Acceptability of alginate enriched bread and its effect on fat digestion in humans.

Lifestyle interventions and physical activity remain the cornerstone of obesity management, as pharmacological therapies (orlistat) are associated with gastrointestinal (GI) side effects. Combining orlistat with fibers can reduce side effects, improving compliance. Therefore, a fiber that inhibits lipase without side effects could help treat obesity. The aims of the present work were to assess whether alginate enriched bread could inhibit fat digestion, and assess the acceptability of alginate bread and its effect on GI wellbeing. A double-blind, randomised, controlled cross-over pilot study (NCT03350958) assessed the impact of an alginate bread meal on; lipid content in ileal effluent and circulating triacylglycerol levels. This was compared against the same meal with non-enriched (control) bread. GI wellbeing and acceptability of alginate bread was compared to control bread through daily wellbeing questionnaires and food diaries (NCT03477981). Control bread followed by alginate bread were consumed for two weeks respectively. Consumption of alginate bread reduced circulating triacylglycerol compared to control (2% reduction in AUC) and significantly increased lipid content in ileal effluent (3.8 g ±â€¯1.6 after 210 min). There were no significant changes to GI wellbeing when comparing alginate bread to control bread. A significant increase in the feeling of fullness occurred with alginate bread compared to baseline and the first week of control bread consumption. This study showed that sustained consumption of alginate enriched bread does not alter GI wellbeing and can decrease lipolysis, increasing lipid leaving the small intestine. Further studies are required to demonstrate that reduced fat digestion through the action of alginate can reduce fat mass or body weight.

Biological activity of alginate and its effect on pancreatic lipase inhibition as a potential treatment for obesity.

Alginates are classed as a dietary fibre and have been shown to inhibit digestive enzymes in vitro, and therefore could be used as an obesity treatment. The current study aims to assess whether alginate in a bread vehicle maintains its inhibition properties despite cooking and digestion, and may therefore be used as a potential treatment for obesity. After 180 min in a model gut that replicates digestion in the mouth, stomach and small intestines alginate bread (AB), control bread (CB), CB with Manucol® DM alginate, free DM alginate and model gut solution were collected. DM, LFR 5/60 and SF200 were heated at 37 °C and 200 °C, with DM also heated at 50, 100 and 150 °C. Samples from the model gut and heated alginate were assessed for molecular size and inhibition properties using viscosity, gel filtration and a lipase turbidity assay. AB does not significantly increase viscosity in the model gut. Viscosity of alginate reduces beyond 100 °C, although alginate retains its inhibition properties up to 150 °C. Cooking into the bread does not reduce the molecular size of the alginate or affect its inhibition properties. These data demonstrate the robustness of alginates lipase inhibition despite the cooking process and digestion. Therefore adding alginate to a bread vehicle may have the potential in the treatment for obesity.

The MUC2 Gene Product: Polymerisation and Post-Secretory Organisation-Current Models.

MUC2 mucin, the primary gel-forming component of intestinal mucus, is well researched and a model of polymerisation and post-secretory organisation has been published previously. Recently, several significant developments have been made which either introduce new ideas or challenge previous theories. New ideas include an overhaul of the MUC2 C-terminal globular structure which is proposed to harbour several previously unobserved domains, and include a site for an extra intermolecular disulphide bridge dimer between the cysteine 4379 of adjacent MUC2 C-termini. MUC2 polymers are also now thought to be secreted attached to the epithelial surface of goblet cells in the small intestine and removed following secretion via a metalloprotease meprin ß-mediated cleavage of the von Willebrand D2 domain of the N-terminus. It remains unclear whether MUC2 forms intermolecular dimers, trimers, or both, at the N-termini during polymerisation, with several articles supporting either trimer or dimer formation. The presence of a firm inner mucus layer in the small intestine is similarly unclear. Considering this recent research, this review proposes an update to the previous model of MUC2 polymerisation and secretion, considers conflicting theories and data, and highlights the importance of this research to the understanding of MUC2 mucus layers in health and disease.

