Factors affecting the composition of the gut microbiota, and its modulation

Gut-brain axis interplay via STAT3 pathway: Implications of Helicobacter pylori derived secretome on inflammation and Alzheimer's disease

Helicobacter pylori is a pathogenic bacterium that causes gastritis and gastric carcinoma. Besides gastric complications its potential link with gut-brain axis disruption and neurological disorders has also been reported. The current study investigated the plausible role and its associated molecular mechanism underlying H. pylori mediated gut-brain axis disruption and neuroinflammation leading to neurological modalities like Alzheimer's disease (AD). We have chosen the antimicrobial resistant and susceptible H. pylori strains on the basis of broth dilution method. We have observed the increased inflammatory response exerted by H. pylori strains in the gastric as well as in the neuronal compartment after treatment with Helicobacter pylori derived condition media (HPCM). Further, elevated expression of STAT1, STAT3, and AD-associated proteins- APP and APOE4 was monitored in HPCM-treated neuronal and neuron-astrocyte co-cultured cells. Excessive ROS generation has been found in these cells. The HPCM treatment to LN229 causes astrogliosis, evidenced by increased glial fibrillary acidic protein. Our results indicate the association of STAT3 as an important regulator in the H. pylori-mediated pathogenesis in neuronal cells. Notably, the inhibition of STAT3 by its specific inhibitor, BP-1-102, reduced the expression of pSTAT3 and AD markers in neuronal compartment induced by HPCM. Thus, our study demonstrates that H. pylori infection exacerbates inflammation in AGS cells and modulates the activity of STAT3 regulatory molecules. H. pylori secretome could affect neurological compartments by promoting STAT3 activation and inducing the expression of AD-associated signature markers. Further, pSTAT-3 inhibition mitigates the H. pylori associated neuroinflammation and amyloid pathology.

Effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice

Pectins are dietary fibers that are attributed with several beneficial immunomodulatory effects. Depending on the degree of esterification (DE), pectins can be classified as high methoxyl pectin (HMP) or low methoxyl pectin (LMP). The aim of this study was to investigate the effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice. Supplementation of the diet with LMP or HMP induced changes in the composition of the intestinal microbiota in mice toward Bacteroides, which was mainly promoted by HMP. Metabolome analysis of stool samples from pectin-fed mice showed a different effect of the two types of pectin on the levels of short-chain fatty acids and bile acids, which was consistent with highly efficient in vivo fermentation of LMP. Analysis of serum antibody levels showed a significant increase in IgG and IgA levels by both pectins, while FACS analysis revealed a decrease of infiltrating inflammatory cells in the intestinal lamina propria by HMP. Our study revealed that the structural properties of the investigated pectins determine fermentability, effects on microbial composition, metabolite production, and modulation of immune responses. Consumption of HMP preferentially altered the gut microbiota and suppressed pro-inflammatory immune responses, suggesting a beneficial role in inflammatory diseases.

Microbiota and Gut-Liver Axis: An Unbreakable Bond?

The gut microbiota, amounting to approximately 100 trillion (1014) microbes represents a genetic repertoire that is bigger than the human genome itself. Evidence on bidirectional interplay between human and microbial genes is mounting. Microbiota probably play vital roles in diverse aspects of normal human metabolism, such as digestion, immune modulation, and gut endocrine function, as well as in the genesis and progression of many human diseases. Indeed, the gut microbiota has been most closely linked to various chronic ailments affecting the liver, although concrete scientific data are sparse. In this narrative review, we initially discuss the basic epidemiology of gut microbiota and the factors influencing their initial formation in the gut. Subsequently, we delve into the gut-liver axis and the evidence regarding the link between gut microbiota and the genesis or progression of various liver diseases. Finally, we summarise the recent research on plausible ways to modulate the gut microbiota to alter the natural history of liver disease.

Understanding Mucosal Physiology and Rationale of Formulation Design for Improved Mucosal Immunity

The oral and nasal cavities serve as critical gateways for infectious pathogens, with microorganisms primarily gaining entry through these routes. Our first line of defense against these invaders is the mucosal membrane, a protective barrier that shields the body's internal systems from infection while also contributing to vital functions like air and nutrient intake. One of the key features of this mucosal barrier is its ability to protect the physiological system from pathogens. Additionally, mucosal tolerance plays a crucial role in maintaining homeostasis by regulating the pH and water balance within the body. Recognizing the importance of the mucosal barrier, researchers have developed various mucosal formulations to enhance the immune response. Mucosal vaccines, for example, deliver antigens directly to mucosal tissues, triggering local immune stimulation and ultimately inducing systemic immunity. Studies have shown that lipid-based formulations such as liposomes and virosomes can effectively elicit both local and systemic immune responses. Furthermore, mucoadhesive polymeric particles, with their prolonged delivery to target sites, have demonstrated an enhanced immune response. This Review delves into the critical role of material selection and delivery approaches in optimizing mucosal immunity.

Bringing gut microbiota into the spotlight of clinical research and medical practice

Despite the increasing scientific interest and expanding role of gut microbiota (GM) in human health, it is rarely reported in case reports and deployed in clinical practice. Proteins and metabolites produced by microbiota contribute to immune system development, energy homeostasis and digestion. Exo- and endogenous factors can alter its composition. Disturbance of microbiota, also known as dysbiosis, is associated with various pathological conditions. Specific bacterial taxa and related metabolites are involved in disease pathogenesis and therefore can serve as a diagnostic tool. GM could also be a useful prognostic factor by predicting future disease onset and preventing hospital-associated infections. Additionally, it can influence response to treatments, including those for cancers, by altering drug bioavailability. A thorough understanding of its function has permitted significant development in therapeutics, such as probiotics and fecal transplantation. Hence, GM should be considered as a ground-breaking biological parameter, and it is advisable to be investigated and reported in literature in a more consistent and systematic way.

The strength of gut microbiota transfer along social networks and genealogical lineages in the house mouse

The gut microbiota of vertebrates is acquired from the environment and other individuals, including parents and unrelated conspecifics. In the laboratory mouse, a key animal model, inter-individual interactions are severely limited and its gut microbiota is abnormal. Surprisingly, our understanding of how inter-individual transmission impacts house mouse gut microbiota is solely derived from laboratory experiments. We investigated the effects of inter-individual transmission on gut microbiota in two subspecies of house mice (Mus musculus musculus and M. m. domesticus) raised in a semi-natural environment without social or mating restrictions. We assessed the correlation between microbiota composition (16S rRNA profiles), social contact intensity (microtransponder-based social networks), and mouse relatedness (microsatellite-based pedigrees). Inter-individual transmission had a greater impact on the lower gut (colon and cecum) than on the small intestine (ileum). In the lower gut, relatedness and social contact independently influenced microbiota similarity. Despite female-biased parental care, both parents exerted a similar influence on their offspring's microbiota, diminishing with the offspring's age in adulthood. Inter-individual transmission was more pronounced in M. m. domesticus, a subspecies, with a social and reproductive network divided into more closed modules. This suggests that the transmission magnitude depends on the social and genetic structure of the studied population.

Rapid biotransformation of STW 5 constituents by human gut microbiome from IBS- and non-IBS donors

STW 5, a blend of nine medicinal plant extracts, exhibits promising efficacy in treating functional gastrointestinal disorders, notably irritable bowel syndrome (IBS). Nonetheless, its effects on the gastrointestinal microbiome and the role of microbiota on the conversion of its constituents are still largely unexplored. This study employed an experimental ex vivo model to investigate STW 5's differential effects on fecal microbial communities and metabolite production in samples from individuals with and without IBS. Using 560 fecal microcosms (IBS patients, n = 6; healthy controls, n = 10), we evaluated the influence of pre-digested STW 5 and controls on microbial and metabolite composition at time points 0, 0.5, 4, and 24 h. Our findings demonstrate the potential of this ex vivo platform to analyze herbal medicine turnover within 4 h with minimal microbiome shifts due to abiotic factors. While only minor taxonomic disparities were noted between IBS- and non-IBS samples and upon treatment with STW 5, rapid metabolic turnover of STW 5 components into specific degradation products, such as 18β-glycyrrhetinic acid, davidigenin, herniarin, 3-(3-hydroxyphenyl)propanoic acid, and 3-(2-hydroxy-4-methoxyphenyl)propanoic acid occurred. For davidigenin, 3-(3-hydroxyphenyl)propanoic acid and 18β-glycyrrhetinic acid, anti-inflammatory, cytoprotective, or spasmolytic activities have been previously described. Notably, the microbiome-driven metabolic transformation did not induce a global microbiome shift, and the detected metabolites were minimally linked to specific taxa. Observed biotransformations were independent of IBS diagnosis, suggesting potential benefits for IBS patients from biotransformation products of STW 5.

