Food Uptake Research Articles

Cellular elimination of nanoparticles.

Exposure of the general population to nanoparticles (NPs) occurs mainly by dermal and oral uptake of consumer products, food and pharmaceutical applications and by inhalation. While cellular uptake mechanisms have been intensely studied it is less well known how NPs are eliminated from the cells. Quantification of the amount of excreted particles is complicated by inherent limitations of the technologies that are suitable to study excretion. Among the mechanisms to decrease intracellular particle concentration active excretion by lysosomal exocytosis appears to be the most important. Lysosomal localization, small particle size and high intracellular and low extracellular particle levels facilitate exocytosis. Transporting epithelia, cells with secretory function and highly proliferative cells are expected to be able to decrease intracellular particle concentrations more efficiently than cells lacking these characteristics. As NPs can influence the extent of exocytosis it is possible that NPs can stimulate their excretion.

Artesunate attenuated progression of atherosclerosis lesion formation alone or combined with rosuvastatin through inhibition of pro-inflammatory cytokines and pro-inflammatory chemokines

BackgroundsInflammation plays an important role in all stages of atherosclerosis, but little is known about the therapeutic effects of quenching inflammation in atherosclerotic lesions formation. PurposeHerein, the effect of artesunate, a derivant from artemisinin from the traditional Chinese herb sweet wormwood, could attenuate the progression of atherosclerosis lesion formation alone or combined with rosuvastatin in Western-type diet (WD) fed ApoE−/− mice, and explored its possible mechanisms. MethodsThe methods such as ELISA for plasma lipids and cytokines analyses, qRT-PCR and western blot for mRNA and protein expressions, and MTT assay for human umbilical vein endothelial cells (HUVECs) viability were used for in vivo and in vitro experiments. ResultsArtesunate could attenuate the progression of atherosclerosis lesion formation alone or combined with rosuvastatin in WD fed ApoE−/− mice without changes in food uptake, body weight and plasma lipids level, but with a significant reduction of pro-inflammatory cytokine, such as TNF-α and IL-6. Furthermore, artesunate could down-regulate the pro-inflammatory chemokines such as IL-8 and MCP-1 in aorta of mice. Besides, artesunate didn't influence IL-8 and MCP-1 secretion in HUVECs up-regulated by TNF-α, but inhibited IL-8 and MCP-1 secretion up-regulated by LPS. ConclusionAS attenuated progression of atherosclerosis lesion formation alone or combined with rosuvastatin through anti-inflammatory effect, resulting in down-regulation of TNF-α and IL-6, and further down-regulating IL-8 and MCP-1 expressions in aorta of WD fed ApoE−/− mice. Rosuvastatin combined with artesunate could more effectively attenuate the progression of atherosclerosis lesions than when treated by one of them, demonstrating that lipid-lowering agents combined with anti-inflammatory agents could provide the greater benefit for cardiovascular disease patients. Artesunate is worth further investigating as a candidate drug for the treatment of atherosclerosis.

Effects of an invasive mussel, Arcuatula senhousia, on local benthic consumers: a laboratory 13C‐labeling study

Filter-feeding bivalves play an important ecological role in aquatic systems through benthic–pelagic coupling. However, the mechanisms by which invasive mussels influence the food uptake by local consumers are little known. We tested the interactive effects of the invasive mussel Arcuatulasenhousia and the native clam Ruditapes decussatus on the uptake of 13C-enriched microalgae, Isochrysis sp., by two polychaetes, the surface deposit feeder Cirriformia tentaculata and the sub-surface deposit feeder Phylo foetida. Polychaetes were exposed to two different densities of A.senhousia and R. decussatus used alone or together. In each treatment, the 13C-concentration throughout the sediment horizon (0–0.5, 0.5–2.5 and 2.5–5 cm) was also quantified. Results showed that, irrespective of bivalve densities, the 13C-uptake by C. tentaculata was lower in the presence of the two bivalves together than in the presence of one bivalve species (either A. senhousia or R. decussatus). This was consistent with decreased 13C-concentrations in the 0–0.5 cm sediment layer in the treatment with the two bivalves together. Contrary to C. tentaculata, no changes were observed among treatments in the 13C-uptake by P. foetida. This possibly reflected a limited 13C-enrichment of the lower sediment layers. Our main findings are: (1) A.senhousia reduces the 13C-uptake by R. decussatus, and (2) A.senhousia reduces the availability of phytoplankton-derived C for deposit feeders by impairing the feeding, incorporation and bio-deposition of R. decussatus. We conclude that the interaction of A.senhousia with native bivalves needs to be taken into consideration in future food web studies.

