Running a marathon induces changes in adipokine levels and in markers of cartilage degradation--novel role for resistin

Running a marathon causes strenuous joint loading and increased energy expenditure. Adipokines regulate energy metabolism, but recent studies have indicated that they also exert a role in cartilage degradation in arthritis. Our aim was to investigate the effects of running a marathon on the levels of adipokines and indices of cartilage metabolism. Blood samples were obtained from 46 male marathoners before and after a marathon run. We measured levels of matrix metalloproteinase-3 (MMP-3), cartilage oligomeric protein (COMP) and chitinase 3-like protein 1 (YKL-40) as biomarkers of cartilage turnover and/or damage and plasma concentrations of adipokines adiponectin, leptin and resistin. Mean marathon time was 3∶30∶46±0∶02∶46 (h:min:sec). The exertion more than doubled MMP-3 levels and this change correlated negatively with the marathon time (r = –0.448, p = 0.002). YKL-40 levels increased by 56% and the effect on COMP release was variable. Running a marathon increased the levels of resistin and adiponectin, while leptin levels remained unchanged. The marathon-induced changes in resistin levels were positively associated with the changes in MMP-3 (r = 0.382, p = 0.009) and YKL-40 (r = 0.588, p<0.001) and the pre-marathon resistin levels correlated positively with the marathon induced change in YKL-40 (r = 0.386, p = 0.008). The present results show the impact of running a marathon, and possible load frequency, on cartilage metabolism: the faster the marathon was run, the greater was the increase in MMP-3 levels. Further, the results introduce pro-inflammatory adipocytokine resistin as a novel factor, which enhances during marathon race and associates with markers of cartilage degradation.

Deoxycholic acid induced changes in electrophysiological parameters and macromolecular permeability in murine small intestine with and without functional enteric nervous system plexuses

BACKGROUND

We have previously shown in mice that the fecal proportion and concentration of the hydrophobic bile acid deoxycholic acid (DCA) is elevated with high-fat feeding and that these changes are able to disrupt the intestinal barrier function. The aim of this study was to investigate whether these changes are mediated by the enteric nervous system (ENS).

METHODS

The function of the ENS in the small intestinal tissues of mice was compromised by two different methods: by removing the seromuscular layer and by incubating the intact tissues with tetrodotoxin (TTX), a neural conduction blocker, before DCA treatment. Tissues with or without functional plexuses were mounted into a Ussing chamber system and treated with 3 mM DCA for 20 min. After DCA treatment, the intestinal permeability to fluorescein was assessed. Short-circuit current (Isc ) and transepithelial resistance (TER) were recorded throughout the experiment.

KEY RESULTS

DCA increased intestinal fluorescein permeability only in tissues where the seromuscular layer was removed. In tissues with intact seromuscular layer, DCA induced a significant increase in TER, which was attenuated by blocking of the neural function by TTX.

CONCLUSIONS & INFERENCES

The results of this study suggest that the DCA-induced increase observed in fluorescein permeability is not mediated through neural pathways, but more due to a direct effect on the epithelium. However, as TTX was able to attenuate the DCA-induced increase in TER, it can be speculated that DCA is also able to elicit responses through neural pathways.

Specific probiotics and virological findings in symptomatic conscripts attending military service in Finland

Background

Viral upper respiratory tract infections occur frequently among conscripts. Probiotics have reduced viral infections in children attending day care. Limited data are available on the effects of probiotics on the nasopharyngeal presence of respiratory viruses.

Objectives

To assess, whether probiotics could decrease nasopharyngeal occurrence of respiratory viruses in Finnish conscripts.

Study design

In a randomized, double-blind, placebo-controlled 90- and 150-day intervention study, 239 nasopharyngeal swab samples were collected from 192 symptomatic conscripts receiving daily chewable probiotic tablet containing Lactobacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis BB-12 (46.9%) or control tablet (53.1%) on visits to a garrison's health care center due to symptoms of infection. The presence of respiratory viruses was tested by PCR-methods, and viral findings were compared between the intervention groups.

Results

184 (76.9%) nasopharyngeal samples were positive for at least one respiratory virus. Picornaviruses were the most common viruses and were detected in 155 (84.2%) of samples. Of these, 143 (92.3%) were rhinovirus-positive and 20 (12.9%) were enterovirus-positive. The control group had 83 (64%) and the probiotic group 72 (66%) picornavirus infections (p = 0.79). Monthly distribution of picornaviruses showed that there were less picornavirus findings after 3 months in the probiotic group than in the control group (p = 0.0069). However, probiotics did not reduce picornavirus occurrence in other months.

Conclusions

Overall, probiotics did not reduce viral occurrence in symptomatic conscripts. However, probiotics decreased the presence of picornaviruses after 3 months, which may imply that probiotics play a role against viruses causing common cold. Further investigations are necessary to clarify the mechanisms involved in order to target specific probiotics on specific respiratory viruses.

The effectiveness and applicability of different lifestyle interventions for enhancing wellbeing: the study design for a randomized controlled trial for persons with metabolic syndrome risk factors and psychological distress

BACKGROUND

Obesity and stress are among the most common lifestyle-related health problems. Most of the current disease prevention and management models are not satisfactorily cost-effective and hardly reach those who need them the most. Therefore, novel evidence-based controlled interventions are necessary to evaluate models for prevention and treatment based on self-management. This randomized controlled trial examines the effectiveness, applicability, and acceptability of different lifestyle interventions with individuals having symptoms of metabolic syndrome and psychological distress. The offered interventions are based on cognitive behavioral approaches, and are designed for enhancing general well-being and supporting personalized lifestyle changes.

METHODS/DESIGN

339 obese individuals reporting stress symptoms were recruited and randomized to either (1) a minimal contact web-guided Cognitive Behavioral Therapy-based (CBT) intervention including an approach of health assessment and coaching methods, (2) a mobile-guided intervention comprising of mindfulness, acceptance and value-based exercises, (3) a face-to-face group intervention using mindfulness, acceptance and value-based approach, or (4) a control group. The participants were measured three times during the study (pre = week 0, post = week 10, and follow-up = week 36). Psychological well-being, lifestyles and habits, eating behaviors, and user experiences were measured using online surveys. Laboratory measurements for physical well-being and general health were performed including e.g. liver function, thyroid glands, kidney function, blood lipids and glucose levels and body composition analysis. In addition, a 3-day ambulatory heart rate and 7-day movement data were collected for analyzing stress, recovery, physical activity, and sleep patterns. Food intake data were collected with a 48 -hour diet recall interview via telephone. Differences in the effects of the interventions would be examined using multiple-group modeling techniques, and effect-size calculations.

DISCUSSION

This study will provide additional knowledge about the effects of three low intensity interventions for improving general well-being among individuals with obesity and stress symptoms. The study will show effects of two technology guided self-help interventions as well as effect of an acceptance and value-based brief group intervention. Those who might benefit from the aforesaid interventions will increase knowledge base to better understand what mechanisms facilitate effects of the interventions.

TRIAL REGISTRATION

Current Clinical Trials NCT01738256, Registered 17 August, 2012.

