyses.

Results

The overall incidence of severe headache or migraine in the study was 2527/12,710 (19.9%). After adjusting for correlation covariates, we found a significant inverse association between dietary fiber intake and severe headache or migraine, with lowest prevalence in the fifth quintile (OR: 0.74, 95% CI: 0.61-0.90). Our study also revealed that for every 10 g/day increase in dietary fiber intake, the prevalence of severe headache or migraine decreased by 11%. However, no such inverse association was found among Mexican Americans, other races, or those with a body mass index (BMI) of 25-30. E-value analysis suggested robustness to unmeasured confounding.

Conclusion

Increasing the intake of fiber-rich foods might protect from severe headache or migraine. More prospective studies should be conducted to confirm their association before dietary recommendations.

A Review of African Medicinal Plants and Functional Foods for the Management of Alzheimer's Disease-related Phenotypes, Treatment of HSV-1 Infection and/or Improvement of Gut Microbiota

Alzheimer's disease (AD), which is a progressive neurodegenerative disorder is the most common form of dementia globally. Several studies have suggested alteration in the gut microbiota and HSV-1 infection as contributing factors to the development of the disease. As at now, there are no AD attenuating agents and AD pharmacotherapy is focused on managing symptoms while plants used in ethnomedicine remain potential sources of drugs for the treatment of the condition. Here, we reviewed published databases for African ethnomedicinal plants and functional foods of African origin that are used in the management of AD-related phenotypes, treatment of herpes simplex virus −1 (HSV-1) and/or improvement of gut microbiota. A total of 101 unique plant species and 24 different types of traditionally prepared African functional foodstuff were identified. Of the 101 identified plant species, 50 species serve as functional foodstuffs. Twenty-three (23) of the ethnomedicinal plant families were successfully identified for the treatment and management of AD-related phenotypes and age-related dementia. Eighteen (18) African plant species from 15 families were also identified as potent remedies for HSV-1; while many African wild fruits (3 species), roots and tubers (7 species), leafy vegetables (14 species), and seaweeds (26 species) were functional foods for modifying AD-related phenotypes. It was concluded that African medicinal plants are potential sources of both AD attenuating agents and phytocompounds that may be used against HSV-1 infection and alteration of gut microbiota. Additionally, a number of African functional foods are important sources of prebiotics and probiotics.

Linseed fibers modulate the production of short-chain fatty acids and improve performance and plasma and skin mucus parameters of silver catfish (Rhamdia quelen)

This study was conducted to evaluate the prebiotic action of distinct linseed fibers on diets for silver catfish (Rhamdia quelen) juvenile. For this, soluble and insoluble fractions of linseed fiber were concentrated separately and combined in four ratios (1:0.5, 1:1, 1:2, 1:4), which were added in diets and evaluated along with a control diet. After 45 days receiving the experimental diets, the animals were submitted to biometry for data collection and samples. The experimental design was completely randomized, data were submitted to analysis of variance, and the means were compared by Tukey's test (P < 0.05). Fish performance was higher for the group that received the 1:2 and 1:4 diets. The production of intestinal acetic acid was higher in fish fed on the 1:2 diet, and butyric acid was higher with 1:4 diet and the propionic acid with the control diet. The control diet led to lower counts of goblet cells. Total proteins and globulins in plasma, mucoprotein, total immunoglobulins, and cutaneous mucus pH were higher in fish fed on diets 1:2 and 1:4. Cortisol levels and intestinal pH were lower in these treatments. The linseed fiber intake increased total plasma immunoglobulins and plasma alkaline phosphatase activity and in mucus. It was concluded that the use of 1:2 and 1:4 soluble fiber/insoluble linseed in the diet beneficially modulates the production of short-chain fatty acids in the digesta, with reflection on growth performance, number of goblet cells in the intestinal epithelium, and improvement in plasma and skin mucus parameters of fish.

Physical activity and nutrition guidelines to help with the fight against COVID-19

As the world is witnessing the epidemic of coronavirus disease 2019, emerging genetics and clinical pieces of evidence suggest a similar immunopathology to those of severe acute respiratory syndrome and Middle East respiratory syndrome. Staying at home to prevent the spread of the virus and consequently being largely inactive is associated with unintended consequences. These can actually enhance the infection risk and exacerbate poor health conditions including impaired immune function. Physical activity is a feasible way of improving health, particularly physical and mental health in a time of social isolation. However, people with certain health conditions in these circumstances may need a special physical activity programme in addition to any exercise they may already be performing via online programmes. This review aims to provide practical guidelines during the COVID-19 quarantine period. We suggest performing aerobic, resistance training, respiratory muscle training and yoga in the healthy, and in those with upper respiratory tract illness, patients with lower respiratory tract illness should be restricted to respiratory muscle training and yoga. In addition, vitamins D and C, omega-3 fatty acids, and regular consumption of fruit and vegetables might be considered as nutritional aids to support the immune system in those affected by COVID-19.

Gut-brain Axis and migraine headache: a comprehensive review

The terminology "gut-brain axis "points out a bidirectional relationship between the GI system and the central nervous system (CNS). To date, several researches have shown that migraine is associated with some gastrointestinal (GI) disorders such as Helicobacter pylori (HP) infection, irritable bowel syndrome (IBS), and celiac disease (CD). The present review article aims to discuss the direct and indirect evidence suggesting relationships between migraine and the gut-brain axis. However, the mechanisms explaining how the gut and the brain may interact in patients with migraine are not entirely clear. Studies suggest that this interaction seems to be influenced by multiple factors such as inflammatory mediators (IL-1β, IL-6, IL-8, and TNF-α), gut microbiota profile, neuropeptides and serotonin pathway, stress hormones and nutritional substances. Neuropeptides including CGRP, SP, VIP, NPY are thought to have antimicrobial impact on a variety of the gut bacterial strains and thus speculated to be involved in the bidirectional relationship between the gut and the brain. According to the current knowledge, migraine headache in patients harboring HP might be improved following the bacteria eradication. Migraineurs with long headache history and high headache frequency have a higher chance of being diagnosed with IBS. IBS and migraine share some similarities and can alter gut microflora composition and thereby may affect the gut-brain axis and inflammatory status. Migraine has been also associated with CD and the condition should be searched particularly in patients with migraine with occipital and parieto-occipital calcification at brain neuroimaging. In those patients, gluten-free diet can also be effective in reducing migraine frequency. It has also been proposed that migraine may be improved by dietary approaches with beneficial effects on gut microbiota and gut-brain axis including appropriate consumption of fiber per day, adhering to a low glycemic index diet, supplementation with vitamin D, omega-3 and probiotics as well as weight loss dietary plans for overweight and obese patients.

