Diet-induced dysbiosis of the intestinal microbiota and the effects on immunity and disease

Integrative review of the gut microbiome’s role in pain management for orthopaedic conditions

The gut microbiome, a complex ecosystem of microorganisms, has a significant role in modulating pain, particularly within orthopaedic conditions. Its impact on immune and neurological functions is underscored by the gut-brain axis, which influences inflammation, pain perception, and systemic immune responses. This integrative review examines current research on how gut dysbiosis is associated with various pain pathways, notably nociceptive and neuroinflammatory mechanisms linked to central sensitization. We highlight advancements in meta-omics technologies, such as metagenomics and metaproteomics, which deepen our understanding of microbiome-host interactions and their implications in pain. Recent studies emphasize that gut-derived short-chain fatty acids and microbial metabolites play roles in modulating neuroinflammation and nociception, contributing to pain management. Probiotics, prebiotics, synbiotics, and faecal microbiome transplants are explored as potential therapeutic strategies to alleviate pain through gut microbiome modulation, offering an adjunct or alternative to opioids. However, variability in individual microbiomes poses challenges to standardizing these treatments, necessitating further rigorous clinical trials. A multidisciplinary approach combining microbiology, immunology, neurology, and orthopaedics is essential to develop innovative, personalized pain management strategies rooted in gut health, with potential to transform orthopaedic pain care.

The same but different: impact of animal facility sanitary status on a transgenic mouse model of Alzheimer's disease

The gut-brain axis has emerged as a key player in the regulation of brain function and cognitive health. Gut microbiota dysbiosis has been observed in preclinical models of Alzheimer's disease and patients. Manipulating the composition of the gut microbiota enhances or delays neuropathology and cognitive deficits in mouse models. Accordingly, the health status of the animal facility may strongly influence these outcomes. In the present study, we longitudinally analyzed the fecal microbiota composition and amyloid pathology of 5XFAD mice housed in a specific opportunistic pathogen-free (SOPF) and a conventional facility. The composition of the microbiota of 5XFAD mice after aging in conventional facility showed marked differences compared to WT littermates that were not observed when the mice were bred in SOPF facility. The development of amyloid pathology was also enhanced by conventional housing. We then transplanted fecal microbiota (FMT) from both sources into wild-type (WT) mice and measured memory performance, assessed in the novel object recognition test, in transplanted animals. Mice transplanted with microbiota from conventionally bred 5XFAD mice showed impaired memory performance, whereas FMT from mice housed in SOPF facility did not induce memory deficits in transplanted mice. Finally, 18 weeks of housing SOPF-born animals in a conventional facility resulted in the reappearance of specific microbiota compositions in 5XFAD vs WT mice. In conclusion, these results show a strong impact of housing conditions on microbiota-associated phenotypes and question the relevance of breeding preclinical models in specific pathogen-free (SPF) facilities.

IMPORTANCE

Housing conditions affect the composition of the gut microbiota. Gut microbiota of 6-month-old conventionally bred Alzheimer's mice is dysbiotic. Gut dysbiosis is absent in Alzheimer's mice housed in highly sanitized facilities. Transfer of fecal microbiota from conventionally bred mice affects cognition. Microbiota of mice housed in highly sanitized facilities has no effect on cognition.

Flammulina velutipes residue Polysaccharide Alleviates Immunosuppression and Intestinal Injury by Modulating Gut Microbiota and Associated Metabolites

This study elucidated the mechanisms underlying the immunoregulatory and gut-microbiota-modulating effects of Flammulina velutipes residue polysaccharide (FVRP) using cyclophosphamide (CTX)-induced mouse models. FVRP supplementation alleviated CTX-induced intestinal damage and boosted antioxidant enzyme activity and cytokine secretion. Additionally, FVRP enhanced the diversity and total species richness of the gut microbiota, promoting the proliferation of beneficial bacteria (e.g., Prevotellaceae), while reducing the abundance of CTX-derived bacteria (Lachnospiraceae and Rikenellaceae). FVRP facilitates the accumulation of short-chain fatty acids. Untargeted metabolomic analyses of cecal content revealed that FVRP treatment notably restored the levels of 32 endogenous metabolites altered by CTX. Based on a pseudosterility mice model, fecal microbiota transplantation (FMT), and fecal filtrate transplantation (FFT), gut microbiota and associated metabolites were demonstrated to play a crucial role in the immunomodulatory and protective effects of FVRP against intestinal injury. In conclusion, FVRP exhibits significant potential as an immune enhancer and natural therapeutic agent for alleviating intestinal inflammatory conditions.

Stomach Microbiome Simplification of a Coral Reef Fish at Its Novel Cold-Range Edge Under Climate Change

Climate-driven range extensions of animals into higher latitudes are often facilitated by phenotypic plasticity. Modifications to habitat preference, behaviour and diet can increase the persistence of range-extending species in novel high-latitude ecosystems. These strategies may be influenced by changes in their gut and stomach microbial communities that are critical to host fitness and potentially adaptive plasticity. Yet, it remains unknown if the gut and stomach microbiome of range-extending species is plastic in their novel ranges to help facilitate these modifications. Here, we categorised stomach microbiome communities of a prevalent range-extending coral reef fish along a 2000-km latitudinal gradient in a global warming hotspot, extending from their tropical core range to their temperate cold range edge. At their cold range edge, the coral reef fish's stomach microbiome showed a 59% decrease in bacterial diversity and a 164% increase in the relative abundance of opportunistic bacteria (Vibrio) compared to their core range. Microbiome diversity was unaffected by fish body size, water temperature, physiology (cellular defence and damage) and habitat type (turf, barren, oyster, kelp and coral) across their range. The observed shifts in microbiome composition suggest dysbiosis and low plasticity of tropical range-extending fishes to novel environmental conditions (e.g., temperate prey and lower seawater temperature) at their novel range edges, which may increase their susceptibility to disease in temperate ecosystems. We conclude that fishes extending their ranges to higher latitudes under ocean warming can experience a simplification (i.e., reduced diversity) of their stomach microbiome, which could restrict their current rate of range extensions or establishment in temperate ecosystems.

Dietary intake in healthy older individuals is associated with lipopolysaccharide binding protein a biomarker of gut function: an exploratory cross-sectional study

Diet, physical function and gut health are important modifiable factors in ageing. However, it is unclear how ageing affects various domains of gut function. Aims of this cross-sectional study were to explore relationships between nutrient intake, physical function, and biomarkers of gut function in older individuals. Healthy participants (n = 94, mean age 71.1 years SD 5.10, 56% female) were recruited to investigate the relationship between nutrient intake (protein, fibre, carbohydrate, fat), physical function (chair rise time, handgrip strength) and lipopolysaccharide (LPS) binding protein (LBP); a marker of gut permeability. Linear regression models, adjusted for age, fat mass/fat free mass ratio, weight and gender, reported LBP changed by; -161.9 ng/mL (95% CI -323.0, -0.8) for every 1 g increase in daily fibre/1,000 kilocalories; 80.5 ng/mL (6.7, 154.2) for 1% increase in daily energy intake as fat; and -88.1 ng/mL (-146.7, -29.6) for 1% increase in daily energy as carbohydrates. When further adjusted for C-reactive protein (CRP), a marker of inflammation, LBP decreased by an additional 6.9 ng/mL for fibre, increased by an additional 4.0 ng/mL for fat and decreased by an additional 3.7 ng/mL for carbohydrate. These findings suggest that in healthy older adults' nutrient intake is associated with LBP, and CRP appears to slightly modify these associations. There were no associations between LBP and handgrip strength or chair rise time. Results suggest that fibre, fat, and carbohydrates are important for maintaining gut function, potentially mediated by inflammation in older adults, although further research is needed to explore the implications for physical function and CRP as a mediator.

Dietary Bacillus subtilis HGcc-1 improves the growth performance, α-amylase and lipase activities, immunity and antioxidant capacity, intestinal microbiota, and heat stress resistance in Pacific white shrimp (Litopenaeus vannamei)

This study aimed to investigate the effects of B. subtilis HGcc-1 supplementation on the growth performance, immunity response, antioxidant capacity, intestinal microbiota and heat stress resistance of Litopenaeus vannamei. The results showed that B. subtilis HGcc-1 increased the activities of α-amylase and lipase and the activities of acid phosphatase and alkaline phosphatase, significantly decreased malondialdehyde content and significantly increased the activities of total antioxidant capacity, glutathione S-transferase, total superoxide dismutase, the expression levels of immune-related genes Toll and prophenoloxidase as compared to the control. Analysis of the intestinal microbial revealed that a significant increase in the relative abundance of Firmicutes, such as Lactococcus. Conversely, there was a decrease in the relative abundance of Proteobacteria, such as Vibrio and Shewanella. Furthermore, B. subtilis HGcc-1 supplementation may help alleviating heat stress injury in shrimp by modulating the Hippo signaling pathway. In summary, this study provided a valuable insight into the functional benefits of B. subtilis HGcc-1 supplementation in shrimp, offering a theoretical basis for its practical application in aquaculture.

