Intestinal microbiota: a source of novel biomarkers in inflammatory bowel diseases?

Gut dysbiosis was inevitable, but tolerance was not: temporal responses of the murine microbiota that maintain its capacity for butyrate production correlate with sustained antinociception to chronic morphine

The therapeutic benefits of opioids are compromised by the development of analgesic tolerance, which necessitates higher dosing for pain management thereby increasing the liability for drug dependence and addiction. Rodent models indicate opposing roles of the gut microbiota in tolerance: morphine-induced gut dysbiosis exacerbates tolerance, whereas probiotics ameliorate tolerance. Not all individuals develop tolerance, which could be influenced by differences in microbiota, and yet no study design has capitalized upon this natural variation. We leveraged natural behavioral variation in a murine model of voluntary oral morphine self-administration to elucidate the mechanisms by which microbiota influences tolerance. Although all mice shared similar morphine-driven microbiota changes that largely masked informative associations with variability in tolerance, our high-resolution temporal analyses revealed a divergence in the progression of dysbiosis that best explained sustained antinociception. Mice that did not develop tolerance maintained a higher capacity for production of the short-chain fatty acid (SCFA) butyrate known to bolster intestinal barriers and promote neuronal homeostasis. Both fecal microbial transplantation (FMT) from donor mice that did not develop tolerance and dietary butyrate supplementation significantly reduced the development of tolerance independently of suppression of systemic inflammation. These findings could inform immediate therapies to extend the analgesic efficacy of opioids.

Balance between bile acid conjugation and hydrolysis activity can alter outcomes of gut inflammation

Conjugated bile acids (BAs) are multi-functional detergents in the gastrointestinal (GI) tract produced by the liver enzyme bile acid-CoA:amino acid N-acyltransferase (BAAT) and by the microbiome from the acyltransferase activity of bile salt hydrolase (BSH). Humans with inflammatory bowel disease (IBD) have an enrichment in both host and microbially conjugated BAs (MCBAs), but their impacts on GI inflammation are not well understood. We investigated the role of host-conjugated BAs in a mouse model of colitis using a BAAT knockout background. Baat-/- KO mice have severe phenotypes in the colitis model that were rescued by supplementation with taurocholate (TCA). Gene expression and histology showed that this rescue was due to an improved epithelial barrier integrity and goblet cell function. However, metabolomics also showed that TCA supplementation resulted in extensive metabolism to secondary BAs. We therefore investigated the BSH activity of diverse gut bacteria on a panel of conjugated BAs and found broad hydrolytic capacity depending on the bacterium and the amino acid conjugate. The complexity of this microbial BA hydrolysis led to the exploration of bsh genes in metagenomic data from human IBD patients. Certain bsh sequences were enriched in people with Crohn's disease particularly that from Ruminococcus gnavus. This study shows that both host and microbially conjugated BAs may provide benefits to those with IBD, but this is dictated by a delicate balance between BA conjugation/deconjugation based on the bsh genes present.

Effects of dietary rosemary ultrafine powder supplementation on aged hen health and productivity: a randomized controlled trial

Recently, poultry industry has been seeking antibiotic residue-free poultry products and safe nutritious feed additives. Whether rosemary ultrafine powder (RUP) affects productive performance by regulating the intestinal microbiome of aged layers remains unclear. Here, we investigated the effects of dietary RUP supplementation on the production performance, egg quality, antioxidant capacity, intestinal microbial structure, and metabolome of aged hens. The results indicate that RUP had no significant effect on production performance but significantly enhanced Thick albumen height, Haugh unit, yolk color (P < 0.05), daily feed intake, and qualified egg rate. Serum content of non-esterified fatty acids, catalase, and glutathione peroxidase increased significantly (P < 0.05). Furthermore, the liver total protein content was significantly increased (P < 0.05). 16S rRNA sequence analysis revealed that RUP significantly impacted both α- and β-diversity of the caecum microbiota. Linear discriminant analysis of effect size and random forest identified Bacteroides, Muribaculum, Butyricimonas, Odoribacter, and Prevotella as biomarkers in groups A and B. In comparing groups A and C, Barnesiella, Turicibacter, and Acholeplasma were critical bacteria, while comparing groups A and D highlighted Barnesiella and Candidatus Saccharimonas as differential bacteria. FAPROTAX analysis of the caecum microbiota revealed that the functional genes associated with harmful substance biodegradation were significantly increased in the RUP-fed group. Based on Spearman correlation analysis, alterations in microbial genera were associated with divergent metabolites. In summary, dietary RUP can improve egg quality and antioxidant capacity and regulate the intestinal microbiome and metabolome in aged breeders. Therefore, RUP can potentially be used as a feed additive to extend breeder service life at an appropriate level of 1.0 g/kg.