Impact of Buckwheat Fermented Milk Combined with High-Fat Diet on Rats' Gut Microbiota and Short-Chain Fatty Acids

The aim of this study was to evaluate the effect of buckwheat fermented milk on intestinal flora and short-chain fatty acids (SCFAs) of rats fed a high-fat diet (HFD). Buckwheat fermented milk was made with Lactobacillus plantarum ST-Ⅲ, Lactobacillus bulgaricus, and Streptococcus thermophilus. Thirty-six males C57BL/6 rats (aged 3 weeks and with 9 to 12 g weight) were subjected to a 2-week adaptive period on a normal diet. After a week of acclimatization, the rats were randomly divided into three groups with 12 rats in each group. The high-fat diet with fermented milk (HFDFM) group received HFD supplemented with fermented milk, and the high-fat diet supplemented with buckwheat fermented milk (HFDBFM) group received HFD plus buckwheat fermented milk. Besides, the gavage dose was 0.4 mL/day. After the feedings, colon levels of cytokines and antioxidant indices of the liver, colon, and duodenum tissues were measured. The composition of intestinal flora of rats and the content of SCFAs were determined by gas chromatography-mass spectrometry and Illumina high-throughput sequencing technology. Supplementation with buckwheat fermented milk significantly inhibited the increases in lipopolysaccharide levels in colon and antioxidant indexes in the HFD-fed rats. In addition, buckwheat fermented milk could significantly enhance Firmicutes and decrease Bacteroidetes compared to HFDFM. In addition, SCFA concentrations in HFDBFM were higher than other groups. In conclusion, buckwheat fermented milk can alleviate the damage of HFD to intestinal flora of rats. It modulates microbiota composition and SCFA concentrations to balance the intestinal environment, which will benefit to rats' intestinal health. PRACTICAL APPLICATION: This study explored the effect of buckwheat fermented milk on the regulation of intestinal microflora and SCFAs in rats fed a high-fat diet. It provides new ideas for the development of buckwheat fermented food.

Assessment of Freeze-Dried Immobilized Lactobacillus casei as Probiotic Adjunct Culture in Yogurts

Freeze-dried immobilized Lactobacillus casei ATCC 393 on casein and apple pieces were assessed as a probiotic adjunct culture for novel probiotic yogurt production. The effect of probiotic culture on physicochemical characteristics, probiotic cell survival, volatile aroma compounds, and sensory quality were evaluated during 28 days of storage at 4 °C. The use of L. casei resulted in lower pH values (3.92–4.12), higher acidity (0.88–1.10 g lactic acid/100 g of yogurt), and lower syneresis (40.8%–42.6%) compared to traditionally produced yogurt (pH 4.29; acidity 0.83 g lactic acid/100 g of yogurt; syneresis 44.1%). Microbiological and strain-specific multiplex PCR (Polymerase Chain Reaction) analysis confirmed that immobilized L. casei ATCC 393 cells were detected in yogurts at levels >7 log cfu g⁻¹ after 28 days. In addition, probiotic supplementation significantly affected the concentrations of key volatile compounds, like acetic and other organic acids, 2-ethyl-1-hexanol, acetoin, and 2-butanone, as revealed by GC-MS (Gas Chromatography–Mass Spectrometry) analysis. Finally, the sensory evaluation demonstrated that the new products exhibited improved characteristics compared to traditionally produced yogurts.

Probiotics for people with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure or portosystemic shunt or both. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient's quality of life and daily functioning, and represent a significant burden on healthcare resources. Probiotics are live micro-organisms, which when administered in adequate amounts, may confer a health benefit on the host.

OBJECTIVES

To determine the beneficial and harmful effects of probiotics in any dosage, compared with placebo or no intervention, or with any other treatment for people with any grade of acute or chronic hepatic encephalopathy. This review did not consider the primary prophylaxis of hepatic encephalopathy.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, conference proceedings, reference lists of included trials, and the World Health Organization International Clinical Trials Registry Platform until June 2016.

SELECTION CRITERIA

We included randomised clinical trials that compared probiotics in any dosage with placebo or no intervention, or with any other treatment in people with hepatic encephalopathy.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We conducted random-effects model meta-analysis due to obvious heterogeneity of participants and interventions. We defined a P value of 0.05 or less as significant. We expressed dichotomous outcomes as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 21 trials with 1420 participants, of these, 14 were new trials. Fourteen trials compared a probiotic with placebo or no treatment, and seven trials compared a probiotic with lactulose. The trials used a variety of probiotics; the most commonly used group of probiotic was VSL#3, a proprietary name for a group of eight probiotics. Duration of administration ranged from 10 days to 180 days. Eight trials declared their funding source, of which six were independently funded and two were industry funded. The remaining 13 trials did not disclose their funding source. We classified 19 of the 21 trials at high risk of bias.We found no effect on all-cause mortality when probiotics were compared with placebo or no treatment (7 trials; 404 participants; RR 0.58, 95% CI 0.23 to 1.44; low-quality evidence). No-recovery (as measured by incomplete resolution of symptoms) was lower for participants treated with probiotic (10 trials; 574 participants; RR 0.67, 95% CI 0.56 to 0.79; moderate-quality evidence). Adverse events were lower for participants treated with probiotic than with no intervention when considering the development of overt hepatic encephalopathy (10 trials; 585 participants; RR 0.29, 95% CI 0.16 to 0.51; low-quality evidence), but effects on hospitalisation and change of/or withdrawal from treatment were uncertain (hospitalisation: 3 trials, 163 participants; RR 0.67, 95% CI 0.11 to 4.00; very low-quality evidence; change of/or withdrawal from treatment: 9 trials, 551 participants; RR 0.70, 95% CI 0.46 to 1.07; very low-quality evidence). Probiotics may slightly improve quality of life compared with no intervention (3 trials; 115 participants; results not meta-analysed; low-quality evidence). Plasma ammonia concentration was lower for participants treated with probiotic (10 trials; 705 participants; MD -8.29 μmol/L, 95% CI -13.17 to -3.41; low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.When probiotics were compared with lactulose, the effects on all-cause mortality were uncertain (2 trials; 200 participants; RR 5.00, 95% CI 0.25 to 102.00; very low-quality evidence); lack of recovery (7 trials; 430 participants; RR 1.01, 95% CI 0.85 to 1.21; very low-quality evidence); adverse events considering the development of overt hepatic encephalopathy (6 trials; 420 participants; RR 1.17, 95% CI 0.63 to 2.17; very low-quality evidence); hospitalisation (1 trial; 80 participants; RR 0.33, 95% CI 0.04 to 3.07; very low-quality evidence); intolerance leading to discontinuation (3 trials; 220 participants; RR 0.35, 95% CI 0.08 to 1.43; very low-quality evidence); change of/or withdrawal from treatment (7 trials; 490 participants; RR 1.27, 95% CI 0.88 to 1.82; very low-quality evidence); quality of life (results not meta-analysed; 1 trial; 69 participants); and plasma ammonia concentration overall (6 trials; 325 participants; MD -2.93 μmol/L, 95% CI -9.36 to 3.50; very low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.