Presentation of the candidate rheumatoid arthritis autoantigen aggrecan by antigen-specific B cells induces enhanced CD4(+) T helper type 1 subset differentiation.

Effective immune responses require antigen uptake by antigen-presenting cells (APC), followed by controlled endocytic proteolysis resulting in the generation of antigen-derived peptide fragments that associate with intracellular MHC class II molecules. The resultant peptide-MHC class II complexes then move to the APC surface where they activate CD4(+) T cells. Dendritic cells (DC), macrophages and B cells act as efficient APC. In many settings, including the T helper type 1 (Th1) -dependent, proteoglycan-induced arthritis model of rheumatoid arthritis, accumulating evidence demonstrates that antigen presentation by B cells is required for optimal CD4(+) T cell activation. The reasons behind this however, remain unclear. In this study we have compared the activation of CD4(+) T cells specific for the proteoglycan aggrecan following antigen presentation by DC, macrophages and B cells. We show that aggrecan-specific B cells are equally efficient APC as DC and macrophages and use similar intracellular antigen-processing pathways. Importantly, we also show that antigen presentation by aggrecan-specific B cells to TCR transgenic CD4(+) T cells results in enhanced CD4(+) T cell interferon-γ production and Th1 effector sub-set differentiation compared with that seen with DC. We conclude that preferential CD4(+) Th1 differentiation may define the requirement for B cell APC function in both proteoglycan-induced arthritis and rheumatoid arthritis.

A Pilot Pre and Post 4 Week Intervention Evaluating the Effect of a Proprietary, Powdered, Plant Based Food on Micronutrient Status, Dietary Intake, and Markers of Health in a Healthy Adult Population.

Background: A "balanced, adequate, and varied diet" is recommended as the basis of nutritionally sound diet by the World Health Organisation and national public health agencies. Huel is a proprietary, on-the-go, powdered, plant based food, providing all 26 essential vitamins and minerals, protein, essential fats, carbohydrate, fibre, and phytonutrients. Objectives: Assessing the effect of solely consuming Huel on micronutrient status, dietary intake and markers of health was achieved through a 4-week intervention of solely Huel powder. Methods: Habitual energy intake was assessed through a one-week lead in period with healthy adult participants (aged 18 or over) logging their food intake, after which only Huel was consumed for 4 weeks. Blood samples and body composition was assessed before and after the lead in week as well the end of the intervention. Thirty participants were recruited with 20 (11 females, median age 31, range 22-44) completing the study, 19 sets of blood samples were collected. 22 blood markers were analysed along with weight, BMI, waist circumference, visceral adipose tissue (VAT), and body composition. All blood micronutrients, except for Thyroid Stimulating Hormone and choline were sent to Royal Victoria Infirmary NHS, Newcastle Laboratory (Newcastle upon Tyne, United Kingdom) for analysis. Results: Fourteen of the parameters significantly changed over the course of the study with circulating haemoglobin, iron, vitamins B12 and D as well as selenium significantly increasing (p < 0.05). HbA1c, total and non-HDL cholesterol, vitamins A and E, potassium, BMI, VAT, and waist circumference all significantly decreased (p < 0.05) post intervention. Conclusion: Although energy intake decreased during the intervention period, the adherence to recommended micronutrient intake, as quantified by the dietary Total Adherence Score, significantly increased which tallies with the preservation or improvement of micronutrient status. This study potentially demonstrates that consuming only Huel for 4 weeks does not negatively affect micronutrient status.

The effect of seaweed enriched bread on carbohydrate digestion and the release of glucose from food.

