Hariom Yadav

• M.Sc., Ph.D.
• Professor (Associate) at University of South Florida

Purpose of Review This review addresses critical gaps in knowledge and provides a literature overview of the molecular pathways connecting gut microbiota dysbiosis to increased intestinal permeability (commonly referred to as “leaky gut”) and its contribution to metabolic disorders. Restoring a healthy gut microbiota holds significant potential for...

Gut microbiota plays a significant role in nutrient extraction, metabolism, and immune function. Thus, the growing number of microbiome studies seek to link the presence and prevalence of specific bacteria, fungi, and viruses with a variety of physiological and disease outcomes. However, recruiting a diverse group of patients has been a challenge....

Rationale Exploring novel metabolites produced by host gut microbiome communication is crucial for understanding their roles in various disease pathologies. We previously uncovered a novel class of lipids, short‐chain fatty acid esters of hydroxy fatty acids (SFAHFAs), in mouse fecal samples and demonstrated their promising physiological functions...

The skin microbiome, a diverse and dynamic ecosystem of microorganisms, plays a pivotal role in maintaining skin health by interacting with skin cells, immune components, and structural barriers. It is essential for skin homeostasis, immune defense, and protection against pathogenic colonization. Dysbiosis in the microbiome has been implicated in n...

The microbiome plays a critical role in both promoting human health and contributing to diseases. Multiple emerging evidence shows that it contributes to aging and cognitive decline; however, the mechanisms are not fully understood. Changes in the microbiome and immune system occur with age, and immune functions are one of the key mechanisms linkin...

Background/Objectives: This study evaluates the potential of electroencephalography (EEG) as a noninvasive tool for distinguishing between healthy individuals (n = 79), those with mild cognitive impairment (MCI; n = 36), and dementia patients (n = 7). Methods: Using a 14-channel Emotiv EPOC-X headset, we analyzed power spectral density during a 2-m...

The microbiome and aging: Unlocking new frontiers in healthy longevity Research conducted by the USF Microbiomes Institute and the MiaGB Consortium is uncovering the significant link between microbial communities and host biology. This understanding could lead to new therapies for age-related conditions. Shalini Jain, Christian Brechot, and Hariom...

Microbiome abnormalities (dysbiosis) significantly contribute to the progression of Alzheimer’s disease (AD). However, the therapeutic efficacy of microbiome modulators in protecting against these ailments remains poorly studied. Herein, we tested a cocktail of unique probiotics, including 5 Lactobacillus and 5 Enterococcus strains isolated from in...

Background The microbiota‐immune‐brain axis is implicated in Alzheimer’s disease. Alterations in gut microbiota and immune functions in mild cognitive impairment (MCI) are inconsistent and remain to be understood. This study aims to investigate immune cell phenotyping and its link with gut microbial composition associated with cognitive function....

Background Emerging studies suggest the interaction of the gut microbiome with physical and cognitive function. However, it remains unknown whether the same microbiome is linked with both functions and/or if they are unique. Method Utilizing data and samples from the Microbiome in Aging Gut and Brain (MiaGB) Consortium cohort, we assessed the whol...

Aging population is increasing, leading to a rise in aging-related conditions, specifically diseases like Alzheimer’s disease and its related dementia (ADRD), which have poor prognosis and lack prevention and treatment strategies. Although we do not fully understand the complex pathology of ADRD, emerging evidence indicates that abnormalities in th...

Aging is associated with intestinal dysbiosis, a condition characterized by diminished microbial biodiversity and inflammation. This leads to increased vulnerability to extraintestinal manifestations such as autoimmune, metabolic, and neurodegenerative conditions and accelerates mortality. As such, modulation of the gut microbiome is a promising wa...

Multiple emerging lines of evidence indicate that the microbiome contributes to aging and cognitive health. However, the roles of distinct microbial components, such as viruses (virome) and their interactions with bacteria (bacteriome), as well as their metabolic pathways (metabolome) in relation to aging and cognitive function, remain poorly under...

Fermented seeds and their bioactive compounds have captivated global interest due to their functional properties. Basil seeds are used worldwide in the food, cosmetic, and pharmaceutical industries, but their functional and nutritional properties after fermentation are not known. The aim of this study was to optimize the effect of fermentation on t...

