Hani El-Nezami

• MAppSc, PhD, RMIT-University, Melbourne
• Professor (Associate) at The University of Hong Kong

Titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) have attracted a great deal of attention due to their excellent electrical, optical, whitening, UV-adsorbing and bactericidal properties. The extensive production and utilization of these NPs increases their chances of being released into the environment and conferring unintended biol...

Inflammatory bowel disease (IBD) is a group of chronic inflammatory gastrointestinal diseases that causes worldwide suffering. Lactobacillus helveticus is a probiotic that can enhance intestinal barrier function via alleviation of excessive inflammatory response. Citrulline, a functional amino acid, has been reported to stimulate muscle synthesis a...

In order to support the multiple levels of sustainable development, the nutritional quality of plant-based protein sources needs to be improved by food technological means. Microbial fermentation is an ancient food technology, utilizing dynamic populations of microorganisms and possessing a high potential to modify chemical composition and cell str...

Background Dietary imbalance and harmful food substances are well established risk factors that can adversely impact human health. The gut microbiome is emerging as a new metabolic organ that can be serendipitously linked to these poor dietary outcomes. Modern manufactured foods and process ingredients can significantly alter gut microbiome composi...

Polyphenols are naturally occurring compounds in plants and they are the most abundant antioxidants in the human diet. Due to their considerable structural diversity, this largely influences their bioavailability. Since a large proportion of polyphenols remains unabsorbed along the gastrointestinal tract, they may accumulate in the large intestine,...

A systematic review and meta-analysis was conducted of studies that address the association of bile acid (BA) with obesity and of studies on the effects of treatment in patients with obesity on BA metabolism, assessed from systemic BA, fibroblast growth factor 19 (FGF19), 7α-hydroxy-4-cholesten-3-one (C4) level, and faecal BA. We searched PubMed, E...

This study examined the protective effects of citrulline enriched-fermented milk with live Lactobacillus helveticus ASCC 511 (LH511) on intestinal epithelial barrier function and inflammatory response in IPEC-J2 cells caused by pathogenic Escherichia coli. Five percent (v/v) of fermented milk with live LH511 and 4 mM citrulline (5%LHFM_Cit-4mM) sig...

An excess of fecal bile acids (BAs) is thought to be one of the mechanisms for diarrhea-predominant irritable bowel syndrome (IBS-D). However, the factors causing excessive BA excretion remain incompletely studied. Given the importance of gut microbiota in BA metabolism, we hypothesized that gut dysbiosis might contribute to excessive BA excretion...

Extensive research has revealed the association of continued oxidative stress with chronic inflammation, which could subsequently affect many different chronic diseases. The mycotoxin deoxynivalenol (DON) frequently contaminates cereals crops worldwide, and are a public health concern since DON ingestion may result in persistent intestinal inflamma...

Bioactive, oxygenated metabolites of polyunsaturated fatty acids (PUFAs) are important indicators of inflammation and oxidative stress but almost nothing is known about their interactions with nanomaterials (NMs). To investigate the effects of nano-sized materials (n-TiO2, n-ZnO, n-Ag) and their bulk-sized or ionic (b-TiO2, b-ZnO, i-Ag) counterpart...

Citrulline is a precursor of arginine and is believed to have the same beneficial effects as arginine. Lactobacillus helveticus ASCC 511 (LH511) utilizes arginine to produce extra energy for cell growth via arginine deiminase (ADI) pathway. Supplementation of both citrulline and LH511 is considered to be beneficial to intestinal tract. LH511 + Cit-...

After over a decade of nanosafety research, it is indisputable that the vast majority of nano-sized particles induce a plethora of adverse cellular responses – the severity of which is linked to the material’s physicochemical properties. Differentiated THP-1 cells were previously exposed for 6 h and 24 h to silver, titanium dioxide, and zinc oxide...

Lactobacillus rhamnosus strain ASCC 1520 with high soy isoflavone transformation ability was used to ferment soymilk and added to the diet of mice. The impact of L. rhamnosus fermentation on soy isoflavone metabolites and intestinal bacterial community, in conjunction with fecal enzyme activity and short‐chain fatty acids (SCFA) excretion was evalu...