AUTHORS' CONCLUSIONS

The majority of included trials suffered from a high risk of systematic error ('bias') and a high risk of random error ('play of chance'). Accordingly, we consider the evidence to be of low quality. Compared with placebo or no intervention, probiotics probably improve recovery and may lead to improvements in the development of overt hepatic encephalopathy, quality of life, and plasma ammonia concentrations, but probiotics may lead to little or no difference in mortality. Whether probiotics are better than lactulose for hepatic encephalopathy is uncertain because the quality of the available evidence is very low. High-quality randomised clinical trials with standardised outcome collection and data reporting are needed to further clarify the true efficacy of probiotics.

Prebiotics and synbiotics: dietary strategies for improving gut health

PURPOSE OF REVIEW

A wide range of dietary carbohydrates, including prebiotic food ingredients, fermentable fibers, and milk oligosaccharides, are able to produce significant changes in the intestinal microbiota. These shifts in the microbial community are often characterized by increased levels of bifidobacteria and lactobacilli. More recent studies have revealed that species of Faecalibacterium, Akkermansia, and other less well studied members may also be enriched. We review the implications of these recent studies on future design of prebiotics and synbiotics to promote gastrointestinal health.

RECENT FINDINGS

Investigations assessing the clinical outcomes associated with dietary modification of the gut microbiota have shown systemic as well as specific health benefits. Both prebiotic oligosaccharides comprised of a linear arrangement of simple sugars, as well as fiber-rich foods containing complex carbohydrates, have been used in these trials. However, individual variability and nonresponding study participants can make the outcome of dietary interventions less predictable. In contrast, synergistic synbiotics containing prebiotics that specifically stimulate a cognate probiotic provide additional options for personalized gut therapies.

SUMMARY

This review describes recent research on how prebiotics and fermentable fibers can influence the gut microbiota and result in improvements to human health.

Evaluation of two local cowpea species for nutrient, antinutrient, and phytochemical compositions and organoleptic attributes of their wheat-based cookies

BACKGROUND

Childhood and adolescent malnutrition is a function of inadequate intake. Cookies are favourite snacks of children and adolescents.

OBJECTIVE

This work determined the nutrient, antinutrient, and phytochemical compositions of two local cowpea (oraludi and apama) flours and evaluated the organoleptic properties of their wheat-based cookies.

DESIGN

The two local cowpea species were processed into flours separately and blended with wheat on a 56-g protein basis. Chemical compositions of the processed cowpea flours were analysed using standard methods. Organoleptic attributes were evaluated with a nine-point Hedonic scale. Statistical analysis, which involved mean and standard deviations, were computed by analysis of variance, and Duncan's new multiple range tests were used to separate and compare group means of sensory evaluation data, with significance accepted at P<0.05.

RESULTS

The results revealed that oraludi had superior percentage values compared to apama in protein (26.22 and 20.88), fat (7.98 and 6.65), and ash (3.81 and 3.13), while apama proved superior in moisture (9.76 and 7.82), crude fibre (5.49 and 4.91), and carbohydrate (54.09 and 49.26). The values were higher for oraludi than apama in iron (8.62 and 6.49 mg), zinc (1.61 and 0.95 mg), and beta-carotene (223.24 and 190.63 mg) but lower in sodium (34.79 and 56.72 mg), potassium (25.73 and 30.65 mg), phosphorus (13.35 and 18.26 mg), thiamine (5.33 and 9.41 mg), vitamin C (16.63 and 21.09 mg), and vitamin E (0.51 and 0.67 mg). Apama had 0.06 mg phytate, 0.09 mg oxalate, 15.22 mg tannins, 3.59 mg flavonoids, and 0.19 mg saponin. Oraludi had 0.03 mg phytate, 0.32 mg oxalate, 15.94 mg tannins, 3.14 mg flavonoid, and 0.13 mg saponin. Mean scores of general acceptability for wheat:apama (80:20) and wheat:oraludi:apama (60:20:20) cookies (7.71 and 7.41) were superior (P<0.05) to others.

CONCLUSIONS

Oraludi and apama proved nutrient dense. Their use improved the acceptability of some of the wheat-based cookies. Use of these local cowpeas in cookie production is, therefore, encouraged.

Constructing personalized longitudinal holo'omes of colon cancer-prone humans and their modeling in flies and mice

Specific host genes and intestinal microbes, dysbiosis, aberrant immune responses and lifestyle may contribute to intestinal inflammation and cancer, but each of these parameters does not suffice to explain why sporadic colon cancer develops at an old age and only in some of the people with the same profile. To improve our understanding, longitudinal multi-omic and personalized studies will help to pinpoint combinations of host genetic, epigenetic, microbiota and lifestyle-shaped factors, such as blood factors and metabolites that change as we age. The intestinal holo’ome – defined as the combination of host and microbiota genomes, transcriptomes, proteomes, and metabolomes – may be imbalanced and shift to disease when the wrong host gene expression profile meets the wrong microbiota composition. These imbalances can be triggered by the dietary- or lifestyle-shaped intestinal environment. Accordingly, personalized human intestinal holo’omes will differ significantly among individuals and between two critical points in time: long before and upon the onset of disease. Detrimental combinations of factors could therefore be pinpointed computationally and validated using animal models, such as mice and flies. Finally, treatment strategies that break these harmful combinations could be tested in clinical trials. Herein we provide an overview of the literature and a roadmap to this end.