IMPORTANCE

STW 5 is an herbal medicinal product with proven clinical efficacy in the treatment of functional gastrointestinal disorders, like functional dyspepsia and irritable bowel syndrome (IBS). The effects of STW 5 on fecal microbial communities and metabolite production effects have been studied in an experimental model with fecal samples from individuals with and without IBS. While only minor taxonomic disparities were noted between IBS- and non-IBS samples and upon treatment with STW 5, rapid metabolic turnover of STW 5 components into specific degradation products with reported anti-inflammatory, cytoprotective, or spasmolytic activities was observed, which may be relevant for the pharmacological activity of STW 5.

Exploring the Gut Microbiome's Role in Inflammatory Bowel Disease: Insights and Interventions

Inflammatory Bowel Disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), is a chronic and relapsing inflammatory condition of the intestine that significantly impairs quality of life and imposes a heavy burden on healthcare systems globally. While the exact etiology of IBD is unclear, it is influenced by genetic, environmental, immunological, and microbial factors. Recent advances highlight the gut microbiome's pivotal role in IBD pathogenesis. The microbial dysbiosis characteristic of IBD, marked by a decline in beneficial bacteria and an increase in pathogenic microbes, suggests a profound connection between microbial imbalance and disease mechanisms. This review explores diagnostic approaches to IBD that integrate clinical assessment with advanced microbiological analyses, highlighting the potential of microbiome profiling as a non-invasive diagnostic tool. In addition, it evaluates conventional and emerging treatments and discusses microbiome-targeted intervention prospects, such as probiotics, symbiotics, and faecal microbiota transplantation. The necessity for future research to establish their efficacy and safety is emphasised.

Combined Nutrition with Exercise: Fueling the Fight Against Sarcopenia Through a Bibliometric Analysis and Review

Objective

This bibliometric analysis and review aimed to examine the current research status and trends in the combination of nutrition and exercise training for sarcopenia. Additionally, it sought to provide researchers with future research directions in this field.

Methods

Relevant publications were obtained from the Web of Science Core Collection (WoSCC) database, covering the period from January 1995 to October 2023. The collected publications were analyzed using CiteSpace, VOSviewer, Bibliometrix, and Review Manager.

Results

Out of the 2528 retrieved publications, the United States emerged as the leading contributor in terms of publication volume. The University of Texas System was identified as the most productive institution. Luc J C van Loon emerged as the most published author in this field. Analysis of keywords revealed recent hot topics and emerging areas of interest, such as "gut microbiota" and "mechanisms". Upon further evaluation, resistance training (RT) and protein supplementation were identified as the most commonly employed and effective methods.

Conclusion

RT and protein supplementation are widely recognized as effective strategies. Future research should focus on investigating the molecular aspects of sarcopenia. Moreover, the potential therapeutic role of gut microbiota in sarcopenia requires further comprehensive investigation in human subjects to establish its correlation.

Long-term Bisphenol S exposure induced gut microbiota dysbiosis, obesity, hepatic lipid accumulation, intestinal lesions and dyslipidemia in mice

Bisphenol S (BPS) is a commonly detected chemical raw material in water, which poses significant threats to both the ecological environment and human health. Despite being recognized as a typical endocrine disruptor and a substitute for Bisphenol A, the toxicological effects of BPS remain nonnegligible. In order to comprehensively understand the health impacts of BPS, a long-term (154 days) exposure experiment was conducted on mice, during which the physiological indicators of the liver, intestine, and blood were observed. The findings revealed that exposure to BPS resulted in dysbiosis of the gut microbiota, obesity, hepatic lipid accumulation, intestinal lesions, and dyslipidemia. Furthermore, there exists a significant correlation between gut microbiota and indicators of host health. Consequently, the identification of specific gut microbiota can be considered as potential biomarkers for the evaluation of risk associated with BPS. This study will effectively address the deficiency in toxicological data pertaining to BPS. The novel BPS data obtained from this research can serve as a valuable reference for professionals in the field.

Enterotype-Dependent Probiotic-Mediated Changes in the Male Rat Intestinal Microbiome In Vivo and In Vitro

Beneficial properties of lactic acid bacteria have been known long ago, but particular interest in probiotics has arisen in the last two decades due to the understanding of the important role of intestinal microflora in human life. Thus, the ability of probiotics to support healthy homeostasis of gut microbiomes has received particular attention. Here, we evaluated the effect of a probiotic consisting of Bifidobacterium longum and Lacticaseibacillus paracasei on the gut microbiome of male rats, assessed their persistence in the fecal biota, and compared probiotic-mediated changes in vitro and in vivo. As expected, microbiomes of two enterotypes were identified in the feces of 21 animals, and it turned out that even a single dose of the probiotic altered the microbial composition. Upon repeated administration, the E1 biota temporarily acquired properties of the E2 type. Being highly sensitive to the intervention of probiotic bacteria at the phylum and genus levels, the fecal microbiomes retained the identity of their enterotypes when transferred to a medium optimized for gut bacteria. For the E2 biota, even similarities between probiotic-mediated reactions in vitro and in vivo were detected. Therefore, fecal-derived microbial communities are proposed as model consortia to optimize the response of resident bacteria to various agents.

Genetically supported causality between gut microbiota and frailty: a two-sample Mendelian randomization study

Background

A mounting body of evidence suggests a strong connection between gut microbiota and the risk of frailty. However, the question of causality remains unanswered. In this study, we employed a Mendelian randomization (MR) approach to assess potential causal relationships between gut microbiota and the risk of frailty.

Materials and methods

Summary statistics for the gut microbiome were obtained from a genome wide association study (GWAS) meta-analysis of the MiBioGen consortium (N = 18,340). Summary statistics for frailty were obtained from a GWAS meta-analysis, including the UK Biobank and TwinGene (N = 175,226). Our primary analysis utilized the inverse variance weighted (IVW) method. To enhance the robustness of our results, we also applied weighted median methods, MR Egger regression, and MR pleiotropy residual sum and outlier test. Finally, we conducted reverse MR analysis to investigate the potential for reverse causality.

Results

IVW method identified 7 bacterial taxa nominally associated with the risk of FI. Class Bacteroidia (p = 0.033) and genus Eubacterium ruminantium group (p = 0.028) were protective against FI. In addition, class Betaproteobacteria (p = 0.042), genus Allisonella (p = 0.012), genus Bifidobacterium (p = 0.013), genus Clostridium innocuum group (p = 0.036) and genus Eubacterium coprostanoligenes group (p = 0.003) were associated with a higher risk of FI. No pleiotropy or heterogeneity were found.

Conclusion

The MR analysis indicates a causal relationship between specific gut microbiota and FI, offering new insights into the mechanisms underlying FI mediated by gut microbiota.

Meta-analysis of the Microbial Diversity Cultured in Bioreactors Simulating the Gut Microbiome

Understanding the intricate ecological interactions within the gut microbiome and unravelling its impact on human health is a challenging task. Bioreactors are valuable tools that have contributed to our understanding of gut microbial ecology. However, there is a lack of studies describing and comparing the microbial diversity cultivated in these models. This knowledge is crucial for refining current models to reflect the gastrointestinal microbiome accurately. In this study, we analysed the microbial diversity of 1512 samples from 18 studies available in public repositories that employed cultures performed in batches and various bioreactor models to cultivate faecal microbiota. Community structure comparison between samples using t-distributed stochastic neighbour embedding and the Hellinger distance revealed a high variation between projects. The main driver of these differences was the inter-individual variation between the donor faecal inocula. Moreover, there was no overlap in the structure of the microbial communities between studies using the same bioreactor platform. In addition, α-diversity analysis using Hill numbers showed that highly complex bioreactors did not exhibit higher diversities than simpler designs. However, analyses of five projects in which the samples from the faecal inoculum were also provided revealed an amplicon sequence variants enrichment in bioreactors compared to the inoculum. Finally, a comparative analysis of the taxonomy of the families detected in the projects and the GMRepo database revealed bacterial families exclusively found in the bioreactor models. These findings highlight the potential of bioreactors to enrich low-abundance microorganisms from faecal samples, contributing to uncovering the gut microbial "dark matter".

