Gut Microbial Community Composition Research Articles

Gonadal sex and chromosome complement influence the gut microbiome in a mouse model of allergic airway inflammation.

Evidence abounds that gut microbiome components are associated with sex disparities in the immune system. However, it remains unclear whether the observed sex disparity in asthma incidence is associated with sex-dependent differences in immune-modulating gut microbiota, and/or its influence on allergic airway inflammatory processes. Using a mouse model of house dust mite (HDM)-induced allergic inflammation and the four core genotypes (FCGs) model, we have previously reported sex differences in lung inflammatory phenotypes. Here, we investigated associations of gut microbiomes with these phenotypes by challenging FCG mice [mouse with female sex chromosome and male gonad (XXM), mouse with female sex chromosome and female gonad (XXF), mouse with male sex chromosome and male gonad (XYM), and mouse with male sex chromosome and female gonad (XYF); n = 7/group] with HDM (25 μg) or PBS intranasally for 5 wk and collecting fecal samples. We extracted fecal DNA and analyzed the 16S microbiome via Targeted Metagenomic Sequencing. We compared α and β diversity across genotypes and assessed the Firmicutes/Bacteroidetes (F/B) ratio. When comparing baseline and after exposure for the FCG, we found that the gut F/B ratio was only increased in the XXM genotype. We also found that α diversity was significantly increased in all FCG mice upon HDM challenge, with the highest increase in the XXF, and the lowest in the XXM genotypes. Similarly, β diversity of the microbial community was also affected by challenge in a gonad- and chromosome-dependent manner. In summary, our results indicated that HDM treatment, gonads, and sex chromosomes significantly influence the gut microbial community composition. We concluded that allergic lung inflammation may be affected by the gut microbiome in a sex-dependent manner involving both hormonal and genetic influences.NEW & NOTEWORTHY Recently, the gut microbiome and its role in chronic respiratory disease have been the subject of extensive research and the establishment of its involvement in immune functions. Using the FCG mouse model, our findings revealed the influence of gonads and sex chromosomes on the microbial community structure before and after exposure to HDM. Our data provide a potential new avenue to better understand mediators of sex disparities associated with allergic airway inflammation.

Antibacterial and gut health effects of Amomum tsao-ko in aquatic feed: A sustainable alternative to chemical antibiotics.

Amomum tsao-ko Crevost et Lemarie (Zingiberaceae), an aromatic plant, has been considered to have diverse medicinal values and economic significance. It has been reported to possess antibacterial, antioxidant, and antidiabetic effects. With the increasing risk of diseases in aquaculture, there is a need for alternative solutions to chemical antibiotics. Plant extracts have shown promise as natural feed additives for aquatic animals. In this study, the antibacterial effect of Amomum tsao-ko crude extracts was evaluated using the Oxford cup method. The extracts exhibited significant antimicrobial activity against Salmonella typhimurium and Salmonella enteritidis. Furthermore, the addition of Amomum tsao-ko to fish feed resulted in notable changes in the gut structure of zebrafish and tilapia. The length and morphology of intestinal villi were enhanced, promoting improved digestion. Analysis of the gut microbial community revealed that Amomum tsao-ko supplementation induced key changes in the gut microbial community composition of both zebrafish and tilapia. Notably, a 1% inclusion of Amomum tsao-ko resulted in a marked rise in Proteobacteria levels in zebrafish, which diminished at 10% dosage. The supplement elicited mixed reactions among other bacterial phyla like Actinobacteria and Verrucomicrobiota. Fluctuations were also observed at the genus level, pointing to the concentration of Amomum tsao-ko playing a pivotal role in influencing the structure of intestinal bacteria. The findings of this study suggest that Amomum tsao-ko has antibacterial properties and can positively influence the gut health of fish. The potential use of Amomum tsao-ko as a natural feed additive holds promise for improving aquaculture practices and reducing reliance on chemical antibiotics. Further research is needed to explore the full potential and applications of Amomum tsao-ko in fish feed development.

Unraveling the gut microbiota of Mexican pinnipeds: the dominance of life histories over phylogeny.

