Gut microbiota in health and disease: an overview focused on metabolic inflammation

Plant-based antioxidant peptides: impact on oxidative stress and gut microbiota

Plant-based peptides can be obtained from natural and climate-friendly sources. These peptides show various bioactivities including antioxidant activity. Oxidative stress has an impact on the gut microbiota causing inflammation, insulin resistance, osteoporosis, cancer, and several chronic diseases like type 2 diabetes, arthritis, hypertension, and atherosclerosis. Therefore, antioxidant peptides may significantly affect oxidative stress as a potential alternative to conventional medication. The production of antioxidant peptides from plant-based protein sources through conventional and innovative approaches may provide promising strategies to improve gut microbiota. Recent studies in plant-based antioxidant peptides (PBAP) focus on their advanced identification and characterization techniques, structure-activity relationship, improvement of extraction and purification, cellular and molecular mechanisms, specific health applications in preventing and managing conditions with gut microbiota, and commercial applications in nutraceuticals. Short-chain fatty acids and reactive sulfur species are specific gut-derived metabolites that can improve metabolic function by modulating oxidative stress and the immune system. This review highlights the influence of food oxidants on the gut microbiota and PBAP-induced modulation of gut microbiota. Moreover, the production of PBAP and the challenges in their application will be discussed.

Unleashing the power of microalgae: a pioneering path to sustainability and achieving the sustainable development goals

This study explores the remarkable potential of algae in addressing global sustainability challenges. Microalgae, in particular, emerge as sustainability champions. Their applications span an impressive array of industries and processes, including food and feed production, biofuels, cosmetics, pharmaceuticals, and environmental remediation. This versatility positions algae as key players in achieving over 50% of UN Sustainable Development Goals (SDGs) simultaneously, addressing issues such as climate action, clean water and sanitation, affordable and clean energy, and zero hunger. From sequestering carbon, purifying wastewater, and producing clean energy to combating malnutrition, algae demonstrates unparalleled potential. Their ability to flourish in extreme conditions and their rapid growth rates further enhance their appeal for large-scale cultivation. As research advances, innovative applications continue to emerge, such as algae-based bioplastics and dye-sensitized solar cells, promising novel solutions to pressing global issues. This study illuminates how harnessing the power of algae can drive us towards a more resilient, sustainable world. By leveraging algae's multifaceted capabilities, we can tackle climate change, resource scarcity, and economic development concurrently. The research highlights the critical role of algae in promoting circular economy principles and achieving a harmonious balance between human needs and environmental preservation, paving the way for a greener, more sustainable future.

Exploring the gut microbiome: A potential biomarker for cancer diagnosis, prognosis, and therapy

The gut microbiome, a complex community of trillions of microorganisms in the intestines, is crucial in maintaining human health. Recent advancements in microbiome research have unveiled a compelling link between the gut microbiome and cancer development and progression. Alterations in the composition and function of the gut microbiome, known as dysbiosis, have been implicated in various types of cancer, including, esophageal, liver, colon, pancreatic, and gastrointestinal. However, the specific gut microbial strains associated with the development or progression of cancers in various tissues remain largely unclear. Here, we summarize current research findings on the gut microbiome of multiple cancers. This review aims to identify key gut microbial targets that closely influence cancer development based on current research findings. To accurately evaluate the effectiveness of the gut microbiome as a clinical tool for cancer, further research is needed to explore its potential as a biomarker and therapeutic strategy.

Water pollution, cholera, and the role of probiotics: a comprehensive review in relation to public health in Bangladesh

Cholera, a disease caused by Vibrio cholerae, remains a pervasive public health threat, particularly in regions with inadequate water sanitation and hygiene infrastructure, such as Bangladesh. This review explores the complex interplay between water pollution and cholera transmission in Bangladesh, highlighting how contaminated water bodies serve as reservoirs for V. cholerae. A key focus is the potential role of probiotics as a novel intervention approach for cholera prevention and management. Probiotics are promising as an adjunctive approach to existing therapies as they can enhance gut barrier function, induce competitive exclusion of pathogens, and modulate host immune responses. Recent probiotic advancements include engineering strains that disrupt V. cholerae biofilms and inhibit their virulence. Integrating probiotics with traditional cholera control measures could significantly enhance their effectiveness and provide a multifaceted approach to combating this persistent disease. This review aims to shed light on the potential of probiotics in revolutionizing cholera management and to offer insights into their application as both preventive and therapeutic tools in the fight against this enduring public health challenge.

Immunosenescence: A new direction in anti-aging research

The immune system is a major regulatory system of the body, that is composed of immune cells, immune organs, and related signaling factors. As an organism ages, observable age-related changes in the function of the immune system accumulate in a process described as 'immune aging. Research has shown that the impact of aging on immunity is detrimental, with various dysregulated responses that affect the function of immune cells at the cellular level. For example, increased aging has been shown to result in the abnormal chemotaxis of neutrophils and decreased phagocytosis of macrophages. Age-related diminished functionality of immune cell types has direct effects on host fitness, leading to poorer responses to vaccination, more inflammation and tissue damage, as well as autoimmune disorders and the inability to control infections. Similarly, age impacts the function of the immune system at the organ level, resulting in decreased hematopoietic function in the bone marrow, a gradual deficiency of catalase in the thymus, and thymic atrophy, resulting in reduced production of related immune cells such as B cells and T cells, further increasing the risk of autoimmune disorders in the elderly. As the immune function of the body weakens, aging cells and inflammatory factors cannot be cleared, resulting in a cycle of increased inflammation that accumulates over time. Cumulatively, the consequences of immune aging increase the likelihood of developing age-related diseases, such as Alzheimer's disease, atherosclerosis, and osteoporosis, among others. Therefore, targeting the age-related changes that occur within cells of the immune system might be an effective anti-aging strategy. In this article, we summarize the relevant literature on immune aging research, focusing on its impact on aging, in hopes of providing new directions for anti-aging research.

Microbiome as an endocrine organ and its relationship with eye diseases: Effective factors and new targeted approaches

Microbiome is an endocrine organ that refers to both the complicated biological system of microbial species that colonize our bodies and their genomes and surroundings. Recent studies confirm the connection between the microbiome and eye diseases, which are involved in the pathogenesis of eye diseases, including age-related macular disorders, diabetic retinopathy, glaucoma, retinitis pigmentosa, dry eye, and uveitis. The aim of this review is to investigate the microbiome in relation to eye health. First, a brief introduction of the characteristics of the gut microorganisms terms of composition and work, the role of dysbiosis, the gut microbiome and the eye microbiome in the progression of eye illnesses are highlighted, then the relationship among the microbiome and the function of the immune system and eye diseases, the role of inflammation and aging and the immune system, It has been reviewed and finally, the control and treatment goals of microbiome and eye diseases, the role of food factors and supplements, biotherapy and antibiotics in relation to microbiome and eye health have been reviewed.

Deciphering the Gut–Liver Axis: A Comprehensive Scientific Review of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a significant global health issue. The condition is closely linked to metabolic dysfunctions such as obesity and type 2 diabetes. The gut–liver axis, a bidirectional communication pathway between the liver and the gut, plays a crucial role in the pathogenesis of NAFLD. This review delves into the mechanisms underlying the gut–liver axis, exploring the influence of gut microbiota, intestinal permeability, and inflammatory pathways. This review also explores the potential therapeutic strategies centered on modulating gut microbiota such as fecal microbiota transplantation; phage therapy; and the use of specific probiotics, prebiotics, and postbiotics in managing NAFLD. By understanding these interactions, we can better comprehend the development and advancement of NAFLD and identify potential therapeutic targets.