The Effects of Natural and Anthropogenic Microparticles on Individual Fitness in Daphnia magna.

Concerns are being raised that microplastic pollution can have detrimental effects on the feeding of aquatic invertebrates, including zooplankton. Both small plastic fragments (microplastics, MPs) produced by degradation of larger plastic waste (secondary MPs; SMPs) and microscopic plastic spheres used in cosmetic products and industry (primary MPs; PMPs) are ubiquitously present in the environment. However, despite the fact that most environmental MPs consist of weathered plastic debris with irregular shape and broad size distribution, experimental studies of organism responses to MP exposure have largely used uniformly sized spherical PMPs. Therefore, effects observed for PMPs in such experiments may not be representative for MP-effects in situ. Moreover, invertebrate filter-feeders are generally well adapted to the presence of refractory material in seston, which questions the potential of MPs at environmentally relevant concentrations to measurably affect digestion in these organisms. Here, we compared responses to MPs (PMPs and SMPs) and naturally occurring particles (kaolin clay) using the cladoceran Daphnia magna as a model organism. We manipulated food levels (0.4 and 9 μg C mL-1) and MP or kaolin contribution to the feeding suspension (<1 to 74%) and evaluated effects of MPs and kaolin on food uptake, growth, reproductive capacity of the daphnids, and maternal effects on offspring survival and feeding. Exposure to SMPs caused elevated mortality, increased inter-brood period and decreased reproduction albeit only at high MP levels in the feeding suspension (74% by particle count). No such effects were observed in either PMP or kaolin treatments. In daphnids exposed to any particle type at the low algal concentration, individual growth decreased by ~15%. By contrast, positive growth response to all particle types was observed at the high algal concentration with 17%, 54% and 40% increase for kaolin, PMP and SMP, respectively. When test particles comprised 22% in the feeding suspension, both MP types decreased food intake by 30%, while kaolin had no effect. Moreover, SMPs were found to homoaggregate in a concentration-dependent manner, which resulted in a 77% decrease of the ingested SMPs compared to PMPs. To better understand MP-processing in the gut, gut passage time (GPT) and evacuation rate of MPs were also assayed. SMPs and PMPs differed in their effects on daphnids; moreover, the particle effects were dependent on the MP: algae ratio in the suspension. When the MP contribution to the particle abundance in the medium changed from 1 to 4%, GPT for daphnids exposed to SMPs increased 2-fold. Our results suggest that MPs and, in particular, SMPs, have a greater capacity to negatively affect feeding in D. magna compared to naturally occurring mineral particles of similar size. Moreover, grazer responses observed in experiments with PMPs cannot be extrapolated to the field where SMPs dominate, because of the greater effects caused by the latter.

Bioaccumulation and retention kinetics of cesium in the Milkfish Chanos chanos from Jakarta Bay

Laboratory radiotracer experiments were conducted to study the uptake, assimilation, and retention of cesium (137Cs) in milkfish (Chanos chanos) from Jakarta Bay. In this study, we have examined the bioaccumulation and distribution of 137Cs in C. chanos obtained from 137Cs-labeled seawater and 137Cs-labeled Artemia sp. feeding. The uptake of 137Cs via seawater displayed a one-compartment model suggesting that the concentration factors of 137Cs within the milkfish (weight 2.46–9.86g) at a steady-state period were between 10.66 and 3.98mLg−1 after 10days of exposure. The depuration rate was observed to be low, with only 22.80–49.14% of 137Cs absorbed by C. chanos, which was absent 6days after exposure. By contrast, depuration occurred quickly for radiolabeled food uptake, reaching 20% of retention within 10days after exposure. Muscles and viscera of the milkfish exhibited the highest degree of end uptake and end depuration of 137Cs from seawater and feeding.

Anti-obesity effect of Crinum asiaticum var. japonicum Baker extract in high-fat diet-induced and monogenic obese mice.