Agricultural Practices and Environmental Factors Drive Microbial Communities in the Mezcal-Producing Agave angustifolia Haw

Mezcal, a traditional Mexican alcoholic beverage, has been a vital source of livelihood for indigenous and rural communities for centuries. However, increasing international demand is exerting pressure on natural resources and encouraging intensive agricultural practices. This study investigates the impact of management practices (wild, traditional, and conventional) and environmental factors on the microbial communities associated with Agave angustifolia, a key species in mezcal production. High-throughput sequencing of the 16S rRNA and ITS2 gene regions revealed distinct prokaryotic and fungal community structures across different plant compartments (endosphere, episphere, and soil), identifying 8214 prokaryotic and 7459 fungal ASVs. Core microbial communities were dominated by Proteobacteria, Actinobacteria, Ascomycota, and Basidiomycota. Alpha diversity analyses showed significant increases in prokaryotic diversity from the endosphere to soil, while fungal diversity remained stable. Notably, conventional management practices were associated with reductions in beneficial microbial taxa. Environmental factors such as precipitation and temperature significantly influenced microbial diversity and composition, especially in the rhizosphere. Beta diversity patterns underscored the strong impact of plant compartment, with management practices and aridity further shaping microbial communities. These results reveal the intricate interactions between management practices, environmental conditions, and microbial diversity, providing valuable insights for the sustainable cultivation of A. angustifolia.

Mitigating Metabolic Dysfunction-associated Steatotic Liver Disease (MASLD): The Role of Bioactive Phytoconstituents in Indian Culinary Spices

PURPOSE OF REVIEW

The term metabolic dysfunction-associated steatotic liver disease (MASLD) refers to a group of progressive steatotic liver conditions that include metabolic dysfunction-associated steatohepatitis (MASH), which has varying degrees of liver fibrosis and may advance to cirrhosis, and independent hepatic steatosis. MASLD has a complex underlying mechanism, with patients exhibiting diverse causes and phases of the disease. India has a pool prevalence of MASLD of 38.6% in adults. In 2023, the term NAFLD has been redefined and changed to MASLD. Currently, there are no drugs approved by the FDA for the treatment of MASLD. This study investigates the potential of bioactive phytoconstituents present in spices as a therapeutic approach for MASLD. Moreover, it offers comprehensive data on several pre-clinical studies of bioactive phytoconstituents derived from spices that primarily focus on treating obesity-associated MASLD.

RECENT FINDINGS

Spices include a high amount of bioactive chemicals and several research have indicated their diverse pharmacological activities. Bioactive phytoconstituents from common Indian spices like cinnamic acid, eugenol, curcumin, allicin, 6-gingerols, capsaicin, piperine, eucalyptol, trigonelline, and linalool have been reported to exhibit anti-MASLD effects both in-vivo and in-vitro. Bioactive phytoconstituents from different culinary species of India have shown promising potential against MASLD in pre-clinical status. Further clinical studies on a large scale would be beneficial for paving the path to the development of a new drug which is the need of time.

Global trends and hotspots of type 2 diabetes in children and adolescents: A bibliometric study and visualization analysis

BACKGROUND

Epidemiological surveys indicate an increasing incidence of type 2 diabetes mellitus (T2DM) among children and adolescents worldwide. Due to rapid disease progression, severe long-term cardiorenal complications, a lack of effective treatment strategies, and substantial socioeconomic burdens, it has become an urgent public health issue that requires management and resolution. Adolescent T2DM differs from adult T2DM. Despite a significant increase in our understanding of youth-onset T2DM over the past two decades, the related review and evidence-based content remain limited.

AIM

To visualize the hotspots and trends in pediatric and adolescent T2DM research and to forecast their future research themes.

METHODS

This study utilized the terms "children", "adolescents", and "type 2 diabetes", retrieving relevant articles published between 1983 and 2023 from three citation databases within the Web of Science Core Collection (SCI, SSCI, ESCI). Utilizing CiteSpace and VoSviewer software, we analyze and visually represent the annual output of literature, countries involved, and participating institutions. This allows us to predict trends in this research field. Our analysis encompasses co-cited authors, journal overlays, citation overlays, time-zone views, keyword analysis, and reference analysis, etc.

RESULTS

A total of 9210 articles were included, and the annual publication volume in this field showed a steady growth trend. The United States had the highest number of publications and the highest H-index. The United States also had the most research institutions and the strongest research capacity. The global hot journals were primarily diabetes professional journals but also included journals related to nutrition, endocrinology, and metabolism. Keyword analysis showed that research related to endothelial dysfunction, exposure risk, cardiac metabolic risk, changes in gut microbiota, the impact on comorbidities and outcomes, etc., were emerging keywords. They have maintained their popularity in this field, suggesting that these areas have garnered significant research interest in recent years.

CONCLUSION

Pediatric and adolescent T2DM is increasingly drawing global attention, with genes, behaviors, environmental factors, and multisystemic interventions potentially emerging as future research hot spots.

Gut microbiome as biomarker for triclosan toxicity in Labeo rohita: bioconcentration, immunotoxicity and metagenomic profiling

Triclosan (TCS) is a lipophilic, broad spectrum antimicrobial agent commonly used in personal care products with a projected continuous escalation in aquatic environments in the post COVID 19 era. There is rich documentation in the literature on the alteration of physiological responses in fish due to TCS exposure; however, studies on gut associated bacteria of fish are still scarce. This is the first attempt to determine changes in bacterial community structure due to exposure of TCS on Labeo rohita, a commercially essential freshwater species, using 16S V3-V4 region ribosomal RNA (rRNA) next-generation sequencing (NGS). Chronic exposure of TCS at environmentally realistic concentrations viz. 1/5th (T1: 0.129 mg/L) and 1/10th (T2: 0.065 mg/L) of LC50 for 28 days resulted in the dose dependent bioconcentration of TCS in the fish gut. Prolonged exposure to TCS leads to disruption of gut bacteria evidenced by down regulation of the host immune system. Additionally, high-throughput sequencing analysis showed alternation in the abundance and diversity of microbial communities in the gut, signifying Proteobacteria and Verrucomicrobia as dominant phyla. Significant changes were also observed in the relative abundance of Chloroflexi and Gammatimonadetes phyla in TCS exposed groups. The study revealed that gut microbiome can be used as a biomarker in assessing the degree of TCS toxicity in commercially important fish species.

The Role of the Gut Microbiome in the Development and Progression of Type 2 Diabetes and Liver Disease

Type 2 diabetes mellitus (T2DM) and progressive liver disease are 2 of the most significant global health concerns, and they have alarming and ever-increasing prevalence. A growing body of literature has demonstrated a potential multilateral link between gut microbiome dysbiosis and the development and progression of the above-mentioned conditions. Modulation of gut microbial composition from the norm is due to changes in diet allied with external factors such as age, genetics, and environmental changes. In this comprehensive review, we recapitulate the research to date investigating the links between gut microbiome dysbiosis and T2DM or liver disease, with special attention to the importance of diet. Additionally, we review the most commonly used tools and methodologies of investigating changes in the gut microbiome, highlighting the advantages and limitations of each strategy, before introducing a novel in vitro approach to the problem. Finally, the review offers recommendations for future research in this field that will allow better understanding of how the gut microbiota affects disease progression and of the prospects for intestinal microbiota-based therapeutic options.

Enhancing resistance to Salmonella typhimurium in yellow-feathered broilers: a study of a strain of Lactiplantibacillus plantarum as probiotic feed additives

Lactiplantibacillus plantarum strains are potentially rich sources of probiotics that could help avoid infections. In order to evaluate their efficacy in bolstering resistance to Salmonella typhimurium infection among chicks. In this study, L. plantarum and commercial probiotics were administered via the water supply at a dosage of 1×109 CFU per chicken from days 1 to 7 to establish a protective system for the chicks. On days 8 and 9, S. typhimurium was attacked to investigate the preventive effects and potential mechanisms of L. plantarum in comparison with commercial probiotics. Post-treatment, we took a broad range of measurements, including body weight, immune organ index changes, the viable count of S. typhimurium in the liver, spleen, and cecum, as well as pathological changes in the liver. Our findings demonstrated that both L. plantarum and the commercial probiotic could safeguard chicks from S. typhimurium infection. The data also suggested that probiotic medication could ease weight loss postinfection, lower the bacterial count in the liver, spleen, and cecum, and attenuate liver pathological damage among all treated participants. Subsequently, we did high-throughput sequencing of 16S rRNA to examine the fecal microbiota of the chicks 5  days post-infection. We discovered that both L. plantarum and the commercial probiotic could fend off the invasion of S. typhimurium by affecting the bacterial population of Anaerotruncus, Colidextribacter, and Lactobacillus. Generally speaking, the addition of L. plantarum as a feed additive protects yellow-feathered broilers from S. typhimurium illness, suggesting great potential for commercial uses in the poultry industry.

