Probiotic yogurt in the elderly with intestinal bacterial overgrowth: endotoxaemia and innate immune functions

A study was conducted in healthy elderly living independently in senior housing to assess the impact of a probiotic yoghurt supplement on small intestinal bacterial overgrowth. Twenty-three participants with positive and thirteen participants with negative hydrogen breath test were studied before and after a period of 4 weeks of probiotic yoghurt administration. Intestinal permeability, plasma endotoxin levels, phagocytic activity of leucocytes, cytokine production by monocytes and free radical response of neutrophils were determined. Intestinal permeability was similar for the two groups and was unaffected by probiotic treatment. Both plasma endotoxin levels and the basal phagocytic activity of leucocytes decreased after yoghurt intake in the two groups. Exposure of monocytes and neutrophils ex vivo led to an increased cytokine response and free radical response, respectively. The normalisation of the various cytokine responses was more apparent in the group with positive breath test. In addition, the plasma levels of lipoplysaccharide binding protein and soluble CD14, lipoplysaccharide pattern recognition receptors and surrogate markers of lipoplysaccharide permeability were diminished by the end of the study. In conclusion, probiotic administration in the elderly normalises the response to endotoxin, and modulates activation markers in blood phagocytes, and therefore may help reduce low-grade chronic inflammatio

A whole-grain cereal-rich diet increases plasma betaine, and tends to decrease total and LDL-cholesterol compared with a refined-grain diet in healthy subjects

Epidemiological studies have repeatedly found that whole-grain (WG) cereal foods reduce the risk of several lifestyle-related diseases, though consistent clinical outcomes and mechanisms are elusive. To compare the effects of a WG-rich diet with a matched refined-grain (RG) diet on plasma biomarkers and bowel health parameters, seventeen healthy subjects (eleven females and six males) completed an exploratory cross-over study with a 2-week intervention diet based on either WG- or RG-based foods, separated by a washout of at least 5 weeks. Both diets were the same except for the use of WG (150g/d) or RG foods. Subjects undertook a 4h postprandial challenge on day 8 of each intervention diet. After 2 weeks, the WG diet tended to decrease plasma total and LDL-cholesterol (both P=0·09), but did not change plasma HDL-cholesterol, fasting glucose, C-reactive protein or homocysteine compared with the RG diet. Plasma betaine and alkylresorcinol concentrations were elevated after 1 week of the WG diet (P=0·01 and P<0·0001, respectively). Clostridium leptum populations in faeces were increased after the WG diet, along with a trend for decreased faecal water pH (P=0·096) and increased stool frequency (P<0·0001) compared with the RG diet. A short controlled intervention trial with a variety of commercially available WG-based products tended to improve biomarkers of CVD compared with a RG diet. Changes in faecal microbiota related to increased fibre fermentation and increased plasma betaine concentrations point to both fibre and phytochemical components of WG being important in mediating any potential health effect

Gut microbiota analysis reveals a marked shift to bifidobacteria by a starter infant formula containing a synbiotic of bovine milk-derived oligosaccharides and Bifidobacterium animalis subsp. lactis CNCM I-3446.

Non-digestible milk oligosaccharides were proposed as receptor decoys for pathogens and as nutrients for beneficial gut commensals like bifidobacteria. Bovine milk contains oligosaccharides, some of which are structurally identical or similar to those found in human milk. In a controlled, randomized double-blinded clinical trial we tested the effect of feeding a formula supplemented with a mixture of bovine milk-derived oligosaccharides (BMOS) generated from whey permeate, containing galacto-oligosaccharides and 3'- and 6'-sialyllactose, and the probiotic Bifidobacterium animalis subsp. lactis (B. lactis) strain CNCM I-3446. Breastfed infants served as reference group. Compared with a non-supplemented control formula, the test formula showed a similar tolerability and supported a similar growth in healthy newborns followed for 12 weeks. The control, but not the test group, differed from the breast-fed reference group by a higher faecal pH and a significantly higher diversity of the faecal microbiota. In the test group the probiotic B. lactis increased by 100-fold in the stool and was detected in all supplemented infants. BMOS stimulated a marked shift to a bifidobacterium-dominated faecal microbiota via increases in endogenous bifidobacteria (B. longum, B. breve, B. bifidum, B. pseudocatenulatum)