Probiotics in respiratory virus infections

Viral respiratory infections are the most common diseases in humans. A large range of etiologic agents challenge the development of efficient therapies. Research suggests that probiotics are able to decrease the risk or duration of respiratory infection symptoms. However, the antiviral mechanisms of probiotics are unclear. The purpose of this paper is to review the current knowledge on the effects of probiotics on respiratory virus infections and to provide insights on the possible antiviral mechanisms of probiotics. A PubMed and Scopus database search was performed up to January 2014 using appropriate search terms on probiotic and respiratory virus infections in cell models, in animal models, and in humans, and reviewed for their relevance. Altogether, thirty-three clinical trials were reviewed. The studies varied highly in study design, outcome measures, probiotics, dose, and matrices used. Twenty-eight trials reported that probiotics had beneficial effects in the outcome of respiratory tract infections (RTIs) and five showed no clear benefit. Only eight studies reported investigating viral etiology from the respiratory tract, and one of these reported a significant decrease in viral load. Based on experimental studies, probiotics may exert antiviral effects directly in probiotic–virus interaction or via stimulation of the immune system. Although probiotics seem to be beneficial in respiratory illnesses, the role of probiotics on specific viruses has not been investigated sufficiently. Due to the lack of confirmatory studies and varied data available, more randomized, double-blind, and placebo-controlled trials in different age populations investigating probiotic dose response, comparing probiotic strains/genera, and elucidating the antiviral effect mechanisms are necessary.

Effects of daily intake of yoghurt enriched with bioactive components on chronic stress responses: a double-blinded randomized controlled trial

Chronic stress has a negative influence on health. The aim was to determine stress reducing effects of yoghurt enriched with bioactive components as compared to normal yoghurt. High-trait anxiety individuals (n = 67) aged 18-63 years participated in a randomized, placebo-controlled, double-blinded intervention with parallel groups. They received either yoghurt enriched with alpha-lactalbumin, casein tripeptides and B vitamins (active) or isoenergetic standard yoghurt (control). To detect changes in psychological and physiological stress, State-Trait Anxiety Inventory, Profile of Mood States, salivary cortisol, inflammatory markers, blood pressure, heart rate variability (HRV) and actigraphy were monitored. We observed higher ratings of vigor (p = 0.047) and reduced feeling of inefficiency (p = 0.048) in the active group. HRV (baseline adjusted mean 49.1 ± 2.3 ms) and recovery index (106.6 ± 33.4) were higher in the active group than in controls (42.5 ± 2.2 ms and 80.0 ± 29.3) (p = 0.046 and p = 0.02, respectively). In conclusion, daily intake of yoghurt enriched with bioactive components may aid in stress coping.

Higher fecal bile acid hydrophobicity is associated with exacerbation of dextran sodium sulfate colitis in mice

Increased luminal bile acid hydrophobicity is associated with cytotoxicity and has been suggested to contribute to gut barrier dysfunction. The aim of this study was to compare 2 high-fat diets and a low-fat diet as to whether they modify fecal bile acid profile and hydrophobicity and/or susceptibility to dextran sodium sulfate (DSS) colitis in C57Bl/6J mice. Control and DSS-Control groups received a low-fat control diet [5.5% of total energy (E%) soy oil, 4.5 E% lard], and the DSS-Lard (5.5 E% soy oil, 54.5 E% lard) and DSS-Fish oil (5.5 E% soy oil, 27.2 E% lard and 27.2% menhaden oil) groups received high-fat diets. Feces for bile acid analysis were collected after 3-wk feeding, followed by induction of dextran DSS colitis (2 d 5% DSS in drinking water + 2 d tap water). Fecal bile acid hydrophobicity was elevated 76% in the lard group (P = 0.051) and 122% in the fish oil group (P = 0.001) compared with control, indicating potentially increased cytotoxicity. DSS caused severe colitis symptoms, evaluated as rectal bleeding, whereas all the controls were symptom free. The median symptom scores were: DSS-Control, 2.3 (IQR = 0.6, 3.0); DSS-Lard, 0.3 (IQR = 0, 2.3); and DSS-Fish oil, 2.4 (IQR = 1.9, 2.8). The only differences were DSS-Control vs. control (P < 0.001) and DSS-Fish oil vs. control (P < 0.001). Severity of symptoms in all colitic mice was positively correlated with fecal bile acid hydrophobicity (Spearman's ρ = 0.43; P = 0.028) and fecal deoxycholic acid concentration (Spearman's ρ = 0.39; P = 0.048). These results suggest that luminal bile acid modification, induced by altered dietary fat composition, may alter susceptibility to DSS colitis.

The use of the probiotic Lactobacillus rhamnosus GG and viral findings in the nasopharynx of children attending day care

Limited data are available on the effects of probiotics on the nasopharyngeal presence of respiratory viruses in children attending day care. In this substudy of a randomized, double-blinded, placebo-controlled 28-week intervention study, nasopharyngeal swab samples were collected, on visits to a physician due to symptoms of infection, from children receiving control milk (N = 97) and children receiving the same milk supplemented with probiotic Lactobacillus rhamnosus GG (N = 97). The presence of 14 respiratory viruses was assessed by PCR methods, and viral findings were compared with symptom prevalences in the intervention groups. Rhinovirus was identified in 28.6% of 315 swab samples, followed by respiratory syncytial virus (12.4%), parainfluenza virus 1 (12.1%), enterovirus (8.9%), influenza A(H1N1)pdm09 (7.9%), human bocavirus 1 (3.8%), parainfluenza virus 2 (3.2%), adenovirus (2.9%), and influenza A(H3N2) (0.6%). The children in the probiotic group had less days with respiratory symptoms per month than the children in the control group (6.48 [95% CI 6.28-6.68] vs. 7.19 [95% CI 6.98-7.41], P < 0.001). Probiotic intervention did not reduce significantly the occurrence of the examined respiratory viruses, or have an effect on the number of respiratory symptoms observed at the time of a viral finding. Rhinovirus, respiratory syncytial virus, and parainfluenza virus 1 were the most common respiratory viruses in symptomatic children. Children receiving Lactobacillus rhamnosus GG had fewer days with respiratory symptoms than children in the control group, although probiotic intervention was not effective in reducing the amount of viral findings or the respiratory symptoms associated with viral findings.

Antihypertensive effects of bioactive tripeptides-a random effects meta-analysis

A meta-analysis of possible antihypertensive effects of small doses of bioactive tripeptides isoleucine-proline-proline and valine-proline-proline in commercial milk products or tablets was carried out. A random effects model was used on 19 randomized, placebo-controlled clinical intervention trials (published 1996-October 2010) consisting of about 1500 prehypertensive or mildly hypertensive subjects.The overall blood pressure lowering for systolic blood pressure was -4.0 mmHg (95% CI -5.9 to -2.1 mmHg, P < 0.001) and for diastolic blood pressure -1.9 mmHg (95% CI -3.1 to -0.8 mmHg, P < 0.001). However, a positive effect was not reported in all the studies. The results suggest that rather small daily doses of the lactotripeptides in different functional food products may offer a valuable option as a non-pharmacological treatment of prehypertension or mild hypertension as part of life-style advice.

A novel mechanism for gut barrier dysfunction by dietary fat: epithelial disruption by hydrophobic bile acids

Impairment of gut barrier is associated with a fat-rich diet, but mechanisms are unknown. We have earlier shown that dietary fat modifies fecal bile acids in mice, decreasing the proportion of ursodeoxycholic acid (UDCA) vs. deoxycholic acid (DCA). To clarify the potential role of bile acids in fat-induced barrier dysfunction, we here investigated how physiological concentrations of DCA and UDCA affect barrier function in mouse intestinal tissue. Bile acid experiments were conducted in vitro in Ussing chambers using 4- and 20-kDa FITC-labeled dextrans. Epithelial integrity and inflammation were assayed by histology and Western blot analysis for cyclooxygenase-2. LPS was studied in DCA-induced barrier dysfunction. Finally, we investigated in a 10-wk in vivo feeding trial in mice the barrier-disrupting effect of a diet containing 0.1% DCA. DCA disrupted epithelial integrity dose dependently at 1-3 mM, which correspond to physiological concentrations on a high-fat diet. Low-fat diet-related concentrations of DCA had no effect. In vivo, the DCA-containing diet increased intestinal permeability 1.5-fold compared with control (P = 0.016). Hematoxylin-eosin staining showed a clear disruption of the epithelial barrier by 3 mM DCA in vitro. A short-term treatment by DCA did not increase cyclooxygenase-2 content in colon preparations. UDCA did not affect barrier function itself, but it ameliorated DCA-induced barrier disruption at a 0.6 mM concentration. LPS had no significant effect on barrier function at 0.5-4.5 μg/ml concentrations. We suggest a novel mechanism for barrier dysfunction on a high-fat diet involving the effect of hydrophobic luminal bile acids.