Despite the development of new and highly effective cancer therapies, emerging evidence suggests that these treatments are associated with long-term side effects, which may contribute to cognitive impairment (CI) or dementia in cancer survivors. Many of these side effects are linked to gut health and a perturbed gut microbiome. However, the role of...

The global population is aging, facing a substantial burden of age-related disorders, including cognitive impairment (CI), Alzheimer's disease (AD), and related dementias (ADRD). The lack of effective strategies for preventing and treating these conditions can be attributed to our incomplete understanding of the biology of aging. Emerging evidence...

Aging-related abnormalities in gut microbiota are associated with cognitive decline, depression, and anxiety, but underlying mechanisms remain unstudied. Here, our study demonstrated that transplanting old gut microbiota to young mice induced inflammation in the gut and brain coupled with cognitive decline, depression, and anxiety. We observed dimi...

The oro-respiratory microbiome is impacted by inhalable exposures such as smoking and has been associated with respiratory health conditions. However, the effect of emerging toxicants, particularly engineered nanoparticles, alone or in co-exposure with smoking, is poorly understood. Here, we investigated the impact of sub-chronic exposure to carbon...

Abstract: The oro-respiratory microbiome is impacted by inhalable exposures such as smoking and has been associated with respiratory health conditions. However, the effect of emerging toxicants, particularly engineered nanoparticles, alone or in co-exposure with smoking, is poorly understood. Here, we investigated the impact of sub-chronic exposure...

The second brain of humans has been known as the microbiome. The microbiome is a dynamic network composed of commensal bacteria, archaea, viruses, and fungi colonized in the human gastrointestinal tract. They play a vital role in human health by metabolizing components, maturation of the immune system, and taking part in the treatment of various di...

Background Western vs. Mediterranean patterned diets have been associated with divergent effects on neurodegenerative diseases including Alzheimer’s Disease (AD). Such effects may be mediated through the gut microbiome, although the exact mechanisms linking diet, microbiome, and brain outcomes remain unclear. Oscillospira, a genus of gut‐dwelling b...

Abnormalities in gut microbiome contribute to age-related diseases, causal to unhealthy aging, and early mortality, but mechanisms still remain largely unknown. Our recent research shows that old microbiota lacks the capacity to produce beneficial metabolites like short-chain fatty acids (SCFAs), which in turn promote gut permeability and systemic...

Advancements in oncology research have led to increased survivorship in patients with cancer. However, cancer treatments like chemotherapy cause debilitating side effects including multi-organ dysfunction and increased risk for chronic diseases, which mimic accelerated aging. Abnormalities in the gut microbiome composition (dysbiosis) increase infl...

Alzheimer’s disease (AD) is a detrimental public health problem affecting millions of older adults in the USA alone, with no or limited treatment options. Emerging evidence indicates the pivotal role of gut microbiota in AD pathology, but mechanisms remain largely unknown. Also, microbiome modulators like probiotics are proven beneficial in prevent...

The prevalence of age-related cognitive decline and dementia is increasing in older adults, with limited prevention and therapeutic options, increasing tremendous burden on healthcare system. Alzheimer’s disease (AD) is the most common age-related cognitive disorder, for which no treatment is available when its pathology is fully developed. Althoug...

Significant scientific advancements have resulted in new and effective therapies for patients with cancer. Although this leads to an increased cancer survivor population, there are several long-term side effects of cancer treatments, including a high risk of developing dementia. Emerging evidence shows that the gut microbiota significantly contribu...

Limited studies to-date have evaluated differences in gut microbiota across a global and temporal scale. Herein, we aim to examine the gut microbiota patterns across geography as defined by continent and countries and how gut microbiota vary across age groups within each geographic region. To approach these questions, we designed a large-scale anal...

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disease characterized by cognitive and behavioral changes in older adults. Emerging evidence suggests poor oral health is associated with AD, but there is a lack of large-scale clinical studies demonstrating this link. Herein, we used the TriNetX database to generate clinical cohorts an...

Short-chain fatty acids (SCFAs) are key nutrients that play a diverse set of roles in physiological function, including regulating metabolic homeostasis. Generated through the fermentation of dietary fibers in the distal colon by the gut microbiome, SCFAs and their effects are partially mediated by their cognate receptors, including free fatty acid...

