The microbiome in early life: self-completion and microbiota protection as health priorities

Metabolic Syndrome: A Narrative Review from the Oxidative Stress to the Management of Related Diseases

Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome's involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.

The Multi-Omics Analysis Revealed a Metabolic Regulatory System of Cecum in Rabbit with Diarrhea

With the comprehensive prohibition of antibiotics in the feed industry in China, the incidence of diarrhea in rabbits increased, such as loss of appetite, vomiting, and excretion of atheromatous feces. In order to explore the pathological and the molecular mechanisms of the diarrhea in the rabbitry fed with antibiotic-free diet, we used microbial metagenomics, transcriptome, and non-targeted metabolomics sequencing. The results showed that the Firmicutes level was significantly decreased (p < 0.001) and the Proteobacteria level was significantly increased (p < 0.05). The functional enrichment of cecum revealed that most differentially expressed genes (DEGs) were expressed in immune, inflammatory, and metabolic processes. The enrichment of the cecal fecal metabolites focused on the bile secretion, antifolate resistance, and tryptophan metabolism pathways, which are mainly associated with inflammation. The results of correlation analysis showed that Fournierella was positively correlated with myricetin, ursolic acid, and furtherly might cause bile secretion and tryptophan metabolism disorder, aggravate intestinal inflammation, change intestinal permeability, and reduce host immunity, leading to diarrhea in rabbits. This study provides a theoretical basis for illustrating the reason for diarrhea and developing new feeds for the health of rabbits.

Impact of Cumulative Environmental and Dietary Xenobiotics on Human Microbiota: Risk Assessment for One Health

Chemical risk assessment in the context of the risk analysis framework was initially designed to evaluate the impact of hazardous substances or xenobiotics on human health. As the need of multiple stressors assessment was revealed to be more reliable regarding the occurrence and severity of the adverse effects in the exposed organisms, the cumulative risk assessment started to be the recommended approach. As toxicant mixtures and their "cocktail effects" are considered to be main hazards, the most important exposure for these xenobiotics would be of dietary and environmental origin. In fact, even a more holistic prism should currently be considered. In this sense, the definition of One Health refers to simultaneous actions for improving human, animal, and environmental health through transdisciplinary cooperation. Global policies necessitate going beyond the classical risk assessment for guaranteeing human health through actions and implementation of the One Health approach. In this context, a new perspective is proposed for the integration of microbiome biomarkers and next generation probiotics potentially impacting and modulating not only human health, but plant, animal health, and the environment.

The Role of the Environment in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease clinicopathologically characterized by esophageal dysfunction. EoE is characterized by eosinophilic histologic inflammation indistinguishable from other atopic diseases such as asthma, eczema, or allergic rhinitis, which often co-occur in patients with EoE. This suggest a possible shared pathophysiology and triggers in the development of EoE with other atopic conditions. Although the evidence of EoE being linked to exposure to allergenic foods is strong, the connection between EoE and aeroallergens is less understood. In this review, we will discuss clinical, epidemiological, and animal studies that investigate how environmental allergens influence the clinical manifestations of EoE and its seasonality. It is also known that the developing immune system is significantly shaped by early-life exposures, pollution, climate change, and those factors that are known to influence development of asthma. We therefore also describe the evidence for and the gaps in our knowledge of the role of early-life exposures, pollution, and climate change in the development of EoE.

Targeting the gut microbiome: A brief report on the awareness, practice, and readiness to engage in clinical interventions in Qatar

BACKGROUND

There has been a growing global interest in the role of gut microbiota in the pathogenesis of diseases and the potentials of targeting the microbiome in clinical interventions. Very few clinical studies in Qatar focused on gut microbiome. This study aimed to assess the awareness of healthcare professionals, scientists, and the general public on the role of gut microbiota in health and diseases and, more specifically, in disorders of the gut-brain axis such as neurodevelopmental disorders (NDDs) or gastrointestinal (GI) disorders. It also aimed to evaluate the readiness of the population to engage in clinical trials involving dietary interventions or fecal transplants.

METHODS

A total of 156 participants were recruited to answer questionnaires-from healthcare professionals and scientists (HSs; n = 44) and the general public (n = 112). Participants from the general public self-reported their diagnosis of NDDs-autism or attention deficit hyperactivity disorder (n = 36)-or GI diseases or disorders (n = 18) or as having none of them (n = 58). Two questionnaires for HSs and for the general public were distributed, and basic descriptive and statistical analyses were conducted using the Fisher's exact test.