Effects of the viability of Lactobacillus rhamnosus GG on rotavirus infection in neonatal rats

AIM: To study the effects of live and dead Lactobacillus rhamnosus GG (GG) on rotavirus infection in a neonatal rat model.

METHODS: At the age of 2 d, suckling Lewis rat pups were supplemented with either live or dead GG and the treatment was continued daily throughout the experiment. At the age of 5 and 6 d the pups received oral rotavirus (RV) SA-11 strain. The pups were sacrificed at the age of 7 or 8 d by decapitation. The gastrointestinal tract was removed and macroscopic observations were done. The consistency of feces in the colon was classified using a four-tier system. RV was detected from the plasma, small intestine, colon and feces by real-time quantitative polymerase chain reaction (PCR).

RESULTS: In this neonatal rat model, RV induced a mild-to-moderate diarrhea in all except one pup of the RV-inoculated rats. RV moderately reduced body weight development from day 6 onwards. On day 7, after 2 d of RV infection, live and dead GG groups gained significantly more weight than the RV group without probiotics [36% (P = 0.001) and 28% (P = 0.031), respectively]. In addition, when compared with the RV control group, both live and dead GG reduced the weight ratio of colon/animal body weight to the same level as in the healthy control group, with reductions of 22% (P = 0.002) and 28% (P < 0.001), respectively. Diarrhea increased moderately in both GG groups. However, the diarrhea incidence and severity in the GG groups were not statistically significantly different as compared with the RV control group. Moreover, observed diarrhea did not provoke weight loss or death. The RV control group had the largest amount of RV PCR-positive samples among the RV-infected groups, and the live GG group had the smallest amount. Rats receiving live GG had significantly less RV in the colon (P = 0.027) when compared with the RV control group. Live GG was also more effective over dead GG in reducing the quantity of RV from plasma (P = 0.047).

CONCLUSION: Both live and dead GG have beneficial effects in RV infection. GG may increase RV clearance from the body and reduce colon swelling.

Nonpathogenic Lactobacillus rhamnosus activates the inflammasome and antiviral responses in human macrophages

In this study, we have utilized global gene expression profiling to compare the responses of human primary macrophages to two closely related, well-characterized Lactobacillus rhamnosus strains GG and LC705, since our understanding of the responses elicited by nonpathogenic bacteria in human innate immune system is limited. Macrophages are phagocytic cells of the innate immune system that perform sentinel functions to initiate appropriate responses to surrounding stimuli. Macrophages that reside on gut mucosa encounter ingested and intestinal bacteria. Bacteria of Lactobacillus genus are nonpathogenic and used in food and as supplements with health-promoting probiotic potential. Our results demonstrate that live GG and LC705 induced quantitatively different gene expression profiles in macrophages. A gene ontology analysis revealed functional similarities and differences in responses to GG and LC705 that were reflected in host defense responses. Both GG and LC705 induced interleukin-1β production in macrophages that required caspase-1 activity. LC705, but not GG, induced type I interferon -dependent gene activation that correlated with its ability to prevent influenza A virus replication and production of viral proteins in macrophages. Our results indicate that nonpathogenic bacteria are able to activate the inflammasome. In addition, our results suggest that L. rhamnosus may prime the antiviral potential of human macrophages.

A spread containing bioactive milk peptides Ile-Pro-Pro and Val-Pro-Pro, and plant sterols has antihypertensive and cholesterol-lowering effects

Lifestyle intervention is recommended as the primary treatment for mild hypertension and hypercholesterolemia. We studied the effects of a spread containing bioactive milk peptides IPP and VPP, as well as plant sterols, on cardiovascular risk factors in 104 hypertensive, hypercholesterolemic subjects in a randomised, placebo-controlled double-blind intervention. Middle-aged subjects consumed 20 g day⁻¹ of a spread containing 4.2 mg of IPP and VPP as well as 2 g of plant sterols for 10 weeks after a 2 week run-in period. Blood pressure was measured at home 3 times a week. Office blood pressure and 24 h ambulatory blood pressure measurements were performed at the end of the run-in and intervention periods. Blood samples were analysed for serum lipids, plasma glucose and inflammation markers. A significant decrease (-4.1 mmHg vs. -0.5 mmHg, p = 0.007) in systolic blood pressure was seen in the active group, compared to placebo at home measurements. Office blood pressure and 24 h nighttime or daytime ambulatory systolic or diastolic pressure did not differ between the groups. Total (-0.16 vs. 0.25 mmol l⁻¹, p = 0.005) and LDL cholesterol (-0.16 vs. 0.18 mmol l⁻¹, p = 0.006) decreased significantly in the active group compared to the placebo. No significant differences between groups were seen for plasma glucose or inflammation markers. The results thus suggest that milk peptides IPP and VPP and plant sterols, in a low-fat spread matrix, produce a clinically significant reduction in systolic blood pressure as well as serum total and LDL cholesterol without adverse effects. Functional foods that affect 2 major risk factors offer a safe and convenient way to reduce the risk of cardiovascular disease by supporting lifestyle intervention.

Early human enterovirus infections in healthy Swedish children participating in the PRODIA pilot study

Human enteroviruses (HEV) are common, especially in childhood and during the enterovirus season, causing mainly asymptomatic infections but also mild and severe illnesses. Numerous studies have shown the association between HEV infections and type 1 diabetes. Here, the prevalence of HEV infections was studied in healthy Swedish children with increased HLA-associated risk for type 1 diabetes participating in the PRODIA pilot study in which children were randomized to receive probiotics or placebo during the first 6 months of life. Stool specimens collected from 197 children in every 3 months from the age of 3 to 24 months were screened for HEV using traditional viral culturing method and identified with reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing of the partial VP1 coding part of the viral genome. Altogether 4.8% (52/1,094) of the specimens were HEV-positive and 22.3% (44/197) of the children excreted HEV during the follow-up. HEV-A and HEV-B were present in 2.1 and 2.7% of the specimens, respectively. HEV-C and HEV-D viruses were not detected. In total, 17 different HEV serotypes were detected and the most common findings were CV-A9 (13.5%), CV-A16 (11.5%), and CV-A2 (9.6%). The majority of the infections (92.3%) were during the enterovirus season extending from July to December. Probiotic treatment did not affect significantly the risk of HEV infections during the 2-year follow-up although a trend for transient decrease for HEV positivity (HEV-A and/or HEV-B) by the age of 12 months was observed in children who received probiotics [OR 0.40; 95% confidence interval 0.15 to 1.08; P-value 0.071, generalized estimating (GEE) analysis]. According to the results, HEV-A findings were nearly as common as HEV-B findings among the healthy children participating in this study. Also it was shown that serotypes belonging to HEV-A species can be detected by means of viral culturing.

