Marie van der Merwe

• Doctor of Philosophy
• Professor (Associate) at University of Memphis

Background: 2′-Fucosyllactose (2′-FL) is an oligosaccharide contained in human milk and possesses prebiotic and anti-inflammatory effects, which may alleviate skeletal muscle atrophy under caloric restriction. This study evaluated the impacts of 12 weeks of 2′-FL supplementation in conjunction with exercise (10,000 steps/day, 5 days/week) and energ...

ABSTRACT Objectives: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder affecting approximately 55 million individuals globally. Diagnosis typically occurs in advanced stages, and there are limited options for reversing symptoms. Preventive strategies are, therefore, crucial. Time Restricted Eating (TRE) or Time Restricted Feeding...

Objective This study aimed to assess the impact of acute and short-term supplementation with NAD3®, a theacrine-containing supplement, on circulating adult stem cell numbers in a healthy male and female population aged 40-70 years. Methods This was a double-blind, placebo-controlled crossover study with 12 participants randomized to receive either...

Probiotics are increasingly used to treat conditions associated with gastrointestinal injury and permeability, including exercise-induced gastrointestinal discomfort. This study assessed safety and efficacy of a probiotic in altering the intestinal milieu and mitigating gastrointestinal symptoms (GIS) in endurance runners. In a double blind, crosso...

Time-restricted feeding (TRF) has increased in popularity among various groups, including fitness enthusiasts. The ideal timing of TRF in relation to daily exercise is unknown. Most fitness enthusiasts consume meals immediately or soon after exercise to improve body composition (e.g., lean mass). We compared two different TRF approaches, as well as...

Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for quantitative metabolomics; however, quantification of metabolites from NMR data is often a slow and tedious process requiring user input and expertise. In this study, we propose a neural network approach for rapid, automated lipid identification and quantification from NMR data. M...

Glucocorticoids (GCs) are some of the most widely prescribed therapies for treating numerous inflammatory diseases and multiple cancer types. With chronic use, GCs’ therapeutic benefits are concurrent with deleterious metabolic side effects, which worsen when combined with a high-fat diet (HFD). One characteristic of the common Western HFD is the p...

Background: The intestinal ecosystem, including epithelium, immune cells, and microbiota, are influenced by diet and timing of food consumption. The purpose of this study was to evaluate various dietary protocols after ad libitum high fat diet (HFD) consumption on intestinal morphology and mucosal immunity. Methods: C57BL/6 male mice were fed a...

Lengthening the daily eating period contributes to the onset of obesity and metabolic syndrome. Dietary approaches, including energy restriction and time-restricted feeding, are promising methods to combat metabolic disorders. This study explored the effect of early and late time-restricted feeding (TRF) on weight and adiposity, food consumption, g...

Poor dietary habits can lead to obesity and insulin resistance—both of which can impair basal heat shock protein (HSP) expression and the HSP stress response in skeletal muscle. It remains unclear if impairments in HSP expression occur during the early stages of diet-induced obesity and metabolic dysfunction. We determined if basal HSP expression (...

Time-restricted feeding (TRF) is becoming a popular way of eating in physically active populations, despite a lack of research on metabolic and performance outcomes as they relate to the timing of food consumption in relation to the time of exercise. The purpose of this study was to determine if the timing of feeding/fasting after exercise training...

Aim: Phytochemicals from fruits and vegetables are known to reduce inflammation and improve overall health. The objective of this study was to determine the effect of a fruit and vegetable concentrate (FVC) and high fiber component on the gut microbiome in an overweight/obese, female population. Methods: The study was a randomized, double blind, pl...

Chemical‐shift‐based fat‐water MRI signal models with single‐ or dual‐R2* correction have been proposed for quantification of fat fraction (FF) and assessment of hepatic steatosis. However, there is a void in our understanding of which model truly mimics the underlying biophysical mechanism of steatosis on MRI signal relaxation. The purpose of this...

Habitual dietary intake is a major determinant of the species composition and functional output of the trillions of microorganisms residing in the human gut. Diet influences which microbes will colonise, flourish or disappear throughout life. An increase in polyphenols, oligosaccharides and fibre, which are all components found in a fruit and veget...