Effect of aerobic exercise and particulate matter exposure duration on the diversity of gut microbiota

Inhalation of ambient particulate matter (PM) can disrupt the gut microbiome, while exercise independently influences the gut microbiome by promoting beneficial bacteria. In this study, we analyzed changes in gut microbial diversity and composition in response to combined interventions of PM exposure and aerobic exercise, extending up to 12 weeks. This investigation was conducted using mice, categorized into five groups: control group (Con), exercise group (EXE), exercise group followed by 3-day exposure to PM (EXE + 3-day PM), particulate matter exposure (PM), and PM exposure with concurrent treadmill exercise (PME). Notably, the PM group exhibited markedly lower alpha diversity and richness compared to the Con group and our analysis of beta diversity revealed significant variations among the intervention groups. Members of the Lachnospiraceae family showed significant enhancement in the exercise intervention groups (EXE and PME) compared to the Con and PM groups. The biomarker Lactobacillus, Coriobacteraceae, and Anaerofustis were enriched in the EXE group, while Desulfovibrionaceae, Mucispirillum schaedleri, Lactococcus and Anaeroplasma were highly enriched in the PM group. Differential abundance analysis revealed that Paraprevotella, Bacteroides, and Blautia were less abundant in the 12-week PM exposure group than in the 3-day PM exposure group. Moreover, both the 3-day and 12-week PM exposure groups exhibited a reduced relative abundance of Bacteroides uniformis, SMB53, and Staphylococcus compared to non-PM exposure groups. These findings will help delineate the possible roles and associations of altered microbiota resulting from the studied interventions, paving the way for future mechanistic research.

Exploring the gut microbiota and its potential as a biomarker in gliomas

Gut microbiome alterations are associated with various cancers including brain tumours such as glioma and glioblastoma. The gut communicates with the brain via a bidirectional pathway known as the gut-brain axis (GBA) which is essential for maintaining homeostasis. The gut microbiota produces many metabolites including short chain fatty acids (SCFAs) and essential amino acids such as glutamate, glutamine, arginine and tryptophan. Through the modulation of these metabolites the gut microbiome is able to regulate several functions of brain cells, immune cells and tumour cells including DNA methylation, mitochondrial function, the aryl hydrocarbon receptor (AhR), T-cell proliferation, autophagy and even apoptosis. Here, we summarise current findings on gut microbiome with respect to brain cancers, an area of research that is widely overlooked. Several studies investigated the relationship between gut microbiota and brain tumours. However, it remains unclear whether the gut microbiome variation is a cause or product of cancer. Subsequently, a biomarker panel was constructed for use as a predictive, prognostic and diagnostic tool with respect to multiple cancers including glioma and glioblastoma multiforme (GBM). This review further presents the intratumoural microbiome, a fascinating microenvironment within the tumour as a possible treatment target that can be manipulated to maximise effectiveness of treatment via personalised therapy. Studies utilising the microbiome as a biomarker and therapeutic strategy are necessary to accurately assess the effectiveness of the gut microbiome as a clinical tool with respect to brain cancers.

Stability of gut microbiome after COVID-19 vaccination in healthy and immuno-compromised individuals

Bidirectional interactions between the immune system and the gut microbiota are key contributors to various physiological functions. Immune-associated diseases such as cancer and autoimmunity, and efficacy of immunomodulatory therapies, have been linked to microbiome variation. Although COVID-19 infection has been shown to cause microbial dysbiosis, it remains understudied whether the inflammatory response associated with vaccination also impacts the microbiota. Here, we investigate the temporal impact of COVID-19 vaccination on the gut microbiome in healthy and immuno-compromised individuals; the latter included patients with primary immunodeficiency and cancer patients on immunomodulating therapies. We find that the gut microbiome remained remarkably stable post-vaccination irrespective of diverse immune status, vaccine response, and microbial composition spanned by the cohort. The stability is evident at all evaluated levels including diversity, phylum, species, and functional capacity. Our results indicate the resilience of the gut microbiome to host immune changes triggered by COVID-19 vaccination and suggest minimal, if any, impact on microbiome-mediated processes. These findings encourage vaccine acceptance, particularly when contrasted with the significant microbiome shifts observed during COVID-19 infection.

The potential of short-chain fatty acid epigenetic regulation in chronic low-grade inflammation and obesity

Obesity and chronic low-grade inflammation, often occurring together, significantly contribute to severe metabolic and inflammatory conditions like type 2 diabetes (T2D), cardiovascular disease (CVD), and cancer. A key player is elevated levels of gut dysbiosis-associated lipopolysaccharide (LPS), which disrupts metabolic and immune signaling leading to metabolic endotoxemia, while short-chain fatty acids (SCFAs) beneficially regulate these processes during homeostasis. SCFAs not only safeguard the gut barrier but also exert metabolic and immunomodulatory effects via G protein-coupled receptor binding and epigenetic regulation. SCFAs are emerging as potential agents to counteract dysbiosis-induced epigenetic changes, specifically targeting metabolic and inflammatory genes through DNA methylation, histone acetylation, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). To assess whether SCFAs can effectively interrupt the detrimental cascade of obesity and inflammation, this review aims to provide a comprehensive overview of the current evidence for their clinical application. The review emphasizes factors influencing SCFA production, the intricate connections between metabolism, the immune system, and the gut microbiome, and the epigenetic mechanisms regulated by SCFAs that impact metabolism and the immune system.

Time-dependent impact of a high-fat diet on the intestinal barrier of male mice

BACKGROUND

Excessive saturated fat intake compromises the integrity of the intestinal mucosa, leading to low-grade inflammation, impaired mucosal integrity, and increased intestinal permeability, resulting in the migration of lipopolysaccharide (LPS) to other tissues.

AIM

To evaluate the chronic effects (at 10 and 16 wk) of a high-fat diet (HFD) (with 50% energy as fat) on the phylogenetic gut microbiota distribution and intestinal barrier structure and protection in C57BL/6 mice.

METHODS

Forty adult male mice were divided into four nutritional groups, where the letters refer to the type of diet (control and HFD or HF) and the numbers refer to the period (in weeks) of diet administration: Control diet for 10 wk, HFD for 10 wk, control diet for 16 wk, and HFD for 16 wk. After sacrifice, biochemical, molecular, and stereological analyses were performed.

RESULTS

The HF groups were overweight, had gut dysbiosis, had a progressive decrease in occludin immunostaining, and had increased LPS concentrations. Dietary progression reduced the number of goblet cells per large intestine area and Mucin2 expression in the HF16 group, consistent with a completely disarranged intestinal ultrastructure after 16 wk of HFD intake.

CONCLUSION

Chronic HFD intake causes overweight, gut dysbiosis, and morphological and functional alterations of the intestinal barrier after 10 or 16 wk. Time-dependent reductions in goblet cell numerical density and mucus production have emerged as targets for countering obesity-driven intestinal damage.

The Interplay between Gut Microbiota and Cognitive Functioning in the Healthy Aging Population: A Systematic Review

BACKGROUND

The gut microbiota in healthy older individuals typically show a decrease in beneficial bacteria like Bifidobacterium and Lactobacillus, alongside an increase in pro-inflammatory microbes such as Enterobacteriaceae and Clostridia. These changes contrast with younger and middle-aged individuals and appear to correlate with cognitive status. Although there is extensive research on gut microbiota and cognitive functions in cognitively impaired elderly individuals, its impact on cognitively healthy elderly populations has not been extensively studied.

METHOD

A comprehensive literature search was conducted across PubMed, EBSCO, Web of Science, and Scopus databases to identify studies exploring the relationship between gut microbiota composition and cognitive functioning in healthy older adults. During the literature screening process, each record was initially assessed by its title, abstract, and keywords to exclude articles that did not align with the scope of this review. Three authors independently screened and retrieved the records. The inclusion criteria included: (1) publication in peer-reviewed journals; (2) studies involving neurologically, cognitively, and medically healthy populations; (3) participants identified as older adults, defined for this review as individuals aged 45 years and older due to the limited number of records; (4) analysis of gut microbiota; and (5) assessment of cognitive function. Subsequently, full texts were analyzed to determine eligibility. The exclusion criteria encompassed: (1) incorrect publication type; (2) inappropriate sample population; (3) unsuitable study design; (4) absence of one or more inclusion criteria; and (5) studies based on animal research. A risk of bias assessment was performed for each included study using the Joanna Briggs Institute (JBI) checklist, ensuring all selected studies met established quality standards.

RESULTS

A total of 6 eligible research articles from a possible 1752 published until March 2024 were identified and included. We categorized the included studies into two groups based on their focus: the taxonomic composition of gut microbiota and the alpha diversity, which is the variety of organisms within a sample. Additionally, two methods were identified for assessing cognition: neuropsychological tests and physiological measurements, notably electroencephalography (EEG). The studies show varying results regarding the abundance of specific bacterial taxa and their cognitive associations. Notably, the relationship between certain bacteria and cognition may vary when analyzed at different taxonomic levels, such as phylum versus family.