This study determined the anti-obesity effect of Crinum asiaticum var. japonicum Baker extract (CAE) on adipocytes and obese mice. The inhibitory effects of CAE on adipocyte differentiation and adipogenesis were determined using differentiation induction medium in 3T3-L1 cells. To get an insight into underlying molecular actions of CAE, we investigated the changes in the expression levels of genes involved in lipogenesis by CAE treatment using qRT-PCR. CAE strongly suppressed adipocyte differentiation through downregulation of PPARγ, C/EBPα, C/EBP β, and aP2. CAE treatment could also suppress the expression levels of ACC, FAS, LPL and HMGCR gene in 3T3-L1 cells. Male C57BL/6 strain and C57BL/6J-ob/ob strain mice were fed with HFD containing 60% fat and normal diet in the presence or absence of 25, 50, and 100mg/kg CAE for 7 weeks. CAE supplementation could highly suppress the body weight gain and epididymal fat accumulation without changes in food uptake in both obese models. Increases in total cholesterol, LDL-cholesterol and triglyceride were highly suppressed in the presence of CAE. In summary, CAE has an anti-obesity effect and this anti-obesity potential might be associated with downregulation of genes involved in adipocyte differentiation and lipogenesis.

Effects Of A Nutritive Administration Of Carbohydrates And Protein By Food On Skeletal Muscle Inflammation And Damage After Acute Endurance Exercise

: Scientific Background: Protein ingestion has been recently described to enhance the effects of carbohydrate drinks on skeletal muscle recovery. The aim of this study was to investigate the beneficial effects of a co-ingestion of carbohydrate and protein by food in amateur sportsmen. METHODS: 16 male subjects performed a 10km run at 80% of individual ANS. Immediately after exercise subjects ingest either nothing (control), carbohydrates by eating white bread, or a combination of carbohydrates and protein by eating white bread and a sour milk cheese. Blood samples were taken at different time points. Serum glucose, serum insulin, serum creatine kinase (CK) and the serum levels of IL6, IL 10, MIF and TNF alpha were determined. RESULTS: Blood glucose was increased by endurance exercise. Blood glucose levels decreased rapidly after exercise, here the strongest decrease could be observed in the bread/cheese group. Food uptake results in strong increase of serum insulin not differing between bread and bread/cheese. CK serum levels as a marker for skeletal muscle damage strongly increased 24h after exercise in the control and bread group but not in the bread cheese group. Exercise resulted in an increase of serum IL 6 and MIF which was reduced in the bread/cheese group. Serum IL 10 was increased by bread/cheese ingestion. TNF alpha serum concentration was decreased by exercise. This decrease was antagonized by bread/cheese ingestion. CONCLUSION: Our data demonstrate that uptake of a combination of protein and carbohydrate by food immediately after endurance exercise effect’s physiological responses like blood glucose levels of the individual’s and antagonize the induction of serum CK, a marker of skeletal muscle damage. Moreover this nutritive carbohydrate/protein uptake seems to influence the inflammatory response of the skeletal muscle indicated by reduced concentrations of proinflammatory markers and an increase of anti-inflammatory markers.

RNA Interference based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly.

Over the past decade RNA interference (RNAi) technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs) that could offer great potential for insect pest management. The diet of insects feeding exclusively on phloem sieves contains water and sugars as main components, and the uptake of the liquid food greatly depends on the osmotic pressure within the insect body. Based on this physiological mechanism, transgenic plants of Nicotiana tabacum were generated expressing double stranded RNA (dsRNA) against both aquaporin (AQP) and a sucrase gene, alpha glucosidase (AGLU). These two genes are involved in osmotic pressure maintenance particularly in sap sucking insects, and the aim was to disrupt osmoregulation within the insect ultimately leading to mortality. Real time quantitative PCR (RT-qPCR) was performed to assess the suppression of gene expression in Bemisia tabaci (B. tabaci) and mortality was recorded during transgenic tobacco feeding bioassays. Feeding of insects on plants expressing dsRNA significantly reduced the transcript level of the target genes in B. tabaci after six days of feeding and more than 70% mortality was observed in B. tabaci fed on transgenic plants compared to the control plants. Our data shows that down-regulation of genes related to osmoregulation may find practical applications for the control of this important pest in cotton and other crops.

In Silico Structure and Sequence Analysis of Bacterial Porins and Specific Diffusion Channels for Hydrophilic Molecules: Conservation, Multimericity and Multifunctionality.