MicroRNA and Gut Microbiota Alter Intergenerational Effects of Paternal Exposure to Polyethylene Nanoplastics

Nanoplastics (NPs), as emerging contaminants, have been shown to cause testicular disorders in mammals. However, whether paternal inheritance effects on offspring health are involved in NP-induced reproductive toxicity remains unclear. In this study, we developed a mouse model where male mice were administered 200 nm polyethylene nanoparticles (PE-NPs) at a concentration of 2 mg/L through daily gavage for 35 days to evaluate the intergenerational effects of PE-NPs in an exclusive male-lineage transmission paradigm. We observed that paternal exposure to PE-NPs significantly affected growth phenotypes and sex hormone levels and induced histological damage in the testicular tissue of both F0 and F1 generations. In addition, consistent changes in sperm count, motility, abnormalities, and gene expression related to endoplasmic reticulum stress, sex hormone synthesis, and spermatogenesis were observed across paternal generations. The upregulation of microRNA (miR)-1983 and the downregulation of miR-122-5p, miR-5100, and miR-6240 were observed in both F0 and F1 mice, which may have been influenced by reproductive signaling pathways, as indicated by the RNA sequencing of testis tissues and quantitative real-time polymerase chain reaction findings. Furthermore, alterations in the gut microbiota and subsequent Spearman correlation analysis revealed that an increased abundance of Desulfovibrio (C21_c20) and Ruminococcus (gnavus) and a decreased abundance of Allobaculum were positively associated with spermatogenic dysfunction. These findings were validated in a fecal microbiota transplantation trial. Our results demonstrate that changes in miRNAs and the gut microbiota caused by paternal exposure to PE-NPs mediated intergenerational effects, providing deeper insights into mechanisms underlying the impact of paternal inheritance.

Therapeutic effects and mechanisms of isoxanthohumol on DSS-induced colitis: regulating T cell development, restoring gut microbiota, and improving metabolic disorders

Ulcerative colitis (UC) is a severe hazard to human health. Since pathogenesis of UC is still unclear, current therapy for UC treatment is far from optimal. Isoxanthohumol (IXN), a prenylflavonoid from hops and beer, possesses anti-microbial, anti-oxidant, anti-inflammatory, and anti-angiogenic properties. However, the potential effects of IXN on the alleviation of colitis and the action of the mechanism is rarely studied. Here, we found that administration of IXN (60 mg/kg/day, gavage) significantly attenuated dextran sodium sulfate (DSS)-induced colitis, evidenced by reduced DAI scores and histological improvements, as well as suppressed the pro-inflammatory Th17/Th1 cells but promoted the anti-inflammatory Treg cells. Mechanically, oral IXN regulated T cell development, including inhibiting CD4+ T cell proliferation, promoting apoptosis, and regulating Treg/Th17 balance. Furthermore, IXN relieved colitis by restoring gut microbiota disorder and increasing gut microbiota diversity, which was manifested by maintaining the ratio of Firmicutes/Bacteroidetes balance, promoting abundance of Bacteroidetes and Ruminococcus, and suppressing abundance of proteobacteria. At the same time, the untargeted metabolic analysis of serum samples showed that IXN promoted the upregulation of D-( +)-mannose and L-threonine and regulated pyruvate metabolic pathway. Collectively, our findings revealed that IXN could be applied as a functional food component and served as a therapeutic agent for the treatment of UC.

An Update on the Role and Potential Molecules in Relation to Ruminococcus gnavus in Inflammatory Bowel Disease, Obesity and Diabetes Mellitus

Ruminococcus gnavus (R. gnavus) is a gram-positive anaerobe commonly resides in the human gut microbiota. The advent of metagenomics has linked R. gnavus with various diseases, including inflammatory bowel disease (IBD), obesity, and diabetes mellitus (DM), which has become a growing area of investigation. The initial focus of research primarily centered on assessing the abundance of R. gnavus and its potential association with disease presentation, taking into account variations in sample size, sequencing and analysis methods. However, recent investigations have shifted towards elucidating the underlying mechanistic pathways through which R. gnavus may contribute to disease manifestation. In this comprehensive review, we aim to provide an updated synthesis of the current literature on R. gnavus in the context of IBD, obesity, and DM. We critically analyze relevant studies and summarize the potential molecular mediators implicated in the association between R. gnavus and these diseases. Across numerous studies, various molecules such as methylation-controlled J (MCJ), glucopolysaccharides, ursodeoxycholic acid (UDCA), interleukin(IL)-10, IL-17, and capric acid have been proposed as potential contributors to the link between R. gnavus and IBD. Similarly, in the realm of obesity, molecules such as hydrogen peroxide, butyrate, and UDCA have been suggested as potential mediators, while glycine ursodeoxycholic acid (GUDCA) has been implicated in the connection between R. gnavus and DM. Furthermore, it is imperative to emphasize the necessity for additional studies to evaluate the potential efficacy of targeting pathways associated with R. gnavus as a viable strategy for managing these diseases. These findings have significantly expanded our understanding of the functional role of R. gnavus in the context of IBD, obesity, and DM. This review aims to offer updated insights into the role and potential mechanisms of R. gnavus, as well as potential strategies for the treatment of these diseases.