CONCLUSIONS

Changes in gut microbiota composition in the elderly, even without a cognitive impairment diagnosis, could potentially serve as early biological markers for Alzheimer's disease or other dementias before mild cognitive impairment appears.

Gut microbial network signatures of early colonizers in preterm neonates with extrauterine growth restriction

BACKGROUND

Extrauterine growth restriction (EUGR) represents a prevalent condition observed in preterm neonates, which poses potential adverse implications for both neonatal development and long-term health outcomes. The manifestation of EUGR has been intricately associated with perturbations in microbial and metabolic profiles. This study aimed to investigate the characteristics of the gut microbial network in early colonizers among preterm neonates with EUGR.

METHODS

Twenty-nine preterm infants participated in this study, comprising 14 subjects in the EUGR group and 15 in the normal growth (AGA) group. Meconium (D1) and fecal samples were collected at postnatal day 28 (D28) and 1 month after discharge (M1). Subsequently, total bacterial DNA was extracted and sequenced using the Illumina MiSeq system, targeting the V3-V4 hyper-variable regions of the 16S rRNA gene.

RESULTS

The outcomes of principal coordinates analysis (PCoA) and examination of the microbial network structure revealed distinctive developmental trajectories in the gut microbiome during the initial three months of life among preterm neonates with and without EUGR. Significant differences in microbial community were observed at the D1 (P = 0.039) and M1 phases (P = 0.036) between the EUGR and AGA groups, while a comparable microbial community was noted at the D28 phase (P = 0.414). Moreover, relative to the AGA group, the EUGR group exhibited significantly lower relative abundances of bacteria associated with secretion of short-chain fatty acids, including Lactobacillus (P = 0.041) and Parabacteroides (P = 0.033) at the D1 phase, Bifidobacterium at the D28 phase, and genera Dysgonomonas (P = 0.042), Dialister (P = 0.02), Dorea (P = 0.042), and Fusobacterium (P = 0.017) at the M1 phase.

CONCLUSION

Overall, the present findings offer crucial important insights into the distinctive gut microbial signatures exhibited by earlier colonizers in preterm neonates with EUGR. Further mechanistic studies are needed to establish whether these differences are the cause or a consequence of EUGR.

Role of the Gut Microbiome and Bacterial Amyloids in the Development of Synucleinopathies

Less than ten years ago, evidence began to accumulate about association between the changes in the composition of gut microbiota and development of human synucleinopathies, in particular sporadic form of Parkinson's disease. We collected data from more than one hundred and thirty experimental studies that reported similar results and summarized the frequencies of detection of different groups of bacteria in these studies. It is important to note that it is extremely rare that a unidirectional change in the population of one or another group of microorganisms (only an elevation or only a reduction) was detected in the patients with Parkinson's disease. However, we were able to identify several groups of bacteria that were overrepresented in the patients with Parkinson's disease in the analyzed studies. There are various hypotheses about the molecular mechanisms that explain such relationships. Usually, α-synuclein aggregation is associated with the development of inflammatory processes that occur in response to the changes in the microbiome. However, experimental evidence is accumulating on the influence of bacterial proteins, including amyloids (curli), as well as various metabolites, on the α-synuclein aggregation. In the review, we provided up-to-date information about such examples.

Effects of Supplementation with Oregano Essential Oil during Late Gestation and Lactation on Serum Metabolites, Antioxidant Capacity and Fecal Microbiota of Sows

A total of 20 healthy white × landrace sows were evenly and randomly divided into two groups, and fed basal diets unsupplemented or supplemented with 500 g/t Meriden-Stim® from day 100 of gestation until day 21 of lactation. Serum and fecal samples were collected from the sows on the final day for subsequent analysis. Compared to the control group, there were no significant differences in the sows' performances; however, an increase was observed in the piglets' weight at weaning (p = 0.08). Moreover, oregano essential oil (OEO) significantly reduced the levels of urea (UREA) (p < 0.01), total cholesterol (TC) (p < 0.05), low-density lipoprotein (LDL-C) (p < 0.05) and alanine aminotransferase (ALT) (p < 0.05) in serum. In terms of antioxidant indexes in serum, the catalase (CAT) and glutathione (GSH) levels showed significant increases (p < 0.05) while the malondialdehyde (MDA) level exhibited a decrease tendency (p = 0.09). 16S rRNA analysis identified the specific bacteria taxa in feces. OEO significantly decreased the relative abundance of Proteobacteria and Actinobacteria at the phylum level (p < 0.05). At the genus level, OEO significantly increased the relative abundance of Lactobacillus and Prevotellaceae UCG 003 and UCG 005, while decreasing that of Escherichia-Shigella (p < 0.05). Taken together, OEO supplementation in maternal diets during late gestation and lactation improved serum metabolites, antioxidant capacity and regulated the intestinal-flora balance of sows, thereby tending to increase the piglets' weight at weaning.

Impact of the diet in the gut microbiota after an inter-species microbial transplantation in fish

Inter-species microbial transplantations offer the possibility of transferring species-specific microbes and their associated functionality. As a conceptual approach, an intestinal microbiota transplant (IMT) between two marine carnivorous fish species that thrive in different environmental conditions was conducted: from donor Atlantic salmon (Salmo salar) to recipient gilthead seabream (Sparus aurata), after obliterating its basal microbiota with an antibiotic treatment. To confirm that the gut microbiota was able to recover after antibiotics without the influence of the diet, a group of gilthead seabream not submitted to the IMT was kept fasted as an internal control. To assess the effect of the diet after the IMT, two groups of gilthead seabream were respectively fed with their typical diet and with Atlantic salmon diet. At 36 days post-IMT, the gut of the individuals fed with their typical diet was dominated by the feed-associated bacteria, while those fed with the salmon diet had developed a unique microbiota from the convergence of the diet, donor, and recipient microbiota. These results suggested that an intestinal microbiota transplantation may be effective if the basal microbiota from the gut is first cleared and a targeted dietary modification is provided to maintain and enrich the novel bacteria species over time.

Dysbiosis of the gut microbiota and its effect on α-synuclein and prion protein misfolding: consequences for neurodegeneration

Abnormal behavior of α-synuclein and prion proteins is the hallmark of Parkinson's disease (PD) and prion illnesses, respectively, being complex neurological disorders. A primary cause of protein aggregation, brain injury, and cognitive loss in prion illnesses is the misfolding of normal cellular prion proteins (PrPC) into an infectious form (PrPSc). Aggregation of α-synuclein causes disruptions in cellular processes in Parkinson's disease (PD), leading to loss of dopamine-producing neurons and motor symptoms. Alteration in the composition or activity of gut microbes may weaken the intestinal barrier and make it possible for prions to go from the gut to the brain. The gut-brain axis is linked to neuroinflammation; the metabolites produced by the gut microbiota affect the aggregation of α-synuclein, regulate inflammation and immunological responses, and may influence the course of the disease and neurotoxicity of proteins, even if their primary targets are distinct proteins. This thorough analysis explores the complex interactions that exist between the gut microbiota and neurodegenerative illnesses, particularly Parkinson's disease (PD) and prion disorders. The involvement of the gut microbiota, a complex collection of bacteria, archaea, fungi, viruses etc., in various neurological illnesses is becoming increasingly recognized. The gut microbiome influences neuroinflammation, neurotransmitter synthesis, mitochondrial function, and intestinal barrier integrity through the gut-brain axis, which contributes to the development and progression of disease. The review delves into the molecular mechanisms that underlie these relationships, emphasizing the effects of microbial metabolites such as bacterial lipopolysaccharides (LPS), and short-chain fatty acids (SCFAs) in regulating brain functioning. Additionally, it looks at how environmental influences and dietary decisions affect the gut microbiome and whether they could be risk factors for neurodegenerative illnesses. This study concludes by highlighting the critical role that the gut microbiota plays in the development of Parkinson's disease (PD) and prion disease. It also provides a promising direction for future research and possible treatment approaches. People afflicted by these difficult ailments may find hope in new preventive and therapeutic approaches if the role of the gut microbiota in these diseases is better understood.