Diffusion channels are involved in the selective uptake of nutrients and form the largest outer membrane protein (OMP) family in Gram-negative bacteria. Differences in pore size and amino acid composition contribute to the specificity. Structure-based multiple sequence alignments shed light on the structure-function relations for all eight subclasses. Entropy-variability analysis results are correlated to known structural and functional aspects, such as structural integrity, multimericity, specificity and biological niche adaptation. The high mutation rate in their surface-exposed loops is likely an important mechanism for host immune system evasion. Multiple sequence alignments for each subclass revealed conserved residue positions that are involved in substrate recognition and specificity. An analysis of monomeric protein channels revealed particular sequence patterns of amino acids that were observed in other classes at multimeric interfaces. This adds to the emerging evidence that all members of the family exist in a multimeric state. Our findings are important for understanding the role of members of this family in a wide range of bacterial processes, including bacterial food uptake, survival and adaptation mechanisms.

Selective feeding by the giant barrel sponge enhances foraging efficiency

AbstractForaging theory predicts the evolution of feeding behaviors that increase consumer fitness. Sponges were among the earliest metazoans on earth and developed a unique filter‐feeding mechanism that does not rely on a nervous system. Once thought indiscriminate, sponges are now known to selectively consume picoplankton, but it is unclear whether this confers any benefit. Additionally, sponges consume dissolved organic carbon (DOC) and detritus, but relative preferences for these resources are unknown. We quantified suspension feeding by the giant barrel sponge Xestospongia muta on Conch Reef, Florida, to examine relationships between diet choice, food resource availability, and foraging efficiency. Sponges consistently preferred cyanobacteria over other picoplankton, which were preferred over detritus and DOC; nevertheless, the sponge diet was mostly DOC (∼70%) and detritus (∼20%). Consistent with foraging theory, less‐preferred foods were discriminated against when relatively scarce, but were increasingly accepted as they became relatively more abundant. Food uptake was limited, likely by post‐capture constraints, yet selective foraging enabled sponges to increase nutritional gains.

Bioaccumulation of PAHs in marine zooplankton: an experimental study in the copepod Pseudodiaptomus marinus

Fil: Arias, Andres Hugo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Bahia Blanca. Instituto Argentino de Oceanografia. Universidad Nacional del Sur. Instituto Argentino de Oceanografia; Argentina. Universidad Nacional del Sur; Argentina

On the amphibious food uptake and prey manipulation behavior in the Balkan-Anatolian crested newt (Triturus ivanbureschi, Arntzen and Wielstra, 2013)

Feeding behavior in salamanders undergoing seasonal habitat shifts poses substantial challenges caused by differences in the physical properties of air and water. Adapting to these specific environments, urodelans use suction feeding predominantly under water as opposed to lingual food prehension on land. This study aims to determine the functionality of aquatic and terrestrial feeding behavior in the Balkan-Anatolian crested newt (Triturus ivanbureschi) in its terrestrial stage. During the terrestrial stage, these newts feed frequently in water where they use hydrodynamic mechanisms for prey capture. On land, prey apprehension is accomplished mainly by lingual prehension, while jaw prehension seems to be the exception (16.67%) in all terrestrial prey capture events. In jaw prehension events there was no detectable depression of the hyo-lingual complex. The success of terrestrial prey capture was significantly higher when T. ivanbureschi used lingual prehension. In addition to prey capture, we studied the mechanisms involved in the subduction of prey. In both media, the newts frequently used a shaking behavior to immobilize the captured earthworms. Apparently, prey shaking constitutes a significant element in the feeding behavior of T. ivanbureschi. Prey immobilization was applied more frequently during underwater feeding, which necessitates a discussion of the influence of the feeding media on food manipulation. We also investigated the osteology of the cranio-cervical complex in T. ivanbureschi to compare it to that of the predominantly terrestrial salamandrid Salamandra salamandra.

Human milk miRNAs primarily originate from the mammary gland resulting in unique miRNA profiles of fractionated milk.

Human milk (HM) contains regulatory biomolecules including miRNAs, the origin and functional significance of which are still undetermined. We used TaqMan OpenArrays to profile 681 mature miRNAs in HM cells and fat, and compared them with maternal peripheral blood mononuclear cells (PBMCs) and plasma, and bovine and soy infant formulae. HM cells and PBMCs (292 and 345 miRNAs, respectively) had higher miRNA content than HM fat and plasma (242 and 219 miRNAs, respectively) (p < 0.05). A strong association in miRNA profiles was found between HM cells and fat, whilst PBMCs and plasma were distinctly different to HM, displaying marked inter-individual variation. Considering the dominance of epithelial cells in mature milk of healthy women, these results suggest that HM miRNAs primarily originate from the mammary epithelium, whilst the maternal circulation may have a smaller contribution. Our findings demonstrate that unlike infant formulae, which contained very few human miRNA, HM is a rich source of lactation-specific miRNA, which could be used as biomarkers of the performance and health status of the lactating mammary gland. Given the recently identified stability, uptake and functionality of food- and milk-derived miRNA in vivo, HM miRNA are likely to contribute to infant protection and development.