Propionic Acid Impact on Multiple Sclerosis: Evidence and Challenges

Accumulating evidence suggests that multiple sclerosis (MS) is an environmentally influenced disorder with contributions from life-time exposure to factors including Epstein-Barr virus infection or shifts in microbiome, diet and lifestyle. One suggested factor is a deficiency in propionic acid, a short-chain fatty acid produced by gut bacteria that may contribute to the disease pathology both in animal models and in human cases of MS. Propionate appears to exert beneficial effects on the immune, peripheral and central nervous systems of people with MS (pwMS), showing immunoregulatory, neuroprotective and neurogenerative effects. These functions are crucial, given that MS is characterized by immune-mediated damage of myelin in the central nervous system. Accordingly, propionate supplementation or a modulated increase in its levels through the microbiome and diet may help counteract the pro-inflammatory state in MS by directly regulating immune system and/or by decreasing permeability of gut barrier and blood-brain barrier. This could potentially improve outcomes when used with immune-modulating therapy. However, while its broad effects are promising, further large clinical trials are necessary to evaluate its efficacy and safety in pwMS and clarify its role as a complementary therapeutic strategy. This review provides a comprehensive analysis of the evidence, challenges and limitations concerning propionic acid supplementation in MS.

Dietary amino acids, macronutrients, vaginal birth, and breastfeeding are associated with the vaginal microbiome in early pregnancy

The vaginal microbiome is a key player in the etiology of spontaneous preterm birth. This study aimed to illustrate maternal environmental factors associated with vaginal microbiota composition and function in pregnancy. Women in healthy pregnancy had vaginal microbial sampling from the posterior vaginal fornix performed at 16 weeks gestation. After shotgun metagenomic sequencing, heatmaps of relative abundance data were generated. Community state type (CST) was assigned, and alpha diversity was calculated. Demography, obstetric history, well-being, exercise, and diet using food frequency questionnaires were collected and compared against microbial parameters. A total of 119 pregnant participants had vaginal metagenomic sequencing performed. Factors with strongest association with beta diversity were dietary lysine (adj-R2 0.113, P = 0.002), valine (adj-R2 0.096, P = 0.004), leucine (adj-R2 0.086, P = 0.003), and phenylalanine (adj-R2 0.085, P = 0.005, Fig. 2D). Previous vaginal delivery and breastfeeding were associated with vaginal beta diversity (adj-R2 0.048, P = 0.003; adj-R2 0.045, P = 0.004), accounting for 8.5% of taxonomy variation on redundancy analysis. Dietary fat, starch, and maltose were positively correlated with alpha diversity (fat +0.002 SD/g, P = 0.025; starch +0.002 SD/g, P = 0.043; maltose +0.440 SD/g, P = 0.013), particularly in secretor-positive women. Functional signature was associated with CST, maternal smoking, and dietary phenylalanine, accounting for 8.9%-11% of the variation in vaginal microbiome functional signature. Dietary amino acids, previous vaginal delivery, and breastfeeding history were associated with vaginal beta diversity. Functional signature of the vaginal microbiome differed with community state type, smoking, dietary phenylalanine, and vitamin K. Increased alpha diversity correlated with dietary fat and starch. These data provide a novel snapshot into the associations between maternal environment, nutrition, and the vaginal microbiome.

IMPORTANCE

This secondary analysis of the MicrobeMom randomized controlled trial reveals that dietary amino acids, macronutrients, previous vaginal birth, and breastfeeding have the strongest associations with vaginal taxonomy in early pregnancy. Function of the vaginal niche is associated mainly by species composition, but smoking, vitamin K, and phenylalanine also play a role. These associations provide an intriguing and novel insight into the association between host factors and diet on the vaginal microbiome in pregnancy and highlight the need for further investigation into the complex interactions between the diet, human gut, and vaginal microbiome.

The Gut Microbiome Advances Precision Medicine and Diagnostics for Inflammatory Bowel Diseases

The gut microbiome emerges as an integral component of precision medicine because of its signature variability among individuals and its plasticity, which enables personalized therapeutic interventions, especially when integrated with other multiomics data. This promise is further fueled by advances in next-generation sequencing and metabolomics, which allow in-depth high-precision profiling of microbiome communities, their genetic contents, and secreted chemistry. This knowledge has advanced our understanding of our microbial partners, their interaction with cellular targets, and their implication in human conditions such as inflammatory bowel disease (IBD). This explosion of microbiome data inspired the development of next-generation therapeutics for treating IBD that depend on manipulating the gut microbiome by diet modulation or using live products as therapeutics. The current landscape of artificial microbiome therapeutics is not limited to probiotics and fecal transplants but has expanded to include community consortia, engineered probiotics, and defined metabolites, bypassing several limitations that hindered rapid progress in this field such as safety and regulatory issues. More integrated research will reveal new therapeutic targets such as enzymes or receptors mediating interactions between microbiota-secreted molecules that drive or modulate diseases. With the shift toward precision medicine and the enhanced integration of host genetics and polymorphism in treatment regimes, the following key questions emerge: How can we effectively implement microbiomics to further personalize the treatment of diseases like IBD, leveraging proven and validated microbiome links? Can we modulate the microbiome to manage IBD by altering the host immune response? In this review, we discuss recent advances in understanding the mechanism underpinning the role of gut microbes in driving or preventing IBD. We highlight developed targeted approaches to reverse dysbiosis through precision editing of the microbiome. We analyze limitations and opportunities while defining the specific clinical niche for this innovative therapeutic modality for the treatment, prevention, and diagnosis of IBD and its potential implication in precision medicine.

The role of the microbiome in immune checkpoint inhibitor colitis and hepatitis

Immune checkpoint inhibitors have revolutionised management for a variety of different types of malignancies. However, gastrointestinal adverse effects, in particular colitis and hepatitis, are relatively common with up to 30 % of patients being affected. The gut microbiome has emerged as a potential contributor to both the effectiveness of immune checkpoint inhibitors and their side effects. This review will attempt to examine the impact the microbiome has on adverse effects as a result of immune checkpoint inhibitors as well as the potential for manipulation of the microbiome as a form of management for immune mediated colitis.

Modulation of gut-microbiota through probiotics and dietary interventions to improve host health

Dietary patterns play an important role in regards to the modulation and control of the gut microbiome composition and function. The interaction between diet and microbiota plays an important role in order to maintain intestinal homeostasis, which ultimately affect the host's health. Diet directly impacts the microbes that inhabit the gastrointestinal tract (GIT), which then contributes to the production of secondary metabolites, such as short-chain fatty acids, neurotransmitters, and antimicrobial peptides. Dietary consumption with genetically modified probiotics can be the best vaccine delivery vector and protect cells from various illnesses. A holistic approach to disease prevention, treatment, and management takes these intrinsically linked diet-microbes, microbe-microbe interactions, and microbe-host interactions into account. Dietary components, such as fiber can modulate beneficial gut microbiota, and they have resulting ameliorative effects against metabolic disorders. Medical interventions, such as antibiotic drugs can conversely have detrimental effects on gut microbiota by disputing the balance between Bacteroides and firmicute, which contribute to continuing disease states. We summarize the known effects of various dietary components, such as fibers, carbohydrates, fatty acids, vitamins, minerals, proteins, phenolic acids, and antibiotics on the composition of the gut microbiota in this article in addition to the beneficial effect of genetically modified probiotics and consequentially their role in regards to shaping human health. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The Influence of Intestinal Microbiota on BDNF Levels

The regulation of neurogenesis, the complex process of producing and differentiating new brain tissue cells, is influenced by a complex interaction of internal and external factors. Over the past decade, extensive research has been conducted on neurotrophins and their key role in adult neurogenesis, as well as their impact on diseases such as depression. Among neurotrophins, the brain-derived neurotrophic factor (BDNF) has been the subject of comprehensive studies on adult neurogenesis, and scientific evidence supports its necessity for neurogenesis in the subventricular zone of the hippocampus. A novel area of research is the emerging role of gut microbiota as a significant contributor to neurogenesis and neurotrophin production. Studies have shown that reduced BDNF levels can lead to mood disorders, which are observed in intestinal dysbiosis, characterized by an imbalance in the composition and quantity of the intestinal microbiota. There is evidence in the literature that there is a link between brain function and gut microbiota. Physical activity, and especially the regularity and intensity of exercise, is important in relation to the level of BDNF and the intestinal microbiota. Probiotics, prebiotics and physical activity may have a positive effect on the intestinal microbiota, and therefore also on the level of the brain-derived neurotrophic factor.