Objective An excess of fecal bile acids (BAs) is thought to be one of the mechanisms for diarrhea-predominant irritable bowel syndrome (IBS-D). However, the factors causing excessive BA excretion remains unclear. Given the importance of gut microbiota in BA metabolism, we hypothesized that gut dysbiosis might contribute to excessive BA excretion in...

Sports nutrition products are developed and targeted mainly for athletes to improve their nutrient intake, performance, and muscle growth. The fastest growing consumer groups for these products are recreational sportspeople and lifestyle users. Although athletes may have elevated physiological protein requirements and they may benefit from dietary...

Oat bran is suggested to attenuate atherosclerotic conditions by regulating dyslipidemia, endothelial function, and oxidative damage. Through the measurement of oxidized polyunsaturated fatty acid (PUFA), oxidative stress, and inflammation status in liver and heart tissues of apolipoprotein E−/− (ApoE−/−), mice fed with high fat diet (HFD) or HFD w...

Antibiotics are a key tool used nowadays in health care industry to fight against bacterial infections; however, repeated antibiotic use or misuses, have led to bacterial resistance, causing significant threats for many people with common bacterial infections. The use of probiotics to enhance gastrointestinal health has been proposed for many years...

Antibiotics are a key tool used nowadays in health care industry to fight against bacterial infections ; however, repeated antibiotic use or misuses, have led to bacterial resistance, causing significant threats for many people with common bacterial infections. The use of probiotics to enhance gastrointestinal health has been proposed for many year...

This study examined modulation effects of cell‐free supernatants of two commonly studied probiotic bacteria Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN) on mucin and cytokine profiles of human intestinal epithelial HT29‐MTX cells. It was found that LGG and EcN supernatants differentially modulated MUC5AC and MUC5B mRNA an...

Deoxynivalenol (DON) is a major mycotoxin contaminant and is known to impair intestinal barrier function. Previous experiments in our laboratory have proven that polyphenols such as resveratrol (RES) may be effective in enhancing epithelial barrier function. Due to the structural similarity of oxyresveratrol (OXY) with RES, it was hypothesized that...

Hepatocellular carcinoma (HCC), the most common primary liver cancer, is one of the dreaded complications of chronic liver disease. Recent experimental and clinical studies have revealed that the alteration of gut-liver axis plays a pivotal role in the onset of chronic liver diseases, including HCC. Altered gut microbiota and endotoxemia are increa...

Intestinal epithelial cells (IECs) lining the gastrointestinal tract establish a barrier between external environments and the internal milieu. An intact intestinal barrier maintains gut health and overall good health of the body by preventing from tissue injury, pathogen infection and disease development. When the intestinal barrier function is co...

In this study, cookies were incorporated with three polyphenols (rosmarinic acid, resveratrol, and epicatechin) at two concentrations (0.02% and 0.2%), and baked under three temperatures (150, 170, and 190 °C) to observe their interaction. They didn’t significantly change the cookie texture, but influence the color and pH. Temperature was a signifi...

Nano-sized metal oxides are currently the most manufactured nanomaterials (NMs), and are increasingly used in consumer products. Recent exposure data reveal a genuine potential for adverse health outcomes for a vast array of NMs, however the underlying mechanisms are not fully understood. To elucidate size-related molecular effects, differentiated...

Zearalenone (ZEA) has long been recognized as a xenoestrogen, while the endocrine disrupting effects of aflatoxin B1 (AFB1) have been identified recently. Due to co-occurrence and endocrine disrupting potentials of ZEA and AFB1, it was hypothesized that co-exposure to ZEA and AFB1 might affect breast cancer cell growth. Consequently, the aim of thi...

The liver is probably the most important organ responsible for protecting humans from exposure to foreign compounds. With its strategic location between the intestinal tract and the circulation system, and its unique metabolic capacity, the liver acts as the first defense barrier metabolizing and detoxifying foreign compounds. In contrast, these fe...