RESULTS

Among the participating HSs, 95% admitted that they had minimum to no knowledge on the role of gut microbes in health and diseases, and only 15.9% felt that their peers were knowledgeable about it. Nevertheless, 97.7% of HSs thought that gut microbiota should be considered when devising treatment plans as 79.1% believed that gut dysbiosis is involved in the pathogenesis of diseases. For the general public, 54% stated that they have read about studies on the potential benefits of microbes in the prevention, treatment, and management of diseases, with a higher proportion of them belonging to the GI group (p = 0.0523). The GI group was also more aware of the existence of the use of fecal transplants for treating their condition (p = 0.01935). Awareness was also reflected in participants' attempts to engage in dietary changes, as 40% tried a dietary intervention, which has noticeably changed their or their child's symptoms. This study reported a highly significant association between being exposed to multiple antibiotic courses before three years of age and being part of the NDD group (p = 0.0003). Public readiness to engage in interventions that target the gut microbiome, such as intensive dietary interventions or even fecal transplants, was perceived by HSs to be lower than what was stated by the public, with 87.96% of public being ready to engage in intensive dietary interventions and 66.98% in fecal transplants.

CONCLUSION

The study revealed that the role of gut microbes in health and diseases, and especially through the gut-brain axis, is still unclear in both the scientific community and general public. While acknowledging the importance of gut microbes, the lack of information regarding the link between lifestyle and gut microbes is considered to hold the public in the precontemplation/contemplation stages of the transtheoretical model of behavioral change. An interdisciplinary approach to new knowledge produced by microbiome studies is needed to run awareness campaigns and continue professional development activities on the benefits of lifestyle-based modulation of gut microbiome, thus engaging the general public in lifestyle changes and facilitating clinical research in human microbiome investigations in Qatar.

Framing the discussion of microorganisms as a facet of social equity in human health

What do “microbes” have to do with social equity? These microorganisms are integral to our health, that of our natural environment, and even the “health” of the environments we build. The loss, gain, and retention of microorganisms—their flow between humans and the environment—can greatly impact our health. It is well-known that inequalities in access to perinatal care, healthy foods, quality housing, and the natural environment can create and arise from social inequality. Here, we focus on the argument that access to beneficial microorganisms is a facet of public health, and health inequality may be compounded by inequitable microbial exposure.

What do microbes have to do with social equity? This Essay explores the argument that access to beneficial microorganisms is a facet of public health, and that health inequality may be compounded by inequitable microbial exposure.

Genistein prevention of hyperglycemia and improvement of glucose tolerance in adult non-obese diabetic mice are associated with alterations of gut microbiome and immune homeostasis

Although studies have linked soy phytoestrogen 4,7,4-trihydroxyisoflavone genistein (GEN) to reduced type 1 diabetes (T1D) risk, the mechanism of dietary GEN on T1D remains unknown. In our studies, adult non-obese diabetic (NOD) mouse model was employed to investigate the effects of GEN exposure on blood glucose level (BGL), glucose tolerance, gut microbiome, and immune responses. Adult male and female NOD mice were fed with either soy-based or casein-based diet, and received GEN at 20mg/kg body weight by gavage daily. The BGL and immune responses (represented by serum antibodies, cytokines and chemokines, and histopathology) were monitored, while the fecal gut microbiome was sequenced for 16S ribosomal RNA to reveal any alterations in gut microbial communities. A significantly reduced BGL was found in NOD males fed with soy-based diet on day 98 after initial dosing, and an improved glucose tolerance was observed on both diets. In addition, an anti-inflammatory response (suggested by reduced IgG2b and cytokine/chemokine levels, and alterations in the microbial taxonomy) was accompanied by an altered β-diversity in gut microbial species. Among the NOD females exposed to GEN, a later onset of T1D was observed. However, the profiles of gut microbiome, antibodies and cytokines/chemokines were all indicative of pro-inflammation. This study demonstrated an association among GEN exposure, gut microbiome alteration, and immune homeostasis in NOD males. Although the mechanisms underlying the protective effects of GEN in NOD mice need to be explored further, the current study suggested a GEN-induced sex-specific effect in inflammatory status and gut microbiome.

The impact of oral probiotics on vaginal Group B Streptococcal colonisation rates in pregnant women: A pilot randomised control study

OBJECTIVE

To perform a pilot project to determine if this research design was appropriate to explore potential causal relationships between oral probiotic use and vaginal Group B Streptococcal (GBS) colonisation rates in pregnant women.

METHOD

Thirty-four GBS-positive women at 36 weeks pregnant were recruited. The participants were randomly allocated to the control group, who received standard antenatal care, or to the intervention group, who received standard antenatal care and a daily oral dose of probiotics for three weeks or until they gave birth. A vaginal GBS swab was collected three weeks post consent or during labour.

FINDINGS

No significant difference was found in vaginal GBS rates between the control and intervention groups. Only seven of 21 women in the intervention group completed the entire 21days of probiotics. A subgroup analysis, including only those who had completed 14days or more of probiotics (n=16), also showed no significant difference in vaginal GBS when compared to the control. The findings did show significantly more vaginal commensals in the probiotics group (p=0.048).