Intestinal Dysbiosis in Subjects with Obesity from Western Mexico and Its Association with a Proinflammatory Profile and Disturbances of Folate (B9) and Carbohydrate Metabolism

Obesity is a public health problem with a growing prevalence worldwide. In Mexico, it is estimated that one out of three adults suffer from obesity. In these patients, the intestinal microbiota (IM) undergoes pathological changes that are associated with a dysbiotic state; however, the microbiota profile of adult subjects with obesity from western Mexico has not been described. To assess this, fecal samples were obtained from 65 participants (Obese = 38; Control = 27). The microbial composition was characterized by 16S rRNA amplicon sequencing. The IM of the group with obesity revealed a clear decrease in richness and diversity (p < 0.001), as well as a significant increase in proinflammatory bacterial groups, mainly genera belonging to the Negativicutes class, Escherichia/Shigella, and Prevotella. Likewise, an increase in short-chain fatty acid-producing bacteria was found, especially the genus Lachnoclostridium. Additionally, PICRUSt2 analysis showed a depletion of vitamin B9 metabolism and an increase in saccharolytic pathways. The IM of patients with obesity possesses a dysbiotic, proinflammatory environment, possibly contributing to lipogenesis and adiposity. Thus, assessing the IM will allow for a better understanding of the pathophysiology of metabolic diseases of high prevalence, such as obesity. These findings are described for the first time in the adult population of western Mexico.

Bacterial Biofilm in Chronic Wounds and Possible Therapeutic Approaches

Wound repair and skin regeneration is a very complex orchestrated process that is generally composed of four phases: hemostasis, inflammation, proliferation, and remodeling. Each phase involves the activation of different cells and the production of various cytokines, chemokines, and other inflammatory mediators affecting the immune response. The microbial skin composition plays an important role in wound healing. Indeed, skin commensals are essential in the maintenance of the epidermal barrier function, regulation of the host immune response, and protection from invading pathogenic microorganisms. Chronic wounds are common and are considered a major public health problem due to their difficult-to-treat features and their frequent association with challenging chronic infections. These infections can be very tough to manage due to the ability of some bacteria to produce multicellular structures encapsulated into a matrix called biofilms. The bacterial species contained in the biofilm are often different, as is their capability to influence the healing of chronic wounds. Biofilms are, in fact, often tolerant and resistant to antibiotics and antiseptics, leading to the failure of treatment. For these reasons, biofilms impede appropriate treatment and, consequently, prolong the wound healing period. Hence, there is an urgent necessity to deepen the knowledge of the pathophysiology of delayed wound healing and to develop more effective therapeutic approaches able to restore tissue damage. This work covers the wound-healing process and the pathogenesis of chronic wounds infected by biofilm-forming pathogens. An overview of the strategies to counteract biofilm formation or to destroy existing biofilms is also provided.

A discovery of potent kaempferol derivatives as multi-target medicines against diabetes as well as bacterial infections: an in silico approach

Flavonoids demonstrate beneficial effects on human health because flavonoids contain important biological properties. Kaempferol is a flavonol, type of flavonoid found in eatable plants and in plants usually employed in ancient drugs (Moringa oleifera, Tilia spp., fern genus spp. and gingko etc.). Some medicinal studies have shown that the use of foods full of kaempferol decreases the risk of many (cancer, vascular) diseases. All the data of 50 kaempferol derivatives were collected from PubChem database. Through Schrödinger software, 3D-QSAR study was performed for 50 compounds by using method of field base. Conformer of kaempferol derivatives was docked against anti-diabetic, anti-microbial co-crystal structures and protein. To monitor the best anti-diabetic and antibacterial agent, particular kaempferol derivatives were downloaded from PubChem database. Virtual screening by molecular docking provided four lead compounds with four different proteins. These hit compounds were found to be potent inhibitor for diabetic enzymes alpha-amylase and DPP IV and had the potential to suppress DNA gyrase and dihydrofolate reductase synthesis. Molecular dynamic simulation of docked complexes evaluates the value of root mean square fluctuation by iMOD server. Kaempferol 3-O-alpha-L-(2, 3-di-Z-p-coumaroyl) rhamnoside (42) compound used as anti-diabetic and kaempferol 3-O-gentiobioside (3) as antibacterial with good results can be used for drug discovery.Communicated by Ramaswamy H. Sarma.

Sleep deprivation alters pubertal timing in humans and rats: the role of the gut microbiome

STUDY OBJECTIVES

Evidence implied that sleeping duration is associated with the timing of puberty and that sleep deprivation triggers early pubertal onset in adolescents. Sleep deprivation can affect metabolic changes and gut microbiota composition. This study investigated the effects of sleep deprivation on pubertal onset and gut microbiota composition in animal models and a human cohort.

METHODS

This study comprised 459 boys and 959 girls from the Taiwan Pubertal Longitudinal Study. Sleep duration was evaluated using the self-report Pittsburgh Sleep Quality Index questionnaire. Early sexual maturation was defined by pediatric endocrinologist assessments. Mediation analyses were done to examine the association between sleep parameters, obesity, and early sexual maturation. Besides, Sprague Dawley juvenile rats were exposed to 4 weeks of chronic sleep deprivation. Vaginal opening (VO) and preputial separation (PS) were observed every morning to determine pubertal onset in female and male rats.

RESULTS

The sleep-deprived juvenile rats in the sleep-deprived-female (SDF) and sleep-deprived-male (SDM) groups experienced delayed VO (mean VO days: 33 days in control; 35 days in SDF; p-value < 0.05) and PS (mean PS days: 42 days in control; 45 days in SDM; p-value < 0.05), respectively. Relative to their non-sleep-deprived counterparts, the sleep-deprived juvenile rats exhibited lower body weight and body fat percentage. Significant differences in relative bacterial abundance at genus levels and decreased fecal short-chain-fatty-acid levels were identified in both the SDF and SDM groups. In the human cohort, insufficient sleep increased the risk of early sexual maturation, particularly in girls (OR, 1.44; 95% CI: 1.09 to 1.89; p-value < 0.01). Insufficient sleep also indirectly affected early sexual maturation in girls, with obesity serving as the mediator.

CONCLUSIONS

Overall, sleep deprivation altered the timing of puberty in both animal and human models but in different directions. In the rat model, sleep deprivation delayed the pubertal onset in juvenile rats through gut dysbiosis and metabolic changes, leading to a low body weight and body fat percentage. In the human model, sleep deprivation led to fat accumulation, causing obesity in girls, which increased the risk of early puberty.

Influence of pancreaticoduodenectomy for periampullary carcinoma on intestinal microbiome and metabolites

Recent growing evidence suggests a role for intestinal microbiome and metabolites in patients' postoperative recovery. Therefore, there is a need to gain insight into the impact of pancreaticoduodenectomy for periampullary carcinoma on microbiome and metabolites and the potential impact of their changes on patients' condition. Based on 16S rDNA gene sequencing and untargeted metabolomic analysis, we found that the diversity and abundance of intestinal microbiome were significantly higher in patients preoperatively than postoperatively, and the level of intestinal probiotics was significantly lower after surgery compared with preoperatively. In addition, the choline metabolism level was increased and the amino acid metabolism level was decreased after surgery. A total of 53 differential microbiome and 52 differential metabolites were detected, and the differential metabolites were mapped to approximately 60 different KEGG metabolic pathways, of which 13 KEGG metabolic pathways had a differential metabolite number greater than 5. A total of 88 colony-metabolite pairs with significant positive correlation and 69 colony-metabolite pairs with significant negative correlation were identified. Our results reveal alterations in intestinal microbiome after pancreaticoduodenectomy, suggesting its association with postoperative complications. Moreover, the elevated choline metabolism level in postoperative patients may predict their poorer prognosis. At the same time, the decreased abundance of such probiotic bacteria as Prevotella spp. in the postoperative intestine of patients will affect the amino acid metabolism of the organism to some extent.

Effects of simulated winter short photoperiods on the microbiome and intestinal metabolism in Huanghe carp (Cyprinus carpio haematopterus)

Objective

As one of the most important environmental signals, photoperiod plays a crucial role in regulating the growth, metabolism, and survival of organisms. The photoperiod shifts with the transition of the seasons. The difference in photoperiod between summer and winter is the greatest under natural conditions. However, the effect of photoperiod on Huanghe carp (Cyprinus carpio haematopterus) was paid little attention. We investigated the impact of artificial manipulation of seasonal photoperiod on Huanghe carp by integrating growth performance, intestinal flora, and intestinal metabolome.

Method

We conducted an 8-week culture experiment with summer photoperiod (14 h light:10 h dark, n = 60) as the control group and winter photoperiod (10 h light:14 h dark, n = 60) based on the natural laws.