Enemy attraction: bacterial agonists for leukocyte chemotaxis receptors

The innate immune system recognizes conserved microorganism-associated molecular patterns (MAMPs), some of which are sensed by G protein-coupled receptors (GPCRs), and this leads to chemotactic leukocyte influx. Recent studies have indicated that these processes are crucial for host defence and rely on a larger set of chemotactic MAMPs and corresponding GPCRs than was previously thought. Agonists, such as bacterial formyl peptides, enterococcal pheromone peptides, staphylococcal peptide toxins, bacterial fermentation products and the Helicobacter pylori peptide HP(2-20), stimulate specific GPCRs. The importance of leukocyte chemotaxis in host defence is highlighted by the fact that some bacterial pathogens produce chemotaxis inhibitors. How the various chemoattractants, receptors and antagonists shape antibacterial host defence represents an important topic for future research.

The therapeutic use of symbiotics

INTRODUCTION

Functional foods are health promoters and their use is associated with reduced risk of chronic degenerative and non-transmissible diseases. Examples are symbiotic. The association of one (or more) probiotic with a one (or more) prebiotic is called symbiotic, being the prebiotics complementary and probiotics synergistic, thus presenting a multiplicative factor on their individual actions.

OBJECTIVE

To assess the evidences on the benefits of the use of symbiotics in the treatment of clinical and surgical situations.

METHODS

The headings symbiotic, probiotic and prebiotic were searched in Pubmed/Medline in the last 15 years, and were selected 25 articles, used for database.

RESULTS

The use of symbiotic may promote an increase in the number of bifidobacteria, glycemic control, reduction of blood cholesterol, balancing the intestinal flora which aids in reducing constipation and/or diarrhea, improves intestinal permeability and stimulation of the immune system. Clinical indications for these products has been expanded, in order to maximize the individual's physiological functions to provide greater. So, with the high interest in the clinical and nutritional control of disease, many studies have been conducted demonstrating the effectiveness of using symbiotic in improving and/or preventing various and/or symptoms of gastrointestinal diseases.

CONCLUSION

Symbiotic behave differently and positively in various pathological situations.

Symbiotic lactobacilli stimulate gut epithelial proliferation via Nox-mediated generation of reactive oxygen species

The resident prokaryotic microbiota of the metazoan gut elicits profound effects on the growth and development of the intestine. However, the molecular mechanisms of symbiotic prokaryotic-eukaryotic cross-talk in the gut are largely unknown. It is increasingly recognized that physiologically generated reactive oxygen species (ROS) function as signalling secondary messengers that influence cellular proliferation and differentiation in a variety of biological systems. Here, we report that commensal bacteria, particularly members of the genus Lactobacillus, can stimulate NADPH oxidase 1 (Nox1)-dependent ROS generation and consequent cellular proliferation in intestinal stem cells upon initial ingestion into the murine or Drosophila intestine. Our data identify and highlight a highly conserved mechanism that symbiotic microorganisms utilize in eukaryotic growth and development. Additionally, the work suggests that specific redox-mediated functions may be assigned to specific bacterial taxa and may contribute to the identification of microbes with probiotic potential.

Effects of Low Level Water-soluble Pentosans, Alkaline-extractable Pentosans, and Xylanase on the Growth and Development of Broiler Chicks

This study investigated the effects of low levels of water-soluble pentosans (WSP), alkaline-extractable pentosans (AEP), and xylanase on the growth and organ development of broiler chicks. Three hundred and fifty 1-d-old female broiler chicks were randomly allocated into seven experimental groups of five pen replicates, with ten chicks per replicate. The control group consumed a corn-soybean meal-based diet. Six dietary treatment groups consumed the basal diet supplemented with one of the following: WSP at 50 mg/kg (WSP50) or 100 mg/kg (WSP100); AEP at 50 mg/kg (AEP50) or 100 mg/kg (AEP100); or xylanase at 3 mg/kg (Xase3) or 6 mg/kg (Xase6). Data including the body weight, digestive organ weights, gut length, rectal digesta viscosity, and gut microflora and pH were collected on d 5, 10, and 15. When compared to the control group, WSP50 promoted body weight gain and organ growth throughout the study, calculated as 3-d averages (p<0.05). WSP100 increased weight gain and enhanced organ development (proventriculus, gizzard, and gut) on d 10 (p<0.05), but the 3-d averages were not different from the control group except for the weight of gizzard. Both Xase3 and Xase6 increased the 3-d average weight gain and the growth of the gizzard (p<0.05). WSP50 increased the digesta viscosity compared to Xase3 on d 10 and 15 (p<0.05). WSP50, Xase3, and Xase6 increased the concentration of Lactobacillus in the rectum when compared to the control group (p<0.05), but only Xase3 lowered the digesta pH in the ileum and cecum on d 10 and 15. AEP had minimal influence on the growth and organ development of broilers. The results showed that low levels of WSP, AEP, and xylanase had different effects and underlying mechanisms on the growth and organ development of broiler chicks. WSP50 could increase the growth performance of broilers fed a corn-soybean meal-based diet.

Reactive oxygen production induced by the gut microbiota: pharmacotherapeutic implications

The resident prokaryotic microbiota of the mammalian intestine influences diverse homeostatic functions, including regulation of cellular growth, maintenance of barrier function, and modulation of immune responses. However, it is unknown how commensal prokaryotic organisms mechanistically influence eukaryotic signaling networks. Recent data has demonstrated that gut epithelia contacted by enteric commensal bacteria rapidly generate reactive oxygen species (ROS). While the induced generation of ROS via stimulation of formyl peptide receptors is a cardinal feature of the cellular response of phagocytes to pathogenic or commensal bacteria, evidence is accumulating that ROS are also similarly elicited in other cell types, including intestinal epithelia, in response to microbial signals. Additionally, ROS have been shown to serve as critical second messengers in multiple signal transduction pathways stimulated by proinflammatory cytokines and growth factors. This physiologically-generated ROS is known to participate in cellular signaling via the rapid and transient oxidative inactivation of a defined class of sensor proteins bearing oxidant-sensitive thiol groups. These proteins include tyrosine phosphatases that serve as regulators of MAP kinase pathways, cytoskeletal dynamics, as well as components involved in control of ubiquitination-mediated NF-κB activation. Consistently, microbial-elicited ROS has been shown to mediate increased cellular proliferation and motility and to modulate innate immune signaling. These results demonstrate how enteric microbiota influence regulatory networks of the mammalian intestinal epithelia. We hypothesize that many of the known effects of the normal microbiota on intestinal physiology, and potential beneficial effects of candidate probiotic bacteria, may be at least partially mediated by this ROS-dependent mechanism.