Structural Heterogeneity and Quantitative FRET Efficiency Distributions of Polyprolines through a Hybrid Atomistic Simulation and Monte Carlo Approach

Förster Resonance Energy Transfer (FRET) experiments probe molecular distances via distance dependent energy transfer from an excited donor dye to an acceptor dye. Single molecule experiments not only probe average distances, but also distance distributions or even fluctuations, and thus provide a powerful tool to study biomolecular structure and dynamics. However, the measured energy transfer efficiency depends not only on the distance between the dyes, but also on their mutual orientation, which is typically inaccessible to experiments. Thus, assumptions on the orientation distributions and averages are usually made, limiting the accuracy of the distance distributions extracted from FRET experiments. Here, we demonstrate that by combining single molecule FRET experiments with the mutual dye orientation statistics obtained from Molecular Dynamics (MD) simulations, improved estimates of distances and distributions are obtained. From the simulated time-dependent mutual orientations, FRET efficiencies are calculated and the full statistics of individual photon absorption, energy transfer, and photon emission events is obtained from subsequent Monte Carlo (MC) simulations of the FRET kinetics. All recorded emission events are collected to bursts from which efficiency distributions are calculated in close resemblance to the actual FRET experiment, taking shot noise fully into account. Using polyproline chains with attached Alexa 488 and Alexa 594 dyes as a test system, we demonstrate the feasibility of this approach by direct comparison to experimental data. We identified cis-isomers and different static local environments as sources of the experimentally observed heterogeneity. Reconstructions of distance distributions from experimental data at different levels of theory demonstrate how the respective underlying assumptions and approximations affect the obtained accuracy. Our results show that dye fluctuations obtained from MD simulations, combined with MC single photon kinetics, provide a versatile tool to improve the accuracy of distance distributions that can be extracted from measured single molecule FRET efficiencies

A pilot study on the application of a symptom-based score for the diagnosis of cow’s milk protein allergy

Objective: A challenge is the recommended test to diagnose cow’s milk protein allergy. However, many parents and physicians prefer to not challenge because the procedure may cause (severe) symptoms. In clinical routine, diagnostic testing is only available for IgE-mediated allergy. The aim of this study was to test the diagnostic accuracy of a symptom-based score to select infants at risk of having cow’s milk protein allergy. Methods: A symptom-based score was developed and consensus was reached that a score of ≥12 would select infants at risk of cow’s milk protein allergy. Diagnosis of cow’s milk protein allergy was demonstrated with a positive challenge after 1-month elimination diet. Results: An open challenge was performed in 85/116 (73%) infants suspected of cow’s milk protein allergy based on a symptom-based score ≥ 12 and was positive in 59/85 (69%). Although “a challenge test” was planned in the protocol, 27% of the parents refused the challenge. The mean decrease after 1 month of elimination diet with an extensive hydrolysate was −8.07 (95% confidence interval = −8.74, −7.40). If the symptom-based score during the elimination diet decreased to 6 or lower, 80% of the infants had a positive challenge test. If the symptom-based score remained >7, the challenge test was positive in only 48% ( p < 0.001). Conclusion: In daily practice, a symptom-based score of ≥12 is a useful tool to select infants at risk of cow’s milk protein allergy. If an elimination diet reduces the symptom-based score to ≤6, the challenge test is positive in 80%

Upper respiratory tract infection in athletes : influence of lifestyle, type of sport, training effort, and immunostimulant intake

Les infections respiratoires de la sphère ORL ( rhinites, otites ...) chez les athlètes. Aspects épidémiologiques. Influence de l'intensité de l'effort, de l'entraînement, sur les paramètres immunitaires : neutrophilie, lymphopénie, baisse de l'activité des cellules tueuses naturelles. Diététique et système immunitaire : effets de l'administration de glucides, de vitamines, d'oligo-éléments, d'immuno-stimulants ( Echinacea purpurea )