The brain-gut axis: communication mechanisms and the role of the microbiome as a neuroprotective factor in the development of neurodegenerative diseases: A literature overview

The study of the brain-gut axis and its impact on cognitive function and in the development of neurodegenerative diseases is a very timely topic of interest to researchers. This review summarizes information on the basic mechanisms of gut-brain communication. We then discuss the roles of the gut microbiome as a neuroprotective factor in neurodegeneration. The gut microbiota is extremely important in maintaining the body's homeostasis, shaping the human immune system and the proper functioning of the brain. The intestinal microflora affects the processes of neuroplasticity, synaptogenesis, and neuronal regeneration. This review aims to explain changes in the composition of the bacterial population of the intestinal microflora among patients with Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Abnormalities in gut microflora composition are also noted in stress, depression, or autism spectrum development. New observations on psychobiotic supplementation in alleviating the symptoms of neurodegenerative diseases are also presented.

Exploring the Bidirectional Effects of Gut Microbiota and Short-Chain Fatty Acids on Urticaria Subtypes Through Mendelian Randomization and Mediation Analysis

Background

Emerging evidence links gut microbiota and their by-products, notably short-chain fatty acids (SCFAs), to urticaria. This study employs multiple Mendelian Randomization (MR) analyses to unravel the complex interactions among gut microbiota, SCFAs, and different subtypes of urticaria, aiming to elucidate the underlying mechanisms and enhance future clinical research.

Methods

We analyzed published genome-wide association study (GWAS) summary statistics to identify associations between gut microbiota and three common subtypes of urticaria: spontaneous, dermatographic, and temperature-triggered. Initial two-sample and reverse MR analyses explored the causality in these relationships. Subsequent multivariate MR analyses investigated the role of SCFAs in modulating these interactions, with multiple sensitivity analyses to ensure robustness.

Findings

Specific taxa were differently associated with various urticaria subtypes. From microbiota to urticaria: one taxon was negatively associated with dermatographic urticaria; seven taxa were negatively associated and four positively associated with temperature-triggered urticaria; four taxa were negatively associated and six positively associated with spontaneous urticaria. Conversely, from urticaria to microbiota: five taxa were negatively associated with dermatographic urticaria; four were negatively and two positively associated with temperature-triggered urticaria; and two were negatively associated with spontaneous urticaria. These associations were observed at a nominal significance level (P < 0.05). After applying Bonferroni correction for multiple testing, these associations did not reach statistical significance. The observed trends, however, provide insights into potential microbiota-urticaria interactions. Multivariate MR analyses elucidated the role of SCFAs, particularly acetate, which plays a crucial role in modulating immune response. Adjusting for acetate revealed direct effects of Actinobacteria, Bifidobacteriales, and Bifidobacteriaceae on spontaneous urticaria, with corresponding mediation effects of -22%, -24.9%, and -24.9% respectively. Similarly, adjustments for Alcaligenaceae and Betaproteobacteria indicated significant negative effects of acetate on dermatographic and spontaneous urticaria, with mediation effects of -21.7% and -23.7%, respectively.

Conclusion

This study confirms the interconnected roles of gut microbiota, SCFAs, and urticaria. It highlights SCFAs' potential mediating role in influencing urticaria through microbiota, providing insights for future therapeutic strategies.

The comparison of gut microbiota between wild and captive Asian badgers (Meles leucurus) under different seasons

The gut microbiota plays an important role in the immunology, physiology and growth and development of animals. However, currently, there is a lack of available sequencing data on the gut microbiota of Asian badgers. Studying the gut microbiota of Asian badgers could provide fundamental data for enhancing productivity and immunity of badgers' breeding, as well as for the protection of wild animals. In this study, we first characterized the composition and structure of the gut microbiota in the large intestines of wild and captive Asian badgers during summer and winter by sequencing the V3-V4 region of the 16S ribosomal RNA gene. A total of 9 dominant phyla and 12 genera among the bacterial communities of the large intestines exhibited significant differences. Our results showed that Firmicutes and Proteobacteria were the most predominant in both wild and captive badgers, regardless of the season. Romboutsia, Streptococcus and Enterococcus may represent potential sources of zoonoses, warranting further attention and study. Our findings indicated that the diversity and availability of food resources were the most important influencing factors on the gut microbiota of Asian badgers, providing fundamental data for the protection and conservation of wild animals. Variation in the gut microbiota due to season, age and sex in both wild and captive Asian badgers should be considered in future research directions. Furthermore, combined multi-omics studies could provide more information for wild animal conservation, and enhancing our understanding of the molecular mechanism between the microbiota and host.

Involvement of gut microbiota in multiple sclerosis-review of a new pathophysiological hypothesis and potential treatment target

Multiple sclerosis (MS) is a chronic inflammatory disease that leads to demyelination and damage to the central nervous system. It is well known, the significance of the involvement and influence of the immune system in the development and course of MS. Nowadays, more and more studies are demonstrating that an important factor that affects the action of the immune system is the gut microbiota. Changes in the composition and interrelationships in the gut microbiota have a significant impact on the course of MS. Dysbiosis affects the disease course mainly by influencing the immune system directly but also by modifying the secreted metabolites and increasing mucosal permeability. The essential metabolites affecting the course of MS are short-chain fatty acids, which alter pro- and anti-inflammatory responses in the immune system but also increase the permeability of the intestinal wall and the blood-brain barrier. Dietary modification alone can have a significant impact on MS. Based on these interactions, new treatments for MS are being developed, including probiotics administration, supplementation of bacterial metabolites, fecal microbiota transplantation, and dietary changes. Further studies may serve to develop new drugs and therapeutic approaches for MS.

The Antidiabetic Potential of Probiotics: A Review

Diabetes has become one of the most prevalent global epidemics, significantly impacting both the economy and the health of individuals. Diabetes is associated with numerous complications, such as obesity; hyperglycemia; hypercholesterolemia; dyslipidemia; metabolic endotoxemia; intestinal barrier damage; insulin-secretion defects; increased oxidative stress; and low-grade, systemic, and chronic inflammation. Diabetes cannot be completely cured; therefore, current research has focused on developing various methods to control diabetes. A promising strategy is the use of probiotics for diabetes intervention. Probiotics are a class of live, non-toxic microorganisms that can colonize the human intestine and help improve the balance of intestinal microbiota. In this review, we summarize the current clinical studies on using probiotics to control diabetes in humans, along with mechanistic studies conducted in animal models. The primary mechanism by which probiotics regulate diabetes is improved intestinal barrier integrity, alleviated oxidative stress, enhanced immune response, increased short-chain fatty acid production, etc. Therefore, probiotic supplementation holds great potential for the prevention and management of diabetes.

Explainable AI-prioritized plasma and fecal metabolites in inflammatory bowel disease and their dietary associations

Fecal metabolites effectively discriminate inflammatory bowel disease (IBD) and show differential associations with diet. Metabolomics and AI-based models, including explainable AI (XAI), play crucial roles in understanding IBD. Using datasets from the UK Biobank and the Human Microbiome Project Phase II IBD Multi'omics Database (HMP2 IBDMDB), this study uses multiple machine learning (ML) classifiers and Shapley additive explanations (SHAP)-based XAI to prioritize plasma and fecal metabolites and analyze their diet correlations. Key findings include the identification of discriminative metabolites like glycoprotein acetyl and albumin in plasma, as well as nicotinic acid metabolites andurobilin in feces. Fecal metabolites provided a more robust disease predictor model (AUC [95%]: 0.93 [0.87-0.99]) compared to plasma metabolites (AUC [95%]: 0.74 [0.69-0.79]), with stronger and more group-differential diet-metabolite associations in feces. The study validates known metabolite associations and highlights the impact of IBD on the interplay between gut microbial metabolites and diet.

Investigating the Impacts of Diet, Supplementation, Microbiota, Gut-Brain Axis on Schizophrenia: A Narrative Review

Schizophrenia is a disease with a complex etiology that significantly impairs the functioning of patients. In recent years, there has been increasing focus on the importance of the gut microbiota in the context of the gut-brain axis. In our study, we analyzed data on the gut-brain axis in relation to schizophrenia, as well as the impacts of eating habits, the use of various supplements, and diets on schizophrenia. Additionally, the study investigated the impact of antipsychotics on the development of metabolic disorders, such as diabetes, dyslipidemia, and obesity. There may be significant clinical benefits to be gained from therapies supported by supplements such as omega-3 fatty acids, B vitamins, and probiotics. The results suggest the need for a holistic approach to the treatment of schizophrenia, incorporating both drug therapy and dietary interventions.