Studying how phylogeny influences the composition and functions of microbiotas within animal hosts is essential for gaining insights into the connection between genetics, ecology, and health in the animal kingdom. However, due to limited comprehensive studies, this influence remains unclear for many wild mammals, including Mexican pinnipeds. We employed 16S rRNA gene deep-sequencing to investigate the impact of phylogeny on the gut microbiota of four pinniped species inhabiting Mexican shores: the Pacific harbor seal (Phoca vitulina richardii), the northern elephant seal (Mirounga angustirostris), the California sea lion (Zalophus californianus), and the Guadalupe fur seal (Arctocephalus philippii townsendi). Our results indicated that factors such as diets and shared life histories exerted more influence on microbiota composition than phylogeny alone. Notably, otariid species sharing similar life histories displayed greater microbiota similarity than phocids, which have distinct life histories and fewer microbiota similarities. Furthermore, harbor seals have more microbial similarities with the two otariid species than with elephant seals. Of particular concern, we observed a higher abundance of potentially pathogenic bacteria (e.g., Photobacterium damselae and Clostridium perfringens) in harbor seals and Guadalupe fur seals compared to other pinnipeds. This finding could pose health threats to these species and nearby human populations.IMPORTANCEPinnipeds in Mexico host microbial communities that remain understudied. While several factors can influence microbiota composition, the role of phylogenetic relationships among these pinnipeds remains unclear due to limited knowledge of the microbiota in certain species. This study aimed to fill this gap by characterizing the composition and function of the gut microbiota in the four pinniped species that occur in Mexico. Our analysis reveals that shared diets and life histories contribute to similarities in the composition of gut microbial communities. This study also highlights the potential differences in the metabolic capabilities and adaptations within the gut microbiota of pinnipeds. Understanding how phylogeny impacts microbial communities enhances our insights into the evolutionary dynamics of marine mammals.

Exploring the role of gut microbiota in human health

The study explores the intricate relationship between the human gut microbiota and health. It analyzes the gut microbiota’s roles in digestion, metabolism, immune responses, and overall well-being. The review discusses the composition and diversity of gut microbial communities, emphasizing their symbiotic relationship with the host. It also examines how gut dysbiosis, or microbial imbalance, relates to health conditions like inflammatory bowel diseases and metabolic disorders. The review highlights research methodologies like metagenomics and metabolomics that deepen our understanding of gut microbiota function. It also explores external factors, such as diet and antibiotic use, in shaping the gut microbiome. The review discusses potential therapeutic interventions like probiotics and fecal microbiota transplantation, suggesting a future for personalized medicine. By synthesizing existing knowledge, the review aims to advance understanding of the gut microbiota’s role in health and suggest future research and interventions.

Intestinal Barrier Impairment Induced by Gut Microbiome and Its Metabolites in School-Age Children with Zinc Deficiency.

Zinc deficiency affects the physical and intellectual development of school-age children, while studies on the effects on intestinal microbes and metabolites in school-age children have not been reported. School-age children were enrolled to conduct anthropometric measurements and serum zinc and serum inflammatory factors detection, and children were divided into a zinc deficiency group (ZD) and control group (CK) based on the results of serum zinc. Stool samples were collected to conduct metagenome, metabolome, and diversity analysis, and species composition analysis, functional annotation, and correlation analysis were conducted to further explore the function and composition of the gut flora and metabolites of children with zinc deficiency. Beta-diversity analysis revealed a significantly different gut microbial community composition between ZD and CK groups. For instance, the relative abundances of Phocaeicola vulgatus, Alistipes putredinis, Bacteroides uniformis, Phocaeicola sp000434735, and Coprococcus eutactus were more enriched in the ZD group, while probiotic bacteria Bifidobacterium kashiwanohense showed the reverse trend. The functional profile of intestinal flora was also under the influence of zinc deficiency, as reflected by higher levels of various glycoside hydrolases in the ZD group. In addition, saccharin, the pro-inflammatory metabolites, and taurocholic acid, the potential factor inducing intestinal leakage, were higher in the ZD group. In conclusion, zinc deficiency may disturb the gut microbiome community and metabolic function profile of school-age children, potentially affecting human health.

The changing metabolic landscape of bile acids - keys to metabolism and immune regulation.