Dietary factors and fluctuating levels of melatonin

Melatonin is secreted principally by the pineal gland and mainly at nighttime. The primary physiological function is to convey information of the daily cycle of light and darkness to the body. In addition, it may have other health-related functions. Melatonin is synthesized from tryptophan, an essential dietary amino acid. It has been demonstrated that some nutritional factors, such as intake of vegetables, caffeine, and some vitamins and minerals, could modify melatonin production but with less intensity than light, the most dominant synchronizer of melatonin production. This review will focus on the nutritional factors apart from the intake of tryptophan that affect melatonin levels in humans. Overall, foods containing melatonin or promoting the synthesis of it by impacting the availability of tryptophan, as well those containing vitamins and minerals which are needed as co-factors and activators in the synthesis of melatonin, may modulate the levels of melatonin. Even so, the influence of daytime diet on the synthesis of nocturnal melatonin is limited, however, the influence of the diet seems to be more obvious on the daytime levels.

Probiotics and irritable bowel syndrome

Background

Irritable bowel syndrome (IBS) is a major cause of abdominal discomfort and gut dysfunction worldwide. It is a poorly understood functional gastrointestinal disorder for which no effective medication is available. It is a benign condition, but its social and economic burden is significant. The symptoms consist of abdominal pain, bloating, flatulence, and irregular bowel movements. Alterations in the intestinal microbiota and mucosal inflammation may contribute to the development of IBS and probiotics could thus relieve the symptoms. This review gives an overview on the existing data on the effects of probiotics on the gastrointestinal symptoms of IBS.

Methods

A PUBMED search was made to review the relevant literature, and additional studies were obtained from the references of the selected articles.

Results

Clinical trials suggest that certain probiotics or combinations of bacteria have beneficial effects on the IBS symptoms. However the heterogeneity of studies, e.g. suboptimal study design, inadequate number of subjects, different doses and vehicles, inadequate length, make it difficult to compare the differences between probiotics and the effect may be strain-specific.

Conclusions

Though evidence is very promising, no general recommendations on the use of probiotics in IBS can be given yet. Further clinical trials and data on the mechanisms of action are needed. Probiotics are considered safe and if future scientific data is able to substantiate their efficacy in IBS, they certainly could be a treatment option in relieving the symptoms in IBS.

Impact of leucine on energy balance

Body weight is determined by the balance between energy intake and energy expenditure. When energy intake exceeds energy expenditure, the surplus energy is stored as fat in the adipose tissue, which causes its expansion and may even lead to the development of obesity. Thus, there is a growing interest to develop dietary interventions that could reduce the current obesity epidemic. In this regard, data from a number of in vivo and in vitro studies suggest that the branched-chain amino acid leucine influences energy balance. However, this has not been consistently reported. Here, we review the literature related to the effects of leucine on energy intake, energy expenditure and lipid metabolism as well as its effects on the cellular activity in the brain (hypothalamus) and in peripheral tissues (gastro-intestinal tract, adipose tissue, liver and muscle) regulating the above physiological processes. Moreover, we discuss how obesity may influence the actions of this amino acid.

Diet promotes sleep duration and quality

Sleep, much like eating, is an essential part of life. The mechanisms of sleep are only partially clear and are the subject of intense research. There is increasing evidence showing that sleep has an influence on dietary choices. Both cross-sectional and epidemiologic studies have demonstrated that those who sleep less are more likely to consume energy-rich foods (such as fats or refined carbohydrates), to consume fewer portions of vegetables, and to have more irregular meal patterns. In this narrative review, we pose the opposite question: can ingested food affect sleep? The purpose of this review is to discuss the evidence linking diet and sleep and to determine whether what we eat and what kind of nutrients we obtain from the food consumed before bedtime matter. In addition, scientific evidence behind traditional sleep-promoting foods such as milk and some herbal products is briefly described. These are reviewed using data from clinical trials, mostly in healthy subjects. In addition, we discuss the possible mechanisms behind these observations. Lastly, we summarize our findings that emerging evidence confirms a link between diet and sleep. Overall, foods impacting the availability of tryptophan, as well as the synthesis of serotonin and melatonin, may be the most helpful in promoting sleep. Although there are clear physiological connections behind these effects, the clinical relevance needs to be studied further.

High-fat-induced intestinal permeability dysfunction associated with altered fecal bile acids

AIM: To investigate whether high-fat-feeding is associated with increased intestinal permeability via alterations in bile acid metabolism.

METHODS: Male C57Bl/6J mice were fed on a high-fat (n = 26) or low-fat diet (n = 24) for 15 wk. Intestinal permeability was measured from duodenum, jejunum, ileum and colon in an Ussing chamber system using 4 kDa FITC-labeled dextran as an indicator. Fecal bile acids were analyzed with gas chromatography. Segments of jejunum and colon were analyzed for the expression of farnesoid X receptor (FXR) and tumor necrosis factor (TNF).

RESULTS: Intestinal permeability was significantly increased by high-fat feeding in jejunum (median 0.334 for control vs 0.393 for high-fat, P = 0.03) and colon (0.335 for control vs 0.433 for high-fat, P = 0.01), but not in duodenum or ileum. The concentration of nearly all identified bile acids was significantly increased by high-fat feeding (P < 0.001). The proportion of ursodeoxycholic acid (UDCA) in all bile acids was decreased (1.4% ± 0.1% in high-fat vs 2.8% ± 0.3% in controls, P < 0.01) and correlated inversely with intestinal permeability (r = -0.72, P = 0.01). High-fat feeding also increased jejunal FXR expression, as well as TNF expression along the intestine, especially in the colon.

CONCLUSION: High-fat-feeding increased intestinal permeability, perhaps by a mechanism related to bile acid metabolism, namely a decreased proportion of fecal UDCA and increased FXR expression.

Decreased training volume and increased carbohydrate intake increases oxidized LDL levels

We studied effects of probiotics and training volume on oxidized LDL lipids (ox-LDL), serum antioxidant potential (s-TRAP) and serum antioxidants (s-α-tocopherol, s-γ-tocopherol, s-retinol, s-β-carotene and s-ubiquinone-10) in marathon runners during 3-months training period, 6-days preparation period and marathon run. Runners (n=127) were recruited for a randomized, double-blind intervention during which they received either Lactobacillus rhamnosus GG (LGG, probiotic group) or placebo drink (placebo group) during whole study. During the preparation period, subjects decreased training and increased carbohydrate intake. Blood samples were taken at baseline, before 6-days preparation, before and immediately after the marathon. Probiotics did not have any effect on ox-LDL, s-TRAP or serum antioxidants levels during the study. Interestingly, ox-LDL increased by 28% and 33% during the preparation period and decreased by 16% and 19% during the marathon run in the placebo and probiotic groups, respectively (in all, P<0.001). No changes were seen in s-TRAP before marathon, but during run s-TRAP raised by 16% in both groups (both, P<0.001). The increase of ox-LDL level during the preparative period after several months' training suggests that aerobic training may reduce the concentration of ox-LDL and that decrease of training together with increased energy intake, mainly carbohydrate, before marathon is capable of increasing the level of ox-LDL.

Human bocavirus in the nasopharynx of otitis-prone children

OBJECTIVES

Human bocavirus (HBoV) is frequently identified in children with respiratory tract infections, and its role in acute otitis media (AOM) has been suggested. The disease associations for the closely related bocaviruses HBoV2-4 remain unknown. Increasing evidence shows that probiotics may reduce the risk of AOM of viral origin. Objectives of the study was to examine the prevalence and persistence of bocaviruses in consecutive nasopharyngeal samples (NPS) of otitis-prone children, and whether an association exists between HBoV and the child's characteristics, respiratory symptoms, and AOM pathogens, and whether probiotics reduce the occurrence of HBoV.