This chapter reviews the common bacterial toxins and mycotoxins involved in food poisoning in milk and dairy products. Food-borne bacterial infection occurs when food contaminated with pathogenic bacteria is consumed. The major type of diseases caused by B. cereus varies from countries to countries. Although the incidence of these bacteria has freq...

Aims: To investigate the in vivo effects of Lactobacillus rhamnosus GG (LGG) on intestinal polyp development and the interaction between this single-organism probiotic and the gut microbiota therein. Methods and results: The Apc(Min/+) mouse model was used to study the potential preventive effect of LGG on intestinal polyposis, while shotgun met...

Background Atherosclerosis appears to have multifactorial causes – microbial component like lipopolysaccharides (LPS) and other pathogen associated molecular patterns may be plausible factors. The gut microbiota is an ample source of such stimulants, and its dependent metabolites and altered gut metagenome has been an established link to atheroscle...

Nano-sized metal oxides are currently the most manufactured nanomaterials (NMs), and are increasingly used in consumer products. Recent exposure data reveal a genuine potential for adverse health outcomes for a vast array of NMs, however the underlying mechanisms are not fully understood. To elucidate size-related molecular effects, differentiated...

Purpose of review: Probiotics can be used as an adjuvant for cancer prevention or/and treatment through their abilities to modulate intestinal microbiota and host immune response. Although most of the recent reviews have focused on the potential role of probiotics against colon cancer, only few of them include the probiotic effect on extraintestin...

Atherosclerosis results from chronic inflammation potentially caused by translocation of bacterial components from the oro-gastrointestinal tract to circulation. Specific probiotics have anti-inflammatory effects and may reduce bacterial translocation. We thereby tested whether a probiotic mixture with documented anti-inflammatory potential could r...

Contamination of food/feedstuffs by mycotoxins is a serious problem worldwide, causing severe economic losses and serious health problems in animals/humans. Deoxynivalenol (DON) is a major mycotoxin contaminant and is known to impair intestinal barrier functions. Grapes and red wine are rich in polyphenols, such as resveratrol (RES), which has stri...

Deoxynivalenol (DON) and zearalenone (ZEA) are mycotoxins produced by Fusarium species, which naturally co-occur in foods/feeds. The gastrointestinal tract represents the first barrier against dietary xenobiotics. The present study aimed to investigate the ability of Lactobacillus rhamnosus GG (LGG) to improve intestinal barrier functions and ameli...

Increasing evidence has demonstrated that in utero exposure to environmental chemicals may interfere with fetal development and increase the risk of disease and cancer development later in life. Ochratoxin A (OTA) has been proven to induce diverse toxic effects including teratogenicity, carcinogenicity, immunotoxicity and potential endocrine disrup...

Lactobacillus rhamnosus GG (LGG) cells have been shown to promote type-1 immune responsiveness; however knowledge of immunomodulation of soluble factors secreted by LGG is limited. This is the first study to investigate whether LGG soluble factors promote a comparable immune responsiveness as the bacterial cells. Both treatments − LGG conditioned m...

Scope: Green tea has been known to confer numerous health benefits such as the prevention of cardiovascular disease, cancers, and obesity. Epigallocatechin-3-gallate (EGCG) is the major polyphenol present in green tea. Since EGCG is a food-derived component, intestinal epithelial cells (IECs) lining the gastrointestinal tract are constantly and di...

Significance Hepatocellular carcinoma is the second most deadly cancer type globally, requiring the development of alternative or complementary therapeutic and prophylactic methods. Here, when feeding a mouse model with a novel probiotic mixture 1 wk before the tumor inoculation, we observed a reduction of the tumor weight and size by 40% compared...

Immunomodulation has been shown to be one of the major functions of probiotic bacteria. This review is presented to provide detailed information on the immunomodulatory properties of probiotics in various animal models and clinical practices. Probiotics can regulate helper T (Th) responses and release of cytokines in a strain-specific manner. For e...

Lactobacillus rhamnosus GG (LGG) is clinically documented in relieving and preventing diarrhea, childhood infections, allergies and atopic eczema but knowledge of its immunomodulatory properties on antigen-presenting cells (APCs) is lacking. Here, immunomodulation of LGG on dendritic cells (DCs), macrophages and monocytes was investigated. Toll-lik...