Lipid profiling by 1 H-NMR has gained increasing utility in many fields due to its intrinsically quantitative, non-destructive nature and the ability to differentiate small molecules based on their spectral location. Most NMR techniques for metabolite quantification use frequency-domain analysis that involves many user-dependent steps such as phase...

Manuka honey, a topical wound treatment used to eradicate bacteria, resolve inflammation, and promote wound healing, is a focus in the tissue engineering community as a tissue template additive. However, its effect on neutrophil extracellular trap formation (NETosis) on a tissue engineering template has yet to be examined. As NETosis has been impli...

Background: Certain dietary fibers have been reported to improve gut health and cellular immunity. Ambrotose is a glyconutrient supplement that contains mannose-rich polysaccharides (acemannan), reported to improve immune function. A more nutrient-dense version of this dietary supplement has been developed recently, with added aloe leaf gel powder...

Objectives Food intake and exercise are considered modulators of the immune system. Specifically, intermittent fasting protocols have been demonstrated to reduce inflammation and alter cytokine responses. The objective of the current study was to determine if a form of intermittent fasting known as time-restricted feeding (TRF) would alter immune p...

Objectives Phytochemicals from fruits and vegetables have the potential to reduce inflammation and improve overall health. This study evaluated the effect of an encapsulated fruit and vegetable juice concentrate (FVC) on the composition and abundances of intestinal microbiota in an overweight/obese, female population and the association with indica...

Background: Synthetic Glucocorticoids (GC) are widely used for their immunosuppressive capability, however chronic use is associated with adverse metabolic effects that are exacerbated when GC is combined with a high fat diet. Omega (n)-3 PUFA supplementation has been shown to rescue GC-induced hyperlipidemia, hyperinsulinemia and inflammation. Ob...

Intermittent fasting refers to a period of unregulated caloric consumption paired with a period of complete, or heavily restricted, caloric consumption. One version of this involves splitting the day into a consumption period and a restricted period, known as time‐restricted feeding (TRF). TRF is shown to improve metabolic health and positively aff...

Background: Fasting and timed feeding strategies normalize obesity parameters even under high-fat dietary intake. Although previous work demonstrated that these dietary strategies reduce adiposity and improve metabolic health, limited work has examined intestinal microbial communities. Objectives: We determined whether timed feeding modifies the...

Objectives: The gut microbiome participates in host metabolic regulation. While the vast majority of microbiome research has focused on bacterial populations, other microorganisms also colonize the mammalian intestine and likely play functionally important roles in host metabolism. The objective of current study was to characterize the role of die...

Objectives: Time-restricted feeding strategies have been shown to normalize obesity parameters, even under high fat feeding conditions. The objective of this study is to examine whether timed feeding alters parameters of gut health or intestinal microbiome composition. Methods: C57BL/6 male mice were randomized to Chow or a high fat diet (HFD) f...

Obesity is a growing epidemic worldwide leading to growing rates of chronic disease and diabetes. A diet rich in omega‐6 fatty acids and refined sugars, known as the “Western diet,” may be one contributing factor. Prevention of weight gain, as well as weight loss, have been shown to be beneficial in preventing obesity‐associated chronic disease. Gr...

Polyunsaturated fatty acids (PUFAs) are essential dietary components. They are not only used for energy, but also act as signaling molecules. The delta-6 desaturase (D6D) enzyme, encoded by the FADS2 gene, is one of two rate limiting enzymes that convert the PUFA precursors – α-linolenic (n-3) and linoleic acid (n-6) to their respective metabolites...

Time-restricted feeding (TRF), alternate day fasting (ADF), and the dietary restriction model known as the Daniel Fast (DF; a vegan/non-processed food diet plan) have garnered attention recently as nutritional interventions to combat obesity. We compared the effects of various dietary models on body composition, physical performance, and metabolic...