Two seaweeds; Ascophyllum nodosum and Fucus vesiculosus, were incorporated into bread at 0.5 and 2% and their effect on blood glucose in vivo and carbohydrate digestion in vitro were studied. In the five way randomised placebo controlled double blind pilot trial (n = 10) each volunteer consumed 100 g of available carbohydrate (from bread) and their blood glucose was measured over two hours. The breads were tested in a human digestion model and compared against control bread and control bread with the equivalent amount of seaweed. In the pilot human study the enriched breads did not cause any significant reductions in iAUC of blood glucose with average reductions of 0.1 ± 44.4%, 8.2 ± 19.3%, 1.0 ± 54.3% and 2.7 ± 31.9% for 0.5% F.vesiculosus, 0.5% A.nodosum, 2% F.vesiculosus, and 2% A.nodosum respectively. However, seaweed added alongside the control bread in vitro significantly reduced the level of carbohydrate digestion compared to the control bread. F.vesiculosus or A.nodosum can reduce carbohydrate digestion, however baking into bread reduces the effect.

Primary bronchial epithelial cell culture from explanted cystic fibrosis lungs.

Lung disease is responsible for more than 95% of morbidity and mortality in cystic fibrosis. The exact pathogenesis of cystic fibrosis lung disease remains poorly understood. Experimental models are therefore vital for use in research. Animal models and immortalized cell lines both have inherent limitations. Explanted lungs removed from people with cystic fibrosis at the time of transplantation represent a potentially valuable but technically and logistically challenging source of primary cystic fibrosis bronchial epithelial cells. In this study, pieces of segmental bronchus from explanted lungs were treated with patient-specific antimicrobials prior to isolation of bronchial epithelial cells. Cultured cells were characterized by their morphology under light microscopy, cytokeratin and hematoxylin-eosin staining, and electrophysiological profile. Primary bronchial epithelial cells were successfully cultured from 15 of 22 patients attempted. The cells exhibited typical epithelial morphology, staining for cytokeratin, lack of responsiveness to forskolin treatment, and remained viable after storage in liquid nitrogen. Seven unsuccessful cultures failed due to early infection with bacteria known to colonize the airways pretransplant. The results show that primary bronchial epithelial cell culture is possible from explanted cystic fibrosis lungs. This provides an important cellular model to elucidate the pathogenic mechanisms in cystic fibrosis lung disease and to investigate potential therapeutic targets.

Current therapies for gastro-oesophageal reflux in the setting of chronic lung disease: state of the art review.

The inter-relationship between chronic respiratory disease and reflux disease in the airway reflux paradigm is extremely complex and remains poorly characterised. Reflux disease is reported to cause or contribute to the severity of a number of respiratory tract diseases including laryngeal disorders, sinusitis, chronic cough, asthma, COPD, idiopathic pulmonary fibrosis, cystic fibrosis, bronchiectasis and bronchiolitis obliterans post lung transplant. It is now appreciated that reflux disease is not simply caused by liquid acid reflux but rather by a variety of chemical refluxates originating from the stomach and duodenum due to a number of different mechanisms. Reflux disease can be challenging to diagnose, particularly proving its role in the causation of direct respiratory epithelial damage. Significant advances in oesophageal assessment and gastric biomarkers have emerged in recent years as our understanding increases. There are a number of treatments available for reflux disease, both medical and surgical, but there is a paucity of large randomised trials to evaluate their efficacy in the setting of chronic respiratory disease. Everyday clinical practice, however, informs us that treatment failure in reflux disease is common. This clinical review summarises associations between reflux disease in the setting of chronic respiratory diseases and examines available evidence regarding potential therapeutic strategies.

The effect of thiamine-coating nanoparticles on their biodistribution and fate following oral administration.