METHODS

In a double-blind, placebo-controlled, randomized, 6-month intervention study, 269 otitis-prone children (aged 9 months to 5.6 years), consumed daily either one capsule of probiotics (Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Bifidobacterium breve 99 and Propionibacterium freudenreichii JS) or placebo. After a clinical examination and NPS collected at three-time points, the presence and persistence of HBoV1-4 DNA in NPS was determined by RT-qPCR at the baseline, after 3, and 6 months.

RESULTS

A high load (>10,000 copies/ml) of HBoV DNA was detected in 26 (17.1%) of 152 children, and 16 (10.5%) showed a prolonged presence of HBoV for at least 3 months. None had DNA of HBoV2-4. Higher number of siblings associated with increased HBoV prevalence (p=0.029). Prevalence or persistence of HBoV was not significantly associated with other characteristics, respiratory symptoms, or AOM pathogens. Probiotic intervention significantly reduced the number of HBoV DNA-positive samples (probiotic vs. placebo: 6.4% vs. 19.0%, OR=0.25, CI 95%=0.07-0.94, p=0.039).

CONCLUSIONS

HBoV, but not HBoV2-4, DNA occurs often in the nasopharynx of otitis-prone children, and may persist for 3-6 months. Probiotic treatment possibly reduced the presence of HBoV.

Colonic methanogenesis in vivo and in vitro and fecal pH after resection of colorectal cancer and in healthy intact colon

PURPOSE

We compared colonic methanogenesis in vivo and in vitro as well as fecal pH in healthy subjects and in patients with resected colorectal cancer thus without the possible confounding effects of the tumor.

METHODS

A total of 144 subjects, 96 with resected colorectal cancer (of whom, 48 were with metastatic disease), 48 healthy subjects with intact colon, were analyzed for breath methane, fecal methanogenesis in vitro and fecal pH. In addition, the association between methanogenesis and pH with cancer site, operation technique and abdominal discomfort was investigated.

RESULTS

In vivo and in vitro methane measurements were in agreement. The percentage of breath methane excretors and fecal pH did not significantly differ in participants resected for colorectal cancer, either with (46%, 6.76) or without (46%, 6.77) metastatic disease, from healthy participants (40%, 6.80). Breath methane excretors had higher fecal pH than nonexcretors (7.05 versus 6.57, P< 0.001) and less abdominal discomfort (30% versus 54%, P = 0.016). Among patients with resected right-sided cancer (n = 15), there were less breath methane excretors (20%) than among those with resected left-sided cancer (51%, n = 81, P = 0.029) as well as lower fecal pH than among those with resected left-sided cancer (6.27 versus 6.86, P = 0.002) and among healthy subjects (6.80, P = 0.010).

CONCLUSIONS

Patients with resected colorectal cancer were as frequently methane producers as healthy subjects with intact colon, and there was no difference in their fecal pH. Low methanogenesis was found in patients with abdominal discomfort and is a possible characteristic, along with low fecal pH, to right-sided colorectal cancer.

Consumption of Galactooligosaccharides together with Probiotics Stimulates the In Vitro Peripheral Blood Mononuclear Cell Proliferation and IFNγ Production in Healthy Men

Probiotics and prebiotics modify the intestinal environment and could have immunomodulatory effects. The proliferation of spontaneous and phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs) and their production of interleukin-4, interleukin-5, transforming growth factor-β1, and interferon-γ (IFNγ) were determined in eighteen men at the baseline and during a 2-week period of probiotics (mixture of Lactobacillus rhamnosus GG, Lactobacillus rhamnosus LC705, Propionibacterium freudenreichii ssp. shermanii JS, and Bifidobacterium breve Bb99) and galactooligosaccharides (GOSs) (3.8 g/day). The spontaneous and stimulated proliferation of PBMC increased from the baseline during probiotics+GOS (P<0.001). The secretion of IFNγ, but not other cytokines, by stimulated PBMC increased during the same period (P<0.05). In conclusion, the consumption of this probiotic mixture including GOS appears to increase the capacity of PBMC to proliferate and release IFNγ selectively in healthy men.

Ile-Pro-Pro and Val-Pro-Pro tripeptide-containing milk product has acute blood pressure lowering effects in mildly hypertensive subjects

Casein-derived tripeptides isoleucine-proline-proline (Ile-Pro-Pro) and valine-proline-proline (Val-Pro-Pro) lower blood pressure (BP) in long-term clinical studies. Their acute effects on BP and vascular function, important for daily dosing scheme, were studied in a placebo-controlled double-blind crossover study using a single oral dose of a fermented milk product containing Ile-Pro-Pro and Val-Pro-Pro as well as plant sterols. Twenty-five subjects with untreated mild hypertension received in random order 250 g of study product (25 mg peptides and 2 g plant sterols) or placebo. Ambulatory BP was monitored for 8 h post-dose and arterial stiffness measured by pulse wave analysis at 2, 4, and 8 h. Blood and urine samples were analyzed for markers of the renin-angiotensin system (RAS) and endothelial function. Baseline adjusted treatment effect for systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial BP was -2.1 mmHg (95% CI: -4.1 to -0.1, p = 0.045), -1.6 mmHg (95% CI: -3.1 to -0.1, p = 0.03), and -1,9 mmHg (95% CI: -3-3 to -0.4, p = 0.0093), respectively, in favor of the active treatment for 8 h post- dose. No significant differences between the treatments were seen in brachial or aortic augmentation index, pulse wave velocity, or markers of RAS. Urinary excretion of cGMP, the second messenger of endothelial nitric oxide, was higher in the active group vs. placebo (p = 0.01). The results indicate that a single dose of a fermented milk product containing Ile-Pro-Pro and Val-Pro-Pro and plant sterols acutely lowers brachial SBP and DBP in mildly hypertensive subjects.

Dietary proteins and food-related reward signals

Proteins play a crucial role in almost all biological processes. Dietary proteins are generally considered as energy yielding nutrients and as a source of amino acids for various purposes. In addition, they may have a role in food-related reward signals. The purpose of this review was to give an overview of the role of dietary proteins in food-related reward and possible mechanisms behind such effects. Dietary proteins may elicit food-related reward by several different postprandial mechanisms, including neural and humoral signals from the gastrointestinal tract to the brain. In order to exert rewarding effects, protein have to be absorbed from the intestine and reach the target cells in sufficient concentrations, or act via receptors ad cell signalling in the gut without absorption. Complex interactions between different possible mechanisms make it very difficult to gain a clear view on the role and intesity of each mechanism. It is concluded that, in principle, dietary proteins may have a role in food-related reward. However, the evidence is based mostly on experiments with animal models and one should be careful in drawing conclusions of clinical relevance.

Similar effects of leucine rich and regular dairy products on muscle mass and functions of older polymyalgia rheumatica patients: a randomized crossover trial

OBJECTIVES

Leucine-rich milk and whey proteins have been suggested for prevention of age related loss of muscle mass and strength i.e. sarcopenia. The effects of milk protein supplementation and low intensity home based physical exercise on body composition and muscle functions were investigated.

DESIGN

A randomized double blind crossover trial.

SETTING

Community dwelling members of Helsinki rheumatoid association.

PARTICIPANTS

Older people (N=47, mean age 69.5 years) suffering from polymyalgia rheumatica.

INTERVENTION

Patients performed as many stand ups as possible twice a day after which they ingested a regular (Control) or a whey protein enriched dairy product with high leucine content (Test). The 8-week intervention periods were separated by a 4-week wash-out.

MEASUREMENTS

Body composition was measured by dual x-ray absorptiometry and muscle functions by hand grip strength, force platform countermovement jump performance, chair stand test, and walking speed.