Results

Winter photoperiod provokes significant weight increases in Huanghe carp. The altered photoperiod contributed to a significant increase in triglyceride and low-density lipoprotein cholesterol levels and the gene expressions of lipid metabolism in the intestine of Huanghe carp. 16s rDNA sequencing revealed that winter photoperiod diminished intestinal flora diversity and altered the abundance. Specifically, the relative abundances of Fusobacteria and Acidobacteriota phyla were higher but Proteobacteria, Firmicutes, and Bacteroidetes phyla were reduced. Analogously, photoperiodic changes induced a significant reduction in the Pseudomonas, Vibrio, Ralstonia, Acinetobacter, and Pseudoalteromonas at the genus level. Additionally, metabolomics analysis showed more than 50% of differential metabolites were associated with phospholipids and inflammation. Microbiome and metabolome correlation analyses revealed that intestinal microbe mediated lipid metabolism alteration.

Conclusion

The winter photoperiod induced intestinal flora imbalance and lipid metabolism modification, ultimately affecting the growth of Huanghe carp. This study provides new insights into the effects of seasonal photoperiodic alteration on the well-being of fish.

Modulation of the Altered Intestinal Microbiota by Use of Antibiotics with a Novel Synbiotic on Wistar Rats

The use of antibiotics unbalances the intestinal microbiota. Probiotics, prebiotics, and synbiotics are alternatives for these unbalances. The effects of a new synbiotic composed of probiotic Saccharomyces boulardii CNCM I-745 and fructans from Agave salmiana (fAs) as prebiotics were assessed to modulate the intestinal microbiota. Two probiotic presentations, the commercial probiotic (CP) and the microencapsulated probiotic (MP) to improve those effects, were used to prepare the synbiotics and feed Wistar rats subjected to antibiotics (AB). Eight groups were studied, including five controls and three groups to modulate the microbiota after the use of antibiotics: G5: AB + MP-synbiotic, G6: AB + CP-synbiotic, and G8: AB + fAs. All treatments were administered daily for 7 days. On days 7 and 21, euthanasia was performed, cecum tissue was recovered and used to evaluate histological analysis and to study microphotograph by TEM, and finally, bacterial DNA was extracted and 16S rRNA gene metabarcode sequencing was performed. Histological analysis showed less epithelial damage and more abundance of the intestinal microbiota in the groups G5, G6, and G8 in comparison with the AB control group after 7 days. Microphotograph of the cecum at 2 weeks post treatment showed that G5 and G6 presented beneficial effects in epithelial reconstruction. Interestingly, in the groups that used the synbiotic without AB (G3 and G4) in addition to contributing to the recovery of the autochthonous microbiota, it promotes the development of beneficial microorganisms; those results were also achieved in the groups that used the synbiotic with AB enhancing the bacterial diversity and regulating the impact of AB.

A single dietary factor, daily consumption of a fermented beverage, can modulate the gut bacteria and fecal metabolites within the same ethnic community

IMPORTANCE

Our study investigated how a traditional drink called Apong, made from fermented rice, affects the gut and health of the Mishing community in India. We compared two groups of people who drink Apong to a group of people who do not drink it. To accomplish this, we studied the gut bacteria, fecal metabolites, and blood samples of the participants. It was found that the people who drank Apong had higher blood pressure but lower blood sugar and protein levels than people who did not drink it. We also found that the gut microbiome composition of people who drank Apong was different from those who did not drink it. Moreover, people who drank Apong had lower levels of isovaleric acid in their feces. Overall, this study shows that a traditional drink like Apong can affect the gut bacteria of a community.

Development of Microrobot with Optical Magnetic Dual Control for Regulation of Gut Microbiota

Microrobots have emerged as a promising precision therapy approach that has been widely used in minimally invasive treatments, targeted drug delivery, and wound cleansing, and they also offer a potential new method for actively modulating gut microbiota. Here, a double-faced microrobot was designed to carry gut bacteria via covalently immobilizing the antibodies, and a corresponding integrated optical and magnetic dual-driving control system was also developed for precise control of the microrobot. The microrobot utilizes magnetic microsphere as its core, with one side coated in gold, which serves as the optical receptor surface and the interface for bacterial attachment. The specific gut bacterium, S. cerevisiae, was immobilized on the gold-coated side using the corresponding antibodies. The dual-driving control system enables the precise modulation of gut bacteria by synergistically manipulating the microrobots' movement via the optical field and magnetic field. The feasibility of independent and coordinated control using optical fields and magnetic fields was validated through experimental and numerical simulation approaches. This work introduces a novel method for the precise modulation of gut microbiota, providing a new avenue for disease treatments based on gut bacteria.

Gut-Brain Axis Deregulation and Its Possible Contribution to Neurodegenerative Disorders

The gut-brain axis is an essential communication pathway between the central nervous system (CNS) and the gastrointestinal tract. The human microbiota is composed of a diverse and abundant microbial community that compasses more than 100 trillion microorganisms that participate in relevant physiological functions such as host nutrient metabolism, structural integrity, maintenance of the gut mucosal barrier, and immunomodulation. Recent evidence in animal models has been instrumental in demonstrating the possible role of the microbiota in neurodevelopment, neuroinflammation, and behavior. Furthermore, clinical studies suggested that adverse changes in the microbiota can be considered a susceptibility factor for neurological disorders (NDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). In this review, we will discuss evidence describing the role of gut microbes in health and disease as a relevant risk factor in the pathogenesis of neurodegenerative disorders, including AD, PD, HD, and ALS.

Dietary Inflammatory Potential in Pediatric Diseases: A Narrative Review

Inflammatory status is one of the main drivers in the development of non-communicable diseases (NCDs). Specific unhealthy dietary patterns and the growing consumption of ultra-processed foods (UPFs) may influence the inflammation process, which negatively modulates the gut microbiota and increases the risk of NCDs. Moreover, several chronic health conditions require special long-term dietary treatment, characterized by altered ratios of the intake of nutrients or by the consumption of disease-specific foods. In this narrative review, we aimed to collect the latest evidence on the pro-inflammatory potential of dietary patterns, foods, and nutrients in children affected by multifactorial diseases but also on the dietetic approaches used as treatment for specific diseases. Considering multifactorial diet-related diseases, the triggering effect of pro-inflammatory diets has been addressed for metabolic syndrome and inflammatory bowel diseases, and the latter for adults only. Future research is required on multiple sclerosis, type 1 diabetes, and pediatric cancer, in which the role of inflammation is emerging. For diseases requiring special diets, the role of single or multiple foods, possibly associated with inflammation, was assessed, but more studies are needed. The evidence collected highlighted the need for health professionals to consider the entire dietary pattern, providing balanced and healthy diets not only to permit the metabolic control of the disease itself, but also to prevent the development of NCDs in adolescence and adulthood. Personalized nutritional approaches, in close collaboration between the hospital, country, and families, must always be promoted together with the development of new methods for the assessment of pro-inflammatory dietary habits in pediatric age and the implementation of telemedicine.

Molecular mechanisms of alcohol's effects on the human body: A review and update

Alcohol consumption has been linked to numerous negative health outcomes although it has some beneficial effects on moderate dosages, the most severe of which being alcohol-induced hepatitis. The number of people dying from this liver illness has been shown to climb steadily over time, and its prevalence has been increasing. Researchers have found that alcohol consumption primarily affects the brain, leading to a wide range of neurological and psychological diseases. High-alcohol-consumption addicts not only experienced seizures, but also ataxia, aggression, social anxiety, and variceal hemorrhage that ultimately resulted in death, ascites, and schizophrenia. Drugs treating this liver condition are limited and can cause serious side effects like depression. Serine-threonine kinases, cAMP protein kinases, protein kinase C, ERK, RACK 1, Homer 2, and more have all been observed to have their signaling pathways disrupted by alcohol, and alcohol has also been linked to epigenetic changes. In addition, alcohol consumption induces dysbiosis by changing the composition of the microbiome found in the gastrointestinal tract. Although more studies are needed, those that have been done suggest that probiotics aid in keeping the various microbiota concentrations stable. It has been argued that reducing one's alcohol intake may seem less harmful because excessive drinking is a lifestyle disorder.

Long-term and trimester-specific effects of prenatal stress on the child gut microbiota

OBJECTIVE

Stress is common among pregnant individuals and is associated with an altered gut microbiota composition in infants. It is unknown if these compositional changes persist into the preschool years when the gut microbiota reaches an adult-like composition. This study aimed to investigate if indicators of prenatal stress (i.e., psychological distress and stress-related physiology) are associated with children's gut microbiota composition and metabolites at 3-4 years of age.