Chronic dietary fiber supplementation with wheat dextrin does not inhibit calcium and magnesium absorption in premenopausal and postmenopausal women

This placebo-controlled, randomized, crossover clinical study examined the effect of chronic wheat dextrin intake on calcium and magnesium absorption. Forty premenopausal and post menopausal women (mean ± SD age 49.9 ± 9.8 years) consumed wheat dextrin or placebo (15 g/day) for 2 weeks prior to (45)calcium ((45)Ca) and (26)magnesium ((26)Mg) absorption testing. After a standardized breakfast, serial blood and urine samples were obtained. The mean ± SD area under the curve from 0 to 9 h for (45)Ca specific activity was 0.81 ± 0.21 for wheat dextrin and 0.82 ± 0.22 for placebo, showing that wheat dextrin had no effect on calcium absorption. The mean ± SD percentage excess of (26)Mg/(24)Mg was 7.8% ± 2.1% for wheat dextrin and 7.9% ± 2.6% for placebo, showing that wheat dextrin had no effect on magnesium absorption. In conclusion, chronic wheat dextrin consumption did not inhibit calcium or magnesium absorption from the gastrointestinal tract in women.

Aging of the human metaorganism: the microbial counterpart

Human beings have been recently reviewed as 'metaorganisms' as a result of a close symbiotic relationship with the intestinal microbiota. This assumption imposes a more holistic view of the ageing process where dynamics of the interaction between environment, intestinal microbiota and host must be taken into consideration. Age-related physiological changes in the gastrointestinal tract, as well as modification in lifestyle, nutritional behaviour, and functionality of the host immune system, inevitably affect the gut microbial ecosystem. Here we review the current knowledge of the changes occurring in the gut microbiota of old people, especially in the light of the most recent applications of the modern molecular characterisation techniques. The hypothetical involvement of the age-related gut microbiota unbalances in the inflamm-aging, and immunosenescence processes will also be discussed. Increasing evidence of the importance of the gut microbiota homeostasis for the host health has led to the consideration of medical/nutritional applications of this knowledge through the development of probiotic and prebiotic preparations specific for the aged population. The results of the few intervention trials reporting the use of pro/prebiotics in clinical conditions typical of the elderly will be critically reviewed.

Clostridium difficile infection: clinical spectrum and approach to management

Clostridium difficile is recognized globally as an important enteric pathogen associated with considerable morbidity and mortality due to the widespread use of antibiotics. The overall incidence of C. difficile-associated diarrhea (CDAD) is increasing due to the emergence of a hypervirulent strain known as NAP1/BI/027. C. difficile acquisition by a host can result in a varied spectrum of clinical conditions inclusive of both colonic and extracolonic manifestations. Repeated occurrence of CDAD, manifested by the sudden re-appearance of diarrhea and other symptoms usually within a week of stopping treatment, makes it a difficult clinical problem. C. difficile infection has also been reported to be involved in exacerbation of inflammatory bowel diseases. The first step in the management of a suspected CDAD case is the withdrawal of the offending agent and changing the antibiotic regimens. Antimicrobial therapy directed against C. difficile viz. metronidazole for mild cases and vancomycin for severe cases is needed. For patients with ileus, oral vancomycin with simultaneous intravenous (IV) metronidazole and intracolonic vancomycin may be given. Depending on the severity of disease, the further line of management may include surgery, IV immunoglobulin treatment or high dose of vancomycin. Adjunctive measures used for CDAD are probiotics and prebiotics, fecotherapy, adsorbents and immunoglobulin therapy. Among the new therapies fidaxomicin has recently been approved by the American Food and Drugs Administration for treatment of CDAD.

Probiotics for patients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure and/or portosystemic shunt. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient's quality of life and daily functioning and represent a significant burden on health care resources. Probiotics are live microorganisms, which when administered in adequate amounts may confer a health benefit on the host.

OBJECTIVES

To quantify the beneficial and harmful effects of any probiotic in any dosage, compared with placebo or no intervention, or with any other treatment for patients with any grade of acute or chronic hepatic encephalopathy as assessed from randomised trials.

SEARCH METHODS

We searched the The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, conference proceedings, reference lists of included trials and the WHO international clinical trials registry until April 2011 registry platform to identify new and ongoing trials.