ABSTRACT Probiotics are live microorganisms, which when administered in food confer numerous health benefits. In previous studies about beneficial effects of probiotic bacteria to health, particularly in the fields of intestinal mucosa defense responses, specific probiotics, in a strain-dependent manner, show certain degree of potential to reinforc...

Poultry are highly susceptible to the immunotoxic effects of the food-borne mycotoxin aflatoxin B1 (AFB1). Exposure impairs cell-mediated and humoral immunity, limits vaccine efficacy, and increases the incidence of costly secondary infections. We investigated the molecular mechanisms of AFB1 immunotoxicity and the ability of a Lactobacillus-based...

Mycotoxins such as aflatoxins, ochratoxins, fumonisins, deoxynivalenol and zearalenone are considered to be of particular concern in relation to human and animal health. Contamination of agricultural products by mycotoxins has become an important issue worldwide over the last three decades. Asia contributes a very large part of the globe with most...

Turkeys are extremely sensitive to aflatoxin B1 (AFB1) which cause decreased growth, immunosuppression and liver necrosis. The purpose of this study was to determine whether probiotic Lactobacillus, shown to be protective in animal and clinical studies, would likewise confer protection in turkeys, which were treated for 11 days with either AFB1 (AF...

Peroxynitrite (ONOO-), the product of radical combination reaction of nitric oxide and superoxide, is a potent biological oxidant involved in a broad spectrum of physiological and pathological processes. Herein we report the development, characterization, and biological applications of a new fluorescent probe HKGreen-4 for peroxynitrite detection a...

Dietary exposure to aflatoxin B1 (AFB1) is detrimental to avian health and leads to major economic losses for the poultry industry. AFB1 is especially hepatotoxic in domestic turkeys (Meleagris gallopavo), since these birds are unable to detoxify AFB1 by glutathione-conjugation. The impacts of AFB1 on the turkey hepatic transcriptome and the potent...

To augment capacity-building for microbiome and probiotic research in Africa, a workshop was held in Nairobi, Kenya, at which researchers discussed human, animal, insect, and agricultural microbiome and probiotics/prebiotics topics. Five recommendations were made to promote future basic and translational research that benefits Africans.

Intestinal epithelial cells (IECs) are a critical component of the innate local immune response. In order to reduce the risk of pathogen infection or xenobiotic intoxication, different host defense mechanisms have been evolved. Evidence has shown that upon ingestion of food or feed contaminated with toxins (e.g., mycotoxins), IECs respond by regula...

Ochratoxin A (OTA) is a common foodborne mycotoxin. Besides its classical toxicities, it is also associated with the impairment of steroidogenesis in rats. It is hypothesized that OTA may act as an endocrine disruptor by intervening 3β-hydroxysteroid dehydrogenase/isomerase (3β-HSD). To address this hypothesis, human placental cells JEG-3 were used...

Defensins are small antimicrobial peptides (AMPs) that play an important role in the innate immune system of mammals. Since the effect of mycotoxin contamination of food and feed on the secretion of intestinal AMPs is poorly understood, the aim of this study was to elucidate individual and combined effects of four common Fusarium toxins, deoxynival...

T helper 17 (T(H)17) is a novel subset of T helper cells that has recently been identified in the hepatocellular carcinoma (HCC) tumor environment. Its presence seems to be linked with HCC progression, possibly via facilitating angiogenesis. The origin of tumor-associated T(H)17 may be related to the gut, in which the differentiation of T cells, es...

Background Atherosclerosis is the major cause of cardiovascular disease and stroke, which are among the top 10 leading causes of death worldwide. Pathogen-associated molecular patterns (PAMPs) can activate toll-like receptors (TLRs) and activate nuclear factor kappa B (NFκB) signaling, a central pathway in inflammation, which regulates genes that e...

It has been indicated that aromatase (CYP19A1) is involved in the metabolism of aflatoxin B1 (AFB1). Therefore, we hypothesized that exposure to AFB1 during pregnancy could disrupt the normal production of steroid hormones in placenta. We examined the metabolism of AFB1 by CYP19A1 and the capability of AFB1 exposure to disrupt CYP19A1 expression as...