DISCUSSION

Five possible reasons for the lack of significant results are: the length of the intervention was too short; the dosage of the probiotics was too low; the wrong strains of probiotics were used; the sample size was inadequate; or oral probiotics are ineffective in impacting vaginal GBS.

IMPLICATIONS

The finding of a significant increase of vaginal commensals in women who completed 14days or more of probiotics supports the potential of probiotics to impact vaginal GBS in pregnancy.

Early-Life Sugar Consumption Affects the Rat Microbiome Independently of Obesity

BACKGROUND

The gut microbiome has been implicated in various metabolic and neurocognitive disorders and is heavily influenced by dietary factors, but there is a paucity of research on the effects of added sugars on the gut microbiome.

OBJECTIVE

With the use of a rodent model, our goal was to determine how added-sugar consumption during the juvenile and adolescent phase of development affects the gut microbiome.

METHODS

Forty-two juvenile male Sprague-Dawley rats [postnatal day (PND) 26; 50-70 g] were given access to 1 of 3 different 11%-carbohydrate solutions designed to model a range of monosaccharide ratios commonly consumed in sugar-sweetened beverages: 1) 35% fructose:65% glucose, 2) 50% fructose:50% glucose, 3) 65% fructose:35% glucose, and 4) control (no sugar). After ad libitum access to the respective solutions for the juvenile and adolescent period (PND 26-80), fecal samples were collected for next-generation 16S ribosomal RNA sequencing and multivariate microbial composition analyses. Energy intake, weight change, and adiposity index were analyzed in relation to sugar consumption and the microbiota.

RESULTS

Body weight, adiposity index, and total caloric intake did not differ as a result of sugar consumption. However, sugar consumption altered the gut microbiome independently of anthropometric measures and caloric intake. At the genus level, Prevotella [linear discriminant analysis (LDA) score = -4.62; P < 0.001] and Lachnospiraceae incertae sedis (LDA score = -3.01; P = 0.03) were reduced, whereas Bacteroides (LDA score = 4.19; P < 0.001), Alistipes (LDA score = 3.88; P < 0.001), Lactobacillus (LDA score = 3.78; P < 0.001), Clostridium sensu stricto (LDA score = 3.77; P < 0.001), Bifidobacteriaceae (LDA score = 3.59; P = 0.001), and Parasutterella (LDA score = 3.79; P = 0.004) were elevated by sugar consumption. No overall pattern could be attributable to monosaccharide ratio.

CONCLUSIONS

Early-life sugar consumption affects the gut microbiome in rats independently of caloric intake, body weight, or adiposity index; these effects are robust across a range of fructose-to-glucose ratios.

The Microbiome

The microbiome is increasingly recognized as a critical component in human development, health, and disease. Its relevance to toxicology and pharmacology involves challenges to current concepts related to absorption, metabolism, gene:environment, and pathways of response. Framing testable hypotheses for experimental and epidemiological studies will require attention to study designs, biosampling, data analysis, and attention to confounders.

Revision of the ICH guideline on detection of toxicity to reproduction for medicinal products: SWOT analysis

SWOT analysis was used to gain insights and perspectives into the revision of the ICH S5(R2) guideline on detection of toxicity to reproduction for medicinal products. The current ICH guideline was rapidly adopted worldwide and has an excellent safety record for more than 20 years. The revised guideline should aim to further improve reproductive and developmental (DART) safety testing for new drugs. Alternative methods to animal experiments should be used whenever possible. Modern technology should be used to obtain high quality data from fewer animals. Additions to the guideline should include considerations on the following: limit dose setting, maternal toxicity, biopharmaceuticals, vaccines, testing strategies by indication, developmental immunotoxicity, and male-mediated developmental toxicity. Emerging issues, such as epigenetics and the microbiome, will most likely pose challenges to DART testing in the future. It is hoped that the new guideline will be adopted even outside the ICH regions.

Assessing Early Life Factors for Eosinophilic Esophagitis: Lessons From Other Allergic Diseases

OPINION STATEMENT

Few studies have been conducted to investigate possible early life determinants for eosinophilic esophagitis. An improved understanding of the etiologic factors implicated in disease development would further elucidate possible disease pathogenesis, inform therapeutic targets for disease treatment, and identify possible modifiable factors for disease prevention in genetically susceptible individuals. Although eosinophilic esophagitis is increasing in incidence and prevalence, the disease remains relatively rare, posing challenges for studying etiologic factors in disease development. Eosinophilic esophagitis is believed to be antigen-mediated, and most patients with EoE have concomitant atopic disease. In recent years, the evolution of our understanding of possible etiologic mechanisms in allergic disease has been informed by our understanding of how early life perturbations can lead to dysbiosis in the colonization of the microflora in the gastrointestinal tract and subsequent dysregulated immune development. Perturbations include factors such as antibiotic use, including prenatal, intra-antepartum, and infancy use of antibiotics, Cesarean delivery, preterm delivery, and neonatal intensive care admission. This article provides a review of these recent developments, as they relate to atopic disease, to inform future directions in the study of early life etiologic factors in the development of eosinophilic esophagitis.