Plant essential oils combined with organic acids restored lipopolysaccharide-induced leaky intestine via gut microbial modulation in weaned piglets

Intestine derived lipopolysaccharide (LPS) is closely related to systemic inflammation and disorders, yet little is known about its roles in the weanling stress of piglets and its potential as a nutritional intervention target. This study aimed to investigate the potential of essential oils (EO) and organic acids (OA) in mitigating weaning stress in piglets by modulating the circulation of intestine derived LPS. Seventy-two weaned piglets at 21 d old with body weight of 8.12 ± 0.168 kg were randomly divided into a control group (CON) and an experimental group, each consisting of six pens with six piglets per pen, and were fed either a basal diet or a basal diet supplemented with 3 kg/t OA + 500 g/t EO (EO + OA). On the 14th day of the feeding trial, 12 weaned piglets were randomly selected from the CON group, and 6 piglets were selected from the experimental group. Based on diet composition and stress treatment, these 18 piglets were divided into the following three groups: 1) CON group. Piglets were fed a basal diet and received an intraperitoneal injection of saline as a control. 2) LPS group. Piglets were fed a basal diet and received an intraperitoneal injection of LPS (100 μg/kg body weight) to induce stress. 3) EO + OA + LPS group. Piglets were fed a basal diet supplemented with EO and OA and received an intraperitoneal injection of LPS (100 μg/kg body weight) to induce stress. The results showed that EO + OA significantly ameliorated the oxidative imbalance and inflammation disorder induced by LPS in piglets' serum and intestine by inhibiting the activation of the Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, compared to the LPS group, supplementation with EO + OA restored LPS-induced reductions in Bcl-2 protein expression in the piglets' intestines (P < 0.05) and mitigated morphological damage; it also enhanced both the protein expression and relative gene expression of the tight junction proteins occludin and claudin-1 (P < 0.05), and reduced the plasma diamine oxidase activity (DAO) and LPS content (P < 0.05). Compared to the CON group, supplementation with EO + OA altered the composition of the intestinal microbiota, increasing beneficial bacteria relative abundance (Faecalibacterium) (P < 0.05) and decreasing harmful bacteria relative abundance [Rikenellaceae_RC9_gut_group (P < 0.01), Negativibacillus (P < 0.05)]. Further analysis revealed that plasma LPS content in piglets was negatively correlated with the relative abundance of Faecalibacterium (r = -0.662, P = 0.021), Akkermansia (r = -0.492, P = 0.031), and average daily gain (ADG) (r = -0.912, P = 0.041). Plasma LPS content was also positively correlated with the plasma inflammatory factors interleukin (IL)-1β (r = 0.591, P = 0.021), IL-6 (r = 0.623, P = 0.021), IL-12 (r = 561, P = 0.031) contents, and the relative abundance of Negativibacillus (r = 0.712, P = 0.041). In summary, the addition of EO + OA prevents the leakage of intestine derived LPS into the circulation by improving intestinal integrity and microbiota composition, thereby enhancing antioxidant and anti-inflammatory abilities and growth performance of weaned piglets.

The impact of altered dietary adenine concentrations on the gut microbiota in Drosophila

The gut microbiota influences host metabolism and health, impacting diseases. Research into how diet affects gut microbiome dynamics in model organisms is crucial but underexplored. Herein, we examined how dietary adenine affects uric acid levels and the gut microbiota over five generations of Drosophila melanogaster. Wild-type W1118 flies consumed diets with various adenine concentrations (GC: 0%, GL: 0.05%, and GH: 0.10%), and their gut microbiota were assessed via Illumina MiSeq sequencing. Adenine intake significantly increased uric acid levels in the GH group > the GC group. Despite no significant differences in the alpha diversity indices, there were significant disparities in the gut microbiota health index (GMHI) and dysbiosis index (MDI) among the groups. Adenine concentrations significantly altered the diversity and composition of the gut microbiota. High adenine intake correlated with increased uric acid levels and microbial population shifts, notably affecting the abundances of Proteobacteria and Firmicutes. The gut microbiota phenotypes included mobile elements, gram-positive bacteria, biofilm-forming bacteria, and gram-negative bacteria. The significantly enriched KEGG pathways included ageing, carbohydrate metabolism, and the immune system. In conclusion, adenine intake increases uric acid levels, alters gut microbiota, and affects KEGG pathways in Drosophila across generations. This study highlights the impact of dietary adenine on uric acid levels and the gut microbiota, providing insights into intergenerational nutritional effects.

Dietary Protease Supplementation Improved Growth Performance and Nutrients Digestion via Modulating Intestine Barrier, Immunological Response, and Microbiota Composition in Weaned Piglets

Despite mounting evidence for dietary protease benefits, the mechanisms beyond enhanced protein degradation are poorly understood. This study aims to thoroughly investigate the impact of protease addition on the growth performance, intestinal function, and microbial composition of weaned piglets. Ninety 28-day-old weaned pigs were randomly assigned to the following three experimental diets based on their initial body weight for a 28-day experiment: (1) control (CC), a basic diet with composite enzymes without protease; (2) negative control (NC), a diet with no enzymes; and (3) dietary protease (PR), a control diet with protease. The results show that dietary proteases significantly enhanced growth performance and boosted antioxidant capacity, increasing the total antioxidant capacity (T-AOC) levels (p < 0.05) while reducing malonaldehyde levels (p < 0.05). Additionally, protease addition reduced serum levels of inflammatory markers TNF-α, IL-1β, and IL-6 (p < 0.05), suppressed mRNA expression of pro-inflammatory factors in the jejunum (p < 0.01), and inhibited MAPK and NF-κB signaling pathways. Moreover, protease-supplemented diets improved intestinal morphology and barrier integrity, including zonula occludens protein 1(ZO-1), Occludin, and Claudin-1 (p < 0.05). Microbiota compositions were also significantly altered by protease addition with increased abundance of beneficial bacteria (Lachnospiraceae_AC2044_group and Prevotellaceae_UCG-001) (p < 0.05) and reduced harmful Terrisporobacter (p < 0.05). Further correlation analysis revealed a positive link between beneficial bacteria and growth performance and a negative association with inflammatory factors and intestinal permeability. In summary, dietary protease addition enhanced growth performance in weaned piglets, beneficial effects which were associated with improved intestinal barrier integrity, immunological response, and microbiota composition.

Resistant starches from dietary pulses modulate the gut metabolome in association with microbiome in a humanized murine model of ageing

Emerging evidence suggests that plant-based fiber-rich diets improve ageing-associated health by fostering a healthier gut microbiome and microbial metabolites. However, such effects and mechanisms of resistant starches from dietary pulses remain underexplored. Herein, we examine the prebiotic effects of dietary pulses-derived resistant starch (RS) on gut metabolome in older (60-week old) mice carrying a human microbiome. Gut metabolome and its association with microbiome are examined after 20-weeks feeding of a western-style diet (control; CTL) fortified (5% w/w) with RS from pinto beans (PTB), black-eyed-peas (BEP), lentils (LEN), chickpeas (CKP), or inulin (INU; reference control). NMR spectroscopy-based untargeted metabolomic analysis yield differential abundance linking phenotypic differences in specific metabolites among different RS groups. LEN and CKP increase butyrate, while INU promotes propionate. Conversely, bile acids and cholesterol are reduced in prebiotic groups along with suppressed choline-to-trimethylamine conversion by LEN and CKP, whereas amino acid metabolism is positively altered. Multi-omics microbiome-metabolome interactions reveal an association of beneficial metabolites with the Lactobacilli group, Bacteroides, Dubosiella, Parasutterella, and Parabacteroides, while harmful metabolites correlate with Butyricimonas, Faecalibaculum, Colidextribacter, Enterococcus, Akkermansia, Odoribacter, and Bilophila. These findings demonstrate the functional effects of pulses-derived RS on gut microbial metabolism and their beneficial physiologic responses in an aged host.

Dietary fiber modulates gut microbiome and metabolome in a host sex-specific manner in a murine model of aging

Emerging evidence reveals the fundamental role of the gut microbiome in human health. Among various factors regulating our gut microbiome, diet is one of the most indispensable and prominent one. Inulin is one of the most widely-studied dietary fiber for its beneficial prebiotic effects by positively modulating the gut microbiome and microbial metabolites. Recent research underscores sexual dimorphism and sex-specific disparities in microbiome and also diet-microbiome interactions. However, whether and how the prebiotic effects of dietary fiber differ among sexes remain underexplored. To this end, we herein examine sex-specific differences in the prebiotic effects of inulin on gut microbiome and metabolome in a humanized murine model of aging i.e., aged mice carrying human fecal microbiota. The findings demonstrate that inulin exerts prebiotic effects, but in a sex-dependent manner. Overall, inulin increases the proportion of Bacteroides, Blautia, and glycine, while decreasing Eggerthella, Lactococcus, Streptococcus, trimethylamine, 3-hydroxyisobutyrate, leucine and methionine in both sexes. However, we note sex-specific effects of inulin including suppression of f_Enteroccaceae:_, Odoribacter, bile acids, malonate, thymine, valine, acetoin, and ethanol while promotion of Dubosiella, pyruvate, and glycine in males. Whereas, suppression of Faecalibaculum, Lachnoclostridium, Schaedlerella, phenylalanine and enhancement of Parasutterella, Phocaeicola, f_Lachnospiraceae;_, Barnesiella, Butyricimonas, glycine, propionate, acetate and glutamate are observed in females. Altogether, the study reveals that prebiotic mechanisms of dietary fiber vary in a sex-dependent manner, underscoring the importance of including both sexes in preclinical/clinical studies to comprehend the mechanisms and functional aspects of dietary interventions for effective extrapolation and translation in precision nutrition milieus.