Effects of Transglutaminase-Induced β-Conglycinin Gels on Intestinal Morphology and Intestinal Flora in Mice at Different High-Intensity Ultrasound Pretreatment Time

TGase-7S gels prepared after different HIU pretreatment times were used to intervene in healthy mice to analyze their effects on growth characteristics and intestinal morphology, and 16S rRNA high-throughput sequencing was applied to fecal samples to investigate the effects of the gel on the structure and diversity of intestinal flora in mice. The results showed that the intestinal tissues of mice in different treatment groups showed better integrity, and the intake of gel increased the length of small intestinal villi in mice, among which the 30-gel group had the highest value of villi length (599.27 ± 44.28) μm (p < 0.05) and showed the neatest and tightest arrangement, indicating that the intake of gel did not have adverse effects on the intestinal tract. The effect of gel ingestion on the diversity of the intestinal microbial community structure was more significant, positively promoting the growth of beneficial bacteria such as Desferriobacterium, Synechococcus, and Bifidobacterium. In addition, the ingestion of the gel improved the intestinal health of mice by altering the physiological functions of the intestinal flora and modulating their participation in various metabolic pathways. The above findings provide some theoretical value for the safety of 7S gel in food applications.

Bacterial protein acetylation: mechanisms, functions, and methods for study

Lysine acetylation is an evolutionarily conserved protein modification that changes protein functions and plays an essential role in many cellular processes, such as central metabolism, transcriptional regulation, chemotaxis, and pathogen virulence. It can alter DNA binding, enzymatic activity, protein-protein interactions, protein stability, or protein localization. In prokaryotes, lysine acetylation occurs non-enzymatically and by the action of lysine acetyltransferases (KAT). In enzymatic acetylation, KAT transfers the acetyl group from acetyl-CoA (AcCoA) to the lysine side chain. In contrast, acetyl phosphate (AcP) is the acetyl donor of chemical acetylation. Regardless of the acetylation type, the removal of acetyl groups from acetyl lysines occurs only enzymatically by lysine deacetylases (KDAC). KATs are grouped into three main superfamilies based on their catalytic domain sequences and biochemical characteristics of catalysis. Specifically, members of the GNAT are found in eukaryotes and prokaryotes and have a core structural domain architecture. These enzymes can acetylate small molecules, metabolites, peptides, and proteins. This review presents current knowledge of acetylation mechanisms and functional implications in bacterial metabolism, pathogenicity, stress response, translation, and the emerging topic of protein acetylation in the gut microbiome. Additionally, the methods used to elucidate the biological significance of acetylation in bacteria, such as relative quantification and stoichiometry quantification, and the genetic code expansion tool (CGE), are reviewed.

Natural products can be potential inhibitors of metalloproteinase II from Bacteroides fragilis to intervene colorectal cancer

Bacteroides fragilis, a gram negative and obligate anaerobe bacterium, is a member of normal gut microbiota and facilitates many essential roles being performed in human body in normal circumstances specifically in Gastrointestinal or GI tract. Sometimes, due to genetics, epigenetics, and environmental factors, Bacteroides fragilis and their protein(s) start interacting with intestinal epithelium thus damaging the lining leading to colorectal cancers (CRC). To identify these protein(s), we incorporated a novel subtractive proteomics approach in the study. Metalloproteinase II (MPII), a Bacteroides fragilis toxin (bft), was investigated for its virulence and unique pathways to demonstrate its specificity and uniqueness in pathogenicity followed by molecular docking against a set of small drug-like natural molecules to discover potential inhibitors against the toxin. All these identified inhibitor-like molecules were analyzed for their ADMET calculations and detailed physiochemical properties to predict their druggability, GI absorption, blood brain barrier and skin permeation, and others. Resultantly, a total of ten compounds with the least binding energies were obtained and were subjected to protein-compound interaction analysis. Interaction analysis revealed the most common ligand-interacting residues in MPII are His 345, Glu 346, His 339, Gly 310, Tyr 341, Pro 340, Asp 187, Phe 309, Lys 307, Ile 185, Thr 308, and Pro 184. Therefore, top three compounds complexed with MPII having best binding energies were selected in order to analyze their trajectories. RMSD, RMSF, Rg and MMPBSA analysis revealed that all compounds showed good binding and keeping the complex stable and compact throughout the simulation time in addition to all properties and qualities of being a potential inhibitor against MPII.

Changes in the gut microbiota of patients with sarcopenia based on 16S rRNA gene sequencing: a systematic review and meta-analysis

Introduction

Sarcopenia, an age-related disease, has become a major public health concern, threatening muscle health and daily functioning in older adults around the world. Changes in the gut microbiota can affect skeletal muscle metabolism, but the exact association is unclear. The richness of gut microbiota refers to the number of different species in a sample, while diversity not only considers the number of species but also the evenness of their abundances. Alpha diversity is a comprehensive metric that measures both the number of different species (richness) and the evenness of their abundances, thereby providing a thorough understanding of the species composition and structure of a community.

Methods

This meta-analysis explored the differences in intestinal microbiota diversity and richness between populations with sarcopenia and non-sarcopenia based on 16 s rRNA gene sequencing and identified new targets for the prevention and treatment of sarcopenia. PubMed, Embase, Web of Science, and Google Scholar databases were searched for cross-sectional studies on the differences in gut microbiota between sarcopenia and non-sarcopenia published from 1995 to September 2023 scale and funnel plot analysis assessed the risk of bias, and performed a meta-analysis with State v.15. 1.

Results

A total of 17 randomized controlled studies were included, involving 4,307 participants aged 43 to 87 years. The alpha diversity of intestinal flora in the sarcopenia group was significantly reduced compared to the non-sarcopenia group: At the richness level, the proportion of Actinobacteria and Fusobacteria decreased, although there was no significant change in other phyla. At the genus level, the abundance of f-Ruminococcaceae; g-Faecalibacterium, g-Prevotella, Lachnoclostridium, and other genera decreased, whereas the abundance of g-Bacteroides, Parabacteroides, and Shigella increased.

Discussion

This study showed that the richness of the gut microbiota decreased with age in patients with sarcopenia. Furthermore, the relative abundance of different microbiota changed related to age, comorbidity, participation in protein metabolism, and other factors. This study provides new ideas for targeting the gut microbiota for the prevention and treatment of sarcopenia.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=475887, CRD475887.

Interaction between bacterial microbiota and nematode parasite communities in sheep's gastrointestinal tract

The economic impact of gastrointestinal (GI) nematode infections on livestock production is well documented worldwide. Increasing evidence supports the hypothesis that parasite colonization induces significant changes in the GI tract environment and, therefore, in the landscape where the microbiota and parasites occur. Understanding the interactions between bacterial and parasite populations in the digestive tract of livestock may be useful to design parasite control strategies based on microbiota modification. The aims of this work were to investigate the impact of the oxytetracycline-mediated manipulation of the gut microbial community on the composition of GI nematode populations in naturally infected sheep and to explore changes in the GI microbial communities after nematode population treatment with the anthelmintic compound monepantel. Extensive manipulation of the GI microbiota with a therapeutic dose of the long-acting oxytetracycline formulation did not induce significant changes in the GI nematode burden. The gut microbiota of treated animals returned to control levels 17 days after treatment, suggesting strong resilience of the sheep microbial community to antibiotic-mediated microbiota perturbation. A significant decrease of the bacterial Mycoplasmataceae family (Log2FC = -4, Padj = 0.001) and a marked increase of the Methanobacteriaceae family (Log2FC = 2.9, Padj = 0.018) were observed in the abomasum of sheep receiving the monepantel treatment. While a comprehensive evaluation of the interactions among GI mycoplasma, methanobacteria and nematode populations deserves further assessment, the bacteria-nematode population interactions should be included in future control programs in livestock production. Understanding how bacteria and parasites may influence each other in the GI tract environment may substantially contribute to the knowledge of the role of microbiota composition in nematode parasite establishment and the role of the parasites in the microbiota composition.

The Importance of Maintaining and Improving a Healthy Gut Microbiota in Athletes as a Preventive Strategy to Improve Heat Tolerance and Acclimatization

Exposure to passive heat (acclimation) and exercise under hot conditions (acclimatization), known as heat acclimation (HA), are methods that athletes include in their routines to promote faster recovery and enhance physiological adaptations and performance under hot conditions. Despite the potential positive effects of HA on health and physical performance in the heat, these stimuli can negatively affect gut health, impairing its functionality and contributing to gut dysbiosis. Blood redistribution to active muscles and peripheral vascularization exist during exercise and HA stimulus, promoting intestinal ischemia. Gastrointestinal ischemia can impair intestinal permeability and aggravate systemic endotoxemia in athletes during exercise. Systemic endotoxemia elevates the immune system as an inflammatory responses in athletes, impairing their adaptive capacity to exercise and their HA tolerance. Better gut microbiota health could benefit exercise performance and heat tolerance in athletes. This article suggests that: (1) the intestinal modifications induced by heat stress (HS), leading to dysbiosis and altered intestinal permeability in athletes, can decrease health, and (2) a previously acquired microbial dysbiosis and/or leaky gut condition in the athlete can negatively exacerbate the systemic effects of HA. Maintaining or improving the healthy gut microbiota in athletes can positively regulate the intestinal permeability, reduce endotoxemic levels, and control the systemic inflammatory response. In conclusion, strategies based on positive daily habits (nutrition, probiotics, hydration, chronoregulation, etc.) and preventing microbial dysbiosis can minimize the potentially undesired effects of applying HA, favoring thermotolerance and performance enhancement in athletes.