Alzheimer's disease (AD) is a progressive, age-related neurodegenerative disorder that affects a large proportion of the elderly population. It currently lacks effective treatments, placing a heavy burden on patients, families, healthcare systems, and society. This is mainly due to our limited comprehension of the pathophysiology of AD progression,...

As we age, our organ functions gradually decline. Circulating factors in the blood and the integrity of organ barriers can become dysfunctional, resulting in a condition known as leaky syndrome. This condition involves the unregulated exchange or leakage of components between organs. However, the triggers of leaky syndrome, as well as its role in a...

The prevalence of age-related cognitive disorders/dementia is increasing, and effective prevention and treatment interventions are lacking due to an incomplete understanding of aging neuropathophysiology. Emerging evidence suggests that abnormalities in gut microbiome are linked with age-related cognitive decline and getting acceptance as one of th...

Intermittent Fasting (IF) is the consumption of food and drinks within a defined time, while the ketogenic diet (KD) switches the metabolism from glucose to fats. Continuation of intermittent fasting leads to the generation of ketones, the exact mechanism for a ketogenic diet. This article discusses the types of IF and KD, the monitoring required,...

Objective Ample evidence exists for the role of abnormal gut microbiota composition and increased gut permeability (‘leaky gut’) in chronic inflammation that commonly co-occurs in the gut in both obesity and diabetes, yet the detailed mechanisms involved in this process have remained elusive. Design In this study, we substantiate the causal role o...

Eating disorders (EDs) are defined by persistent disturbances in eating behaviors and affect at least 9% of the population worldwide. Over time, they place physical, psychological, and social burdens on affected individuals and increase the risk for several chronic diseases. EDs (or “disordered eating”) may present at any age, but they are most com...

The prevalence of cognitive decline and dementia is increasing in older adults, their prognosis is poor. Multiple emerging evidence shows that early intervention can delay and /or prevent their progression, however, early-detection markers are invasive, expensive, and not easy to routinely measure. Saliva can be an attractive source of early cognit...

The prevalence of age-related cognitive disorders is increasing. Effective prevention and treatment interventions are unavailable due to a poor understanding of aging biology. Multiple emerging evidence indicates that the gut microbiome is linked with age-related disorders; however, their clinical importance in differentiating and predicting the ri...

Chronic inflammation is a key risk factor for age‐related progression of cognitive decline and Alzheimer’s disease (AD); however, its etiology remains elusive. Multiple emerging evidence indicates that abnormalities in the gut microbiome (dysbiosis) contribute to the pathology of cognitive decline and Alzheimer’s disease, by elevating gut permeabil...

Correction for 'Bioactive peptides derived from milk proteins and their health beneficial potentials: an update' by Ravinder Nagpal et al., Food Funct., 2011, 2, 18-27, DOI: 10.1039/C0FO00016G.

In recent years, appreciation for the gut microbiome and its relationship to human health has emerged as a facilitator of maintaining healthy physiology and a contributor to numerous human diseases. The contribution of the microbiome in modulating the gut-brain axis has gained significant attention in recent years, extensively studied in chronic br...

Here, we generated a novel intestine-specific knockout mouse model for FFA3 (Vil-FFA3) and performed a comprehensive metabolic characterization of mice in response to an obesogenic challenge. We found that Vil-FFA3 mice fed with a Western diet were largely protected from obesity, exhibiting significantly lower levels of fat mass, lower intestinal i...

Bringing together expert researchers in the fields of microbiome, metabolism, and nutrition research, this book compiles the current state of knowledge from authorities specifically on how diet regulates microbial function with metabolic implications for the human host. Chapters cover the broad concepts of microbial-host interactions under the diet...

Carbon nanotubes (CNTs) are emerging environmental and occupational toxicants known to induce lung immunotoxicity. While the underlying mechanisms are evolving, it is yet unknown whether inhaled CNTs would cause abnormalities in gut microbiota (dysbiosis), and if such microbiota alteration plays a role in the modulation of CNT-induced lung immunoto...

Type 2 diabetes (T2D) is a complex and heterogeneous chronic metabolic disorder disease that is associated with high blood sugar. Because of the side effects of synthetic drugs on T2D patients and their economic burden, interest in plant-derived functional foods like grains with biological activities has developed. Based on scientific reports, whol...