"Cross-talk" between gut microbiome dysbiosis and osteoarthritis progression: a systematic review

Objectives

The aim of this systematic review was to summarize the available literature on gut microbiome (GMB) and osteoarthritis (OA), analyze the correlation between GMB and OA, and explore potential underlying mechanisms.

Methods

A systematic search of the PubMed, Embase, Cochrane, and Web of Science with the keywords "Gut Microbiome" and "Osteoarthritis" was conducted to identify the human and animal studies exploring the association between GMB and OA. The retrieval time range was from the database inception to July 31, 2022. Studies reported the other arthritic diseases without OA, reviews, and studies focused on the microbiome in other parts of the body with OA, such as oral or skin, were excluded. The included studies were mainly reviewed for GMB composition, OA severity, inflammatory factors, and intestinal permeability.

Results

There were 31 studies published met the inclusion criteria and were analyzed, including 10 human studies and 21 animal studies. Human and animal studies have reached a consistent conclusion that GMB dysbiosis could aggravate OA. In addition, several studies have found that alterations of GMB composition can increase intestinal permeability and serum levels of inflammatory factors, while regulating GMB can alleviate the changes. Owing to the susceptibility of GMB to internal and external environments, genetics, and geography, the included studies were not consistent in GMB composition analysis.

Conclusion

There is a lack of high-quality studies evaluating the effects of GMB on OA. Available evidence indicated that GMB dysbiosis aggravated OA through activating the immune response and subsequent induction of inflammation. Future studies should focus on more prospective, cohort studies combined with multi-omics to further clarify the correlation.

Gut microbiome as a therapeutic target for liver diseases

The prominent role of gut in regulating the physiology of different organs in a human body is increasingly acknowledged, to which the bidirectional communication between gut and liver is no exception. Liver health is modulated via different key components of gut-liver axis. The gut-derived products mainly generated from dietary components, microbial metabolites, toxins, or other antigens are sensed and transported to the liver through portal vein to which liver responds by secreting bile acids and antibodies. Therefore, maintaining a healthy gut microbiome can promote homeostasis of this gut-liver axis by regulating the intestinal barrier function and reducing the antigenic molecules. Conversely, liver secretions also regulate the gut microbiome composition. Disturbed homeostasis allows luminal antigens to reach liver leading to impaired liver functioning and instigating liver disorders. The perturbations in gut microbiome, permeability, and bile acid pool have been associated with several liver disorders, although precise mechanisms remain largely unresolved. Herein, we discuss functional fingerprints of a healthy gut-liver axis while contemplating mechanistic understanding of pathophysiology of liver diseases and plausible role of gut dysbiosis in different diseased states of liver. Further, novel therapeutic approaches to prevent the severity of liver disorders are discussed in this review.

Prebiotic mechanisms of resistant starches from dietary beans and pulses on gut microbiome and metabolic health in a humanized murine model of aging

Dietary pulses, being a rich source of fiber and proteins, offer an ideal and inexpensive food choice for older adults to promote gut and metabolic health. However, the prebiotic effects of dietary pulses-derived resistant starches (RS), compared to RS from cereals and tubers, remain relatively underexplored, particularly in context to their gut modulatory potential in old age. We herein investigate the prebiotic effects of pulses-derived RS on the gut microbiome and intestinal health in aged (60-week old) mice colonized with human microbiota. C57B6/J mice were fed for 20 weeks with either a western-style high-fat diet (control; CTL) or CTL diet supplemented (5% w/w) with RS from pinto beans (PTB), black-eyed-peas (BEP), lentils (LEN), chickpeas (CKP), or inulin (INU; reference control). We find that the RS supplementation modulates gut microbiome in a sex-dependent manner. For instance, CKP enriched α-diversity only in females, while β-diversity deviated for both sexes. Further, different RS groups exhibited distinct microbiome differences at bacterial phyla and genera levels. Notably, LEN fostered Firmicutes and depleted Proteobacteria abundance, whereas Bacteroidota was promoted by CKP and INU. Genus Dubosiella increased dominantly in males for all groups except PTB, whilst Faecalibaculum decreased in females by CKP and INU groups. Linear discriminant analysis effect size (LEfSe) and correlational analyzes reveal RS-mediated upregulation of key bacterial genera associated with short-chain fatty acids (butyrate) production and suppression of specific pathobionts. Subsequent machine-learning analysis validate decreased abundance of notorious genera, namely, Enterococcus, Odoribacter, Desulfovibrio, Alistipes and Erysipelatoclostridium among RS groups. CKP and LEN groups partly protected males against post-prandial glycemia. Importantly, RS ameliorated high-fat diet-induced gut hyperpermeability and enhanced expression of tight-junction proteins (claudin-1 and claudin-4), which were more pronounced for LEN. In addition, IL10 upregulation was more prominent for LEN, while TNF-α was downregulated by LEN, CKP, and INU. Together, these findings demonstrate that RS supplementation beneficially modulates the gut microbiome with a reduction in gut leakiness and inflammation, indicating their prebiotic potential for functional food and nutritional applications.

Metagenomic Insights into the Anti-Obesity Effect of a Polysaccharide from Saccharina japonica

Saccharina japonica polysaccharides exhibit great potential to be developed as anti-obesity and prebiotic health products, but the underlying mechanism has not been adequately addressed. In this study, we investigated the potential mechanism of a S. japonica polysaccharide fraction (SjC) in preventing high-fat-diet (HFD)-induced obesity in mice using 16S rRNA gene and shotgun metagenomic sequencing analysis. SjC was characterized as a 756 kDa sulfated polysaccharide and 16 weeks of SjC supplementation significantly alleviated HFD-induced obesity, insulin resistance, and glucose metabolism disorders. The 16S rRNA and metagenomic sequencing analysis demonstrated that SjC supplementation prevented gut microbiota dysbiosis mainly by regulating the relative abundance of Desulfovibrio and Akkermansia. Metagenomic functional profiling demonstrated that SjC treatment predominantly suppressed the amino acid metabolism of gut microbiota. Linking of 16S rRNA genes with metagenome-assembled genomes indicated that SjC enriched at least 22 gut bacterial species with fucoidan-degrading potential including Desulfovibrio and Akkermansia, which showed significant correlations with bodyweight. In conclusion, our results suggest that SjC exhibits a promising potential as an anti-obesity health product and the interaction between SjC and fucoidan-degrading bacteria may be associated with its anti-obesity effect.

Proteomic Analysis Identifies Three Reliable Biomarkers of Intestinal Inflammation in the Stools of Patients With Inflammatory Bowel Disease

BACKGROUND

Faecal biomarkers have emerged as important tools in managing of inflammatory bowel disease [IBD], which includes Crohn's disease [CD] and ulcerative colitis [UC].

AIM

To identify new biomarkers of gut inflammation in the stools of IBD patients using a proteomic approach.

METHODS

Proteomic analysis of stools was performed in patients with both active CD and CD in remission and in controls by 2-DIGE and MALDI-TOF/TOF MS. An ELISA was used to confirm results in a second cohort of IBD patients and controls.

RESULTS

2-DIGE analysis detected 70 spots in the stools of patients with active CD or patients in remission CD and in controls. MALDI-TOF/TOF MS analysis identified 21 proteins with Chymotrypsin C, Gelsolin and Rho GDP-dissociation inhibitor 2 [RhoGDI2] best correlating with the levels of intestinal inflammation. Results were confirmed in a second cohort of IBD patients and controls [57 CD, 60 UC, 31 controls]. The identified faecal markers significantly correlated with the severity of intestinal inflammation in IBD patients [SES-CD in CD, Mayo endoscopic subscore in UC] [CD; Chymotrypsin-C: r = 0.64, p < 0.001; Gelsolin: r = 0.82, p < 0.001; RhoGDI2: r = 0.64, p < 0.001; UC; Chymotrypsin-C: r = 0.76, p < 0.001; Gelsolin: r = 0.75, p < 0.001; RhoGDI2: r = 0.63, p < 0.001]. Moreover, ROC analysis showed that Gelsolin [p < 0.0002] and RhoGDI2 [p < 0.0001] in CD, and RhoGDI2 [p = 0.0004] in UC, have higher sensitivity and specificity than faecal calprotectin in discriminating between patients and controls.