SELECTION CRITERIA

We included randomised trials that compared probiotics in any dosage with placebo or no intervention, or with any other treatment in patients with hepatic encephalopathy.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed the risk of bias of the included trials and extracted data on relevant outcomes, with differences resolved by consensus. We conducted random-effects model meta-analysis due to obvious heterogeneity of patients and interventions. A P value of 0.05 or less was defined as significant. Dichotomous outcomes are expressed as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials of which 550 participants were randomised. Four of the seven trials compared a probiotic with placebo or no treatment in 245 participants, another trial compared a probiotic with lactulose in 40 participants , and the remaining two trials compared a probiotic with both placebo and lactulose in 265 participants. Each trial used different types of probiotics. Duration of administration of the experimental intervention varied from 10 days to 180 days. Two trials were industry funded, and five were unclear about origin of funding. All trials had high risk of bias. When probiotics were compared with no treatment, there was no significant difference in all-cause mortality (2 trials, 105 participants; 1/57 (2%) versus 1/48 (2%): RR 0.72; 95% CI 0.08 to 6.60), lack of recovery (4 trials, 206 participants; 54/107 (50%) versus 68/99 (69%): RR 0.72; 95% CI 0.49 to 1.05), adverse events (3 trials, 145 participants; 2/77 (3%) versus 6/68 (9%): RR 0.34; 95% CI 0.08 to 1.42), quality of life (1 trial, 20 participants contributed to the physical quality of life measurement, 20 participants contributed to the mental quality of life: MD Physical 0.00; 95% CI -5.47 to 5.47; MD Mental 4.00; 95% CI -1.82 to 9.82), or change of/or withdrawal from treatment (3 trials, 175 participants; 11/92 (12%) versus 7/83 (8%): RR 1.28; 95% CI 0.52 to 3.19). No trial reported sepsis or duration of hospital stay as an outcome. Plasma ammonia concentration was significantly lower for participants treated with probiotic at one month (3 trials, 226 participants: MD -2.99 μmol/L; 95% CI -5.70 to -0.29) but not at two months (3 trials, 181 participants: MD -1.82 μmol/L; 95% CI -14.04 to 10.41). Plasma ammonia decreased the most in the participants treated with probiotic at three months (1 trial, 73 participants: MD -6.79 μmol/L; 95% CI -10.39 to -3.19). When probiotics were compared with lactulose no trial reported all-cause mortality, quality of life, duration of hospital stay, or septicaemia. There were no significant differences in lack of recovery (3 trials, 173 participants; 47/87 (54%) versus 44/86 (51%): RR 1.05; 95% CI 0.75 to 1.47), adverse events (2 trials, 111 participants; 3/56 (5%) versus 6/55 (11%): RR 0.57; 95% CI 0.06 to 5.74), change of/or withdrawal from treatment at one month (3 trials, 190 participants; 8/95 (8%) versus 7/95 (7%): RR 1.10; 95% CI 0.40 to 3.03), plasma ammonia concentration (2 trials, 93 participants: MD -6.61 μmol/L; 95% CI -30.05 to 16.84), or change in plasma ammonia concentration (1 trial, 77 participants: MD 1.16 μmol/L; 95% CI -1.96 to 4.28).

AUTHORS' CONCLUSIONS

The trials we located suffered from a high risk of systematic errors ('bias') and high risk of random errors ('play of chance'). While probiotics appear to reduce plasma ammonia concentration when compared with placebo or no intervention, we are unable to conclude that probiotics are efficacious in altering clinically relevant outcomes. Demonstration of unequivocal efficacy is needed before probiotics can be endorsed as effective therapy for hepatic encephalopathy. Further randomised clinical trials are needed.

Enteric commensal bacteria induce extracellular signal-regulated kinase pathway signaling via formyl peptide receptor-dependent redox modulation of dual specific phosphatase 3

The normal microbial occupants of the mammalian intestine are crucial for maintaining gut homeostasis, yet the mechanisms by which intestinal cells perceive and respond to the microbiota are largely unknown. Intestinal epithelial contact with commensal bacteria and/or their products has been shown to activate noninflammatory signaling pathways, such as extracellular signal-related kinase (ERK), thus influencing homeostatic processes. We previously demonstrated that commensal bacteria stimulate ERK pathway activity via interaction with formyl peptide receptors (FPRs). In the current study, we expand on these findings and show that commensal bacteria initiate ERK signaling through rapid FPR-dependent reactive oxygen species (ROS) generation and subsequent modulation of MAP kinase phosphatase redox status. ROS generation induced by the commensal bacteria Lactobacillus rhamnosus GG and the FPR peptide ligand, N-formyl-Met-Leu-Phe, was abolished in the presence of selective inhibitors for G protein-coupled signaling and FPR ligand interaction. In addition, pretreatment of cells with inhibitors of ROS generation attenuated commensal bacteria-induced ERK signaling, indicating that ROS generation is required for ERK pathway activation. Bacterial colonization also led to oxidative inactivation of the redox-sensitive and ERK-specific phosphatase, DUSP3/VHR, and consequent stimulation of ERK pathway signaling. Together, these data demonstrate that commensal bacteria and their products activate ROS signaling in an FPR-dependent manner and define a mechanism by which cellular ROS influences the ERK pathway through a redox-sensitive regulatory circuit.

Fermentation of β-glucans derived from different sources by bifidobacteria: evaluation of their bifidogenic effect

β-Glucans obtained from barley, seaweed, bacteria, and mushroom sclerotia were incubated with pure cultures of Bifidobacterium infantis, Bifidobacterium longum, and Bifidobacterium adolescentis for a 24 h batch fermentation to evaluate their bifidogenic effect with inulin as the positive control. The pH value in all culture media was decreased by 0.5-1.5 units. All β-glucans supported the growth of the three bifidobacteria with B. infantis, having a relatively larger increase in populations (3-4 log(10) colony forming units). B. infantis produced almost double the amount of total short-chain fatty acids (SCFAs) than the other two bifidobacteria. The SCFA profile of B. infantis had a relatively higher proportion of propionic and butyric acid but less acetic acid than the other bifidobacteria. The utilization of all the β-glucans isolated from different sources regardless of their differences in glycosidic linkages and molecular weight by all three bifidobacteria was comparable to that of inulin.

Aging of the human metaorganism: the microbial counterpart

Human beings have been recently reviewed as 'metaorganisms' as a result of a close symbiotic relationship with the intestinal microbiota. This assumption imposes a more holistic view of the ageing process where dynamics of the interaction between environment, intestinal microbiota and host must be taken into consideration. Age-related physiological changes in the gastrointestinal tract, as well as modification in lifestyle, nutritional behaviour, and functionality of the host immune system, inevitably affect the gut microbial ecosystem. Here we review the current knowledge of the changes occurring in the gut microbiota of old people, especially in the light of the most recent applications of the modern molecular characterisation techniques. The hypothetical involvement of the age-related gut microbiota unbalances in the inflamm-aging, and immunosenescence processes will also be discussed. Increasing evidence of the importance of the gut microbiota homeostasis for the host health has led to the consideration of medical/nutritional applications of this knowledge through the development of probiotic and prebiotic preparations specific for the aged population. The results of the few intervention trials reporting the use of pro/prebiotics in clinical conditions typical of the elderly will be critically reviewed.