RESULTS

The 16-week home-based post-exercise supplementation resulted in a 1.8% increase (p = 0.052) in lower limb muscle mass. Walking speed (+5.3%, p = 0.007) and chair stand test performance (-12.2 %, p < 0.001) were also improved. Furthermore, a tendency for increased jump power (+3.0%, p = 0.084) was observed. However, significant and consistent differences were not found in the changes of muscle mass indices or muscle functions between supplements, but the test supplement tended to prevent accumulation of body fat.

CONCLUSION

A low intensity home based exercise program combined with post-exercise milk protein supplementation is feasible despite some gastrointestinal complaints and seems effective in improving the muscle mass and functions of older persons with a inflammatory disease. Further studies are needed to establish, whether and to what extent the use of leucine-enriched whey products prevent or treat age-associated sarcopenia and whether they are superior to the present commercial milk products.

Lactobacillus rhamnosus GG and Streptococcus thermophilus induce suppressor of cytokine signalling 3 (SOCS3) gene expression directly and indirectly via interleukin-10 in human primary macrophages

In the present study we have characterized T helper type 2 (Th2) [interleukin (IL)-10]/Th1 (IL-12) cytokine expression balance in human primary macrophages stimulated with multiple non-pathogenic Gram-positive bacteria used in the food industry and as probiotic substances. Bacteria representing Lactobacillus, Bifidobacterium, Lactococcus, Leuconostoc, Propionibacterium and Streptococcus species induced anti-inflammatory IL-10 production, although quantitative differences between the bacteria were observed. S. thermophilus was able to induce IL-12 production, while the production of IL-12 induced by other bacteria remained at a low level. The highest anti-inflammatory potential was seen with bifidobacteria, as evidenced by high IL-10/IL-12 induction ratios. All studied non-pathogenic bacteria were able to stimulate the expression of suppressor of cytokine signalling (SOCS) 3 that controls the expression of proinflammatory cytokine genes. Lactobacillus and Streptococcus species induced SOCS3 mRNA expression directly in the absence of protein synthesis and indirectly via bacteria-induced IL-10 production, as demonstrated by experiments with cycloheximide (CHX) and anti-IL-10 antibodies, respectively. The mitogen-activated protein kinase (MAPK) p38 signalling pathway played a key role in bacteria-induced SOCS3 gene expression. Enhanced IL-10 production and SOCS3 gene expression induced by live non-pathogenic Lactobacillus and Streptococcus is also likely to contribute to their immunoregulatory effects in vivo.

A probiotic mixture including galactooligosaccharides decreases fecal β-glucosidase activity but does not affect serum enterolactone concentration in men during a two-week intervention

A high serum concentration of enterolactone, an enterolignan produced by colonic microbiota from precursors in cereals, vegetables, and fruits, is associated with reduced risk of acute coronary events. Probiotics and prebiotics modify colonic metabolism and may affect the serum enterolactone concentration. The effects of a probiotic mixture alone and with galactooligosaccharides (GOS) on serum enterolactone concentration and fecal metabolism were investigated in 18 healthy men. Participants received 3 interventions, each for 2 wk: 1) probiotics [Lactobacillus rhamnosus strains GG (LGG) and LC705, Propionibacterium freudenreichii ssp. shermanii JS, and Bifidobacterium breve Bb99, for a total amount of 2 × 10(10) CFU/d]; 2) probiotics and GOS 3.8 g/d; 3) probiotics, GOS, and rye bread (minimum 120 g/d). Serum enterolactone and fecal dry weight, enzyme activities, pH, SCFA, lactic acid bacteria, bifidobacteria, propionibacteria, and the strains LGG and LC705 were determined. The serum enterolactone concentration (nmol/L) tended to be decreased from baseline [mean (95% CI) 18.6 (10.8-26.4)] by probiotics alone [15.2 (7.8-22.7); P = 0.095], was not significantly affected by probiotics with GOS [21.5 (13.2-29.8)], and was increased by probiotics with GOS and rye bread [24.6 (15.4-33.7); P < 0.05]. Probiotics alone did not affect fecal β-glucosidase activity and bifidobacteria, but probiotics with GOS decreased β-glucosidase activity and increased bifidobacteria compared with baseline (P < 0.05) and with probiotics alone (P < 0.01). In conclusion, this probiotic mixture with or without GOS does not significantly affect serum enterolactone concentration. Because probiotics with GOS decreased fecal β-glucosidase activity but not serum enterolactone, the reduced fecal β-glucosidase, within the range of activities measured, does not seem to limit the formation of enterolactone.

Probiotic Lactobacillus rhamnosus downregulates FCER1 and HRH4 expression in human mast cells

AIM: To investigate the effects of four probiotic bacteria and their combination on human mast cell gene expression using microarray analysis.

METHODS: Human peripheral-blood-derived mast cells were stimulated with Lactobacillus rhamnosus (L. rhamnosus) GG (LGG^®), L. rhamnosus Lc705 (Lc705), Propionibacterium freudenreichii ssp. shermanii JS (PJS) and Bifidobacterium animalis ssp. lactis Bb12 (Bb12) and their combination for 3 or 24 h, and were subjected to global microarray analysis using an Affymetrix GeneChip^® Human Genome U133 Plus 2.0 Array. The gene expression differences between unstimulated and bacteria-stimulated samples were further analyzed with GOrilla Gene Enrichment Analysis and Visualization Tool and MeV Multiexperiment Viewer-tool.

RESULTS: LGG and Lc705 were observed to suppress genes that encoded allergy-related high-affinity IgE receptor subunits α and γ (FCER1A and FCER1G, respectively) and histamine H4 receptor. LGG, Lc705 and the combination of four probiotics had the strongest effect on the expression of genes involved in mast cell immune system regulation, and on several genes that encoded proteins with a pro-inflammatory impact, such as interleukin (IL)-8 and tumour necrosis factor alpha. Also genes that encoded proteins with anti-inflammatory functions, such as IL-10, were upregulated.

CONCLUSION: Certain probiotic bacteria might diminish mast cell allergy-related activation by downregulation of the expression of high-affinity IgE and histamine receptor genes, and by inducing a pro-inflammatory response.

Factors associated with acute respiratory illness in day care children

The aim of this study was to investigate the relationship between child characteristics, parental and environmental factors and the occurrence of acute respiratory illness (ARI) and acute otitis media (AOM) among Finnish children attending day care centres (DCCs). The study was a cross-sectional questionnaire of 594 children aged 1-6 y from 18 DCCs in Helsinki, Finland. Recurrent (> or =4 diseases/y) ARI was present in 44% of the 1-3-y-olds and 23% of the 4-6-y-olds, and recurrent AOM in 15% and 2.5%, respectively. Parent atopic disease (odds ratio (OR) 1.53, p = 0.033), mother's academic education (OR 1.77, p = 0.008) and a medium length of DCC attendance compared to a short period (OR 1.67, p = 0.049) increased, while furry pets (OR 0.44, p = 0.003) and older child age (OR 0.38, p < 0.001) reduced the risk of recurrent ARI. Recurrent ARI (OR 3.96, p = 0.008), mother's academic education (OR 5.02, p = 0.003), and a medium length of DCC attendance compared to a short period (OR 3.34, p = 0.044) increased, while partial breastfeeding > or =6 months (OR 0.20, p = 0.002) and older child age (OR 0.05, p < 0.001) reduced the risk of recurrent AOM. Parental and environmental factors had a significant impact on recurrent ARI and AOM episodes in children attending DCCs. These risk factors should be considered in future studies intending to reduce DCC infections.