[This corrects the article DOI: 10.1155/2012/902917.].

Decades of aging research established several well-characterized theories of aging, yet as the studies often focus on different cellular mechanisms there is overall agreement that organismal aging is characterized by multi-factorial degenerative processes resulting from multiple alterations of different molecular pathways compromising cellular or t...

Human lifestyle and dietary behaviors contribute to disease onset and progression. Neurodegenerative diseases (NDDs), considered multifactorial disorders, have been associated with changes in the gut microbiome. NDDs display pathologies that alter brain functions with a tendency to worsen over time. NDDs are a worldwide health problem; in the US al...

The gut microbiota, an often forgotten organ, have a tremendous impact on human health. It has long been known that the gut microbiota are implicated in cancer development, and more recently, the gut microbiota have been shown to influence cancer metastasis to distant organs. Although one of the most common sites of distant metastasis is the bone,...

Inflammaging characterized with increased low grade inflammation in older adults is common determinant of unhealthy aging; and is a major risk factor of morbidity and mortality in older adults. The precise origin of inflammation in older adults is not known, however, emerging evidence indicate that increased intestinal epithelial permeability (leak...

Background and aims: Despite the reported salutary benefits of a Mediterranean diet (MD) on a wide variety of health conditions, the specific microbial changes associated with an MD within the gastrointestinal (GI) tract are not well studied. Specifically, although population and survey-based studies have shown microbial changes, there are no publ...

Multiple emerging evidence indicates that the gut microbiota contributes to the pathology of Alzheimer’s disease (AD)—a debilitating public health problem in older adults. However, strategies to beneficially modulate gut microbiota and its sensing signaling pathways remain largely unknown. Here, we screened, validated, and established the agonists...

Background: Alzheimer's disease (AD) is the most common form of dementia, particularly in older adults, with clinical manifestations of progressive cognitive decline and functional impairment. The prevalence of AD and related dementia is mounting worldwide, but its etiology remains unresolved, with no available preventative or ameliorative therapy...

The association between healthy aging and gut microbiota (GM) was made first by the Nobel Prize winner Elie Metchnikoff in 1908. However only in the last two decades, there is convincing evidence that the process of aging influences the GM and vice versa. With considerable metabolic activity, the GM is a virtual organ that starting from birth is in...

Increased chronic inflammation is one of the key risk factors of aging-related disorders although its precise etiology remains elusive. Here, we demonstrate that aged, but not young, microbiota triggers inflammation by promoting gut permeability (leaky gut) via disruption of mucus barriers. Levels of the beneficial short-chain fatty acid, butyrate,...

Obesity and poor diet often go hand-in-hand, altering metabolic signaling and thereby impacting breast cancer risk and outcomes. We have recently demonstrated that dietary patterns modulate mammary microbiota populations. An important and largely open question is whether the microbiome of the gut and mammary gland mediates the dietary effects on br...

Background The objective of this study was to increase understanding of the complex interactions between diet, obesity, and the gut microbiome of adult female non-human primates (NHPs). Subjects consumed either a Western (n=15) or Mediterranean (n=14) diet designed to represent human dietary patterns for 31 months. Body composition was determined u...

Iron is an essential element for the mammalian body however, its homeostasis must be regulated accurately for appropriate physiological functioning. Alterations in physiological iron levels can lead to moderate to severe iron disorders like chronic and acute iron deficiency (anemia) or iron overload. Hepcidin plays an important role in regulating h...

The prevalence of type 2 diabetes mellitus (T2D) is increasing worldwide, and there are no long-term preventive strategies to stop this growth. Emerging research shows that perturbations in the gut microbiome significantly contribute to the development of T2D, while microbiome modulators may be beneficial for T2D prevention. However, microbiome mod...

The prevalence of type-2 diabetes mellitus (T2D) is increasing worldwide and there are no long-term preventive strategies to stop this growth. Emerging research shows that perturbations in the gut microbiome significantly contribute to the development of T2D, while microbiome modulators may be beneficial for T2D prevention. However, microbiome modu...