Bile acids regulate nutrient absorption and mitochondrial function, they establish and maintain gut microbial community composition and mediate inflammation, and they serve as signalling molecules that regulate appetite and energy homeostasis. The observation that there are hundreds of bile acids, especially many amidated bile acids, necessitates a revision of many of the classical descriptions of bile acids and bile acid enzyme functions. For example, bile salt hydrolases also have transferase activity. There are now hundreds of known modifications to bile acids and thousands of bile acid-associated genes, especially when including the microbiome, distributed throughout the human body (for example, there are >2,400 bile salt hydrolases alone). The fact that so much of our genetic and small-molecule repertoire, inboth amount and diversity, is dedicated to bile acid function highlights the centrality of bile acids as key regulators of metabolism and immune homeostasis, which is, in large part, communicated via the gut microbiome.

Aldicarb disturbed bile acid, steroid hormone and oxylipin homeostasis in C57BL/6 J mice

Mounting evidence has shown that the gut microbiota plays a key role in human health. The homeostasis of the gut microbiota could be affected by many factors, including environmental chemicals. Aldicarb is a carbamate insecticide used to control a variety of insects and nematode pests in agriculture. Aldicarb is highly toxic and its wide existence has become a global public health concern. In our previous study, we have demonstrated that aldicarb disturbed the gut microbial community structure and composition. However, the impacts of aldicarb on gut microbiota-derived metabolites, bile acids, remain elusive. In present study, we performed targeted metabolomics analysis to explore the effects of aldicarb exposure on bile acids, as well as steroid hormones and oxylipins in the serum, feces and liver of C57BL/6 J mice. Our results showed that aldicarb exposure disturbed the level of various bile acids, steroid hormones and oxylipins in the serum and feces of C57BL/6 J mice. In the liver, the level of cortisol was decreased, meanwhile 15,16-dihydroxyoctadeca-9,12-dienoic acid was increased in aldicarb-treated mice. Metagenomic sequencing analysis showed that the relative abundance of a bile salt hydrolase, choloylglycine hydrolase (EC:3.5.1.24) and a sulfatase enzyme involved in steroid hormone metabolism, arylsulfatase, was significantly increased by aldicarb exposure. Furthermore, correlations were found between gut microbiota and various serum metabolites. The results from this study are helpful to improve the understanding of the impact of carbamate insecticides on host and microbial metabolism.

Preliminary exploratory research on the application value of oral and intestinal meta-genomics in predicting subjects' occupations-A case study of the distinction between students and migrant workers.

In the field of forensic science, accurately determining occupation of an individual can greatly assist in resolving cases such as criminal investigations or disaster victim identifications. However, estimating occupation can be challenging due to the intricate relationship between occupation and various factors, including gender, age, living environment, health status, medication use, and lifestyle habits such as alcohol consumption and smoking. All of these factors can impact the composition of oral or gut microbial community of an individual. In this study, we collected saliva and feces samples from individuals representing different occupational sectors, specifically students and manual laborers. We then performed metagenomic sequencing on the DNA extracted from these samples to obtain data that could be analyzed for taxonomic and functional annotations in five different databases. The correlation between occupation with microbial information was assisted from the perspective of α and β diversity, showing that individuals belonging to the two occupations hold significantly different oral and gut microbial communities, and that this correlation is basically not affected by gender, drinking, and smoking in our datasets. Finally, random forest (RF) models were built with recursive feature elimination (RFE) processes. Models with 100% accuracy in both training and testing sets were constructed based on three species in saliva samples or on a single pathway annotated by the KEGG database in fecal samples, namely, "ko04145" or Phagosome. Although this study may have limited representativeness due to its small sample size, it provides preliminary evidence of the potential of using microbiome information for occupational inference.