Casein-derived tripeptide Ile-Pro-Pro improves angiotensin-(1-7)- and bradykinin-induced rat mesenteric artery relaxation

AIMS

Milk casein-derived bioactive tripeptides isoleucine-proline-proline (Ile-Pro-Pro) and valine-proline-proline (Val-Pro-Pro) lower blood pressure in animal models of hypertension and humans. In some studies, their angiotensin-converting enzyme (ACE)-inhibitory effect has been demonstrated. Besides classical ACE-angiotensin II-AT(1)-receptor pathway (ACE-Ang II- AT(1)), the significance of ACE2-angiotensin-(1-7)-Mas-receptor (ACE2-Ang-(1-7)-Mas) axis in the blood pressure regulation has now been acknowledged. The present study was aimed to further evaluate the renin-angiotensin system (RAS)-related vascular effects of Ile-Pro-Pro in vitro using rat mesenteric arteries.

MAIN METHODS

Superior mesenteric arteries of spontaneously hypertensive rat (SHR) were isolated, cut into rings and mounted in standard organ bath chambers. Endothelium-intact arterial rings were incubated in Krebs solution either with Ile-Pro-Pro, proline-proline (Pro-Pro), isoleucine (Ile), proline (Pro) or captopril for 6h at +37°C and vascular reactivity was measured.

KEY FINDINGS

In the presence of AT(1)-antagonist valsartan, Ang II induced vasodilatation, which was more pronounced in the arteries incubated with Ile-Pro-Pro (P<0.05) compared to the other compounds. Ang-(1-7)-induced vasodilatation was augmented by Ile-Pro-Pro or Pro (P<0.001 vs. control). Mas-receptor antagonist A-779 did not alter the responses. Ile-Pro-Pro and Pro augmented also bradykinin-induced relaxations (P<0.001 vs. control). Control arteries and arteries incubated with captopril showed only slight relaxations at higher bradykinin concentrations.

SIGNIFICANCE

Casein-derived tripeptide Ile-Pro-Pro and amino acid Pro enhance the vasodilatory effect of Ang-(1-7) and bradykinin. The role of ACE2-Ang-(1-7)-Mas axis in the modulation of vascular tone by these compounds seems probable.

Persistence of probiotic strains in the gastrointestinal tract when administered as capsules, yoghurt, or cheese

Most clinical studies of probiotics use freeze-dried, powdered bacteria or bacteria packed in capsules. However, probiotics are commercially available in various food matrices, which may affect their persistence in the gastrointestinal tract. The objective of the study was to compare oral and faecal recovery during and after administration of a combination of Lactobacillus rhamnosus GG and LC705, Propionibacterium freudenreichii subsp. shermanii JS, and Bifidobacterium animalis subsp. lactis Bb12 as capsules, yoghurt, or cheese. This randomized, parallel-group, open-label trial (n=36) included a 4-week run-in, 2-week intervention, and 3-week follow-up period. Participants consumed 10(10)cfu/day of probiotic combination and provided saliva and faecal samples before, during, and after the intervention. Strain-specific real-time PCR was used to quantify the strains. L. rhamnosus GG was the only probiotic strain regularly recovered in saliva samples. During the intervention period it was recovered in the saliva of 88% of the volunteers at least once. No difference was found between the yoghurt and cheese groups. At the end of the intervention, L. rhamnosus GG and LC705 counts were high in faecal samples of all product groups (8.08 and 8.67log(10) genome copies/g, respectively). There was no matrix effect on strain quantity in faeces or the recovery time after ceasing the intervention. For P. freudenreichii subsp. shermanii JS and B. animalis subsp. lactis Bb12, a matrix effect was found at the end of the intervention (P<0.01 and P<0.001, respectively) and in the recovery time during follow-up (P<0.05 for both). Yoghurt yielded the highest faecal quantity of JS and Bb12 strains (8.01 and 9.89log(10) genome copies/g, respectively). The results showed that the administration matrix did not influence the faecal quantity of lactobacilli, but affected faecal counts of propionibacteria and bifidobacteria that were lower when consumed in cheese. Thus, the consumption of probiotics in yoghurt matrix is highly suitable for studying potential health benefits and capsules provide a comparable means of administration when the viability of the strain in the capsule product is confirmed.

Effect of a multispecies probiotic supplement on quantity of irritable bowel syndrome-related intestinal microbial phylotypes

BACKGROUND

Probiotics can alleviate the symptoms of irritable bowel syndrome (IBS), possibly by stabilizing the intestinal microbiota. Our aim was to determine whether IBS-associated bacterial alterations were reduced during multispecies probiotic intervention consisting of Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99. The intervention has previously been shown to successfully alleviate gastrointestinal symptoms of IBS.

METHODS

The faecal microbiotas of 42 IBS subjects participating in a placebo-controlled double-blind multispecies probiotic intervention were analysed using quantitative real-time polymerase chain reaction (qPCR). Eight bacterial targets within the gastrointestinal microbiota with a putative IBS association were measured.

RESULTS

A phylotype with 94% similarity to Ruminococcus torques remained abundant in the placebo group, but was decreased in the probiotic group during the intervention (P = 0.02 at 6 months). In addition, the clostridial phylotype, Clostridium thermosuccinogenes 85%, was stably elevated during the intervention (P = 0.00 and P = 0.02 at 3 and 6 months, respectively). The bacterial alterations detected were in accordance with previously discovered alleviation of symptoms.

CONCLUSIONS

The probiotic supplement was thus shown to exert specific alterations in the IBS-associated microbiota towards the bacterial 16S rDNA phylotype quantities described previously for subjects free of IBS. These changes may have value as non-invasive biomarkers in probiotic intervention studies.

Effects of milk casein-derived tripeptides Ile-Pro-Pro, Val-Pro-Pro, and Leu-Pro-Pro on enzymes processing vasoactive precursors in vitro

Milk-based drinks containing casein-derived tripeptides isoleucine-proline-proline (Ile-Pro-Pro) and valine-proline-proline (Val-Pro-Pro) have been shown to possess antihypertensive and vascular endothelium-protecting properties in hypertensive animal models. Furthermore in clinical intervention trials they reduce blood pressure and arterial stiffness. The exact mechanisms are not known, but inhibition of angiotensin converting enzyme 1 (ACE1) has been suggested mainly to mediate these beneficial effects. The present study investigated the in vitro effects of three tripeptides: Ile-Pro-Pro, Val-Pro-Pro and leqcine-proline-proline (Leu-Pro-Pro) on four renin-angiotensin system enzymes: ACE1, ACE2, chymase, and cathepsin G. Also their effects on arginase I, a critical enzyme in L-arginine-nitric oxide pathway, were studied. It was shown, apparently for the first time, that the inhibitory effects of Ile-Pro-Pro, Val-Pro-Pro and Leu-Pro-Pro on ACE1 at micromolar concentrations are competitive in nature. Therefore the efficacy of inhibition is largely dependent on the amount of substrate present. Inhibition of ACE2 and arginase I was reached only at concentrations three orders of magnitude greater. No inhibition of chymase and cathepsin G was observed by the tripeptides. The findings support the hypothesis that Ile-Pro-Pro, Val-Pro-Pro and Leu-Pro-Pro act favourably on blood pressure mainly by selective inhibition of ACE1.

Long-term intervention with Lactobacillus helveticus fermented milk reduces augmentation index in hypertensive subjects

BACKGROUND

The milk casein-derived biologically active tripeptides, isoleucyl-prolyl-proline (Ile-Pro-Pro) and valyl-prolyl-proline (Val-Pro-Pro), have documented antihypertensive effect probably related to reduced angiotensin formation. It has been suggested that these tripeptides may reduce arterial stiffness and improve endothelial function. Our aim was to evaluate whether the milk-based drink containing Ile-Pro-Pro and Val-Pro-Pro influence arterial stiffness, measured as augmentation index (AIx), and endothelial function in man.