Increasing Healthy Start food and vitamin voucher uptake for low income pregnant women (Early Years Collaborative Leith Pioneer Site)

Poverty has a detrimental impact on health and wellbeing. Healthy Start food and vitamin vouchers provide support for low income families across the UK, but at least 25% of eligible...

Millet Grain Processing, Utilization and Its Role in Health Promotion: A Review

The enormously increasing population is raising needs for solving the problem of food scarcity. Researchers and nutritionists are working hard to find the cheaper and larger sources of nutrients to deal with this scarcity. Pearl millet, a staple crop is economically feasible for poorer section of the world’s population and works are going on for the improvement in the bio-accessibility of the minerals for increasing its utilization. Researches are proving pearl millet comparably better in nutritional quality with high protein content, energy, minerals like iron and zinc, vitamins, dietary fibre, less glycemic index and phytochemicals like antioxidants. New advanced techniques applied for post-harvest technology and value addition are giving out more products of wide acceptance in rural as well as urban areas. In relation with the nutritional quality, convenience of food uptake and other sensory properties, many food processing technologies have been developed. These techniques are widely used now-a-days and are milling, decortication, soaking, germination/malting, fermentation etc. These processes increase the nutritional value and are very effective in dealing with undernourishment problem and other food and health management practices. A large scale implementation of these technologies or commercialized use will increase the ease of adopting their products at wide scale. This type of commercialization will not only deal with the undernourishment problem but also will earn great profits for all the persons in chain from producer like farmers to the consumers but will require policy-support and campaign for health, ecological sustainability and nutritional benefits of the crop. So this review focusses on pearl millet’s high nutritional aspects, the post-harvest techniques potent for its improvement at large scale and the related health benefits to support the need at rural as well as urban level.

Usefully Persistent? Anticoagulants as Quantitative Markers of Bait Uptake in Brushtail Possums

Prolonged persistence of second-generation anticoagulant rodenticides (SGARs) in animal tissues facilitates trophic transfer of residues, with exposure of predatory and scavenging non-target wildlife now widely reported. In many instances, antico-agulant residue levels measured in wildlife are apparently sublethal, although longer-term effects of such exposures are currently not well understood. Conversely, prolonged metabolic persistence is of practical utility when compounds are used as biological markers to determine food uptake by animals. We required two effective and distinct marker compounds to progress field-based research on optimal baiting strategies to manage introduced brushtail possums in New Zealand. Two SGARs (flocoumafen and bromadiolone) were evaluated, as neither are currently registered for application as rodenticides in areas typically subject to possum management. All captive possums ingesting small, sublethal (2-6 g) quantities of food containing 0.0005% (by weight) of either SGAR were reliably marked by the presence of residual concentrations in liver as measured by HPLC analysis. This marking persisted for at least six weeks, and liver concentrations in marked possums did not decline between three and six weeks after the marker was ingested. Marking was also quantitative for both SGARs with a correlation between liver residue concentration and the amount of marker ingested. Using such marker baits would provide at least a six-week period in which to recover possums in field research. By recording bodyweight and testing liver samples from such possums for both markers, regression equations generated from the work reported here will enable back-estimation, with confidence intervals, of the amounts of marker bait eaten by each possum.

Real time monitoring of aminothiol level in blood using a near-infrared dye assisted deep tissue fluorescence and photoacoustic bimodal imaging.

The development of molecular probes for the detection and imaging of biological thiols is a major step forward diagnosing various types of diseases. Previously reported thiol imaging strategies were mainly based on a single mode of imaging with a limited application in vivo. In this work, we introduced an unsymmetrical near-infrared (NIR) squaraine dye (USq) as an exogenous contrast agent for photoacoustic and fluorescence bimodal imaging of thiol variations in live animals. USq exhibits a narrow absorption band at 680 nm that generates a photoacoustic signal and a strong NIR emission at 700 nm (ΦF = 0.27), which is applicable for deep tissue optical imaging. Both photoacoustic and fluorescence signals could selectively disappear in the presence of different thiols. Through in vitro and in vivo imaging studies, unique imaging capability of USq was demonstrated, and the effect of food uptake on the increased level of aminothiols in blood was confirmed.