CONCLUSIONS

We show for the first time that 2-DIGE is a reliable method to detect proteins in human stools. Three novel faecal biomarkers of gut inflammation have been identified that display good specificity and sensitivity for identifying IBD and significantly correlate with IBD severity.

Fecal Protein Analysis of Dusp6 Knockout C57BL/6J Mice by Metaproteomics

The research of obesity and gut microbiota has been carried out for years, yet the study process was in a slow pace for several challenges to conquer. As a complex status of disorder, the contributing factors refer to gut microbiota about obesity were controversial in a wide range. In terms of proteomics, 2D-DIGE technology is a powerful method for this study to identify fecal proteins from lean microbiota in Dusp6 knockout C57BL/6J mice, exploring the protein markers of the ability resisting to diet-induced obesity (DIO) transferred to the host mice after fecal microbiota transplantation. The results showed that the fecal microbiota expressed 289 proteins differentially with 23 proteins identified, which were considered to be the reasons to assist the microbiota exhibiting distinct behavior. By means of proteomics technology, we had found that differentially expressed proteins of lean microbiota determined the lean microbial behavior might be able to resist leaky gut. To sum up our study, the proteomics strategies offered as a tool to demonstrate and analyze the features of lean microbiota, providing new speculations in the behavior about the gut microbiota reacting to DIO.

Role of oral and gut microbiota in childhood obesity

Childhood obesity not only causes damage to children's respiratory, cardiovascular, endocrine, motor, and other systems but also is a significant risk factor for metabolic diseases such as obesity in adulthood, which has become one of the serious public health problems worldwide. The etiology and pathogenesis of obesity are complex. In addition to genetic and lifestyle factors, recent studies have found that the microbes in the digestive tract play a crucial role in the occurrence and development of obesity. Among them, the gut microbiota has been confirmed to be one of the important pathogenic factors of obesity, which can mediate the occurrence and development of obesity by interfering with the balance of host energy metabolism and inducing low-grade chronic inflammation throughout the host. Targeting the gut microbiota to treat obesity through various methods such as fecal microbiota transplantation, dietary intervention, and probiotic supplementation has become a research hotspot in obesity treatment. In addition, the oral microbiota is also considered closely related to the occurrence and development of obesity due to its regulatory effect on the balance of gut microbiota. Exploring the relationship between oral and gut microbiota and childhood obesity elucidates the pathogenesis and treatment concepts of childhood obesity from a new perspective. It may provide new methods for the prevention and treatment of childhood obesity in the future.

Advances in the study of selenium and human intestinal bacteria

Selenium (Se) is an essential trace element for humans and has conveyed great a wide range of interests due to its contribution to health. Presently, the regulatory mechanisms of selenium on human health, especially the regulatory mechanisms of selenium on human intestinal (gut) microflora and its effects on diseases are receiving attention from academic circles. This review involves the effects of selenium on physical health, the relationship between selenium and intestinal microflora, and the progress of research between selenium, intestinal microflora, and diseases. Furthermore, the current status of research on the selenium, intestinal microflora, and diseases is also presented.

Usnea improves high-fat diet- and vitamin D3-induced atherosclerosis in rats by remodeling intestinal flora homeostasis

Background: Usnea has various pharmacological properties, including anti-inflammatory, antitumor, antioxidant, antiviral, and cardiovasculoprotective effects. Aim of the study: To investigate the potential mechanisms underlying the anti-atherosclerosis (AS) activity of Usnea ethanol extract (UEE) via the regulation of intestinal flora. Materials and Methods: The chemical composition of UEE was determined using ultra-performance liquid chromatography with quadrupole exactive orbitrap mass spectrometry (UPLC-Q-EOMS). Thirty-six male Sprague-Dawley rats were divided into six groups. A high-fat diet and intraperitoneal vitamin D3 injections were used to establish a rat model of AS. After 4 weeks of treatment with UEE, hematoxylin-eosin staining was performed to evaluate the pathomorphology of the aorta, liver, and colon. The composition and diversity of the rat intestinal flora were determined using high-throughput 16S rRNA sequencing. Enzyme-linked immunosorbent assays were used to measure the levels of plasma trimethylamine oxide (TMAO), serum bile acid (BA), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). The protein expression of cholesterol 7α-hydroxylase (CYP7A1) and flavin monooxygenase 3 (FMO3) in the liver and zonula occludens-1 (ZO-1) and occludin in colon tissue was detected via western blotting. Results: Forty-four compounds were identified in UEE. In the rat model of AS, UEE significantly prevented calcium deposition; decreased the serum levels of TC, TG, LDL-C, LPS, TNF-α, and IL-6; and increased the serum level of HDL-C. Additionally, all UEE dosages decreased the relative abundance of Verrucomicrobiota while increased that of Bacteroidetes. FMO3 protein expression and TMAO levels decreased, whereas CYP7A1 protein expression and BA levels increased. The absorption of intestinal-derived LPS was minimized. Furthermore, the protein expression of ZO-1 and occludin was upregulated. Conclusion: UEE ameliorated AS. The underlying mechanism was the reversal of imbalances in the intestinal flora by Usnea, thereby inhibiting calcium deposition, abnormal lipid metabolism, and inflammatory response.

The interaction among gut microbes, the intestinal barrier and short chain fatty acids

The mammalian gut is inhabited by a massive and complicated microbial community, in which the host achieves a stable symbiotic environment through the interdependence, coordination, reciprocal constraints and participation in an immune response. The interaction between the host gut and the microbiota is essential for maintaining and achieving the homeostasis of the organism. Consequently, gut homeostasis is pivotal in safeguarding the growth and development and potential productive performance of the host. As metabolites of microorganisms, short chain fatty acids are not only the preferred energy metabolic feedstock for host intestinal epithelial cells, but also exert vital effects on antioxidants and the regulation of intestinal community homeostasis. Herein, we summarize the effects of intestinal microorganisms on the host gut and the mechanisms of action of short chain fatty acids on the four intestinal barriers of the organism, which will shed light on the manipulation of the intestinal community to achieve precise nutrition for specific individuals and provide a novel perspective for the prevention and treatment of diseases.

Association of antibiotic-consumption patterns with the prevalence of hematological malignancies in European countries

Hematological malignancies are considered the fifth most common cancer in the world. Several risk factors and probable etiological agents have been suspected in the pathomechanism of those malignancies as infections, chemicals, irradiation, etc., and recently, the contribution of the altered gut flora, dysbiosis, was identified also as a possible additional factor to the existing ones. Host, and external factors, like antibiotics, which were identified as a major disruptor of the "normal" gut flora, influence the composition of the microbiome. Considering the several-fold differences in antibiotic consumption patterns and the incidence of hematological malignancies in European countries, the hypothesis was raised that the dominant consumption of certain antibiotic classes might influence the incidence of different hematological malignancies through the modification of gut flora. Comparisons were performed between the average antibiotic consumption databases reported yearly by ECDC (2009–2019) and the incidence rate of Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), multiple myeloma (MM), and leukemia (LEU) estimated for 2020 in 30 European countries. Applying Spearman calculations, significant positive correlation has been found between the incidence of HL and tetracycline (J01A) consumption (r = 0.399, p = 0.029), NHL and narrow spectrum, beta-lactamase resistant penicillin (J01CF) (r = 0.580, p = 0.001), MM and tetracycline (r = 0.492, p = 0.006), penicillin (J01C) (r = 0.366, p = 0.047), narrow spectrum, beta-lactamase resistant penicillin (J01CF) (r = 0.574, p = 0.001), while strong, significant negative correlation has been recorded between NHL and cephalosporin (r = − 0.460, p = 0.011), and quinolone (r = − 0.380, p = 0.038). The incidence of LEU did not show any positive or negative association with any antibiotic classes using Spearman calculation. Multivariate ordinal logistic regression (OR) indicated increased risk between HL and the total consumption of systemic antibiotics (J01 p: 0.038), and tetracyclin (J01A p: 0.002). Similarly, increased risk has been detected between the MM and tetracyclin (J01A p: 0.02), and narrow spectrum, beta-lactamase resistant penicillin (J01CF p: 0.042) and decreased risk between cephalosporin and MM (J01D p:0.022). LEU showed increased risk with the consumption of macrolides (p: 0.047).