The Impact of Dietary Interventions on the Microbiota in Inflammatory Bowel Disease: A Systematic Review

BACKGROUND AND AIMS

Diet plays an integral role in the modulation of the intestinal environment, with the potential to be modified for management of individuals with inflammatory bowel disease [IBD]. It has been hypothesised that poor 'Western-style' dietary patterns select for a microbiota that drives IBD inflammation and, that through dietary intervention, a healthy microbiota may be restored. This study aimed to systematically review the literature and assess current available evidence regarding the influence of diet on the intestinal microbiota composition in IBD patients, and how this may affect disease activity.

METHODS

MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane Library were searched from January 2013 to June 2023, to identify studies investigating diet and microbiota in IBD.

RESULTS

Thirteen primary studies met the inclusion criteria and were selected for narrative synthesis. Reported associations between diet and microbiota in IBD were conflicting due to the considerable degree of heterogeneity between studies. Nine intervention studies trialled specific diets and did not demonstrate significant shifts in the diversity and abundance of intestinal microbial communities or improvement in disease outcomes. The remaining four cross-sectional studies did not find a specific microbial signature associated with habitual dietary patterns in IBD patients.

CONCLUSIONS

Diet modulates the gut microbiota, and this may have implications for IBD; however, the body of evidence does not currently support clear dietary patterns or food constituents that are associated with a specific microbiota profile or disease marker in IBD patients. Further research is required with a focus on robust and consistent methodology to achieve improved identification of associations.

Dietary therapies for adult and pediatric inflammatory bowel disease

Diet is an environmental exposure implicated in the development of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Dietary therapy is also a tool for management of these conditions. Nutrition therapy for IBD has been shown to reduce intestinal inflammation, promote healing, and alleviate symptoms, as well as improve patients' nutrition status. Although the mechanisms of action of most nutrition therapies for IBD are not well understood, the diets are theorized to eliminate triggers for gut dysbiosis and mucosal immune dysfunction associated with the typical Western diet. Exclusive enteral nutrition and the Crohn's disease exclusion diet are increasingly being used as the primary treatment modality for the induction of remission and/or maintenance therapy in children, and in some adults, with CD. Several other diets, such as the Mediterranean diet, anti-inflammatory diet for IBD, and diets excluding gluten, FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), lactose, or other compounds, may be helpful in symptom management in both CD and UC, though evidence for biochemical efficacy is limited. In this review, we discuss the role of diet components in IBD pathogenesis and examine diets currently used in the management of children and adults with IBD. We also address practical, psychosocial, and cultural considerations for dietary therapy across diverse populations.

Eating away cancer: the potential of diet and the microbiome for shaping immunotherapy outcome

The gut microbiome (GMB) plays a substantial role in human health and disease. From affecting gut barrier integrity to promoting immune cell differentiation, the GMB is capable of shaping host immunity and thus oncogenesis and anti-cancer therapeutic response, particularly with immunotherapy. Dietary patterns and components are key determinants of GMB composition, supporting the investigation of the diet-microbiome-immunity axis as a potential avenue to enhance immunotherapy response in cancer patients. As such, this review will discuss the role of the GMB and diet on anti-cancer immunity. We demonstrate that diet affects anti-cancer immunity through both GMB-independent and GMB-mediated mechanisms, and that different diet patterns mold the GMB's functional and taxonomic composition in distinctive ways. Dietary modulation therefore shows promise as an intervention for improving cancer outcome; however, further and more extensive research in human cancer populations is needed.

How the Western Diet Thwarts the Epigenetic Efforts of Gut Microbes in Ulcerative Colitis and Its Association with Colorectal Cancer

Ulcerative colitis (UC) is an autoimmune disease in which the immune system attacks the colon, leading to ulcer development, loss of colon function, and bloody diarrhea. The human gut ecosystem consists of almost 2000 different species of bacteria, forming a bioreactor fueled by dietary micronutrients to produce bioreactive compounds, which are absorbed by our body and signal to distant organs. Studies have shown that the Western diet, with fewer short-chain fatty acids (SCFAs), can alter the gut microbiome composition and cause the host's epigenetic reprogramming. Additionally, overproduction of H2S from the gut microbiome due to changes in diet patterns can further activate pro-inflammatory signaling pathways in UC. This review discusses how the Western diet affects the microbiome's function and alters the host's physiological homeostasis and susceptibility to UC. This article also covers the epidemiology, prognosis, pathophysiology, and current treatment strategies for UC, and how they are linked to colorectal cancer.

Soy sauce-like seasoning enhances the growth of Agathobacter rectalis and the production of butyrate, propionate, and lactate

The short-chain fatty acids responsible for gut homeostasis are volatile fatty acids produced by commensal bacteria in the gut as fermentation products from undigested food components. Among the short-chain fatty acids, butyrate is important for maintaining intestinal tract anaerobic conditions, promoting epithelial barrier functions, and inducing regulatory T cells that suppress inflammatory bowel disease and allergic diarrhea. However, the type of food-derived molecular components and mechanisms by which they regulate the growth and butyrate production of butyrate-producing bacteria are not clearly understood. Agathobacter rectalis is a butyrate-producing bacterium highly colonized in the gut of the Japanese population. In this study, we investigated the effects on A. rectalis of a soy sauce-like seasoning made by brewing with a low salt concentration. The soy sauce-like seasoning promoted the growth of A. rectalis 2.6-fold. An ethanol precipitate prepared from the soy sauce-like seasoning was critical for promoting the growth of A. rectalis and the production of butyrate, propionate, and lactate. Fourier transform infrared spectroscopy (FT-IR) analysis suggested that polysaccharides were active ingredients in the ethanol precipitate of the soy sauce-like seasoning. Inulin, a representative prebiotic with effects against butyrate-producing bacteria, had a limited effect on the growth of A. rectalis compared with the soy sauce-like seasoning. Our results indicate that polysaccharides in a soy sauce-like seasoning contributed to the growth of A. rectalis and enhanced production of butyrate, propionate, and lactate.

Gastric Cancer, Immunotherapy, and Nutrition: The Role of Microbiota

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of gastric cancer (GC), which still represents the third leading cause of cancer-related death in Western countries. However, ICI treatment outcomes vary between individuals and need to be optimized. Recent studies have shown that gut microbiota could represent a key influencer of immunotherapy responses. At the same time, the nutritional status and diet of GC patients are also predictive of immunotherapy treatment response and survival outcomes. The objective of this narrative review is to gather recent findings about the complex relationships between the oral, gastric, and gut bacterial communities, dietary factors/nutritional parameters, and immunotherapy responses. Perigastric/gut microbiota compositions/functions and their metabolites could be predictive of response to immunotherapy in GC patients and even overall survival. At the same time, the strong influence of diet on the composition of the microbiota could have consequences on immunotherapy responses through the impact of muscle mass in GC patients during immunotherapy. Future studies are needed to define more precisely the dietary factors, such as adequate daily intake of prebiotics, that could counteract the dysbiosis of the GC microbiota and the impaired nutritional status, improving the clinical outcomes of GC patients during immunotherapy.

Efficacy and mechanism of acupuncture for functional constipation in older adults: study protocol for a randomized controlled trial

Introduction

Functional constipation (FC) is a common functional gastrointestinal disorder in clinical practice, with the prevalence of which increasing with age. With the increasing aging of the population worldwide, this problem is bound to become more prominent. Acupuncture is effective and recommended for the treatment of FC. However, little is known about how acupuncture affects the gut microbiota and inflammatory cytokines and thus improves gut function. Meanwhile, there are few high-quality clinical trials specifically focusing on acupuncture in treating FC in older people. The objective of this study is to assess the efficacy and safety of acupuncture in treating FC in older people. Additionally, the research aims to explore the mechanism of action of acupuncture in treating FC in older people by affecting intestinal microbiota and inflammation cytokines.

Methods and analysis

This study is designed as a single-center, randomized, sham-controlled clinical trial. A total of 98 eligible FC patients will be randomized in a 1:1 ratio into an acupuncture group and a sham acupuncture group. Both groups will receive 24 treatments over 8 weeks with a 12-week follow-up. The primary outcome of the study is the treatment response rate, which is the proportion of participants with ≥3 mean weekly Complete Spontaneous Bowel Movements (CSBMs) over weeks 3-8. The secondary outcomes will include the proportion of participants with ≥3 mean weekly CSBMs during other assessment periods; the percentage of patients with ≥1 increase in mean weekly CSBMs from baseline; the average changes in CSBMs; Patient Assessment of Constipation-Symptoms (PAC-SYM), Bristol Stool Scale, Patient Assessment of Constipation Quality of Life Questionnaire (PAC-QOL), Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS) and weekly usage of emergency bowel medications. Adverse events will be recorded throughout the study. Data for the outcomes will be collected at Week 0 (baseline), Week 4 (the intervention period), Week 8 (the post-treatment), Week 12 (the follow-up period) and Week 20 (the follow-up period). In addition, changes in intestinal microbiota will be analyzed using 16S rRNA high-throughput detection, and the concentration of relevant inflammatory cytokines in serum will be measured by ELISA based on blood samples. The intention-to-treat analysis will be performed in this study.Clinical trial registration: [https://www.chictr.org.cn/], identifier [ChiCTR2300070735].

