Ruud Albers

Background: Using dietary interventions to steer the metabolic output of the gut microbiota towards specific health-promoting metabolites is often challenging due to interpersonal variation in treatment responses. Methods: In this study, we combined the ex vivo SIFR® (Systemic Intestinal Fermentation Research) technology with untargeted metabolite...

The human gut microbiota is characterized by large interpersonal differences, which are not only linked to health and disease but also determine the outcome of nutritional interventions. In line with the growing interest for developing targeted gut microbiota modulators, the selectivity of a carrot-derived rhamnogalacturonan I (cRG-I) was compared...

An adequate and balanced supply of nutrients is essential for maintaining health, and an optimal immune response is fast, contained and properly controlled, curbing infections quickly while minimizing damage. Several micronutrients contribute to normal immune function and certain dietary fibers, for example pectic polysaccharides, can play an impor...

Respiratory infections place a heavy burden on the health care system, particularly in the winter months. Individuals with a vulnerable immune system, such as very young children and the elderly, and those with an immune deficiency, are at increased risk of contracting a respiratory infection. Most respiratory infections are relatively mild and aff...

Acute respiratory infections are an important health concern. Traditionally, polysaccharide-enriched extracts from plants, containing immunomodulatory rhamnogalacturonan-I (RG-1), were used prophylactically. We established the effects of dietary supplementation with carrot-derived RG-I (cRG-I, 0–0.3–1.5 g/day) in 177 healthy individuals (18–65 year...

The human gut microbiome is currently recognized to play a vital role in human biology and development, with diet as a major modulator. Therefore, novel indigestible polysaccharides that confer a health benefit upon their fermentation by the microbiome are under investigation. Based on the recently demonstrated prebiotic potential of a carrot-deriv...

The prevalence of acute respiratory infections and their impact on quality of life underlies the need for efficacious solutions that are safe, sustainable and economically viable. Polysaccharides in several (traditional) plant extracts have been shown to be immunostimulatory, and some studies suggest beneficial effects against respiratory infection...

An experimental human challenge model with an attenuated diarrheagenic Escherichia coli (E. coli) strain has been used in food intervention studies aimed to increase resistance to E. coli infection. This study was designed to refine and expand this challenge model. In a double-blind study, healthy male subjects were orally challenged with 1E10 or 5...

Modulation of the gut microbiome as a means to improve human health has recently gained increasing interest. In this study, it was investigated whether cRG-I, a carrot-derived pectic polysaccharide, enriched in rhamnogalacturonan-I (RG-I) classifies as a potential prebiotic ingredient using novel in vitro models. First, digestion methods involving...

The dietary fibre product examined is a pectic polysaccharide extract from carrot (Daucus carota), enriched for pectin fragments comprising mainly rhamnogalacturonan-I (RG-I) (abbreviated product name cRG-I). To assess the safety of cRG-I for use as food ingredient, repeated-dose oral toxicity and in vitro genotoxicity studies were conducted. In th...

De rol van voeding voor een goed werkend immuunsysteem wordt steeds duidelijker. Een goed gebalanceerde voeding kan bijdragen aan het voorkomen van ziekte in het vroege leven (allergie, infecties) en het late leven (ontsteking, infecties). Het belang van macro- en micronutriënten voor het normaal functioneren van het immuunsysteem is reeds lang bek...

Nutrition research, like most biomedical disciplines, adopted and often uses experimental approaches based on Beadle and Tatum's one gene-one polypeptide hypothesis, thereby reducing biological processes to single reactions or pathways. Systems thinking is needed to understand the complexity of health and disease processes requiring measurements of...

Resilience or the ability of our body to cope with daily-life challenges has been proposed as a new definition of health, with restoration of homeostasis as target resultant of various physiological stress responses. Challenge models may thus be a sensitive measure to study the body's health. The objective of this study was to select a dietary chal...

Optimal functioning of the immune system is crucial to human health, and nutrition is one of the major exogenous factors modulating different aspects of immune function. Currently, no single marker is available to predict the effect of a dietary intervention on different aspects of immune function. To provide further guidance on the assessment and...