Prebiotic Potential of Dietary Beans and Pulses and Their Resistant Starch for Aging-Associated Gut and Metabolic Health

Dietary pulses, including dry beans, lentils, chickpeas, and dry peas, have the highest proportion of fiber among different legume cultivars and are inexpensive, easily accessible, and have a long shelf-life. The inclusion of pulses in regular dietary patterns is an easy and effective solution for achieving recommended fiber intake and maintaining a healthier gut and overall health. Dietary pulses-derived resistant starch (RS) is a relatively less explored prebiotic ingredient. Several in vitro and preclinical studies have elucidated the crucial role of RS in fostering and shaping the gut microbiota composition towards homeostasis thereby improving host metabolic health. However, in humans and aged animal models, the effect of only the cereals and tubers derived RS has been studied. In this context, this review collates literature pertaining to the beneficial effects of dietary pulses and their RS on gut microbiome-metabolome signatures in preclinical and clinical studies while contemplating their potential and prospects for better aging-associated gut health. In a nutshell, the incorporation of dietary pulses and their RS in diet fosters the growth of beneficial gut bacteria and significantly enhances the production of short-chain fatty acids in the colon.

Association Between Gut Microbiota and Osteoarthritis: A Review of Evidence for Potential Mechanisms and Therapeutics

Osteoarthritis (OA) is a multifactorial joint disease characterized by degeneration of articular cartilage, which leads to joints pain, disability and reduced quality of life in patients with OA. Interpreting the potential mechanisms underlying OA pathogenesis is crucial to the development of new disease modifying treatments. Although multiple factors contribute to the initiation and progression of OA, gut microbiota has gradually been regarded as an important pathogenic factor in the development of OA. Gut microbiota can be regarded as a multifunctional “organ”, closely related to a series of immune, metabolic and neurological functions. This review summarized research evidences supporting the correlation between gut microbiota and OA, and interpreted the potential mechanisms underlying the correlation from four aspects: immune system, metabolism, gut-brain axis and gut microbiota modulation. Future research should focus on whether there are specific gut microbiota composition or even specific pathogens and the corresponding signaling pathways that contribute to the initiation and progression of OA, and validate the potential of targeting gut microbiota for the treatment of patients with OA.

Exercise for the Diabetic Gut-Potential Health Effects and Underlying Mechanisms

It can be assumed that changes in the gut microbiota play a crucial role in the development of type 2 diabetes mellitus (T2DM). It is generally accepted that regular physical activity is beneficial for the prevention and therapy of T2DM. Therefore, this review analyzes the effects of exercise training on the gut microbiota composition and the intestinal barrier function in T2DM. The current literature shows that regular exercise can influence the gut microbiota composition and the intestinal barrier function with ameliorative effects on T2DM. In particular, increases in the number of short-chain fatty acid (SCFA)-producing bacteria and improvements in the gut barrier integrity with reduced endotoxemia seem to be key points for positive interactions between gut health and T2DM, resulting in improvements in low-grade systemic inflammation status and glycemic control. However, not all aspects are known in detail and further studies are needed to further examine the efficacy of different training programs, the role of myokines, SCFA-producing bacteria, and SCFAs in the relevant metabolic pathways. As microbial signatures differ in individuals who respond differently to exercise training programs, one scientific focus could be the development of computer-based methods for the personalized analysis of the gut microbiota in the context of a microbiota/microbiome-based training program.

It takes guts to learn: machine learning techniques for disease detection from the gut microbiome

Associations between the human gut microbiome and expression of host illness have been noted in a variety of conditions ranging from gastrointestinal dysfunctions to neurological deficits. Machine learning (ML) methods have generated promising results for disease prediction from gut metagenomic information for diseases including liver cirrhosis and irritable bowel disease, but have lacked efficacy when predicting other illnesses. Here, we review current ML methods designed for disease classification from microbiome data. We highlight the computational challenges these methods have effectively overcome and discuss the biological components that have been overlooked to offer perspectives on future work in this area.

Microbiome Research and Multi-Omics Integration for Personalized Medicine in Asthma

Asthma is a multifactorial inflammatory disorder of the respiratory system characterized by high diversity in clinical manifestations, underlying pathological mechanisms and response to treatment. It is generally established that human microbiota plays an essential role in shaping a healthy immune response, while its perturbation can cause chronic inflammation related to a wide range of diseases, including asthma. Systems biology approaches encompassing microbiome analysis can offer valuable platforms towards a global understanding of asthma complexity and improving patients' classification, status monitoring and therapeutic choices. In the present review, we summarize recent studies exploring the contribution of microbiota dysbiosis to asthma pathogenesis and heterogeneity in the context of asthma phenotypes-endotypes and administered medication. We subsequently focus on emerging efforts to gain deeper insights into microbiota-host interactions driving asthma complexity by integrating microbiome and host multi-omics data. One of the most prominent achievements of these research efforts is the association of refractory neutrophilic asthma with certain microbial signatures, including predominant pathogenic bacterial taxa (such as Proteobacteria phyla, Gammaproteobacteria class, especially species from Haemophilus and Moraxella genera). Overall, despite existing challenges, large-scale multi-omics endeavors may provide promising biomarkers and therapeutic targets for future development of novel microbe-based personalized strategies for diagnosis, prevention and/or treatment of uncontrollable asthma.

Distinct Gut Microbiota Signatures in Mice Treated with Commonly Used Food Preservatives

Diet is one of the most important factors regulating and influencing the composition of our gut microbiome, but the specific effects of commonly used antimicrobial agents i.e., food preservatives present within foods, are not completely understood. In this study, we examined the effect of the three widely used food-grade preservatives i.e., benzoic acid, potassium sorbate, and sodium nitrite, in recommended levels, on the gut microbiota diversity and composition in a mouse model. The analysis of β-diversity reveals distinct signatures of the gut microbiota between mice consuming different preservatives. Further analyses of α-diversity indices also show that the three preservatives induce specific patterns of microbial diversity, with diversity being lowest in mice consuming potassium sorbate. In terms of bacterial abundance, each of the three preservatives demonstrated unique microbial signatures, mainly affecting the proportions of bacterial taxa belonging to Bacteroidetes, Verrucomicrobia, and Proteobacteria. Specifically, we find the increased proportion of Bacteroides, Blautia, Ruminococcus, Oscillospira, and Dorea in mice fed with benzoate; increased abundance of Firmicutes, Turicibacter, and Alkaliphilus by sodium nitrate; and increased proportion of Parabacteroides and Adlercreutzia by potassium sorbate. The findings improve our understanding of how food-grade preservatives may influence the gut microbiota composition and diversity and should facilitate prospective studies investigating diet-microbiome interactions in relation to intestinal and metabolic health.

Gut-microbiota derived bioactive metabolites and their functions in host physiology

Every individual harbours a complex, diverse and mutualistic microbial flora in their intestine and over the time it became an integral part of the body, affecting a plethora of activities of the host. Interaction between host and gut-microbiota affects several aspects of host physiology. Gut-microbiota affects host metabolism by fermenting unabsorbed/undigested carbohydrates in the large intestine. Not only the metabolic functions, any disturbances in the composition of the gut-microbiota during first 2-3 years of life may impact on the brain development and later affects cognition and behaviour. Thus, gut-dysbiosis causes certain serious pathological conditions in the host including metabolic disorders, inflammatory bowel disease and mood alterations, etc. Microbial-metabolites in recent times have emerged as key mediators and are responsible for microbiota induced beneficial effects on host. This review provides an overview of the mechanism of microbial-metabolite production, their respective physiological functions and the impact of gut-microbiome in health and diseases. Metabolites from dietary fibres, aromatic amino acids such as tryptophan, primary bile acids and others are the potential substances and link microbiota to host physiology. Many of these metabolites act as signalling molecules to a number of cells types and also help in the secretion of hormones. Moreover, interaction of microbiota derived metabolites with their host, immunity boosting mechanisms, protection against pathogens and modulation of metabolism is also highlighted here. Understanding all these functional attributes of metabolites produced from gut-microbiota may lead to the opening of a new avenue for preventing and developing potent therapies against several diseases.