Gut Microbiota in Patients with Prediabetes

Prediabetes is characterized by abnormal glycemic levels below the type 2 diabetes threshold, and effective control of blood glucose may prevent the progression to type 2 diabetes. While the association between the gut microbiota, glucose metabolism, and insulin resistance in diabetic patients has been established in previous studies, there is a lack of research regarding these aspects in prediabetic patients in Asia. We aim to investigate the composition of the gut microbiota in prediabetic patients and their differences compared to healthy individuals. In total, 57 prediabetic patients and 60 healthy adult individuals aged 18 to 65 years old were included in this study. Biochemistry data, fecal samples, and 3 days of food records were collected. Deoxyribonucleic acid extraction and next-generation sequencing via 16S ribosomal ribonucleic acid metagenomic sequencing were conducted to analyze the relationship between the gut microbiota and dietary habits. Prediabetic patients showed a lower microbial diversity than healthy individuals, with 9 bacterial genera being less abundant and 14 others more abundant. Prediabetic patients who consumed a low-carbohydrate (LC) diet exhibited higher diversity in the gut microbiota than those who consumed a high-carbohydrate diet. A higher abundance of Coprococcus was observed in the prediabetic patients on an LC diet. Compared to healthy individuals, the gut microbiota of prediabetic patients was significantly different, and adopting an LC diet with high dietary fiber consumption may positively impact the gut microbiota. Future studies should aim to understand the relationship between the gut microbiota and glycemic control in the Asian population.

Etiopathogenesis of Psoriasis: Integration of Proposed Theories

Psoriasis is a chronic inflammatory disease characterized by squamous and erythematous plaques on the skin and the involvement of the immune system. Global prevalence for psoriasis has been reported around 1-3% with a higher incidence in adults and similar proportions between men and women. The risk factors associated with psoriasis are both extrinsic and intrinsic, out of which a polygenic predisposition is a highlight out of the latter. Psoriasis etiology is not yet fully described, but several hypothesis have been proposed: 1) the autoimmunity hypothesis is based on the over-expression of antimicrobial peptides such as LL-37, the proteins ADAMTSL5, K17, and hsp27, or lipids synthesized by the PLA2G4D enzyme, all of which may serve as autoantigens to promote the differentiation of autoreactive lymphocytes T and unleash a chronic inflammatory response; 2) dysbiosis of skin microbiota hypothesis in psoriasis has gained relevance due to the observations of a loss of diversity and the participation of pathogenic bacteria such as Streptococcus spp. or Staphylococcus spp. the fungi Malassezia spp. or Candida spp. and the virus HPV, HCV, or HIV in psoriatic plaques; 3) the oxidative stress hypothesis, the most recent one, describes that the cell injury and the release of proinflammatory mediators and antimicrobial peptides that leads to activate of the Th1/Th17 axis observed in psoriasis is caused by a higher release of reactive oxygen species and the imbalance between oxidant and antioxidant mechanisms. This review aims to describe the mechanisms involved in the three hypotheses on the etiopathogeneses of psoriasis.

Prebiotic effect of galacto-N-biose on the intestinal lactic acid bacteria as enhancer of acetate production and hypothetical colonization

Galacto-N-biose (GNB) is an important core structure of glycan of mucin glycoproteins in the gastrointestinal (GI) mucosa. Because certain beneficial bacteria inhabiting the GI tract, such as bifidobacteria and lactic acid bacteria, harbor highly specialized GNB metabolic capabilities, GNB is considered a promising prebiotic for nourishing and manipulating beneficial bacteria in the GI tract. However, the precise interactions between GNB and beneficial bacteria and their accompanying health-promoting effects remain elusive. First, we evaluated the proliferative tendency of beneficial bacteria and their production of beneficial metabolites using gut bacterial strains. By comparing the use of GNB, glucose, and inulin as carbon sources, we found that GNB enhanced acetate production in Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, Lactobacillus gasseri, and Lactobacillus johnsonii. The ability of GNB to promote acetate production was also confirmed by RNA-seq analysis, which indicated the upregulation of gene clusters that catalyze the deacetylation of N-acetylgalactosamine-6P and biosynthesize acetyl-CoA from pyruvate, both of which result in acetate production. To explore the in vivo effect of GNB in promoting acetate production, antibiotic-treated BALB/cA mice were administered with GNB with L. rhamnosus, resulting in a fecal acetate content that was 2.7-fold higher than that in mice administered with only L. rhamnosus. Moreover, 2 days after the last administration, a 3.7-fold higher amount of L. rhamnosus was detected in feces administered with GNB with L. rhamnosus than in feces administered with only L. rhamnosus. These findings strongly suggest the prebiotic potential of GNB in enhancing L. rhamnosus colonization and converting L. rhamnosus into higher acetate producers in the GI tract.

IMPORTANCE

Specific members of lactic acid bacteria, which are commonly used as probiotics, possess therapeutic properties that are vital for human health enhancement by producing immunomodulatory metabolites such as exopolysaccharides, short-chain fatty acids, and bacteriocins. The long residence time of probiotic lactic acid bacteria in the GI tract prolongs their beneficial health effects. Moreover, the colonization property is also desirable for the application of probiotics in mucosal vaccination to provoke a local immune response. In this study, we found that GNB could enhance the beneficial properties of intestinal lactic acid bacteria that inhabit the human GI tract, stimulating acetate production and promoting intestinal colonization. Our findings provide a rationale for the addition of GNB to lactic acid bacteria-based functional foods. This has also led to the development of therapeutics supported by more rational prebiotic and probiotic selection, leading to an improved healthy lifestyle for humans.

Effect of Lifelong Exposure to Dietary Plant and Marine Sources of n-3 Polyunsaturated Fatty Acids on Morphologic and Gene Expression Biomarkers of Intestinal Health in Early Life

Altered intestinal health is also associated with the incidence and severity of many chronic inflammatory conditions, which could be attenuated via dietary n-3 PUFA interventions. However, little is known about the effect of lifelong exposure to n-3 PUFA from plant and marine sources (beginning in utero via the maternal diet) on early life biomarkers of intestinal health. Harems of C57Bl/6 mice were randomly assigned to one of three isocaloric AIN-93G modified diets differing in their fat sources consisting of the following: (i) 10% safflower oil (SO, enriched in n-6 PUFA), (ii) 3% flaxseed oil + 7% safflower oil (FX, plant-based n-3 PUFA-enriched diet), or (iii) 3% menhaden fish oil + 7% safflower oil (MO, marine-based n-3 PUFA-enriched diet). Mothers remained on these diets throughout pregnancy and offspring (n = 14/diet) continued on the same parental diet until termination at 3 weeks of age. In ileum, villi:crypt length ratios were increased in both the FX and MO dietary groups compared to SO (p < 0.05). Ileum mRNA expression of critical intestinal health biomarkers was increased by both n-3 PUFA-enriched diets including Relmβ and REG3γ compared to SO (p < 0.05), whereas only the FX diet increased mRNA expression of TFF3 and Muc2 (p < 0.05) and only the MO diet increased mRNA expression of ZO-1 (p < 0.05). In the proximal colon, both the FX and MO diets increased crypt lengths compared to SO (p < 0.05), whereas only the MO diet increased goblet cell numbers compared to SO (p < 0.05). Further, the MO diet increased proximal colon mRNA expression of Relmβ and REG3γ (p < 0.05) and both MO and FX increased mRNA expression of Muc2 compared to SO (p < 0.05). Collectively, these results demonstrate that lifelong exposure to dietary n-3 PUFA, beginning in utero, from both plant and marine sources, can support intestinal health development in early life. The differential effects between plant and marine sources warrants further investigation for optimizing health.

Assessment of dietary interventions including low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet as management for fructose intolerance

OBJECTIVES

Abdominal pain remains one of the most common referral reasons to pediatric gastroenterology. Dietary intolerances are often considered but due to various factors are hardly pursued. We observed that diet review in large number of children with abdominal pain was high in sugary foods which led to food intolerance investigation and dietary intervention.

METHODS

A retrospective review was conducted of patients presenting with abdominal pain, diarrhea, or vomiting and negative GI evaluation, who underwent fructose breath testing. Patients younger than 20 years old who were seen between June 1, 2018 and March 1, 2021 were included. Statistical analysis was performed in R.