Effects of In Vitro Fermentation of Polysialic Acid and Sialic Acid on Gut Microbial Community Composition and Metabolites in Healthy Humans

The influence of polysialic acid (PSA) and sialic acid (SA) on the gut microbial community composition and metabolites in healthy humans was investigated using a bionic gastrointestinal reactor. The results indicated that PSA and SA significantly changed the gut microbiota and metabolites to different degrees. PSA can increase the relative abundances of Faecalibacterium and Allisonella, whereas SA can increase those of Bifidobacterium and Megamonas. Both can significantly increase the content of short-chain fatty acids. The results of metabolome analysis showed that PSA can upregulate ergosterol peroxide and gallic acid and downregulate the harmful metabolite N-acetylputrescine. SA can upregulate 4-pyridoxic acid and lipoic acid. PSA and SA affect gut microbiota and metabolites in different ways and have positive effects on human health. These results will provide a reference for the further development of PSA- and SA-related functional foods and health products.

Gut microbiota contribute to variations in honey bee foraging intensity.

Gut microbiomes are increasingly recognized for mediating diverse biological aspects of their hosts, including complex behavioral phenotypes. Although many studies have reported that experimental disruptions to the gut microbial community result in atypical host behavior, studies that address how gut microbes contribute to adaptive behavioral trait variation are rare. Eusocial insects represent a powerful model to test this, because of their simple gut microbiota and complex division of labor characterized by colony-level variation in behavioral phenotypes. Although previous studies report correlational differences in gut microbial community associated with division of labor, here, we provide evidence that gut microbes play a causal role in defining differences in foraging behavior between European honey bees (Apis mellifera). We found that gut microbial community structure differed between hive-based nurse bees and bees that leave the hive to forage for floral resources. These differences were associated with variation in the abundance of individual microbes, including Bifidobacterium asteroides, Bombilactobacillus mellis, and Lactobacillus melliventris. Manipulations of colony demography and individual foraging experience suggested that differences in gut microbial community composition were associated with task experience. Moreover, single-microbe inoculations with B. asteroides, B. mellis, and L. melliventris caused effects on foraging intensity. These results demonstrate that gut microbes contribute to division of labor in a social insect, and support a role of gut microbes in modulating host behavioral trait variation.

Sutterella and its metabolic pathways positively correlate with vaccine-elicited antibody responses in infant rhesus macaques.

It is becoming clearer that the microbiota helps drive responses to vaccines; however, little is known about the underlying mechanism. In this study, we aimed to identify microbial features that are associated with vaccine immunogenicity in infant rhesus macaques. We analyzed 16S rRNA gene sequencing data of 215 fecal samples collected at multiple timepoints from 64 nursery-reared infant macaques that received various HIV vaccine regimens. PERMANOVA tests were performed to determine factors affecting composition of the gut microbiota throughout the first eight months of life in these monkeys. We used DESeq2 to identify differentially abundant bacterial taxa, PICRUSt2 to impute metagenomic information, and mass spectrophotometry to determine levels of fecal short-chain fatty acids and bile acids. Composition of the early-life gut microbial communities in nursery-reared rhesus macaques from the same animal care facility was driven by age, birth year, and vaccination status. We identified a Sutterella and a Rodentibacter species that positively correlated with vaccine-elicited antibody responses, with the Sutterella species exhibiting more robust findings. Analysis of Sutterella-related metagenomic data revealed five metabolic pathways that significantly correlated with improved antibody responses following HIV vaccination. Given these pathways have been associated with short-chain fatty acids and bile acids, we quantified the fecal concentration of these metabolites and found several that correlated with higher levels of HIV immunogen-elicited plasma IgG. Our findings highlight an intricate bidirectional relationship between the microbiota and vaccines, where multiple aspects of the vaccination regimen modulate the microbiota and specific microbial features facilitate vaccine responses. An improved understanding of this microbiota-vaccine interplay will help develop more effective vaccines, particularly those that are tailored for early life.