Intervention with inulin prior to and during sanative therapy to further support periodontal health: study protocol for a randomized controlled trial

Background

Periodontal disease is a chronic state of inflammation that can destroy the supporting tissues around the teeth, leading to the resorption of alveolar bone. The initial strategy for treating periodontal disease is non-surgical sanative therapy (ST). Periodontal disease can also induce dysbiosis in the gut microbiota and contribute to low-grade systemic inflammation. Prebiotic fibers such as inulin can selectively alter the intestinal microbiota and support homeostasis by improving gut barrier functions and preventing inflammation. Providing an inulin supplement prior to and post-ST may influence periodontal health while providing insight into the complex relationship between periodontal disease and the gut microbiota. The primary objective is to determine if inulin is more effective than the placebo at improving clinical periodontal outcomes including probing depth (PD) and bleeding on probing (BOP). Secondary objectives include determining the effects of inulin supplementation pre- and post-ST on salivary markers of inflammation and periodontal-associated pathogens, as these outcomes reflect more rapid changes that can occur.

Methods

We will employ a single-center, randomized, double-blind, placebo-controlled study design and recruit and randomize 170 participants who are receiving ST to manage the periodontal disease to the intervention (inulin) or placebo (maltodextrin) group. A pilot study will be embedded within the randomized controlled trial using the first 48 participants to test the feasibility for the larger, powered trial. The intervention period will begin 4 weeks before ST through to their follow-up appointment at 10 weeks post-ST. Clinical outcomes of periodontal disease including the number of sites with PD ≥ 4 mm and the presence of BOP will be measured at baseline and post-ST. Salivary markers of inflammation, periodontal-associated pathogens, body mass index, and diet will be measured at baseline, pre-ST (after 4 weeks of intervention), and post-ST (after 14 weeks of intervention).

Discussion

We expect that inulin will enhance the positive effect of ST on the management of periodontal disease. The results of the study will provide guidance regarding the use of prebiotics prior to and as a supportive adjunct to ST for periodontal health.

Trial registration

ClinicalTrials.gov NCT04670133. Registered on 17 December 2020.

Impact of interval training with probiotic (L. plantarum / Bifidobacterium bifidum) on passive avoidance test, ChAT and BDNF in the hippocampus of rats with Alzheimer's disease

It has been suggested that gut microbiota dysbiosis can lead to Alzheimer's disease (AD), inducing the production of many AD-related pre-inflammatory cytokines. On the other hand, daily probiotic administration and regular exercise training are assumed to improve clinical AD-related symptoms. To take this line of research further, this study was aimed at investigating the impact of moderate-intensity interval training (MIIT) with a combined administration of Lactobacillus plantarum and Bifidobacterium bifidum (probiotic, BROB) on the passive avoidance test (Shuttle Box), choline acetyltransferase (ChAT) and the brain derived neurotrophic factor (BDNF) in the hippocampus of a rat model of AD. Forty male Wistar rats (280 ± 20 g) were divided into five groups (n = 8 in each) of control, amyloid beta peptide (Aβ), Aβ + MIIT (AD rats undergoing MIIT), Aβ + PROB (AD rats fed Lactobacillus plantarum and Bifidobacterium bifidum), and Aβ + MIIT + PROB (AD rats receiving both treatments). AD was induced by the intra-cerebroventricular injection of Aβ1-42 peptide. MIIT was performed on rodent treadmill for 8 weeks (5 days per week). The probiotic was also fed daily to the related groups for 8 weeks. BDNF and ChAT in the hippocampus were measured by real time PCR (RT-PCR) and immunohistochemistry (IHC), respectively. Cresyl violet staining of brain tissue was performed to evaluate the dead cells. Results of tissue staining showed that the induction of the Alzheimer's led to the destruction of hippocampal cells and induced neurodegeneration (p = 0.001). Results of the shuttle box test showed that short-term memory was improved in the Aβ + MIIT + PROB group compared to the Aβ group, while death cells (dark cells) were decreased in all the other three groups (MIIT, BROB, and Aβ + MIIT + PROB). Levels of ChAT as well as the BDNF mRNA in the Aβ + MIIT + PROB group showed a significant increase compared to the Aβ group. In conclusion, it seems that the use of the combined administration of Lactobacillus plantarum and Bifidobacterium bifidum with interval aerobic exercise can have neuroprotective effects on AD.

Gut Microbiota Mediates the Preventive Effects of Dietary Capsaicin Against Depression-Like Behavior Induced by Lipopolysaccharide in Mice

Capsaicin (CAP) is an active ingredient in chili pepper that is frequently consumed. It exerts various pharmacological activities, and also has potential effects on mental illness. However, its mechanism of antidepressant effects is still unclear. Based on the emerging perspective of the gut-brain axis, we investigated the effects of dietary CAP on gut microbes in mice with depression-like behaviors induced by lipopolysaccharide (LPS). C57BL/6J male mice (four weeks old) were given specific feed (standard laboratory chow or laboratory chow plus 0.005% CAP) for 4 months. During the last five days, LPS (0.052/0.104/0.208/0.415/0.83 mg/kg, 5-day) was injected intraperitoneally to induce depression. Behavioral indicators and serum parameters were measured, and gut microbiota were identified by sequencing analysis of the 16S gene. This study showed that dietary CAP improved depressive-like behavior (sucrose preference test, forced swimming test, tail suspension test) and levels of 5-HT and TNF-α in serum of LPS-induced mice with depression-like behaviors. In addition, CAP could recover abnormal changes in depression-related microbiota. Especially at the genus level, CAP enhanced the variations in relative abundance of certain pivotal microorganisms like Ruminococcus, Prevotella, Allobaculum, Sutterella, and Oscillospira. Correlation analysis revealed changes in microbiota composition that was closely related to depressive behavior, 5-HT and TNF-α levels. These results suggested that dietary CAP can regulate the structure and number of gut microbiota and play a major role in the prevention of depression.

An 8-Week Administration of Bifidobacterium bifidum and Lactobacillus plantarum Combined with Exercise Training Alleviates Neurotoxicity of Aβ and Spatial Learning via Acetylcholine in Alzheimer Rat Model

This study aimed to determine the effects of 8 weeks of an administration of Bifidobacterium bifidum and Lactobacillus plantarum combined with exercise training on neurotoxicity of Aβ, spatial learning, acetylcholine (ACH), and vascular endothelial growth factor (VEGF) in Alzheimer rats. Twenty-five Wistar rats were randomly divided into 5 groups (n = 5 in each): (1) healthy control (control), (2) Alzheimer disease (AD), (3) AD with treadmill exercise (AD + Exe), (4) AD with probiotic (combined administration of Bifidobacterium bifidum and Lactobacillus plantarum) treatment (AD + Pro), and (5) AD with treadmill exercise and probiotic treatment (AD + Exe + Pro). AD was induced by intra-cerebroventricular injection of Aβ1-42 peptide. Then, the training groups exercised on treadmill for 8 weeks, 5 days per weeks. The rats were treated daily with probiotic supplements via gavage for 8 weeks. The Morris water maze (MWM) test was administered to measure spatial learning. Then, the animals were sacrificed and Vegf and ACH were analyzed using the qPCR and immunohistochemistry (IHC) methods, respectively. Results showed that the β-amyloid plaques were significantly increased in the brains of the AD group compared with the control group (p < 0.001). The combined use of probiotics and exercise training significantly increased the time spent in the target quadrant after removing the platform, compared with the AD group in the Morris water maze test (p < 0.001). Crystal violet analysis showed that sole (p < 0.01) and combined exercise training and probiotic supplementation (p < 0.001) significantly reduced the number of dead cells in the brains of rats compared with the AD group. AD significantly decreased Vegf mRNA and ACH in the CA1 area of the hippocampus (p < 0.001). However, mono and combined therapy (exercise and probiotics) significantly increased ACH in the rats' brain compared with the AD group. Overall, 8 weeks of an administration of Bifidobacterium bifidum and Lactobacillus plantarum combined with exercise training can improve spatial learning impairment in the AD rats. Exercise and probiotics seem to offer potential benefits to AD patients by upregulating ACH.