RESULTS

There were 110 pediatric patients during the study period who underwent fructose breath testing, with 31% male and 69% female. The average age was 12.14 ± 4.01 years, and the average BMI was 21.21 ± 6.12. Abdominal pain was the most common presenting symptom (74.5%) followed by diarrhea and vomiting. Seventy-seven patients (70%) had a positive fructose breath test and were diagnosed with dietary intolerance to fructose. The 56 (67.5%) of those patients experienced symptoms during the breath test. Forty-three patients improved with dietary intervention. Twenty-seven on low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet and 16 on other diets.

CONCLUSIONS

Based on analysis of our cohort of children with abdominal pain and high incidence of fructose intolerance as well as improvement in symptoms, following dietary changes, this condition should be considered and treated. Further investigation is needed to improve diagnostic testing but also into understanding mechanisms behind symptom presentation in this population.

No Association Between Allergic Diseases and Constipation in Japanese Ulcerative Colitis Patients: A Cross-Sectional Study

BACKGROUND

Constipation is a common gastrointestinal symptom in patients with ulcerative colitis (UC). Several studies on the general population have demonstrated a link between allergic diseases and constipation. However, evidence regarding the association between allergic diseases and constipation in UC is limited. This study aims to evaluate this issue in Japanese patients with UC.

METHODS

This cross-sectional study recruited consecutive 387 patients with UC. We used a self-administered questionnaire to estimate the prevalence of physician-diagnosed allergic diseases. The definition of constipation was based on Rome I criteria and/or medication for constipation.

RESULTS

The prevalence of constipation was 12.5%. The prevalence rates of asthma, atopic dermatitis, pollen allergy, food allergy, and drug allergy were 11.8%, 9.0%, 36.3%, 6.2%, and 8.3%, respectively. Allergic diseases were not associated with constipation (adjusted odds ratio [OR] with asthma (adjusted OR 0.98 [95% confidence interval [CI] 0.27-2.80]), atopic dermatitis (adjusted OR 0.67 [95% CI 0.10-2.56]), pollen allergy (adjusted OR 0.92 [95% CI 0.41-1.97]), food allergy (adjusted OR 0.76 [95% CI 0.11-2.95]), and drug allergy (adjusted OR 1.06 [95% CI 0.28-3.24]). Additionally, the number of allergic diseases was not associated with the prevalence of constipation.

CONCLUSIONS

In Japanese UC patients, no association between allergic diseases and constipation was found.

Cow's Milk Allergy May Induce Lipid Metabolism Disorder in BALB/c Mice via Exosomes

Allergic diseases and lipid-metabolism-disorder-derived diseases are both significant public health issues. Recent studies have shown that exosomes are associated with the course of allergic diseases and are involved in lipid metabolism. In this study, exosomes derived from cow's milk allergic (CMA) mice medially loaded lesser proteins favoring cholesterol metabolism. The levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) in the serum were increased in the CMA mice, and hepatic lipid deposition was observed in the liver, but these phenomena were improved by inhibiting the exosome release. Specifically, the higher expression of the sterol regulatory element binding factor 2 (SREBP2) protein and HMGCR gene in the liver of CMA mice indicated an increase in cholesterol synthesis. NPC1L1 was also highly expressed in the small intestine of CMA mice, and fecal TC level was decreased, suggesting that the reabsorption of cholesterol was elevated. The biosynthesis of cholesterol, the reverse cholesterol transport (RCT) process, and the synthesis of bile acid in the liver were improved by inhibiting exosome release, as well as the reabsorption of cholesterol in the small intestine. This study has for the first time demonstrated the lipid metabolism disorder caused by CMA, especially the important role of exosomes in food allergies and lipid metabolism.

Next-generation prebiotics: Maillard-conjugates of 2'-fucosyllactose and lactoferrin hydrolysates beneficially modulate gut microbiome composition and health promoting activity in a murine model

Current prebiotics are predominantly carbohydrates. However, great competition exists among gut microbes for the scarce protein in the colon, as most consumed protein is digested and absorbed in the small intestine. Herein we evaluated in-vivo novel next-generation prebiotics: protein-containing-prebiotics, for selectively-targeted delivery of protein to colonic probiotics, to boost their growth. This system is based on micellar-particles, composed of Maillard-glycoconjugates of 2'-Fucosyllactose (2'-FL, human-milk-oligosaccharide) shell, engulfing lactoferrin peptic-then-tryptic hydrolysate (LFH) core. This core-shell structure lowers protein-core digestibility, while the prebiotic glycans are hypothesized to serve as molecular-recognition ligands for selectively targeting probiotics. To study the efficacy of this novel prebiotic, we fed C57BL/6JRccHsd mice with either 2'-FL-LFH Maillard-glycoconjugates, unconjugated components (control), or saline (blank). Administration of 2'-FL-LFH significantly increased the levels of short-chain-fatty-acids (SCFAs)-producing bacterial families (Ruminococcaceae, Lachnospiraceae) and genus (Odoribacter) and the production of the health-related metabolites, SCFAs, compared to the unconjugated components and to saline. The SCFAs-producing genus Prevotella significantly increased upon 2'-FL-LFH consumption, compared to only moderate increase in the unconjugated components. Interestingly, the plasma-levels of inflammation-inducing lipopolysaccharides (LPS), which indicate increased gut-permeability, were significantly lower in the 2'-FL-LFH group compared to the unconjugated-components and the saline groups. We found that Maillard-glycoconjugates of 2'-FL-LFH can serve as novel protein-containing prebiotics, beneficially modulating gut microbial composition and its metabolic activity, thereby contributing to host health more effectively than the conventional carbohydrate-only prebiotics.

Egg Yolk Lipids Alleviated Dextran Sulfate Sodium-Induced Colitis by Inhibiting NLRP3 Inflammasome and Regulating Gut Microbiota

The increasing incidence of inflammatory bowel disease (IBD) has become a global phenomenon. Egg yolk lipids are one of the essential dietary foods, but its effects on intestinal immunity remain unclear. Here, egg yolk lipids are obtained using ethanol extraction and a total of 601 kinds of lipids are detected via lipidomics, including 251 kinds of triglycerides, 133 kinds of phosphatidylcholines, 44 kinds of phosphatidylethanolamines. Then, the study finds that egg yolk lipids significantly alleviate dextran sulfate sodium-induced colitis and reduce the production of inflammatory factors. Meanwhile, egg yolk lipids also maintain intestinal barrier integrity and decrease lipopolysaccharide translocation by alleviating intestinal structure damage and increasing the numbers of goblet cells and mucin 2. Mechanistically, egg yolk lipids attenuate colitis by inhibiting the assembly and activation of NLRP3 inflammasome. Moreover, the study also finds that egg yolk lipids reverse gut microbiota dysbiosis referring to increased relative abundance of Bacteroides acidifaciens and decrease relative abundance of Akkermansia muciniphila, as well as increased short chain fatty acids concentration in the gut. Together, the study elucidates the anti-colitis effect of egg yolk lipids and provides positive evidences for egg yolk lipids involving in dietary strategy and IBD therapy.

Diagnosis and Management of Gastrointestinal Manifestations in Children with Cystic Fibrosis

Cystic fibrosis (CF) is primarily known for its pulmonary consequences, which are extensively explored in the existing literature. However, it is noteworthy that individuals with CF commonly display gastrointestinal (G-I) manifestations due to the substantial presence of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in the intestinal tract. Recognized as pivotal nonpulmonary aspects of CF, G-I manifestations exhibit a diverse spectrum. Identifying and effectively managing these manifestations are crucial for sustaining health and influencing the overall quality of life for CF patients. This review aims to synthesize existing knowledge, providing a comprehensive overview of the G-I manifestations associated with CF. Each specific G-I manifestation, along with the diagnostic methodologies and therapeutic approaches, is delineated, encompassing the impact of innovative treatments targeting the fundamental effects of CF on the G-I tract. The findings underscore the imperative for prompt diagnosis and meticulous management of G-I manifestations, necessitating a multidisciplinary team approach for optimal care and enhancement of the quality of life for affected individuals. In conclusion, the authors emphasize the urgency for further clinical studies to establish a more robust evidence base for managing G-I symptoms within the context of this chronic disease. Such endeavors are deemed essential for advancing understanding and refining the clinical care of CF patients with G-I manifestations.

The Role of Dietary Habits in the Pathogenesis and Development of Inflammatory Bowel Disease: A Narrative Review

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic immune-mediated disease. The incidence of IBD is influenced by various genetic and environmental factors, with dietary habits gaining significant scientific interest. While the role of diet in the pathogenesis and development of IBD is still debated, recent studies have demonstrated its potential impact. However, conflicting findings exist regarding the efficacy of dietary interventions in the treatment and control of IBD. This review aimed to summarize the current understanding of the relationship between diet and IBD, highlighting the different perspectives and reasonings observed in recent studies. Overall, it has been shown that dietary habits play a role in the incidence of IBD, and adopting a controlled dietary approach may help manage the disease. Consequently, diet can be considered a predictive and prognostic factor in IBD.