Cellular senescence contributes to age-related disorders including physical dysfunction, disabilities and mortality caused by tissue inflammation and damage. Senescent cells accumulate in multiple tissues with aging and at etiological sites of multiple chronic disorders. The senolytic drug combination, Dasatinib plus Quercetin (D+Q), is known to re...

Gut microbiota and its metabolites like short chain fatty acids (SCFAs) are linked with pathology of Alzheimer’s disease (AD)- a debilitating public health problem in older adults. However, strategies to beneficially modulate gut microbiota and its sensing signaling pathways remain largely unknown. Here, we screened, validated and established the a...

Older adults are suffering from several aging-related illnesses including cognitive decline and effective strategies to prevent and/or treat them are lacking, because of a poor understanding of therapeutic targets. Low-grade inflammation is a key risk factor of aging-related morbidities and mortalities, and it is often higher in older adults. Altho...

Background Alzheimer’s disease (AD) is progressive debilitating public health problem, with no successful preventive and therapeutic strategy. Emerging evidence indicate that the gut microbiome and its metabolites like short chain fatty acids (SCFAs; such as acetate, propionate, butyrate) contribute in AD pathology. SCFAs function as gut microbiome...

Decade old studies demonstrated that microbes living in our gut (microbiota) contribute in both maintaining normal metabolic function and pathology of metabolic diseases such as obesity and diabetes. Emerging evidence suggest that gut microbiota influences the personalized effects of diets and drugs, and impact–gut brain axis and leaky gut-inflamma...

The epigenome is an overall epigenetic state of an organism, which is as important as that of the genome for normal development and functioning of an individual. Epigenetics involves heritable but reversible changes in gene expression through alterations in DNA methylation, histone modifications and regulation of non-coding RNAs in cells, without a...

An important yet poorly understood facet in the life cycle of a successful pathogen is the host-to-host transmission. Hospital-acquired infections (HAI) resulting from the transmission of drug-resistant pathogens affect hundreds of millions of patients worldwide. Klebsiella pneumoniae ( Kpn ), a gram-negative bacterium, is notorious for causing HAI...

Transient receptor potential (TRP) channel family proteins are sensors for pain, which sense a variety of thermal and noxious chemicals. Sensory neurons innervating the gut abundantly express TRPA1 and TRPV1 channels and are in close proximity of gut microbes. Emerging evidence indicates a bi-directional gut–brain cross-talk in several entero-neuro...

Background Recently, we reported that patients with mild cognitive impairment (MCI) harbor specific signature of bacteria in their gut and that a modified Mediterranean ketogenic diet (MMKD) improves Alzheimer's disease (AD) markers in cerebrospinal fluid (CSF) and the signatures of gut bacteria. However, other microbial population such as gut fung...

Abstract Probiotics have several health benefits by modulating gut microbiome; however, techno-functional limitations such as viability controls have hampered their full potential applications in the food and pharmaceutical sectors. Therefore, the focus is gradually shifting from viable probiotic bacteria towards non-viable paraprobiotics and/or pr...

Transient receptor potential (TRP) channel family proteins are sensors for pain, which sense variety of thermal and noxious chemicals. Sensory neurons innervating the gut abundantly express TRPA1 and TRPV1 channels and are in close proximity of gut microbes. Emerging evidence indicates a bi-directional gut-brain cross-talk in several entero-neurona...

The role of the gut microbiome in human health is becoming apparent. The major functional impact of the gut microbiome is transmitted through the microbial metabolites that are produced in the gut and interact with host cells either in the local gut environment or are absorbed into circulation to impact distant cells/organs. Short-chain fatty acids...

The gut microbiome plays an important role in obesity and Type 2 diabetes (T2D); however, it remains unclear whether the gut microbiome could clarify the dietary versus genetic origin of these ailments. Moreover, studies examining the gut microbiome in diet- versus genetically induced obesity/T2D in the same experimental set-up are lacking. We here...

Role of gut microbiome in human health is becoming apparent. The major functional impact of gut microbiome is transmitted through the microbial metabolites that are produced in the gut and interact with host cells either in the local gut environment or get absorbed in the circulation to impact distant cells/organs. Short chain fatty acids (SCFAs) a...

Inflammation is a major risk factor of morbidity and mortality in older adults. Although its precise etiology is unknown, low-grade inflammation in older adults is commonly associated with increased intestinal epithelial permeability (leaky gut) and abnormal (dysbiotic) gut microbiota. The increasing older population and lack of treatments to reduc...