Environment and diet are two major factors affecting the human gut microbiome. In this study, we used a pig model to determine the impact of these two factors during lactation on the gut microbiome, immune system, and growth performance. We assigned 80 4-day-old pigs from 20 sows to two rearing strategies at lactation: conventional rearing on sow’s...

Adipose tissue is a central player in whole body energy homeostasis. During nutrient excess, energy is stored in adipocytes as triglycerides. The resulting expansion of visceral adipose tissue is a known risk factor for chronic disease and has been shown to be exacerbated by both a high fat diet and chronic glucocorticoid therapy. Acutley, glucocor...

Obesity and its associated low grade inflammation is a major risk factor for the development of many diseases including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular disease. Time restricted feeding (TRF), in which food consumption is restricted to certain hours of the day, is a dietary approach that improves metabolic param...

Background: Humans consuming a purified vegan diet known as the "Daniel Fast" realize favorable changes in blood lipids, oxidative stress, and inflammatory biomarkers, with subjective reports of improved physical capacity. Objective: We sought to determine if this purified vegan diet was synergistic with exercise in male rats. Methods: Long⁻Ev...

The amount, composition, and sources of nutrition support provided to preterm infants is critical for normal growth and development, and particularly for structural and functional neurodevelopment. Although omega-3 long chain polyunsaturated fatty acids (LC-PUFA), and particularly docosahexanoic acid (DHA), are considered of particular importance,...

Time-restricted feeding (TRF) limits the duration of food availability without altering diet composition and can combat obesity in humans and mice. For this study we evaluated the effect of timing of food access during a TRF protocol on weight gain, adiposity, and inflammation. Young male C57BL/6 mice were placed on a high-fat (HF) diet (45% fat) f...

Introduction Polyunsaturated fatty acids (PUFAs) are essential dietary components. They are not only used for energy, but also act as signaling molecules. The delta‐6 desaturase (D6D) enzyme, encoded by the FADS2 gene, is one of two rate limiting enzymes that convert the PUFA precursors – α‐linolenic (n‐3) and linoleic acid (n‐6) to their respectiv...

Background Endurance athletes search for diet regimens that will improve performance and decrease gastrointestinal disturbances during training and events. Although the intestine can adapt to changes in the amount and composition of dietary inputs, the responses to the combination of endurance exercise and diet are poorly understood. Methods We eva...

Reproduction, an energetically costly process, is subject to nutritional and metabolic control. There is a high occurrence of female infertility in obese women, and Polycystic Ovarian Syndrome (PCOS), a condition characterized by androgen excess and oligo‐ and amenorrhea, is highly associated with obesity and diabetes mellitus. Obesity is character...

Obesity and metabolic syndrome are now recognized as significant health concerns for survivors of pediatric Acute Lymphoblastic Leukemia (ALL) and are consequences of their treatment. The majority of weight gain occurs during the induction phase of therapy (first 28 days), when patients receive various chemotherapies in addition to high dose glucoc...

Background . Inflammation is associated with strenuous exercise and methylsulfonylmethane (MSM) has been shown to have anti-inflammatory properties. Methods . Physically active men were supplemented with either placebo or MSM (3 grams per day) for 28 days before performing 100 repetitions of eccentric knee extension exercise. Ex vivo and in vitro t...

A translational preterm pig model analogous to infants born at 28 weeks of gestation revealed that continuous positive airway pressure results in limited lung recruitment but does not prevent respiratory distress syndrome (RDS); whereas, assist-control + volume guarantee (AC+VG) ventilation improves recruitment, but can cause injury, highlighting t...

During processes such as DNA replication and transcription, DNA topoisomerase I (Top1) catalyzes the relaxation of DNA supercoils. The nuclear enzyme is also the cellular target of camptothecin (CPT) chemotherapeutics. Top1 contains four domains: the highly conserved core and C-terminal domains involved in catalysis, a coiled-coil linker domain of...

Respiratory distress syndrome (RDS) and bronchopulmonary dysplasia remain the leading causes of preterm infant morbidity, mortality, and lifelong disability. Research to improve outcomes requires translational large animal models for RDS. Preterm pigs delivered by caesarian section at gestation days (GD) 98, 100, 102, and 104 days were provided 24...