Probiotics and milk calcium may increase resistance to intestinal infection, but their effect on growth and iron and zinc status of Indonesian children is uncertain. We investigated the hypotheses that cow milk with added probiotics would improve growth and iron and zinc status of Indonesian children, whereas milk calcium alone would improve growth...

To monitor inflammation in a meaningful way, the markers used must be valid: they must reflect the inflammatory process under study and they must be predictive of future health status. In 2009, the Nutrition and Immunity Task Force of the International Life Sciences Institute, European Branch, organized an expert group to attempt to identify robust...

To investigate the effects of calcium and probiotics on the incidence and duration of acute diarrhea and acute respiratory tract infections (ARTIs) in low-socioeconomic communities of Jakarta, Indonesia. We conducted a 6-month, double-blind, placebo-controlled study in 494 healthy children aged 1 to 6 years who received low-lactose milk with low ca...

In the developing world major public health issues such as malnutrition and compromised physical development are intimately linked to altered gut morphology and function with underlying chronic inflammatory responses. In these societies the downward spiral of malnutrition and infections does not seem to be remedied by well-informed nutritional inte...

The effect of a tea fortified with five herbs selected from Indian traditional medicine (Ayurveda) for their putative immunoenhancing effect (Withania somnifera, Glycyrrhzia glabra, Zingiber officinale, Ocimum sanctum and Elettaria cardamomum) on innate immunity was investigated. Ex vivo natural killer (NK) cell activity was assessed after consumpt...

Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Th...

Natural Killer (NK) cells are important in the first response against viruses and tumours. Compounds that modulate human NK cell activity offer interesting prophylactic and therapeutic options, however, a systematic screening tool is lacking. Development of suitable NK cell lines or receptor-based assays is hindered by the highly complicated regula...

Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. Therefore, probiotic strains should be able to survive passage through the human gastrointestinal tract. Human gastrointestinal tract survival of probiotics in a low-fat spread matrix has, however, never been tested. The objective o...

Supplementation of nutritional deficiencies helps to improve immune function and resistance to infections in malnourished subjects. However, the suggested benefits of dietary supplementation for immune function in healthy well nourished subjects is less clear. Among the food constituents frequently associated with beneficial effects on immune funct...

Normal functioning of the immune system is crucial to the health of man, and diet is one of the major exogenous factors modulating individual immunocompetence. Recently, nutrition research has focused on the role of foods or specific food components in enhancing immune system responsiveness to challenges and thereby improving health and reducing di...

Immunotoxicity comprises direct toxicity to components of the immune system, resulting in suppressed function or inadvertent stimulation. Consequences may be reduced resistance to infections or tumours, or promotion of allergy or autoimmunity. Other types of immunotoxicity include allergy or autoimmunity by compounds that cause the immune system to...

There is clear evidence that nutritional supplementation helps to restore immune function and contributes to optimal resistance to infections in malnourished people. However, the literature is less clear on the suggested benefits of dietary supplementation for immune function in healthy, well nourished subjects. Such studies are hampered by large v...

We compared the effects of supplementing with vitamins A, C, and E, selenium, and zinc on a range of innate and specific T-helper 1 (Th1) and Th2-driven adaptive immune responses. BALB/c mice were fed semi-purified AIN93 diets and randomly assigned to receive a diet supplemented with 120 mg/kg of vitamin A, 2500 mg/kg of vitamin C, 1000 mg/kg of vi...

Greatly increasing dietary flaxseed oil [rich in the n-3 polyunsaturated fatty acid (PUFA) alpha-linolenic acid (ALA)] or fish oil [rich in the long-chain n-3 PUFAs eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids] can reduce markers of immune cell function. The effects of more modest doses are unclear, and it is not known whether ALA has the...

To study the effects of two different mixtures of the main conjugated linoleic acid (CLA) isomers cis-9, trans-11 CLA and trans-10, cis-12 CLA on human immune function. Double-blind, randomized, parallel, reference-controlled intervention study. Seventy-one healthy males aged 31-69 y received one of the following treatments: (1). mixture of 50% c9,...