The contribution of gut microbiome and its metabolites like short chain fatty acids (SCFAs; such as acetate, propionate, butyrate) became apparent to impact human health. SCFAs not only feed the intestinal cells, but also function as gut microbiome sensors on distinct cell types through activating G‐couple protein receptors like free fatty acid rec...

Inflammation is a major risk factor of morbidity and mortality in older adults. Although its precise etiology is unknown, low grade inflammation in older adults is commonly associated with increased intestinal epithelial permeability (leaky gut) and abnormal (dysbiotic) gut microbiota. The lack of treatments to reduce aging‐related microbiota dysbi...

In obesity and diabetes, abnormal gut microbiota and increased gut permeability (leaky gut) are common risk factors which in turn contributes in increasing chronic low grade inflammation. However, precise mechanism(s) whether and how gut microbiota contributes in induction of leaky gut remain largely unknown. Here we, demonstrated that obese/ diabe...

Aging-related illnesses are increasing and effective strategies to prevent and/or treat them are lacking. This is because of a poor understanding of therapeutic targets. Low-grade inflammation is often higher in older adults and remains a key risk factor of aging-related morbidities and mortalities. Emerging evidence indicates that abnormal (dysbio...

Background There is significant interest in effective oral drug delivery of therapeutic substances. For probiotics, there is a particular need for a delivery platform that protects the bacteria from destruction by the acidic stomach while enabling targeted delivery to the intestine where microbiota naturally reside. The use of probiotics and how th...

An important yet poorly understood facet in the life cycle of a successful pathogen is the host-to-host transmission. Hospital-acquired infections (HAI) resulting from the transmission of drug-resistant pathogens affect hundreds of millions of patients worldwide. Klebsiella pneumoniae (Kpn), a gram-negative bacterium, is notorious for causing HAI,...

Obesity became an epidemic public health problem and continuously increasing every year. For the longest time, the pathologic framework for obesity had been simple: caloric intake is greater than the energy output, which by far still true, however, the underlying reasons for increased energy intake and reduced energy expenditure remain largely unkn...

Increased inflammation associated with leaky gut is a major risk factor for morbidity and mortality in older adults; however, successful preventive and therapeutic strategies against these conditions are not available. In this study, we demonstrate that a human-origin Lactobacillus paracasei D3-5 strain (D3-5), even in the non-viable form, extends...

Increased inflammation associated with leaky gut is a major risk factor for morbidity and mortality in older adults; however, successful preventive and therapeutic strategies are not available to ameliorate these conditions. In this study, we demonstrate that a human-origin Lactobacillus paracasei D3-5 strain (D3-5), even when dead, extended life s...

Obesity epidemic responsible for increase in diabetes, heart diseases, infections and cancer shows no signs of abating. Obesity in children is also on rise, indicating the urgent need of strategies for prevention and intervention that must begin in early life. While originally posited that obesity results from the simple concept of consuming more c...

Background: Alzheimer's disease (AD) prevalence is increasing, but its etiology remains elusive. Gut microbes can contribute to AD pathology and may help identifying novel markers and therapies against AD. Herein, we examine how the gut microbiome differs in older adults with mild cognitive impairment compared to cognitively normal counterparts, a...

The emerging role of the gut microbiome in several human diseases demands a breakthrough of new tools, techniques and technologies. Such improvements are needed to decipher the utilization of microbiome modulators for human health benefits. However, the large-scale screening and optimization of modulators to validate microbiome modulation and predi...

Candida albicans is the fourth most common cause of systemic nosocomial infections, posing a significant risk in immunocompromised individuals. As the majority of systemic C. albicans infections stem from endogenous gastrointestinal (GI) colonization, understanding the mechanisms associated with GI colonization is essential in the development of no...

Objectives To compare the gut microbiome and short-chain fatty acids (SCFAs) in subjects with or without mild cognitive impairment (MCI) and study the effect of a modified Mediterranean-ketogenic diet (MMKD) and a low-fat American Heart Association Diet (AHAD) on gut microbiome, SCFAs, and cerebrospinal fluid (CSF) biomarkers of AD. Methods A rand...