Screening of Staple Food Crops for their Phytosterol and Nutritional Contents to Determine their Hyperlipidemia Controlling Potential

Screening of Staple Food Crops for their Phytosterol and Nutritional Contents to Determine their Hyperlipidemia Controlling Potential Phytosterol rich food uptake is a key factor in controlling hyperlipidemia. This goal can be achieved by screening staple foods for their phytosterol contents along other nutritional facts. Therefore, seven staple food crops (i.e. wheat, kabuli chickpea, desi chickpea, barley, rice, corn and millet) were evaluated for their dietary benefits, with a special focus on phytosterol contents. Plants were tested for their nutritional and palatability components through organic extraction and calorimetric methods. Moreover, isozyme analysis of Oxidosqualene Cyclase was performed through Native Polyacrylamide Gel Electrophoresis. Data were analysed through MYSTAT (Kroeger, Chicago, USA) and GELANALYZER (Lazar, Hungry). It was recorded that barley (Malt) had maximum phytosterol contents (0.239 g/ kg), which can be potentially used for control of hyperlipidemia. Corn was the most palatable and safest food crop due to its biochemical combination related to palatability. Vitamin analysis revealed that barley was rich in all tested water soluble vitamin contents except Folic acid; which was the highest in corn (0.006 g/ kg). Moreover, barley exhibited maximum number of isozymes for oxidosqualene cyclase (OSC). Other crops had variable number of isozymes for OSC, but lesser than barley. Current investigation is highly important in relation to population health management. It recommends barley as a recommended staple food crop for control of hyperlipidemia.

Diversionary feeding: an effective management strategy for conservation conflict?

Human population growth has led to increased contact between people and wildlife, with adverse impacts for both, such as damage to economic crops and wildlife persecution. Diversionary feeding, where food is used to draw animals away from problem activities or locations, is sometimes proposed as a socially acceptable conservation action, but little information exists on its success or what influences its efficacy. Here, we review literature on diversionary feeding and evaluate factors contributing to its success or failure. Success varied greatly among studies and successful uptake of diversionary food did not consistently produce outcomes that met stakeholder objectives. Studies often failed to report results in sufficient detail to allow a quantitative evaluation of efficiency. Of 30 trials presented in 21 studies, 13 enabled assessment of outcomes related to the ultimate objective of reducing conflict (related to threatened prey density, crop yield or nuisance reports) and only five of these were considered successful by the researchers conducting the study. A grand mean increase of 15 % in respective measures of success at the outcome stage was found across all studies. Although diversionary feeding is considered expensive, cost-effectiveness analyses were rarely conducted. Only a third of studies reported information on costs and benefits that could be used to inform future management actions. We propose a decision-making framework that incorporates ecological knowledge, financial costs and evidence from previous studies to aid the planning and implementation of diversionary feeding in an adaptive format. Future studies of diversionary feeding should clearly report objectives, results, costs and effort to allow the return-on-investment to be calculated for different levels of management effort.

Predator effects on the feeding and bioirrigation activity of ecosystem-engineered Lanice conchilega reefs

Ecosystem engineers can considerably affect the community composition, abundance and species richness of their environment. This study investigates the existence of positive or negative feedbacks of species that compose the community in intertidal biogenic reefs constructed by the ecosystem engineer Lanice conchilega. This tubeworm creates attractive nursery and feeding grounds for the predatory brown shrimp Crangon crangon, while at the same time is preyed upon by C. crangon. The effect of the predation pressure exerted by C. crangon on the bioirrigation and feeding activity of the tubeworm is up until now unknown and it is hypothesised that these activities are affected by the high densities of C. crangon in the reefs. A mesocosm experiment was set up to investigate the effects of predation pressure on the bioirrigation and feeding activity of L. conchilega in the i) absence; ii) restricted presence; and iii) unrestricted presence of C. crangon. Bioirrigation was quantified by the decrease of an artificially introduced bromide (Br−) tracer, while feeding activity was measured from the incorporation of 13C via stable isotope analysis. The bioirrigation rate of the L. conchilega reef equalled about 30L·m−2·d−1 and was not affected by the presence of the predator. The food uptake of the tubeworm was however about three times lower in the unrestricted presence of C. crangon, presumably due to the retraction of the worm's body and tentacles in its tube induced by physical contact with the predator. Notwithstanding the impacted food uptake of L. conchilega, the tubeworm maintains its functional role in the presence of predators in soft-bottom intertidal areas.