We have tested the effect of dietary fatty acids on aspects of innate and specific adaptive T helper (Th) 1- and Th2-driven immune responses in a murine sensitisation model using dinitrochlorobenzene as sensitiser. Six groups of fifteen BALB/c mice were fed diets containing 30 % fat (by energy) for 8 weeks. Diets were rich in saturated fatty acids,...

A large number of chemicals induce or exacerbate autoimmune-like diseases in man. Because of the complexity of processes involved, these adverse effects are often if not always missed in standard toxicity testing. To date no validated and generally applicable predictive animal model exists and only a few chemicals have actually been shown to induce...

HgCl2 and diphenylhydantoin (DPH) are prototype chemicals associated with diverse (auto)immune effects in genetically susceptible individuals. Both chemicals activate T cells, and the balance of Th1 versus Th2 activation may influence the clinical outcome of exposure. It is unknown which chemically created neoantigens are responsible for Th activat...

This article reviews the ability of the simple popliteal lymph node assay (PLNA) and variations thereof to assess the immunostimulating potential of low-molecular-weight xenobiotics, including pharmaceuticals. In essence, all variations of the PLNA detect the immune reaction in the popliteal lymph node to subcutaneous injection of a chemical into t...

Exposure to certain drugs and environmental chemicals can provoke the onset of autoimmune disease in susceptible individuals by releasing (self) epitopes for which tolerance has not been established, while simultaneously providing the necessary adjuvant activity. The resulting response type is influenced by the genotype of exposed individuals and r...

This paper reviews the suitability of the popliteal lymph node (PLN) assay as a preclinical screening test to predict the potential of systemically administered pharmaceuticals to induce allergic or autoimmune responses. The basic assay provides a rapid, simple, and objective method to grade the immunostimulating capacity of compounds. Secondary PL...

Various drugs and other chemicals can induce T-cell-dependent B-cell activation which may lead to allergic or autoimmune-like diseases. Because the nature of the relevant (neo-) antigens is generally not known and probably depends on the chemical, we have explored the potential use of reporter antigens to determine T-cell-dependent B-cell activatio...

Bypass of T-cell tolerance via non-cognate graft-versus-host (GVH)-like help from T-helper (Th) cells activated by chemically altered or induced epitopes, has been postulated as a mechanism underlying chemical induction of autoimmunity. To functionally test this hypothesis, we assessed whether the autoimmunogenic chemicals HgCl2 and diphenylhydanto...

Various environmental and iatrogenic chemicals have been implicated in the induction of autoimmune responses and biomarkers for identification of such chemicals are imperative. The present study was initiated to examine whether induction of stress protein (HSP) synthesis is a common effect of immunoactive chemicals. This would be interesting becaus...

HgCl2 induces a CD4+ T-cell-dependent systemic autoimmune disease in susceptible strains of rats and mice. In rats, autoreactive T cells were shown to be involved, whereas in mice, attention has focussed on the demonstration of 'Hg-specific' T cells. To clarify these seemingly different T cell involvements, T cells from B10.S mice treated with HgCl...

We describe here a new type of solid support for the ELISPOT assay, the PVDF membrane. In parallel tests, spot yields on this membrane were superior to those obtained with the frequently used nitrocellulose (NC) membrane, coated with the same rat anti-IgM and anti-IgG antibodies, incubated with the same rat spleen cell suspensions, and developed wi...

In this study, it is examined whether the organotin compound di-n-butyltindichloride (DBTC), which has been shown to inhibit immature thymocyte proliferation, is able to disturb the binding between thymocytes and thymic epithelial cells (TEC). To that end, an enzyme-linked binding assay was developed in which the amount of binding of Thy-1+ (mAb ER...

These studies describe the phase I and II metabolism of 7-ethoxycoumarin (7-EC) in the isolated, perfused intestinal loop. Following cytochrome P450-dependent oxidative deethylation of 7-EC by intestinal epithelial cells, the product, 7-hydroxycoumarin (7-HC), undergoes phase II conjugation to form both the glucuronide and sulfate conjugates. The c...