Background and aims: GP-TCM is the 1st EU-funded Coordination Action consortium dedicated to traditional Chinese medicine (TCM) research. This paper aims to summarise the objectives, structure and activities of the consortium and introduces the position of the consortium regarding good practice, priorities, challenges and opportunities in TCM rese...

Mycotoxins such as the aflatoxins and deoxynivalenol (DON) are frequent contaminants of food. Aflatoxin B1 (AFB1) and DON affect the immune system and restrict growth; additionally AFB1 is carcinogenic. To date there are limited descriptive biomarker data concerning maternal exposures during pregnancy, and none on co-exposures to these mycotoxins....

Ochratoxin A (OTA) is one of the most frequent mycotoxins detected in human blood worldwide. Apart from its well known nephrotoxicity, OTA-induced teratogenicity and carcinogenicity proven in animals are potential effects also in humans. Pregnant women have been exposed to this food contaminant via dietary exposure in a continuous and widespread ma...

Herbal medicine has been used for thousands of years. It is estimated that 80% of world population rely on traditional herbal medicine for primary health care. In recent years, herbal remedies have been considered as dietary supplement for disease prevention and as alternative/complementary medicine. A wide variety of herbal medicines are readily a...

Herbal medicine has been used for thousands of years. It is estimated that 80% of world population rely on traditional herbal medicine for primary health care. In recent years, herbal remedies have been considered as dietary supplement for disease prevention and as alternative/complementary medicine. A wide variety of herbal medicines are readily a...

: Mycotoxins pose an unavoidable problem in agricultural crop production and methods to control contamination are constantly sought. In this chapter we focus on the use of lactic acid bacteria (LAB) as a potential means to minimize mycotoxin contamination and toxicity. Experimental evidence is reviewed on the antifungal and antimycotoxigenic proper...

To characterize transplacental transfer of melamine and related mechanisms as well as toxicity using human placental perfusion and cultured cells. Transfer and toxicity were analyzed in 4-h perfusions with 10 μM or 1 mM melamine, or 10 μM melamine with 10 nM cyanuric acid (CYA). Efflux transporters were studied in accumulation assay and toxicity in...

Melamine-tainted food can induce kidney stones both in humans and animals and in domestic animals, severe cases caused acute kidney failure and death. Although increasing water intake can ameliorate kidney stone formation, its effect on melamine (Mel)-induced kidney stones has not been studied. We have analysed the effect of restricted ingestion of...

Enzymes involved in drug and xenobiotic metabolism have been considered to exist in two groups: phase I and phase II enzymes. Cytochrome P450 isoenzymes (CYPs) are the most important phase I enzymes in the metabolism of xenobiotics. The products of phase I metabolism are then acted upon by phase II enzymes, including glutathione S-transferases (GST...

DNA damage is an essential component of the genesis of colonic cancer. Gut microbial products and food components are thought to be principally responsible for the damage that initiates disease progression. Modified Ames tests and Comet assays have been developed for measuring mutagenicity and genotoxicity. Their relevance to oncogenesis remains to...

Previous studies have indicated that aromatase (CYP19A1) is involved in the metabolism of aflatoxin B1 (AFB1). We hypothesized that exposure to AFB1 contaminated food during pregnancy could disrupt the normal production of steroid hormones in placenta. We examined the capability of AFB1 exposure to disrupt CYP19A1 expression as a putative endocrine...

Cardiovascular diseases (CVD) are the number one cause of death globally: more people die annually from the disease than from any others (Loscalzo 2005). About 17.1 million people were estimated to have died from the disease in 2004, and it is estimated to increase to 23.6 million by 2030. The majority of CVD deaths are due to heart disease and str...

Traditional Chinese medicine (TCM) is widely used in the European Union (EU) and attracts intense research interests from European scientists. As an emerging area in Europe, TCM research requires collaboration and coordination of actions. Good Practice in Traditional Chinese Medicine Research in the Post-genomic Era, also known as GP-TCM, is the fi...