Thiamine-coated nanoparticles were prepared by two different preparative methods and evaluated to compare their mucus-penetrating properties and fate in vivo. The first method of preparation consisted of surface modification of freshly poly(anhydride) nanoparticles (NP) by simple incubation with thiamine (T-NPA). The second procedure focused on the preparation and characterization of a new polymeric conjugate between the poly(anhydride) backbone and thiamine prior the nanoparticle formation (T-NPB). The resulting nanoparticles displayed comparable sizes (about 200 nm) and slightly negative surface charges. For T-NPA, the amount of thiamine associated to the surface of the nanoparticles was 15 µg/mg. For in vivo studies, nanoparticles were labelled with either 99mTc or Lumogen® Red. T-NPA and T-NPB moved faster from the stomach to the small intestine than naked nanoparticles. Two hours post-administration, for T-NPA and T-NPB, >30% of the given dose was found in close contact with the intestinal mucosa, compared with a 13.5% for NP. Interestingly, both types of thiamine-coated nanoparticles showed a greater ability to cross the mucus layer and interact with the surface of the intestinal epithelium than NP, which remained adhered in the mucus layer. Four hours post-administration, around 35% of T-NPA and T-NPB were localized in the ileum of animals. Overall, both preparative processes yielded thiamine decorated carriers with similar physico-chemical and biodistribution properties, increasing the versatility of these nanocarriers as oral delivery systems for a number of biologically active compounds.

Encapsulation of stevia rebaudiana Bertoni aqueous crude extracts by ionic gelation - Effects of alginate blends and gelling solutions on the polyphenolic profile.

We formulated and characterised two alginate blends for the encapsulation of stevia extract (SE) via ionic gelation through an extrusion technique. Calcium chloride in SE and calcium chloride solutions were assessed as crosslinkers to overcome phenolic losses by diffusion and increase encapsulation efficiency (EE). Regardless of the blend, all stevia-loaded beads exhibited high EE (62.7-101.0%). The size of the beads decreased as EE increased. Fourier transform infrared analysis showed increased hydrogen bonding between SE and alginates, confirming the successful incorporation of SE within the matrix. Untargeted metabolomics profiling identified 479 free and encapsulated polyphenolic compounds. Flavonoids (catechin and luteolin equivalents) were predominant in SE whereas tyrosols and 5-pentadecylresorcinol equivalents were predominant in all bead formulations. Three-common discriminant compounds were exclusive to each blend and were inversely affected by the crosslinking conditions. Both alginate blends have been shown to be feasible as carrier systems of stevia extracts independent of crosslinking conditions.

Efficacy and safety concerns over the use of mucus modulating agents for drug delivery using nanoscale systems.

Drug delivery to the mucus covered mucosae is fraught with difficulties and many different approaches have been developed to permeate the mucus barrier. Generally by modifying the delivery system to avoid interaction with the mucus. These modifications are reviewed here in terms of efficacy and safety. These are particular problems for oral delivery the pharmaceutical industry's favoured route for drug administration. For effective delivery through the gastrointestinal tract a drug must pass through three barriers in sufficient amounts to yield a biological effect. These barriers are the digestive barrier in the lumen, the mucus barrier, and the epithelial barrier. Other approaches involve mucolytic agents added with or prior to the delivery system or agents regulating mucus production and are reviewed here. In terms of safety, a key property of a mucus modulating delivery system is that it must not damage the protective function of the mucus layer.

Reflux in idiopathic pulmonary fibrosis: treatment informed by an integrated approach.

After MDT work-up and review, gastro-oesophageal reflux and pulmonary aspiration were found to be common in IPF patients; surgery was recommended in only 10% http://ow.ly/rO3T30lU17o.

Evolutionary conservation of the antimicrobial function of mucus: a first defence against infection.

Mucus layers often provide a unique and multi-functional hydrogel interface between the epithelial cells of organisms and their external environment. Mucus has exceptional properties including elasticity, changeable rheology and an ability to self-repair by re-annealing, and is therefore an ideal medium for trapping and immobilising pathogens and serving as a barrier to microbial infection. The ability to produce a functional surface mucosa was an important evolutionary step, which evolved first in the Cnidaria, which includes corals, and the Ctenophora. This allowed the exclusion of non-commensal microbes and the subsequent development of the mucus-lined digestive cavity seen in higher metazoans. The fundamental architecture of the constituent glycoprotein mucins is also evolutionarily conserved. Although an understanding of the biochemical interactions between bacteria and the mucus layer are important to the goal of developing new antimicrobial strategies, they remain relatively poorly understood. This review summarises the physicochemical properties and evolutionary importance of mucus, which make it so successful in the prevention of bacterial infection. In addition, the strategies developed by bacteria to counteract the mucus layer are also explored.