Gut microbiota changes in Hexagrammos otakii during development and association with diets based on metagenomics sequencing

The development of microbial communities is important for the growth of the fat greenling Hexagrammos otakii; however, the relationship between microbial communities and fish diet is poorly understood. Here, we used metagenomics sequencing to investigate the gut microbiota of H. otakii at three key time points during development. The gut microbial diversity and community composition of H. otakii presented stage-specific signatures and appeared to shift with different diets and environmental conditions such as NH4 + -NO2- etc. Metagenomics analysis indicated that the dominant phyla were Proteobacteria and Firmicutes. With dietary changes from rotifers and Artemia to formulated feed, the dominant genera shifted from Vibrio and Photobacterium to Lactococcus, and variations in the gut microbiota increased with age. Based on metagenomics functional annotation using the Kyoto Encyclopedia of Genes and Genomes database, growth and diet at different stages affected the metabolic function of the gut microbiome by activating carbohydrate and amino acid metabolism while weakening lipid and nucleotide metabolism. In addition, as predicted by the Carbohydrate-Active enZymes database, glycoside hydrolase and glycosyl transferases may be involved in food degradation. Our results suggest that the H. otakii gut microbiota assembly was coupled to animal development and host age-associated biotic features and changes. Diet had a considerable effect on these distinct communities at different times, indicating that the fish gut microbiota rapidly adapted to dietary shifts. The microbiota therefore likely plays an indispensable role in nutrient turnover and fermentation. These findings can provide guidance for the development of probiotics and the application of feed additives.

Diet-driven microbiome changes and physical activity in cancer patients

Exploring the role of the gut microbiome in oncology is gaining more attention, mainly due to its ability to shape the immune system in cancer patients. A well-balanced microbial composition forms a symbiotic relationship with the host organism. Mounting evidence supports the potential of modifiable lifestyle factors, such as diet and physical activity, in restoring intestinal dysbiosis related to cancer development and treatment. In this Minireview, we describe the host-microbiome interplay following different dietary patterns, including a high-fat diet, fiber-rich diet, diet rich in rice and beans, Mediterranean diet, ketogenic diet, and physical activity in preclinical findings and clinical settings. According to the results, nutrition is a critical factor influencing the composition of gut microbial communities. Therefore, knowledge about the patient’s nutritional status in pre-treatment and treatment becomes crucial for further management. A combination of individualized dietary habits and professional training plans might help to maintain gut homeostasis, potentially improving the response to anti-cancer therapy and the quality of life in cancer survivors. However, a deep understanding of underlying mechanisms and large clinical trials are needed to uncover clinically relevant correlations for personalized treatment approaches leading to better outcomes for cancer patients.

Eating patterns contribute to shaping the gut microbiota in the mucosal simulator of the human intestinal microbial ecosystem.

Eating patterns, i.e. meal frequency and circadian timing of meals, are often modified in weight loss and metabolic healing strategies. However, in-depth research into the effects on the gut microbiome remains scarce, particularly across various colon regions and niches. We identified eating patterns to contribute in shaping the in vitro gut biomass production, metabolism, and microbial community compositions by subjecting four faecal microbiomes to a pattern that is standardized for a dynamic gut model (feeding at 09, 17, and 01 h), a typical Western (breakfast, lunch, and dinner at 09, 13, and 19 h, respectively), and a time-restricted pattern (single meal at 09 h). While eating patterns moderately affected the microbiome (2.4% and 1.8% significant variation in proportional and quantitative microbial compositions, respectively), significant changes were noted in the time-restricted pattern, including increased Bacteroides, Butyricicoccus, Dialister, and Faecalibacterium abundances. Sampling every 4 h revealed no significant circadian fluctuations in biomass production, microbial community compositions, or functionality. Longer fasting times favoured the growth of slower-growing species, such as Akkermansia, Dialister, and Parasutterella over faster-growers, such as Pseudomonas and Stenotrophomonas. Our findings illustrate the importance of recording and considering eating patterns as a gut microbiome determinant in in vivo and in vitro dietary intervention studies.

Consistent spatial patterns in microbial taxa of red squirrel gut microbiomes.

Gut microbiomes are diverse ecosystems whose drivers of variation remain largely unknown, especially in time and space. We analysed a dataset with over 900 red squirrel (Tamiasciurus hudsonicus) gut microbiome samples to identify the drivers of gut microbiome composition in this territorial rodent. The large-scale spatiotemporal replication in the data analysed was an essential component of understanding the assembly of these microbial communities. We identified that the spatial location of the sampled squirrels in their local environment is a key contributor to gut microbial community composition. The non-core gut microbiome (present in less than 75% of gut microbiome samples) had highly localised spatial patterns throughout different seasons and different study areas in the host squirrel population. The core gut microbiome, on the other hand, showed some spatial patterns, though fewer than in the non-core gut microbiome. Environmental transmission of microbiota is the likely contributor to the spatiotemporal distribution observed in the North American red squirrel gut microbiome.