Background and aims Despite advances in ventilation support, acute lung disease (ALD) remains the leading cause of morbidity, mortality, and disability after preterm birth. There is a need for a spontaneous translational model of ALD after preterm birth. Methods Preterm pigs delivered at gestation days (GD) 98, 100, 102, and 104 days were provided...

Respiratory distresssyndrome and the more severe sequel bronchopulmonary dysplasia remain the leading causes of morbidity, mortality, and lifelong disability after preterm birth, with inadequate surfactant secretion a key contributor. We present the preterm pig as a translational model for lung disease after preterm birth. Preterm pigs were deliver...

We showed previously that nonmyeloablative total lymphoid irradiation/rabbit anti-thymocyte serum (TLI/ATS) conditioning facilitates potent donor-recipient immune tolerance following bone marrow transplantation (BMT) across MHC barriers via recipient invariant NKT (iNKT) cell-derived IL-4-dependent expansion of donor Foxp3(+) naturally occurring re...

Transformed and cultured cell lines have significant shortcomings for investigating the characteristics and responses of native villus enterocytes in situ. Interpretations of results from intact tissues are complicated by the presence of underlying tissues and the crypt compartment. We describe a simple, novel, and reproducible method for preparing...

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL CD1d-restricted invariant natural killer T (iNKT) cells are rare but potent innate regulatory cells capable of immune modulation via robust production of Th1/Th2 cytokines, as well as tumor immunosurveillance via direct cytotoxicity. Protocols to expand iNKT cells and au...

Every year individuals receive hematopoietic stem cell transplantation (HSCT) to eradicate malignant and nonmalignant disease. The immunobiology of allotransplantation is an area of ongoing discovery, from the recipient's conditioning treatment prior to the transplant to the donor cell populations responsible for engraftment, graft-versus-host dise...

Murine total lymphoid irradiation (TLI) + anti-thymocyte serum (ATS) has been well-translated to human transplantation (Lowsky et al, NEJM 2005). Though host TLI/ATS treatment allows post-transplant donor Foxp3+ Treg expansion, >90% of donor CD4+CD25+ cells are Foxp3neg. We now show that the latter are Tr1-type regulatory T cells. BALB/c (H-2d) hos...

In eukaryotes, DNA topoisomerase I (Top1) catalyzes the relaxation of supercoiled DNA by a conserved mechanism of transient DNA strand breakage, rotation, and religation. The unusual architecture of the monomeric human enzyme comprises a conserved protein clamp, which is tightly wrapped about duplex DNA, and an extended coiled-coil linker domain th...

DNA topoisomerase I (Top1p) catalyzes the relaxation of supercoiled DNA via a concerted mechanism of DNA strand cleavage and religation. Top1p is the cellular target of the anti-cancer drug camptothecin (CPT), which reversibly stabilizes a covalent enzyme-DNA intermediate. Top1p clamps around duplex DNA, wherein the core and C-terminal domains are...

Eukaryotic DNA topoisomerase I (Top1p) catalyzes the relaxation of supercoiled DNA and constitutes the cellular target of camptothecin (CPT). Mutation of conserved residues in close proximity to the active site tyrosine (Tyr(727) of yeast Top1p) alters the DNA cleavage religation equilibrium, inducing drug-independent cell lethality. Previous studi...

Streptococcus pneumoniae is the most common cause of bacterial meningitis of high mortality and morbidity. Neurological sequelae include paralysis, mental retardation, and learning disorders. In humans, neurons of the hippocampus undergo apoptosis as a result of meningitis. Phosphatidylcholine (PtdCho) is an essential component of mammalian cell me...

NADPH oxidase is upregulated in smooth muscle cells (SMCs) in response to growth factor stimulation, concomitant with increased reactive oxygen species (ROS) production. We investigated the role of ROS production by NADPH oxidase in SMC responses to growth factors and in atherosclerotic lesion formation in ApoE(-/-) mice. SMCs from wild-type, p47ph...