Action of reactive oxygen species on colonic mucus secretions.

Reactive oxygen species (ROS) have been implicated in the pathogenesis of many colonic diseases. Mucus is the colon's first line of defence against luminal agents. This study has therefore characterised ROS action on colonic mucus secretions. ROS were produced using peroxide-based systems of different concentrations. The effects of these systems were tested on native colonic mucus gels, isolated colonic mucins, and in vivo models. Colonic mucus gels were resistant to ROS breakdown. Mucins were susceptible to ROS attack, causing loss of terminal sugars and protein and mucin fragmentation. The in vivo thickness of the mucus barrier was reduced by up to 50% by ROS (above 5 mM peroxide). A 5 mM peroxide caused a significant increase in resting mucus thickness of ca. 15%. All ROS-generating systems caused mucosal damage once the loosely adherent mucus had been removed. As native mucus gel is more resistant to ROS damage than purified mucin, nonmucin components of mucus may have extensive ROS-scavenging properties. Low levels of luminal colonic ROS increase the protection afforded by the mucus barrier in vivo. Higher levels of ROS significantly reduce this protection. In vitro modeling of mucus degradation by ROS does not necessarily correlate with the dynamic, in vivo situation.

Upper airway mucin gene expression: a review.

INTRODUCTION: The gel-like properties of mucus depend primarily on its content of mucins. The protein backbones of mucins are encoded by mucin genes. Of the currently known 20 mucin genes that encode protein backbone of mucins, 16 have been identified in the airways. METHOD: We explored the current knowledge about upper airway mucin expression in health and disease conditions using a Medline search. We have also studied upper airway mucin gene expression and compared our results with the results from other studies. RESULTS: MUC5AC, MUC5B, and MUC2 are the principal gel-forming mucins secreted in the airway. However, the spectrum of mucin expression in chronic upper airway diseases such as nasal polyps, chronic sinusitis, middle ear effusion, and cystic fibrosis is generally wide and variable. DISCUSSION: The wide spectrum of upper airway mucin expression is possibly caused by various anatomic and histologic features as well as physiologic and pathologic variables. These variables have not been fully explored yet, and the majority of airway mucin expression studies used small numbers of samples. CONCLUSION: Studies including adequate numbers of samples (patients) are more likely to reveal a clearer profile and more precise expression patterns. Generating a clear profile of mucin expression patterns in health and disease requires the analysis of different variables, which can alter that expression. It is also essential to understand the various molecular mechanisms controlling mucin gene and protein expression. This could lead to the invention of novel therapeutic modalities to treat upper airway diseases.

Mucin gene expression in hypertrophic adenoids.

CONCLUSION: Membrane-bound mucin MUC4 represents the predominant mucin expressed in the adenoid epithelium followed by MUC5AC (gel-forming mucin). This may suggest that membrane-bound mucins could be involved in pathogen binding and immunological stimulation. OBJECTIVES: The aim of this study was to investigate mucin expression in hypertrophic adenoids. MATERIALS AND METHODS: Adenoidal samples were obtained from 12 children. The expression of eight mucin genes, MUC1-4, MUC5AC, 5B, 6 and 7 was studied by in situ hybridization utilizing digoxigenin-labelled oligonucleotide probes. RESULTS: The dominant mucin genes were MUC4, 3 and 5AC, while MUC1, 2, 5B and 7 were sparsely expressed and MUC6 was not expressed. Expression patterns were very different from those in the upper airways. Most samples expressed two membrane-bound mucins (MUC4 and 3) and one secretory mucin (MUC5AC).