Variations in the Relative Abundance of Gut Bacteria Correlate with Lipid Profiles in Healthy Adults.

The gut microbiome is a versatile system regulating numerous aspects of host metabolism. Among other traits, variations in the composition of gut microbial communities are related to blood lipid patterns and hyperlipidaemia, yet inconsistent association patterns exist. This study aims to assess the relationships between the composition of the gut microbiome and variations in lipid profiles among healthy adults. This study used data and samples from 23 adult participants of a previously conducted dietary intervention study. Circulating lipid measurements and whole-metagenome sequences of the gut microbiome were derived from 180 blood and faecal samples collected from eight visits distributed across an 11-week study. Lipid-related variables explained approximately 4.5% of the variation in gut microbiome compositions, with higher effects observed for total cholesterol and high-density lipoproteins. Species from the genera Odoribacter, Anaerostipes, and Parabacteroides correlated with increased serum lipid levels, whereas probiotic species like Akkermansia muciniphila were more abundant among participants with healthier blood lipid profiles. An inverse correlation with serum cholesterol was also observed for Massilistercora timonensis, a player in regulating lipid turnover. The observed correlation patterns add to the growing evidence supporting the role of the gut microbiome as an essential regulator of host lipid metabolism.

Assessment of intestinal status in MPLW515L mutant myeloproliferative neoplasms mice model

The MPLW515L mutation is a prevalent genetic mutation in patients with myeloproliferative neoplasms (MPN), and utilizing this mutation in mice model can provide important insights into the disease. However, the relationship between intestinal homeostasis and MPN mice model remains elusive. In this study, we utilized a retroviral vector to transfect hematopoietic stem cells with the MPLW515L mutation, creating mutated MPN mice model to investigate their intestinal status. Our results revealed that the MPLW515L in MPN mice model aggravated inflammation in the intestines, decreased the levels of tight junction proteins and receptors for bacteria metabolites. Additionally, there was increased activation of the caspase1/IL-1β signaling pathway and a significant reduction in phos-p38 levels in the intestinal tissue in MPN mice. The MPLW515L mutation also led to up-expression of anti-microbial genes in the intestinal tract. Though the mutation had no impact on the alpha diversity and dominant bacterial taxa, it did influence the rare bacterial taxa/sub-communities and consequently impacted intestinal homeostasis. Our findings demonstrate the significance of MPLW515L mice model for studying MPN disease and highlight the mutation's influence on intestinal homeostasis, including inflammation, activation of the IL-1β signaling pathway, and the composition of gut microbial communities.

The effects of sodium propionate on intestinal barrier function of genetically improved farmed tilapia in a high-lipid formulation

Sodium propionate has long been used as a feed additive in fish diets for its remarkable anti-mold properties. In this study, two-month old genetically improved farmed (GIF) tilapia (initial weight 0.55 ± 0.0004 g/fish) were fed with five isonitrogenous diets, including a low-fat diet (LFD), high-fat diet (HFD), 0.25% sodium propionate-supplemented HFD (HFSP0.25), 0.5% sodium propionate-supplemented HFD (HFSP0.5) and 1.0% sodium propionate-supplemented HFD (HFSP1.0). This study investigated the effects of sodium propionate on fish growth performance, intestinal epithelium integrity and permeability, intestinal “physiological hypoxia” and gut microbiota composition of GIF tilapia fed with the HFD. After a four-week feeding trial, sodium propionate supplementation (0.25%, 0.5% and 1.0%) had no effects on survival rate, body weight gain and feed conversion ratio of GIF tilapia. However, feeding the HFSP0.5 and HFSP1.0 impaired tight junctions and lamina propria compared to feeding the HFD (P < 0.05). Serum fluorescence intensities of fish fed the HFSP0.5 and HFSP1.0 were higher than that fed the HFD after an oral gavage of fluorescein isothiocyanate-labeled carboxymethylated dextran (P < 0.05). Besides, the level of serum endotoxin was higher in fish fed the HFSP1.0 (P < 0.05). The expressions of genes encoding tight junction-related proteins including occludin and claudin-1 were remarkably decreased by feeding the HFSP0.5 and HFSP1.0 (P < 0.05). Moreover, intestinal pimonidazole retention was significantly reduced by HFSP1.0 feeding (P < 0.05). Furthermore, feeding the HFSP0.5 significantly increased the relative abundance of Cetobacterium somerae (P < 0.05) while feeding the HFSP1.0 significantly increased the relative abundance of Plesiomonas shigelloides (P < 0.05) in the gut. Consistently, the presence of Cetobacterium somerae was observed in the liver and muscle of fish fed the HFSP0.5 as well as in the muscle of fish fed the HFSP1.0. Presence of Plesiomonas shigelloides was observed in the liver of fish fed the HFSP1.0. In conclusion, higher levels of sodium propionate (0.5% and 1.0%) disrupt intestinal epithelium integrity and increase intestinal permeability of GIF tilapia when fed a HFD. Besides, sodium propionate at 1.0% additive amount abolishes intestinal “physiological hypoxia”. Sodium propionate supplementation alters the species diversity and composition of gut microbial community.