METHODS

Maternal-child pairs (n = 131) were from the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort. Each trimester, psychological distress was measured as symptoms of anxiety (Symptom Checklist-90-R) and depressed mood (Edinburgh Postnatal Depression Scale), whereas salivary cortisol was quantified as a measure of stress-related physiology. Child stool samples were collected at 3-4 years to evaluate gut microbiota composition using 16S rRNA gene sequencing and fecal metabolome using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Associations between prenatal distress and cortisol with the gut microbiota were determined using Pearson and Spearman correlations and corrected for multiple testing. Associations between prenatal distress and cortisol with the fecal metabolome were assessed using Metaboanalyst.

RESULTS

Symptoms of depressed mood during the 2nd and 3rd trimesters and anxiety during the 2nd trimester of pregnancy were associated with increased alpha diversity of the child's gut microbiota. Cortisol levels during the 1st trimester were also associated with increased Faith PD diversity (r = 0.32), whereas cortisol levels during the 2nd trimester were associated with reduced Shannon diversity (r = -0.27). Depression scores during the 2nd and 3rd trimesters were associated with reductions in the relative abundances of Eggerthella, Parasutterella, and increases in Ruminococcaceae (rs = -0.28, rs = -0.32, rs = 0.32, respectively), as well as the fecal metabolome (e.g., branched-chain amino acid metabolism). Cortisol levels during the 2nd trimester correlated with 7 bacterial taxa, whereas 1st-trimester cortisol levels were associated with the child's fecal metabolome.

CONCLUSIONS

Prenatal distress and cortisol were associated with both child gut microbiota composition and fecal metabolome at preschool age. Understanding these associations may allow for the identification of microbiota-targeted interventions to support child developmental outcomes affected by prenatal stress.

Gut microbiota and child behavior in early puberty: does child sex play a role?

A growing number of studies have indicated relations between the gut microbiota and mental health. However, to date, there is a scarcity of microbiota studies in community samples in early puberty. The current preregistered study (https://osf.io/wu2vt) investigated gut microbiota composition in relation to sex in low-risk children and explored behavioral associations with gut microbiota composition and metabolites in the same samples, together with the potential role of sex. Fecal microbiota composition was analyzed in 12-year-old children (N = 137) by 16S rRNA gene sequencing and quantitative PCR. Modest sex differences were observed in beta diversity. Generalized linear models showed consistent behavioral relations to both relative and absolute abundances of individual taxa, including positive associations between Parasutterella and mother-reported internalizing behavior, and negative associations between Odoribacter and mother-reported externalizing behavior. Additionally, Prevotella 9 was positively related to mother-reported externalizing behavior, confirming earlier findings on the same cohort at 5 years of age. Sex-related differences were found in behavioral relations to Ruminiclostridium 5, Alistipes, Streptococcus, Ruminiclostridium 9, Ruminococcaceae UCG-5, and Dialister, for relative abundances, as well as to Family XIII AD3011 group and an unidentified bacterium within the Tenericutes, for absolute abundances. Limited behavioral relations were observed regarding alpha diversity and fecal metabolites. Our findings describe links between the gut microbiota and child behavior, together with differences between child sexes in these relations, in low-risk early pubertal children. Importantly, this study confirmed earlier findings in this cohort of positive relations between Prevotella 9 and externalizing behavior at age 10 years. Results also show the merit of including absolute abundances in microbiota studies.

Exercise and the gut microbiome: implications for supportive care in cancer

PURPOSE

Growing recognition of the gut microbiome as an influential modulator of cancer treatment efficacy and toxicity has led to the emergence of clinical interventions targeting the microbiome to enhance cancer and health outcomes. The highly modifiable nature of microbiota to endogenous, exogenous, and environmental inputs enables interventions to promote resilience of the gut microbiome that have rapid effects on host health, or response to cancer treatment. While diet, probiotics, and faecal microbiota transplant are primary avenues of therapy focused on restoring or protecting gut function in people undergoing cancer treatment, the role of physical activity and exercise has scarcely been examined in this population.

METHODS

A narrative review was conducted to explore the nexus between cancer care and the gut microbiome in the context of physical activity and exercise as a widely available and clinically effective supportive care strategy used by cancer survivors.

RESULTS

Exercise can facilitate a more diverse gut microbiome and functional metabolome in humans; however, most physical activity and exercise studies have been conducted in healthy or athletic populations, primarily using aerobic exercise modalities. A scarcity of exercise and microbiome studies in cancer exists.

CONCLUSIONS

Exercise remains an attractive avenue to promote microbiome health in cancer survivors. Future research should elucidate the various influences of exercise modalities, intensities, frequencies, durations, and volumes to explore dose-response relationships between exercise and the gut microbiome among cancer survivors, as well as multifaceted approaches (such as diet and probiotics), and examine the influences of exercise on the gut microbiome and associated symptom burden prior to, during, and following cancer treatment.

Does the ketogenic diet improve neurological disorders by influencing gut microbiota? A systematic review

BACKGROUND

The aim of this systematic review is to evaluate the changes in gut microbiota (GM) induced by the Ketogenic Diets (KD) as a potential underlying mechanism in the improvement of neurological diseases.

METHODS

A comprehensive search was conducted on three electronic databases, including PubMed/Medline, Web of Science, and Scopus until December 2022. The inclusion criteria were studies that described any changes in GM after consuming KD in neurological patients. Full text of studies such as clinical trials and cohorts were added. The quality assessment of cohort studies was conducted using the Newcastle-Ottawa Quality Assessment Scale and for the clinical trials using the Cochrane Collaboration tool. The search, screening, and data extraction were performed by two researchers independently.

RESULTS

Thirteen studies examining the effects of the KD on the GM in neurological patients were included. Studies have shown that KD improves clinical outcomes by reducing disease severity and recurrence rates. An increase in Proteobacteria phylum, Escherichia, Bacteroides, Prevotella, Faecalibacterium, Lachnospira, Agaricus, and Mrakia genera and a reduction in Firmicutes, and Actinobacteria phyla, Eubacterium, Cronobacter, Saccharomyces, Claviceps, Akkermansia and Dialister genera were reported after KD. Studies showed a reduction in concentrations of fecal short-chain fatty acids and branched-chain fatty acids and an increase in beta Hydroxybutyrate, trimethylamine N-oxide, and N-acetylserotonin levels after KD.

CONCLUSION

The KD prescribed in neurological patients has effectively altered the GM composition and GM-derived metabolites.

The importance of the intestinal microbiota in humans and dogs in the neonatal period

The neonatal period represents a critical stage for the establishment and development of the gut microbiota, which profoundly influences the future health trajectory of individuals. This review examines the importance of intestinal microbiota in humans and dogs, aiming to elucidate the distinct characteristics and variations in the composition between these two species. In humans, the intestinal microbiota contributes to several crucial physiological processes, including digestion, nutrient absorption, immune system development, and modulation of host metabolism. Dysbiosis, an imbalance or disruption of the gut microbial community, has been linked to various disorders, such as inflammatory bowel disease, obesity, and even neurological conditions. Furthermore, recent research has unveiled the profound influence of the gut-brain axis, emphasizing the bidirectional communication between the gut microbiota and the central nervous system, impacting cognitive function and mental health. Similarly, alterations in the canine intestinal microbiota have been associated with gastrointestinal disorders, including chronic enteropathy, such as inflammatory bowel disease, food allergies, and ulcerative histiocytic colitis. However, our understanding of the intricacies and functional significance of the intestinal microbiota in dogs remains limited. Understanding the complex dynamics of the intestinal microbiota in both humans and dogs is crucial for devising effective strategies to promote health and manage disease. Moreover, exploring the similarities and differences in the gut microbial composition between these two species can facilitate translational research, potentially leading to innovative therapeutic interventions and strategies to enhance the well-being of both humans and dogs.

Brain modulation by the gut microbiota: From disease to therapy

BACKGROUND

The gut microbiota (GM) and brain are strongly associated, which significantly affects neuronal development and disorders. GM-derived metabolites modulate neuronal function and influence many cascades in age-related neurodegenerative disorders (NDDs). Because of the dual role of GM in neuroprotection and neurodegeneration, understanding the balance between beneficial and harmful bacteria is crucial for applying this approach to clinical therapies.

AIM OF THE REVIEW

This review briefly discusses the role of the gut-brain relationship in promoting brain and cognitive function. Although a healthy gut environment is helpful for brain function, gut dysbiosis can disrupt the brain's environment and create a vicious cycle of degenerative cascades. The ways in which the GM population can affect brain function and the development of neurodegeneration are also discussed. In the treatment and management of NDDs, the beneficial effects of methods targeting GM populations and their derivatives, including probiotics, prebiotics, and fecal microbial transplantation (FMT) are also highlighted.