Chicory inulin does not increase stool weight or speed up intestinal transit time in healthy male subjects

Inulin is a non-digestible oligosaccharide classified as a prebiotic, a substrate that promotes the growth of certain beneficial microorganisms in the gut. We examined the effect of a 20 g day(-1) supplement of chicory inulin on stool weight, intestinal transit time, stool frequency and consistency, selected intestinal microorganisms and enzymes, fecal pH, short chain fatty acids and ammonia produced as by-products of bacterial fermentation. Twelve healthy male volunteers consumed a well-defined, controlled diet with and without a 20 g day(-1) supplement of chicory inulin (degree of polymerization (DP) ranging for 2-60), with each treatment lasting for 3 weeks in a randomized, double-blind crossover trial. Inulin was consumed in a low fat ice cream. No differences were found in flavor or appeal between the control and inulin-containing ice creams. Inulin consumption resulted in a significant increase in total anaerobes and Lactobacillus species and a significant decrease in ammonia levels and β-glucuronidase activity. Flatulence increased significantly with the inulin treatment. No other significant differences were found in bowel function with the addition of inulin to the diet. Thus, inulin is easily incorporated into a food product and has no negative effects on food acceptability. Twenty grams of inulin was well tolerated, but had minimal effects on measures of laxation in healthy, human subjects.

Commensal-epithelial signaling mediated via formyl peptide receptors

Commensal bacteria and/or their products engender beneficial effects to the mammalian gut, including stimulating physiological cellular turnover and enhancing wound healing, without activating overt inflammation. In the present study, we observed commensal bacteria-mediated activation of the noninflammatory extracellular signal-regulated kinase[ERK]/mitogen-activated protein kinase and Akt signaling pathways in gut epithelial cells and delineated a mechanism for this bacterially activated signaling. All tested strains of commensal bacteria induced ERK phosphorylation without stimulating pro-inflammatory phospho-IκB or pro-apoptotic phospho-c-Jun NH(2)-terminal kinase, with Lactobacillus species being most potent. This pattern of signaling activation was recapitulated using the peptide N-formyl-Met-Leu-Phe, a bacterial product known to stimulate signaling events in mammalian phagocytes. Sensing of N-formyl-Met-Leu-Phe by gut epithelial cells occurs via recently characterized formyl peptide receptors located in the plasma membrane. Both commensal bacteria and N-formyl-Met-Leu-Phe application to the apical surface of polarized gut epithelial cells resulted in specific formyl peptide receptor activation. In addition, pretreatment of model epithelia and murine colon with Boc2 (a specific peptide antagonist) or pertussis toxin (a G(i)-protein inhibitor) abolished commensal-mediated ERK phosphorylation. Taken together, these data show that commensal bacteria specifically activate the ERK/mitogen-activated protein kinase pathway in an formyl peptide receptor-dependent manner, delineating a mechanism by which commensal bacteria contribute to cellular signaling in gut epithelia.

Guidance for substantiating the evidence for beneficial effects of probiotics: probiotics in chronic inflammatory bowel disease and the functional disorder irritable bowel syndrome

Ulcerative colitis and Crohn's disease, the 2 distinct idiopathic pathologies of inflammatory bowel diseases, are spontaneously relapsing, immunologically mediated disorders of the gastrointestinal tract. Selected probiotics strains have been proven to be clinically effective in maintaining remission in patients with ulcerative colitis. None of the probiotics thus far tested has been shown to be effective in induction of remission or in maintenance of remission in patients with Crohn's disease. The multispecies probiotics mixture of 8 strains seems effective in the maintenance of remission in pouchitis. Irritable bowel syndrome is a functional bowel disorder manifested by chronic, recurring abdominal pain or discomfort associated with disturbed bowel habit in the absence of structural abnormalities likely to account for these symptoms. Recently conducted appropriately powered studies with different (combinations of) probiotics show positive results on reduction of symptoms, although a considerable placebo effect is also found. Mechanistic studies aimed at pathophysiological mechanisms of inflammatory bowel diseases can identify new targets for probiotic bacteria.

Probiotics and prevention of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating disease affecting primarily premature infants. Despite advances in neonatal care, the mortality rate following NEC has not changed significantly in the past 30 years. New preventative measures are needed. In this review, we will provide information to assess the possible role of probiotics, prebiotics and related agents in the prevention of this devastating disease. We will also discuss short and long term safety issues as well as potential alternatives. Although it is tempting to rebuild the intestinal microbiota using the agents such as pro and prebiotics during infancy, routine use is not yet warranted a cautious approach on the basis of sounds scientific data is needed.

A human, double-blind, placebo-controlled, crossover trial of prebiotic, probiotic, and synbiotic supplementation: effects on luminal, inflammatory, epigenetic, and epithelial biomarkers of colorectal cancer

BACKGROUND

Diet is an important factor in colorectal carcinogenesis; thus, dietary supplements may have a role in colorectal cancer prevention.

OBJECTIVE

The objective was to establish the relative luminal, epithelial, and epigenetic consequences of prebiotic, probiotic, and synbiotic dietary supplementation in humans.

DESIGN

This was a randomized, double-blind, placebo-controlled, 4-wk crossover trial of resistant starch and Bifidobacterium lactis, either alone or as a combined synbiotic preparation, in 20 human volunteers. Rectal biopsy, feces, and serum samples were collected. The rectal mucosal endpoints were DNA methylation at 16 CpG island loci and LINE-1, epithelial proliferation (Ki67 immunohistochemistry), and crypt cellularity. The fecal endpoints were short-chain fatty acid concentrations, pH, ammonia, and microbiological profiles (by denaturing gradient gel electrophoresis and sequencing). Serum endpoints were a panel of cytokines and high-sensitivity C-reactive protein.

RESULTS

Seventeen subjects completed the entire study. The synbiotic intervention fostered a significantly different fecal stream bacterial community than did either the prebiotic (P = 0.032) or the probiotic (P = 0.001) intervention alone, in part because of a greater proportion of patients harboring fecal Lachnospiraceae spp. These changes developed in the absence of any significant differences in fecal chemistry. There were no differences in epithelial kinetics.

CONCLUSIONS

This synbiotic supplementation with B. lactis and resistant starch, in the doses used, induced unique changes in fecal microflora but did not significantly alter any other fecal, serum, or epithelial variables. This trial was registered in the Australian New Zealand Clinical Trials Registry at www.anzctr.org.au as ACTRN012606000115538.