Important denominator between autoimmune comorbidities: a review of class II HLA, autoimmune disease, and the gut.

Human leukocyte antigen (HLA) genes are associated with more diseases than any other region of the genome. Highly polymorphic HLA genes produce variable haplotypes that are specifically correlated with pathogenically different autoimmunities. Despite differing etiologies, however, many autoimmune disorders share the same risk-associated HLA haplotypes often resulting in comorbidity. This shared risk remains an unanswered question in the field. Yet, several groups have revealed links between gut microbial community composition and autoimmune diseases. Autoimmunity is frequently associated with dysbiosis, resulting in loss of barrier function and permeability of tight junctions, which increases HLA class II expression levels and thus further influences the composition of the gut microbiome. However, autoimmune-risk-associated HLA haplotypes are connected to gut dysbiosis long before autoimmunity even begins. This review evaluates current research on the HLA-microbiome-autoimmunity triplex and proposes that pre-autoimmune bacterial dysbiosis in the gut is an important determinant between autoimmune comorbidities with systemic inflammation as a common denominator.

Comparison of the Gut Microbial Communities of Domestic and Wild Mallards (Anas platyrhynchos) Based on High-Throughput Sequencing Technology.

Mallards (Anas platyrhynchos) are currently one of the most popular species in rare bird breeding in several southern provinces of China, but there have been no studies comparing the gut microbial communities of domestic and wild mallards. In this study, 16S rRNA gene high-throughput sequencing technology was used to compare the composition and diversity of gut microbial communities in domestic and wild mallards. Alpha diversity analysis showed significant differences in gut microbial communities between the two groups of mallards, and the diversity and richness of gut microbial communities were significantly higher in wild mallards than in domestic mallards. Beta diversity analysis showed that the two groups of stool samples were mostly separated on the principal coordinate analysis (PCoA) plot. In domestic mallards, Firmicutes (68.0% ± 26.5%) was the most abundant bacterial phylum, followed by Proteobacteria (24.5% ± 22.9%), Bacteroidetes (3.1% ± 3.2%), Fusobacteria (2.2% ± 5.9%), and Actinobacteria (1.1% ± 1.8%). The dominant bacterial phyla in wild mallards were Firmicutes (79.0% ± 10.2%), Proteobacteria (12.9% ± 9.5%), Fusobacteria (3.4% ± 2.5%), and Bacteroidetes (2.8% ± 2.4%). At the genus level, a total of 10 dominant genera (Streptococcus, Enterococcus, Clostridium, Lactobacillus, Soilbacillus, Bacillus, Acinetobacter, Comamonas, Shigella, and Cetobacterium) with an average relative abundance greater than 1% were detected in the fecal samples of both groups. The average relative abundance of five potential pathogenic genera (Streptococcus, Enterococcus, Acinetobacter, Comamonas, and Shigella) was higher in domestic mallards than in wild mallards. The enrichment of pathogenic bacteria in the intestinal tract of domestic mallards should be of sufficient concern.