KEY SCIENTIFIC CONCEPT OF THE REVIEW

In this review, we aimed to provide a deeper understanding of the mechanisms of the gut microbe-brain relationship and their twin roles in neurodegeneration progression and therapeutic applications. Here, we attempted to highlight the different pathways connecting the brain and gut, together with the role of GM in neuroprotection and neuronal development. Furthermore, potential roles of GM metabolites in the pathogenesis of brain disorders and in strategies for its treatment are also investigated. By analyzing existing in vitro, in vivo and clinical studies, this review attempts to identify new and promising therapeutic strategies for central nervous system (CNS) disorders. As the connection between the gut microbe-brain relationship and responses to NDD treatments is less studied, this review will provide new insights into the global mechanisms of GM modulation in disease progression, and identify potential future perspectives for developing new therapies to treat NDDs.

Effects of metformin on the gut microbiota: A systematic review

BACKGROUND

The gut microbiota is increasingly recognized as a crucial factor in human health and disease. Metformin, a commonly prescribed medication for type 2 diabetes, has been studied for its potential impact on the gut microbiota in preclinical models. However, the effects of metformin on the gut microbiota in humans remain uncertain.

SCOPE OF REVIEW

We conducted a systematic review of clinical trials and observational studies to assess the existing knowledge on the impact of metformin on the gut microbiota in humans. The review focused on changes in bacterial composition and diversity following metformin treatment.

MAJOR CONCLUSIONS

Thirteen studies were included in the analysis. The results revealed alterations in the abundance of bacterial genera from various phyla, suggesting that metformin may selectively influence certain groups of bacteria in the gut microbiota. However, the effects on gut microbiota diversity were inconsistent across populations, with conflicting findings on changes in alpha and beta diversity measures. Overall, the use of metformin was associated with changes in the abundance of specific bacterial genera within the gut microbiota of human populations. However, the effects on gut microbiota diversity were not consistent, highlighting the need for further research to understand the underlying mechanisms and clinical significance of these changes.

Bacterial Proteases as Potentially Exploitable Modulators of SARS-CoV-2 Infection: Logic from the Literature, Informatics, and Inspiration from the Dog

(1) Background: The COVID-19 pandemic left many intriguing mysteries. Retrospective vulnerability trends tie as strongly to odd demographics as to exposure profiles, genetics, health, or prior medical history. This article documents the importance of nasal microbiome profiles in distinguishing infection rate trends among differentially affected subgroups. (2) Hypothesis: From a detailed literature survey, microbiome profiling experiments, bioinformatics, and molecular simulations, we propose that specific commensal bacterial species in the Pseudomonadales genus confer protection against SARS-CoV-2 infections by expressing proteases that may interfere with the proteolytic priming of the Spike protein. (3) Evidence: Various reports have found elevated Moraxella fractions in the nasal microbiomes of subpopulations with higher resistance to COVID-19 (e.g., adolescents, COVID-19-resistant children, people with strong dietary diversity, and omnivorous canines) and less abundant ones in vulnerable subsets (the elderly, people with narrower diets, carnivorous cats and foxes), along with bioinformatic evidence that Moraxella bacteria express proteases with notable homology to human TMPRSS2. Simulations suggest that these proteases may proteolyze the SARS-CoV-2 spike protein in a manner that interferes with TMPRSS2 priming.

Age and severity-dependent gut microbiota alterations in Tunisian children with autism spectrum disorder

Alterations in gut microbiota and short chain fatty acids (SCFA) have been reported in autism spectrum disorder (ASD). We analysed the gut microbiota and fecal SCFA in Tunisian autistic children from 4 to 10 years, and results were compared to those obtained from a group of siblings (SIB) and children from the general population (GP). ASD patients presented different gut microbiota profiles compared to SIB and GP, with differences in the levels of Bifidobacterium and Collinsella occurring in younger children (4-7 years) and that tend to be attenuated at older ages (8-10 years). The lower abundance of Bifidobacterium is the key feature of the microbiota composition associated with severe autism. ASD patients presented significantly higher levels of propionic and valeric acids than GP at 4-7 years, but these differences disappeared at 8-10 years. To the best of our knowledge, this is the first study on the gut microbiota profile of Tunisian autistic children using a metataxonomic approach. This exploratory study reveals more pronounced gut microbiota alterations at early than at advanced ages in ASD. Although we did not account for multiple testing, our findings suggest that early interventions might mitigate gut disorders and cognitive and neurodevelopment impairment associated to ASD.

Engineered live bacteria as disease detection and diagnosis tools

Sensitive and minimally invasive medical diagnostics are essential to the early detection of diseases, monitoring their progression and response to treatment. Engineered bacteria as live sensors are being developed as a new class of biosensors for sensitive, robust, noninvasive, and in situ detection of disease onset at low cost. Akin to microrobotic systems, a combination of simple genetic rules, basic logic gates, and complex synthetic bioengineering principles are used to program bacterial vectors as living machines for detecting biomarkers of diseases, some of which cannot be detected with other sensing technologies. Bacterial whole-cell biosensors (BWCBs) can have wide-ranging functions from detection only, to detection and recording, to closed-loop detection-regulated treatment. In this review article, we first summarize the unique benefits of bacteria as living sensors. We then describe the different bacteria-based diagnosis approaches and provide examples of diagnosing various diseases and disorders. We also discuss the use of bacteria as imaging vectors for disease detection and image-guided surgery. We conclude by highlighting current challenges and opportunities for further exploration toward clinical translation of these bacteria-based systems.

Effects of probiotic supplementation on the gut microbiota composition of adults: a systematic review of randomized clinical trials

Researchers have associated the therapeutic potential of probiotics with its ability to modulate gut microbiota, which is considered an "invisible organ" of the human body. The present study investigates the effects of probiotic supplementation on the gut microbiota composition of adults. The authors conducted a systematic review of the literature published in six different databases. The search followed PRISMA guidelines and aimed to identify randomized clinical trials on probiotic supplementation. All relevant publications indexed up to May 28, 2021, were retrieved. Then, the authors defined the inclusion and exclusion criteria. Two independent reviewers performed study screening, data extraction, and quality assessment. A total of 2,404 publications were retrieved, and eight studies met the eligibility criteria. The included randomized clinical trials were published between 2015 to 2020. The worldwide studies included adults aged from 18 to 79 years, most of whom were women (66.5%). Only one of the included studies observed significant effects on fecal microbiota composition in the relative abundance of Bacteroidetes and Firmicutes phyla in comparison with the placebo treatment. Overall, this systematic review could not draw consistent conclusions on the effects of probiotic supplementation on the gut microbiota composition of adults.

The Role of Bacteriophages in the Gut Microbiota: Implications for Human Health

Bacteriophages (phages) are nano-sized viruses characterized by their inherent ability to live off bacteria. They utilize diverse mechanisms to absorb and gain entry into the bacterial cell wall via the release of viral genetic material, which uses the replication mechanisms of the host bacteria to produce and release daughter progeny virions that attack the surrounding host cells. They possess specific characteristics, including specificity for particular or closely related bacterial species. They have many applications, including as potential alternatives to antibiotics against multi-resistant bacterial pathogens and as control agents in bacteria-contaminated environments. They are ubiquitously abundant in nature and have diverse biota, including in the gut. Gut microbiota describes the community and interactions of microorganisms within the intestine. As with bacteria, parasitic bacteriophages constantly interact with the host bacterial cells within the gut system and have obvious implications for human health. However, it is imperative to understand these interactions as they open up possible applicable techniques to control gut-implicated bacterial diseases. Thus, this review aims to explore the interactions of bacteriophages with bacterial communities in the gut and their current and potential impacts on human health.

Shrimp microbiome and immune development in the early life stages

With its contribution to nutrition, development, and disease resistance, gut microbiome has been recognized as a crucial component of the animal's health and well-being. Microbiome in the gastrointestinal tract constantly interacts with the host animal's immune systems as part of the normal function of the intestines. Interactions between the microbiome and the immune system are complex and dynamic, with the microbiome shaping immune development and function. In contrast, the immune system modulates the composition and activity of the microbiome. In shrimp, as with all other aquatic animals, the interaction between the microbiome and the animals occurs at the early developmental stages. This early interaction is likely essential to the development of immune responses of the animal as well as many key physiological developments that further contribute to the health of shrimp. This review provides background knowledge on the early developmental stage of shrimp and its microbiome, examines the interaction between the microbiome and the immune system in the early life stage of shrimp, and discusses potential pitfalls and challenges associated with microbiome research. Understanding the interaction between the microbiome and shrimp immune system at this crucial developmental stage could have the potential to aid in the establishment of a healthy microbiome, improve shrimp survival, and provide ways to shape the microbiome with feed supplements or other strategies.