ζ potential changing nanoparticles as cystic fibrosis transmembrane conductance regulator gene delivery system: an in vitro evaluation.

AIM: Aim of the study was the development of ζ potential changing nanoparticles as gene delivery system for the cystic fibrosis transmembrane conductance regulator gene. METHODS: Chitosan and carboxymethyl cellulose were modified with phosphotyrosine, a substrate for the brush border enzyme alkaline phosphatase. With these synthesized derivatives, different nanoparticle formulations, including the cystic fibrosis transmembrane conductance regulator gene were prepared by ionic gelation. RESULTS: A change from negative to positive ζ potential after enzymatic cleavage could be observed. Transfection studies with HEK-293 and Caco-2 cells showed transfection rates comparable to Lipofectamine 2000. Transfection efficiencies were significantly decreased when phosphate cleavage and thus ζ potential change was inhibited by phosphatase inhibitor. CONCLUSION: The developed nanoparticles represent a promising gene delivery system.

Ivacaftor and symptoms of extra-oesophageal reflux in patients with cystic fibrosis and G551D mutation.

BACKGROUND: Extra-oesophageal reflux (EOR) may lead to microaspiration in patients with cystic fibrosis (CF), a probable cause of deteriorating lung function. Successful clinical trials of ivacaftor highlight opportunities to understand EOR in a real world study. METHODS: Data from 12 patients with CF and the G551D mutation prescribed ivacaftor (150mg bd) was collected at baseline, 6, 26 and 52weeks. The changes in symptoms of EOR were assessed by questionnaire (reflux symptom index (RSI) and Hull airway reflux questionnaire (HARQ)). RESULTS: Six patients presented EOR at baseline (RSI >13; median 13; range 2-29) and 5 presented airway reflux (HARQ >13; median 12; range 3 to 33). Treatment with ivacaftor was associated with a significant reduction of EOR symptoms (P<0∙04 versus baseline) denoted by the reflux symptom index and Hull airway reflux questionnaire. CONCLUSION: Ivacaftor treatment was beneficial for patients with symptoms of EOR, thought to be a precursor to microaspiration.

The Potential Role of Aspiration in the Asthmatic Airway.

BACKGROUND: Many people with asthma remain suboptimally controlled despite current treatments. Reasons include comorbidities that could aggravate asthma, including gastroesophageal reflux. We aimed to investigate whether aspiration occurs in patients with asthma and, if so, does it correlate with asthma control? METHODS: Patients had Asthma Control Questionnaire 7 (ACQ-7), fractional exhaled nitric oxide, and spirometry performed to characterize their level of asthma control. Barium swallow with provocation was performed to assess for predisposition to aspiration. Patients underwent bronchoscopic investigation, with BAL pepsin measured as a marker of aspiration. RESULTS: Seventy-eight patients stratified by disease severity (Global Initiative for Asthma) into mild (35.8%), moderate (21.7%) and severe (42.3%) were studied. Pepsin was detectable in BAL in 46/78 (58.9%). There were no differences between pepsin levels in patients with different disease severity. Furthermore, no significant associations were seen between pepsin level and measures of asthma control, FEV1, ACQ-7 or exacerbation frequency. Similarly no associations were found with adjustments for smoking history, BMI, proton pump inhibitor use, eosinophil count or IgE. When stratified into eosinophilic or neutrophilic asthmatic populations on the basis of BAL, there was no relationship to detected pepsin concentrations. A positive barium swallow (seen in 33/60 patients) did not correlate with BAL pepsin level and we found no significant association between barium swallow result and ACQ-7, Global Initiative for Asthma, exacerbation frequency or FEV1 using either univariate or multivariate analyses. CONCLUSIONS: This study suggests that the importance of aspiration on current asthma symptom control and exacerbation rate may be overstated. However, this study did not address the role of aspiration and future risk of exacerbation.