The Alteration of Intestinal Microbiota Profile and Immune Response in Epinephelus coioides during Pathogen Infection

Epinephelus coioides, or grouper, is a high economic value fish species that plays an important role in the aquaculture industry in Asia. However, both viral and bacterial diseases have threatened grouper for many years, especially nervous necrosis virus, grouper iridovirus and Vibrio harveyi, which have caused a bottleneck in the grouper industry. Currently, intestinal microbiota can provide novel insights into the pathogenesis-related factors involved in pathogen infection. Hence, we investigated the comparison of intestinal microbiota communities in control group and pathogen-infected grouper through high-throughput sequencing of the 16S rRNA gene. Our results showed that microbial diversity was decreased, whereas microbial richness was increased during pathogen infection. The individuals in each group were distributed distinctly on the PLSDA diagram, especially the GIV group. Proteobacteria and Firmicutes were the most abundant bacterial phyla in all groups. Interestingly, beneficial genera, Faecalibacterium and Bifidobacterium, predominated in the intestines of the control group. In contrast, the intestines of pathogen-infected grouper had higher levels of harmful genera such as Sphingomonas, Atopostipes, Staphylococcus and Acinetobacter. Additionally, we investigated the expression levels of innate and adaptive immune-related genes after viral and bacterial infection. The results revealed that immunoglobulin T and proinflammatory cytokine levels in the intestine increased after pathogen infection. Through these unique bacterial compositions in diseased and uninfected fish, we could establish a novel therapeutic approach and bacterial marker for preventing and controlling these diseases.

Effect of Moxibustion on the Intestinal Flora of Rats with Knee Osteoarthritis Induced by Monosodium Iodoacetate

In this study, a knee osteoarthritis (KOA) rat model induced by monosodium iodoacetate (MIA) was used to study the effect of moxibustion on improving knee cartilage damage and its effect on the intestinal flora. The experimental rats were divided into the normal group (N), model group (M), moxibustion treatment group (MS), and diclofenac sodium treatment group (DS). After 4 weeks, cartilage pathological damage in the knee joint was evaluated using hematoxylin-eosin and safranin O-fast green staining analysis. ELISAs and Western blots were used to detect the expression levels of IL-1β and TNF-α in the serum and cartilage, respectively. The total DNA of the fecal samples was extracted and subjected to high-throughput sequencing of the V3-V4 region of the 16S rRNA gene to analyze the changes in the intestinal flora. In the model group, the cartilage was obviously damaged, the expression levels of IL-1β and TNF-α in the serum and cartilage were increased, and the abundance and diversity of the intestinal flora were decreased. Moxibustion treatment significantly improved the cartilage damage and reduced the concentration of inflammatory factors in the serum and cartilage. The high-throughput sequencing results showed that compared to the model group, the moxibustion treatment regulated some specific species in the intestinal microorganisms rather than the α diversity. In conclusion, our findings suggest that moxibustion treatment may work through two aspects in rats. On one hand, it directly acts on knee cartilage to promote repair, and on the other hand, it regulates the composition of the intestinal flora and reduces the production of inflammatory factors.

Diet and Nutritional Factors in Male (In)fertility-Underestimated Factors

In up to 50% of cases, infertility issues stem solely from the male. According to some data, the quality of human semen has deteriorated by 50%–60% over the last 40 years. A high-fat diet and obesity, resulting from an unhealthy lifestyle, affects the structure of spermatozoa, but also the development of offspring and their health in later stages of life. In obese individuals, disorders on the hypothalamic-pituitary-gonadal axis are observed, as well as elevated oestrogen levels with a simultaneous decrease in testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels. Healthy dietary models clearly correlate with better sperm quality and a smaller risk of abnormalities in parameters such as sperm count, sperm concentration and motility, and lower sperm DNA fragmentation. Apart from mineral components such as zinc and selenium, the role of omega-3 fatty acids and antioxidant vitamins should be emphasized, since their action will be primarily based on the minimization of oxidative stress and the inflammation process. Additionally, the incorporation of carnitine supplements and coenzyme Q10 in therapeutic interventions also seems promising. Therefore, it is advisable to have a varied and balanced diet based on vegetables and fruit, fish and seafood, nuts, seeds, whole-grain products, poultry, and low-fat dairy products.

Gut microbiota composition and frailty in elderly patients with Chronic Kidney Disease

Background

Frailty is common in older patients affected by chronic kidney disease (CKD). Since gut microbiota (gMB) may contribute to frailty, we explored possible associations between gMB and frailty in CKD.

Methods

We studied 64 CKD patients (stage 3b-4), categorized as frail (F, 38) and not frail (NF, 26) according to Fried criteria, and 15 controls (C), all older than 65 years. In CKD we assessed serum C-reactive protein, blood neutrophil/lymphocyte ratio, Malnutrition-inflammation Score (MIS); gMB was studied by denaturing gel gradient electrophoresis (DGGE), high-throughput sequencing (16S r-RNA gene), and quantitative real-time PCR (RT-PCR).

Results

No differences in alpha diversity between CKD and C and between F and NF patients emerged, but high-throughput sequencing showed significantly higher abundance of potentially noxious bacteria (Citrobacter, Coprobacillus, etc) and lower abundance of saccharolytic and butyrate-producing bacteria (Prevotella spp., Faecalibacterium prausnitzii, Roseburia spp.), in CKD respect to C. Mogibacteriaceae family and Oscillospira genus abundance was positively related to inflammatory indices in the whole CKD cohort, while that of Akkermansia, Ruminococcus and Eubacterium genera was negatively related. Compared with NF, in F there was a higher abundance of some bacteria (Mogibacteriacee, Coriobacteriacee, Eggerthella, etc), many of which have been described as more abundant in other diseases.

Conclusions

These results suggest that inflammation and frailty could be associated to gMB modifications in CKD.

Modulating the Intestinal Microbiota: Therapeutic Opportunities in Liver Disease

Gut microbiota has been demonstrated to have a significant impact on the initiation, progression and development of complications associated with multiple liver diseases. Notably, nonalcoholic fatty liver diseases, including nonalcoholic steatohepatitis and cirrhosis, severe alcoholic hepatitis, primary sclerosing cholangitis and hepatic encephalopathy, have strong links to dysbiosis - or a pathobiological change in the microbiota. In this review, we provide clear and concise discussions on the human gut microbiota, methods of identifying gut microbiota and its functionality, liver diseases that are affected by the gut microbiota, including novel associations under research, and provide current evidence on the modulation of gut microbiota and its effects on specific liver disease conditions.

Intestinal alkaline phosphatase targets the gut barrier to prevent aging

Gut barrier dysfunction and gut-derived chronic inflammation play crucial roles in human aging. The gut brush border enzyme intestinal alkaline phosphatase (IAP) functions to inhibit inflammatory mediators and also appears to be an important positive regulator of gut barrier function and microbial homeostasis. We hypothesized that this enzyme could play a critical role in regulating the aging process. We tested the role of several IAP functions for prevention of age-dependent alterations in intestinal homeostasis by employing different loss-of-function and supplementation approaches. In mice, there is an age-related increase in gut permeability that is accompanied by increases in gut-derived portal venous and systemic inflammation. All these phenotypes were significantly more pronounced in IAP-deficient animals. Oral IAP supplementation significantly decreased age-related gut permeability and gut-derived systemic inflammation, resulted in less frailty, and extended lifespan. Furthermore, IAP supplementation was associated with preserving the homeostasis of gut microbiota during aging. These effects of IAP were also evident in a second model system, Drosophilae melanogaster. IAP appears to preserve intestinal homeostasis in aging by targeting crucial intestinal alterations, including gut barrier dysfunction, dysbiosis, and endotoxemia. Oral IAP supplementation may represent a novel therapy to counteract the chronic inflammatory state leading to frailty and age-related diseases in humans.

Intestinal Availability and Metabolic Effects of Dietary Camelina Sphingolipids during the Metabolic Syndrome Onset in Mice

Sphingolipids appear as a promising class of components susceptible to prevent the onset of the metabolic syndrome (MetS). Gut availability and effects of Camelina sativa sphingolipids were investigated in a mouse model of dietary-induced MetS. Seed meals from two Camelina sativa lines enriched, respectively, in C24- and C16-NH_2^- glycosyl-inositol-phosphoryl-ceramides (NH₂GIPC) were used in hypercaloric diets. After 5 weeks on these two hypercaloric diets, two markers of the MetS were alleviated (adiposity and insulin resistance) as well as inflammation markers and colon barrier dysfunction. A more pronounced effect was observed with the C16-NH₂GIPC-enriched HC diet, in particular for colon barrier function. Despite a lower digestibility, C16-NH₂GIPC were more prevalent in the intestine wall. Sphingolipids provided as camelina meal can therefore counteract some deleterious effects of a hypercaloric diet in mice at the intestinal and systemic levels. Interestingly, these beneficial effects seem partly dependent on sphingolipid acyl chain length.