Childhood constipation and diet

Constipation is a common problem in children. However, there is much controversy surrounding the etiology, diagnosis and treatment of functional constipation observed in childhood. Despite the high frequency of this problem documented in the literature, there is little research that assesses the direct relationship between the food consumed and the eventual stool consistency. Breastfeeding is an excellent way to prevent constipation in infants and toddlers, as is fruit and vegetable consumption in older children. The aim of this review is to investigate available tools in the literature concerning constipation in children and to discuss the relationship between constipation and diet in childhood.

Microbes in gastrointestinal health and disease

Most, if not all, animals coexist with a complement of prokaryotic symbionts that confer a variety of physiologic benefits. In humans, the interaction between animal and bacterial cells is especially important in the gastrointestinal tract. Technical and conceptual advances have enabled rapid progress in characterizing the taxonomic composition, metabolic capacity, and immunomodulatory activity of the human gut microbiota, allowing us to establish its role in human health and disease. The human host coevolved with a normal microbiota over millennia and developed, deployed, and optimized complex immune mechanisms that monitor and control this microbial ecosystem. These cellular mechanisms have homeostatic roles beyond the traditional concept of defense against potential pathogens, suggesting these pathways contribute directly to the well-being of the gut. During their coevolution, the bacterial microbiota has established multiple mechanisms to influence the eukaryotic host, generally in a beneficial fashion, and maintain their stable niche. The prokaryotic genomes of the human microbiota encode a spectrum of metabolic capabilities beyond that of the host genome, making the microbiota an integral component of human physiology. Gaining a fuller understanding of both partners in the normal gut-microbiota interaction may shed light on how the relationship can go awry and contribute to a spectrum of immune, inflammatory, and metabolic disorders and may reveal mechanisms by which this relationship could be manipulated toward therapeutic ends.

Efficacy of probiotics in irritable bowel syndrome: a meta-analysis of randomized, controlled trials

PURPOSE

This study was designed to evaluate whether probiotics improve symptoms in patients with irritable bowel syndrome.

METHODS

PubMed, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched for studies that investigated the efficacy of probiotics in the management of irritable bowel syndrome. Clinical improvement was the key outcome of interest. Data were searched within the time period of 1966 through September 2007.

RESULTS

Eight randomized, placebo-controlled, clinical trials met our criteria and were included in the analysis. Pooling of eight trials for the outcome of clinical improvement yielded a significant relative risk of 1.22 (95 percent confidence interval, 1.07-1.4; P = 0.0042).

CONCLUSIONS

Probiotics may improve symptoms of irritable bowel syndrome and can be used as supplement to standard therapy.

Inulin-enriched pasta affects lipid profile and Lp(a) concentrations in Italian young healthy male volunteers

BACKGROUND

Inulin has been suggested to have beneficial effects on lipids, especially on triglyceridemia. Few data are available about the effects of inulin on Lipoprotein(a), a low-density lipoprotein-like particle considered as an independent risk factor for atherosclerosis. Adding inulin to pasta could be a preventive strategy for delaying the onset of atherosclerosis.

AIM OF THE STUDY

was to evaluate the effects of inulin-enriched pasta on lipid profile and on Lipoprotein(a) in young healthy subjects.

METHODS

Twenty-two young healthy male volunteers entered a randomized double blind cross-over study consisting of a 2-weeks run-in period, a baseline assessment, two 5-weeks study periods (11% inulin-enriched or control pasta), and an 8-weeks wash-out period in between. Serum lipid concentrations were evaluated by routine biochemical analyses and plasma Lipoprotein(a) concentrations by ELISA. The size of apolipoprotein(a) isoforms was determined by Western blot and immunodetection.

RESULTS

Significant differences at baseline and in the treatment groups were found for HDL-cholesterol (P = 0.004), total cholesterol/HDL-cholesterol ratio (P = 0.006), triglycerides (P = 0.04), and Lipoprotein(a) (P = 0.02) concentrations (data analyzed by Friedman test). Dunn's multiple comparison test was used to assess the significance of differences between inulin-enriched pasta diet vs. baseline. HDL-cholesterol concentrations increased by 35.9%; total cholesterol/HDL-cholesterol ratio, triglycerides, and Lipoprotein(a) concentrations decreased by 22.2, 23.4, and 16.5% respectively.

CONCLUSIONS

Inulin-enriched pasta administration induced significant effects on lipid pattern parameters in young healthy volunteers, including a significant reduction in Lipoprotein(a) concentrations.

Effect of Lactobacillus GG and conditioned media on IL-1beta-induced IL-8 production in Caco-2 cells

OBJECTIVE

To evaluate the anti-inflammatory effect of Lactobacillus casei rhamnosus GG (LGG) and its conditioned media (CM) in stimulated Caco-2 cells and to characterize the components of LGG that have the anti-inflammatory effect.

MATERIAL AND METHODS

Caco-2 cells were stimulated with IL-1beta with or without LGG or LGG-CM. Production of IL-8 was measured by enzyme-linked immunosorbent assay (ELISA). The transcriptional activities of the IL-8 gene and the NF-kappaB-responsive gene were evaluated by a transient transfection of the luciferase reporter gene. The effect on IkappaBalpha degradation was evaluated by Western blot analysis. To determine the nature of the immunomodulatory molecules, the LGG was modified to the following: treated with antibiotics, 4% formaldehyde, incubation at 95 degrees C, or sonication.

RESULTS

We demonstrated that the pretreatment of Caco-2 cells with LGG significantly inhibited IL-1beta-induced IL-8 production. Furthermore, LGG attenuated the IL-1beta-induced transcriptional activation of the IL-8 gene and the NF-kappaB-responsive gene, and attenuated the IL-1beta-induced IkappaBalpha degradation. Formaldehyde-fixed or antibiotics-treated LGG maintained the inhibitory effect, but heated LGG lost this effect. Sonicated LGG debris had a similar inhibitory effect with whole bacterial cells. LGG-CM attenuated IL-1beta-induced IL-8 production. This effect was maintained even when the conditioned media were heated.

CONCLUSIONS

LGG inhibited IL-1beta-induced IL-8 production in Caco-2 and this effect occurred at the transcriptional level, at least in part, by inhibition of the NF-kappaB signaling pathway. Both the structural material of LGG and the soluble factor secreted from LGG inhibited the IL-1beta-induced IL-8 production, and thus different substances may cause the effects.