Diet, Microbiota and Immune System in Type 1 Diabetes Development and Evolution

Type 1 diabetes (T1D) is the second most frequent autoimmune disease in childhood. The long-term micro- and macro-vascular complications of diabetes are associated with the leading causes of disability and even mortality in young adults. Understanding the T1D etiology will allow the design of preventive strategies to avoid or delay the T1D onset and to help to maintain control after developing. T1D development involves genetic and environmental factors, such as birth delivery mode, use of antibiotics, and diet. Gut microbiota could be the link between environmental factors, the development of autoimmunity, and T1D. In this review, we will focus on the dietary factor and its relationship with the gut microbiota in the complex process involved in autoimmunity and T1D. The molecular mechanisms involved will also be addressed, and finally, evidence-based strategies for potential primary and secondary prevention of T1D will be discussed.

Update on Pediatric Cough

Despite the high prevalence of cough in children, the topic has been poorly researched. Although pediatricians recognize that chronic cough in children is different from that in adults, this difference seems less recognizable to other health professionals. During childhood, the respiratory tract and nervous system undergo a series of anatomical and physiological maturation processes that influence the cough reflex. Additionally, immunological responses undergo developmental and memorial processes that make infection and congenital abnormalities the overwhelming cause of cough in children. The lack of comprehensive clinical data regarding chronic cough in children has initially required pediatricians to adopt an adult approach to the problem. In the last 10 years, however, research has led to the reconsideration of the etiology of chronic cough in children. Currently, attention has focused on protracted bacterial bronchitis as a major cause of chronic cough in preschool-aged children and as a possible precursor of bronchiectasis. New research horizons are emerging for both the treatment and prevention of particular causes of chronic cough in children.

Biomarkers for the 21st century: listening to the microbiome

The field of environmental research has benefited greatly from the concept of biomarkers, which originally expanded our thinking by opening the "black box" between environmental exposures and manifestations of disease and dysfunction in exposed populations, as laid out in a highly influential article published in 1987 by an expert committee convened by the National Research Council. Advances in biomedical research now challenge us to revise this concept to include the microbiome as a critical stage in the progression from exposure to outcome. Incorporating the microbiome into the basic 1987 model can spur new advances and understanding in environmental health. The human microbiome as a whole comprises the majority of cells and genes of the super-organism (host and microbiome). Site-specific microbiomes are the first to encounter xenobiotics, prior to absorption across gut, skin, or respiratory system. A growing literature indicates that these microbial communities may participate in biotransformation and thus constitute a compartment to add to the original biomarker schematic. In addition, these microbiomes interact with the "niche" in which they are located and thus transduce responses to and from the host organism. Incorporating the microbiome into the environmental health paradigm will enlarge our concepts of susceptibility as well as the interactions between xenobiotics and other factors that influence the status and function of these barrier systems. This article reviews the complexities of host:microbiome responses to xenobiotics in terms of redefining toxicokinetics and susceptibility. Our challenge is to consider these multiple interactions between and within the microbiome, the immune system, and other systems of the host in terms of exposure to exogenous agents, including environmental toxicants.

The Microbiome and Sustainable Healthcare

Increasing prevalences, morbidity, premature mortality and medical needs associated with non-communicable diseases and conditions (NCDs) have reached epidemic proportions and placed a major drain on healthcare systems and global economies. Added to this are the challenges presented by overuse of antibiotics and increased antibiotic resistance. Solutions are needed that can address the challenges of NCDs and increasing antibiotic resistance, maximize preventative measures, and balance healthcare needs with available services and economic realities. Microbiome management including microbiota seeding, feeding, and rebiosis appears likely to be a core component of a path toward sustainable healthcare. Recent findings indicate that: (1) humans are mostly microbial (in terms of numbers of cells and genes); (2) immune dysfunction and misregulated inflammation are pivotal in the majority of NCDs; (3) microbiome status affects early immune education and risk of NCDs, and (4) microbiome status affects the risk of certain infections. Management of the microbiome to reduce later-life health risk and/or to treat emerging NCDs, to spare antibiotic use and to reduce the risk of recurrent infections may provide a more effective healthcare strategy across the life course particularly when a personalized medicine approach is considered. This review will examine the potential for microbiome management to contribute to sustainable healthcare.