METHODS

In a double-blind parallel group intervention study, 89 hypertensive subjects received daily peptide milk containing a low dose of tripeptides (5 mg/day) for 12 weeks and a high dose (50 mg/day) for the following 12 weeks, or a placebo milk drink to titrate the dose-response effect. Arterial stiffness was assessed by pulse wave analysis at the beginning and end of each intervention period. Endothelial function was tested by examining pulse wave reflection response to sublingual nitroglycerin and salbutamol inhalation. Blood pressure was measured by using office and 24-h ambulatory blood pressure measurement.

RESULTS

At the end of the second intervention period, AIx decreased significantly in the peptide group compared with the placebo group (peptide group -1.53% (95% confidence interval (CI) -2.95 to -0.12), placebo group 1.20% (95% CI 0.09-2.32), P=0.013). No change in endothelial function index was observed (peptide group 0.02 (95% CI -0.06 to 0.08), placebo group 0.04 (95% CI -0.04 to 0.12), P=0.85). There were no statistically significant differences between the effects of the peptide and placebo treatment on office and 24-h ambulatory blood pressure.

CONCLUSIONS

Long-term treatment with Lactobacillus helveticus-fermented milk containing bioactive peptides reduces arterial stiffness expressed as AIx in hypertensive subjects.

Even low-grade inflammation impacts on small intestinal function

Independent of the cause and location, inflammation - even when minimal - has clear effects on gastrointestinal morphology and function. These result in altered digestion, absorption and barrier function. There is evidence of reduced villus height and crypt depth, increased permeability, as well as altered sugar and peptide absorption in the small intestine after induction of inflammation in experimental models, which is supported by some clinical data. Identification of inflammatory factors which may promote the process of gastrointestinal dysfunction as well as clinical research to verify experimental observations of inflammatory modulation of gastrointestinal function are required. Moreover, nutritional strategies to support functional restitution are needed.

Constipation is relieved more by rye bread than wheat bread or laxatives without increased adverse gastrointestinal effects

Rye bread and lactobacilli modify the colonic environment and have the potential to relieve constipation and could be a safe and convenient alternative to laxatives. The effects of rye bread and cultured buttermilk with Lactobacillus rhamnosus GG (LGG) on bowel function and colon metabolism were investigated and compared with laxatives in 51 constipated adults. They were randomized to receive whole-grain rye bread (minimum 240 g/d), LGG (2 x 10(10) colony-forming units/d), whole-grain rye bread (minimum 240 g/d) + LGG (2 x 10(10) colony-forming units/d), white wheat bread (maximum 192 g/d), or laxatives (as usual for a participant) for 3 wk. Participants recorded their dietary habits, bowel function, and gastrointestinal symptoms. Fecal weight, pH, SCFA and bacterial enzyme activities, total intestinal transit time (TITT), and breath hydrogen were determined. Rye bread, compared with white wheat bread, shortened TITT by 23% (P = 0.040), increased weekly defecations by 1.4 (P = 0.014), softened feces [odds ratio (OR) 3.98; P = 0.037], eased defecation (OR 5.08; P = 0.018), increased fecal acetic acid and butyric acid contents by 24% (P = 0.044) and 63% (P <0.001), respectively, and reduced fecal beta-glucuronidase activity by 23% (P = 0.014). Compared with laxatives, rye bread reduced TITT by 41% (P = 0.006), fecal beta-glucuronidase activity by 38% (P = 0.033), and fecal pH by 0.31 units (P = 0.006). LGG did not relieve constipation or significantly affect colonic metabolism. Gastrointestinal adverse effects did not significantly differ among the study groups. In conclusion, rye bread relieves mild constipation and improves colonic metabolism compared with white wheat bread and commonly used laxatives without increasing gastrointestinal adverse effects.

High intestinal IgA associates with reduced risk of IgE-associated allergic diseases

Development of oral tolerance and its stimulation by probiotics are still incomprehensible. Microbial stimulation of the gut may induce a subtle inflammation and induce secretion of mucosal IgA, which participates in antigen elimination. In a cohort of allergy-prone infants receiving probiotics and prebiotics or placebo we studied intestinal IgA and inflammation in the development of eczema, food allergy, asthma, and rhinitis (allergic diseases). We performed a nested unmatched case-control study of 237 infants participating in a randomized double-blind placebo-controlled allergy-prevention trial using a combination of four probiotic strains pre-natally and during 6 months form birth. We measured faecal IgA, alpha1-antitrypsin (alpha1-AT), tumour necrosis factor-alpha (TNF-alpha), and calprotectin at the age of 3 and 6 months. By age 2 yr, 124 infants had developed allergic disease or IgE-sensitization (cases) and 113 had not (controls). In infants with high faecal IgA concentration at the age of 6 months, the risk of having any allergic disease before the age of 2 yr tended to reduce [odds ratio (OR: 0.52)] and the risk for any IgE-associated (atopic) disease reduced significantly (OR: 0.49). High faecal calprotectin at the age of 6 months associated also with lower risk for IgE-associated diseases up to age 2 yr (OR: 0.49). All faecal inflammation markers (alpha1-AT, TNF-alpha, and calprotectin) correlated positively with faecal IgA (p < 0.001). Probiotics tended to augment faecal IgA (p = 0.085) and significantly increased faecal alpha1-AT (p = 0.001). High intestinal IgA in early life associates with minimal intestinal inflammation and indicates reduced risk for IgE-associated allergic diseases.

Elevated pro-inflammatory and lipotoxic mucosal lipids characterise irritable bowel syndrome

AIM

To investigate the pathophysiology of irritable bowel syndrome (IBS) by comparing the global mucosal metabolic profiles of IBS patients with those of healthy controls.

METHODS

Fifteen IBS patients fulfilling the Rome II criteria, and nine healthy volunteers were included in the study. A combined lipidomics (UPLC/MS) and metabolomics (GC x GC-TOF) approach was used to achieve global metabolic profiles of mucosal biopsies from the ascending colon.

RESULTS

Overall, lipid levels were elevated in patients with IBS. The most significant upregulation was seen for pro-inflammatory lysophosphatidylcholines. Other lipid groups that were significantly upregulated in IBS patients were lipotoxic ceramides, glycosphingolipids, and di- and triacylglycerols. Among the metabolites, the cyclic ester 2(3H)-furanone was almost 14-fold upregulated in IBS patients compared to healthy subjects (P = 0.03).

CONCLUSION

IBS mucosa is characterised by a distinct pro-inflammatory and lipotoxic metabolic profile. Especially, there was an increase in several lipid species such as lysophospholipids and ceramides.

Elevated pro-inflammatory and lipotoxic mucosal lipids characterise irritable bowel syndrome

AIM: To investigate the pathophysiology of irritable bowel syndrome (IBS) by comparing the global mucosal metabolic profiles of IBS patients with those of healthy controls.

METHODS: Fifteen IBS patients fulfilling the Rome II criteria, and nine healthy volunteers were included in the study. A combined lipidomics (UPLC/MS) and metabolomics (GC × GC-TOF) approach was used to achieve global metabolic profiles of mucosal biopsies from the ascending colon.

RESULTS: Overall, lipid levels were elevated in patients with IBS. The most significant upregulation was seen for pro-inflammatory lysophosphatidylcholines. Other lipid groups that were significantly upregulated in IBS patients were lipotoxic ceramides, glycosphingolipids, and di- and triacylglycerols. Among the metabolites, the cyclic ester 2(3H)-furanone was almost 14-fold upregulated in IBS patients compared to healthy subjects (P = 0.03).

CONCLUSION: IBS mucosa is characterised by a distinct pro-inflammatory and lipotoxic metabolic profile. Especially, there was an increase in several lipid species such as lysophospholipids and ceramides.