Inflammation, Frailty and Cardiovascular Disease

Chronic inflammation, which is called "inflamm-aging" , is characterized by an increased level of inflammatory cytokines in response to physiological and environmental stressors, and causes the immune system to function consistently at a low level, even though it is not effective. Possible causes of inflammaging include genetic susceptibility, visceral obesity, changes in gut microbiota and permeability, chronic infections and cellular senescence. Inflammation has a role in the development of many age-related diseases, such as frailty. Low grade chronic inflammation can also increase the risk of atherosclerosis and insulin resistance which are the leading mechanisms in the development of cardiovascular diseases (CVD). As it is well known that the risk of CVD is higher in older people with frailty and the risk of frailty is higher in patients with CVD, there may be relationship between inflammation and the development of CVD and frailty. Therefore, this important issue will be discussed in this chapter.

Association of suboptimal health status with intestinal microbiota in Chinese youths

Suboptimal health status (SHS), a physical state between health and disease, is a subclinical and reversible stage of chronic disease. Previous studies have shown alterations in the intestinal microbiota in patients with some chronic diseases. This study aimed to investigate the association between SHS and intestinal microbiota in a case-control study with 50 SHS individuals and 50 matched healthy controls. Intestinal microbiota was analysed by MiSeq 250PE. Alpha diversity of intestinal microbiota in SHS individuals was higher compared with that of healthy controls (Simpson index, W = 2238, P = .048). Beta diversity was different between SHS and healthy controls (P = .018). At the phylum level, the relative abundance of Verrucomicrobia was higher in the SHS group than that in the controls (W = 2201, P = .049). Compared with that of the control group, nine genera were significantly higher and five genera were lower in abundance in the SHS group (all P < .05). The intestinal microbiota, analysed by a random forest model, was able to distinguish individuals with SHS from the controls, with an area under the curve of 0.79 (95% confidence interval: 0.77-0.81). We demonstrated that the alteration of intestinal microbiota occurs with SHS, an early stage of disease, which might shed light on the importance of intestinal microbiota in the primary prevention of noncommunicable chronic diseases.

Anti-Inflammatory Activity of Isomaltodextrin in a C57BL/6NCrl Mouse Model with Lipopolysaccharide-Induced Low-Grade Chronic Inflammation

：The purpose of this study was to identify the anti-inflammatory activity and mechanism of isomaltodextrin (IMD) in a C57BL/6NCrl mouse model with lipopolysaccharide (LPS)-induced systemic low-grade chronic inflammation and the effect on inflammation-induced potential risk of metabolic disorders. Pre-treatment of IMD decreased the production of pro-inflammatory mediators, TNF-α and MCP-1, and stimulated the production of the anti-inflammatory mediator, adiponectin by increasing the protein expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) in the white adipose tissues. IMD administration reduced plasma concentrations of endotoxin, decreased macrophage infiltration into adipocytes, and increased expression of mucin 2, mucin 4, and the tight junction protein claudin 4. These results suggest that IMD administration exerted an anti-inflammatory effect on mice with LPS-induced inflammation, potentially by decreasing circulating endotoxin, suppressing pro-inflammatory mediators and macrophage infiltration, or by improving mucus or tight junction integrity. IMD exerted protein expression of insulin receptor subset-1 (IRS-1). IMD alleviated the disturbance of gut microflora in LPS-treated mice, as the number of B. bifidum, L. casei, and B. fragilis increased, and E. coli and C. difficile decreased, when compared to LPS-treated mice. The analysis of short chain fatty acids (SCFAs) further supported that the concentrations of acetic and butyric acids were positively correlated with IMD, as well as the number of beneficial bacteria. This study provides evidence that IMD possesses anti-inflammatory properties and exerts beneficial functions to prevent systemic low-grade chronic inflammation and reduces the risk of developing insulin resistance and associated metabolic diseases.

The Impact of the Microbiome on Immunosenescence

Human microbiome investigations now provide evidence that changes in the microbiome over time and their interaction with the immune, endocrine, and nervous systems are associated with a wide array of disorders. Human immunological studies typically absent a microbiome consideration in their investigations. An area of recent exploration is the role of the microbiome as a critical partner in the development and function of the human immune system in aging. It is well known that immunologic maturation is influenced by a lifetime of interactions of the host with its companion microbiome. It is generally not well recognized that intestinal microbes play an essential role in the development and expansion of gut mucosal and systemic immune function. Gut microbial communities of elderly people have different composition and behavior compared to healthy younger adults. Comorbidities associated with microbial pathogens and an aberrant immune system tend to increase with aging. This review underscores the impact of the human-microbiome interface on the development and function of the immune system and on immunosenescence. These changes have important implications regarding health and health system utilization in the elderly population.

Neurobehavioral dysfunction in non-alcoholic steatohepatitis is associated with hyperammonemia, gut dysbiosis, and metabolic and functional brain regional deficits

Non-alcoholic steatohepatitis (NASH) is one of the most prevalent diseases worldwide. While it has been suggested to cause nervous impairment, its neurophysiological basis remains unknown. Therefore, the aim of this study is to unravel the effects of NASH, through the interrelationship of liver, gut microbiota, and nervous system, on the brain and human behavior. To this end, 40 Sprague-Dawley rats were divided into a control group that received normal chow and a NASH group that received a high-fat, high-cholesterol diet. Our results show that 14 weeks of the high-fat, high-cholesterol diet induced clinical conditions such as NASH, including steatosis and increased levels of ammonia. Rats in the NASH group also demonstrated evidence of gut dysbiosis and decreased levels of short-chain fatty acids in the gut. This may explain the deficits in cognitive ability observed in the NASH group, including their depressive-like behavior and short-term memory impairment characterized in part by deficits in social recognition and prefrontal cortex-dependent spatial working memory. We also reported the impact of this NASH-like condition on metabolic and functional processes. Brain tissue demonstrated lower levels of metabolic brain activity in the prefrontal cortex, thalamus, hippocampus, amygdala, and mammillary bodies, accompanied by a decrease in dopamine levels in the prefrontal cortex and cerebellum and a decrease in noradrenalin in the striatum. In this article, we emphasize the important role of ammonia and gut-derived bacterial toxins in liver-gut-brain neurodegeneration and discuss the metabolic and functional brain regional deficits and behavioral impairments in NASH.

Targeting the Gut Microbiota to Treat Cachexia

Cachexia occurs in many chronic diseases and is associated with increased morbidity and mortality. It is treated by nutritional support but often with limited effectiveness, leading to the search of other therapeutic strategies. The modulation of gut microbiota, whether through pro-, pre-, syn- or antibiotics or fecal transplantation, is attracting ever-growing interest in the field of obesity, but could also be an interesting and innovative alternative for treating cachexia. This article reviews the evidence linking the features of malnutrition, as defined by the Global Leadership Initiative on Malnutrition [low body mass index (BMI), unintentional body weight loss, low muscle mass, low appetite, and systemic inflammation] and the gut microbiota in human adults with cachexia-associated diseases, and shows the limitations of the present research in that field with suggestions for future directions.

Gut microbiota and obesity-associated osteoarthritis

Obesity is a well-known primary risk factor for osteoarthritis (OA). In recent decades, the biomechanics-based theoretical paradigm for the pathogenesis of obesity-associated OA has been gradually but fundamentally modified. This modification is a result of accumulating evidence that biological factors also contribute to the etiology of the disease. The gut microbiota is a complicated ecosystem that profoundly influences the health of the host and can be modulated by the combined effects of environmental stimuli and genetic factors. Recently, enteric dysbacteriosis has been identified as a causal factor in the initiation and propagation of obesity-associated OA in animal models. Gut microbes and their components, microbe-associated lipid metabolites, and OA interact at both systemic and local levels through mechanisms that involve interplay with the innate immune system. However, the demonstration of causality in humans will require further studies. Nonetheless, probiotics, prebiotics, dietary habits and exercise, which aid the restoration of a healthy microbial community, are potential therapeutic approaches in the treatment of obesity-associated OA.