IntroductionMycotoxin problemLactobacillus rhamnosus strain effectively binds aflatoxin: in vitro findingsAnimal models for studying the aflatoxin–probiotic interactionField studies with Lactobacillus rhamnosus strain in aflatoxin-exposed populations

The probiotic terminology has matured over the years and currently a unified definition has been formed. Lactic acid bacteria (LAB) and bifidobacteria have been reported to remove heavy metals, cyanotoxins and mycotoxins from aqueous solutions. The binding processes appear to be species and strain specific. The most efficient microbial species and...

Probiotic bacteria have well-established beneficial effects in the management of diarrhoeal diseases. Newer evidence suggests that probiotics have the potential to reduce the risk of developing inflammatory bowel diseases and intestinal bacterial overgrowth after gut surgery. In liver health, the main benefits of probiotics might occur through prev...

Aflatoxin B1 (AFB1), a common dietary contaminant, is a major risk factor of hepatocellular carcinoma (HCC). Early onset of HCC in some countries in Africa and South-East Asia indicates the importance of early life exposure. Placenta is the primary route for various compounds, both nutrients and toxins, from the mother to the fetal circulation. Fur...

Aflatoxin B1--a potential endocrine disruptor--up-regulates CYP19A1 in JEG-3 cells.

The bacterial enzymes beta-glucosidase, beta-glucuronidase, and urease may contribute to the development of colon cancer by generating carcinogens. A reduction in the activity of these enzymes by certain lactic acid bacteria is considered to be beneficial. This study examined fecal beta-glucosidase, beta-glucuronidase, and urease activities during...

Deoxynivalenol (DON) contamination of cereal crops occurs frequently, and may cause acute exposure at high levels or chronic more moderate exposure. DON has proven toxicity including restriction of enterocyte differentiation, which may play a part in DON induced gastroenteritis. The probiotic bacteria Lactobacillus rhamnosus strain GG (GG) can bind...

Aim: In an effort to investigate the mechanism by which Yinchenhao decoction (YCHD) acts on liver injury, we investigated the potential antifibrogenic effects of YCHD in an experimental liver fibrosis rat model, with special focus on the mechanisms inhibiting the activation and promoting apoptosis of hepatic stellate cells (HSC). Methods: The rats...

The burden of hepatocellular carcinoma (HCC) has been increasing in Egypt with a doubling in the incidence rate in the past 10 years. This has been attributed to several biological (e.g. hepatitis B and C virus infection) and environmental factors (e.g. aflatoxin, AF). Other factors such as cigarette smoking, occupational exposure to chemicals such...

The primary objective of this study was to compare the removal of cadmium, lead, aflatoxin B1 and microcystin-LR from aqueous solution by Lactobacillus rhamnosus GG, L. rhamnosus LC705, Propionibacterium freudenreichii shermanii JS and Bifidobacterium breve Bbi99/E8, separately and in combination. The removal of toxins and heavy metals was assessed...

Aflatoxins are a major risk factor for hepatocellular carcinoma (HCC), and thus understanding the pattern of aflatoxin exposure in different regions is important in order to develop targeted intervention strategies. Given the early onset of HCC in many countries early life exposures may be important. This study investigated aflatoxin exposure in Eg...

We have reported previously that rye bread (RB) as a part of the conventional diet affects bowel function and the metabolic activity of the microbiota differently in men and women. Because a higher intake of fiber by men could explain the difference in response, in the present randomized crossover trial, we studied the effects of a RB with increase...

The probiotic Lactobacillus rhamnosus GG (GG) is able to bind the potent hepatocarcinogen aflatoxin B1 (AFB1) and thus potentially restrict its rapid absorption from the intestine. In this study we investigated the potential of GG to reduce AFB1 availability in fully differentiated Caco-2 cell monolayers, adapted to express CYP3A4. To study intesti...

Aflatoxins are potent toxins and carcinogens which can be excreted in the milk of exposed lactating mothers mainly in the form of aflatoxin M(1) (AFM(1)). We previously evaluated the level and frequency of AFM(1) in breast milk in a group of Egyptian mothers attending the New El-Qalyub Hospital, Qalyubiyah governorate, Egypt. In this study, fifty o...