Classical and Innovative Evidence for Therapeutic Strategies in Retinal Dysfunctions

The human retina is a complex anatomical structure that has no regenerative capacity. The pathogenesis of most retinopathies can be attributed to inflammation, with the activation of the inflammasome protein platform, and to the impact of oxidative stress on the regulation of apoptosis and autophagy/mitophagy in retinal cells. In recent years, new therapeutic approaches to treat retinopathies have been investigated. Experimental data suggest that the secretome of mesenchymal cells could reduce oxidative stress, autophagy, and the apoptosis of retinal cells, and in turn, the secretome of the latter could induce changes in mesenchymal cells. Other studies have evidenced that noncoding (nc)RNAs might be new targets for retinopathy treatment and novel disease biomarkers since a correlation has been found between ncRNA levels and retinopathies. A new field to explore is the interaction observed between the ocular and intestinal microbiota; indeed, recent findings have shown that the alteration of gut microbiota seems to be linked to ocular diseases, suggesting a gut-eye axis. To explore new therapeutical strategies for retinopathies, it is important to use proper models that can mimic the complexity of the retina. In this context, retinal organoids represent a good model for the study of the pathophysiology of the retina.

Modified Gexia-Zhuyu Tang inhibits gastric cancer progression by restoring gut microbiota and regulating pyroptosis

BACKGROUND

Gexia-Zhuyu Tang (GZT), a traditional Chinese medicine formula, is used to treat a variety of diseases. However, its roles in gastric cancer (GC) remain unclear.

OBJECTIVE

The aim of this study was to explore the roles and underlying molecular mechanisms of modified GZT in GC.

METHODS

The effects of modified GZT on GC were investigated by constructing mouse xenograft models with MFC cell line. The fecal samples from low-dose, high-dose, and without modified GZT treatment groups were collected for the 16S rRNA gene sequencing and fecal microbiota transplantation (FMT). Histopathological alterations of mice were evaluated using the hematoxylin-eosin (HE). Immunohistochemical (IHC) analysis with Ki67 and GSDMD was performed to measure tissue cell proliferation and pyroptosis, respectively. Proteins associated with pyroptosis, invasion, and metastasis were detected by Western blotting. Enzyme-linked immunosorbent assay (ELISA) was used to assess inflammation-related factors levels.

RESULTS

Modified GZT inhibited GC tumor growth and reduced metastasis and invasion-related proteins expression levels, including CD147, VEGF, and MMP-9. Furthermore, it notably promoted caspase-1-dependent pyroptosis, as evidenced by a dose-dependent increase in TNF-α, IL-1β, IL-18, and LDH levels, along with elevated protein expression of NLRP3, ASC, and caspase-1. Additionally, modified GZT increased species abundance and diversity of the intestinal flora. FMT assay identified that modified GZT inhibited GC tumor progression through regulation of intestinal flora.

CONCLUSIONS

Modified GZT treatment may promote pyroptosis by modulating gut microbiota in GC. This study identifies a new potential approach for the GC clinical treatment.

Twnbiome: a public database of the healthy Taiwanese gut microbiome

With new advances in next generation sequencing (NGS) technology at reduced costs, research on bacterial genomes in the environment has become affordable. Compared to traditional methods, NGS provides high-throughput sequencing reads and the ability to identify many species in the microbiome that were previously unknown. Numerous bioinformatics tools and algorithms have been developed to conduct such analyses. However, in order to obtain biologically meaningful results, the researcher must select the proper tools and combine them to construct an efficient pipeline. This complex procedure may include tens of tools, each of which require correct parameter settings. Furthermore, an NGS data analysis involves multiple series of command-line tools and requires extensive computational resources, which imposes a high barrier for biologists and clinicians to conduct NGS analysis and even interpret their own data. Therefore, we established a public gut microbiome database, which we call Twnbiome, created using healthy subjects from Taiwan, with the goal of enabling microbiota research for the Taiwanese population. Twnbiome provides users with a baseline gut microbiome panel from a healthy Taiwanese cohort, which can be utilized as a reference for conducting case-control studies for a variety of diseases. It is an interactive, informative, and user-friendly database. Twnbiome additionally offers an analysis pipeline, where users can upload their data and download analyzed results. Twnbiome offers an online database which non-bioinformatics users such as clinicians and doctors can not only utilize to access a control set of data, but also analyze raw data with a few easy clicks. All results are customizable with ready-made plots and easily downloadable tables. Database URL: http://twnbiome.cgm.ntu.edu.tw/ .

Calorie restriction mimetic drugs could favorably influence gut microbiota leading to lifespan extension

Calorie restriction (CR) can prolong human lifespan, but enforcing long-term CR is difficult. Thus, a drug that reproduces the effects of CR without CR is required. More than 10 drugs have been listed as CR mimetics (CRM), and some of which are conventionally categorized as upstream-type CRMs showing glycolytic inhibition, whereas the others are categorized as downstream-type CRMs that regulate or genetically modulate intracellular signaling proteins. Intriguingly, recent reports have revealed the beneficial effects of CRMs on the body such as improving the host body condition via intestinal bacteria and their metabolites. This beneficial effect of gut microbiota may lead to lifespan extension. Thus, CRMs may have a dual effect on longevity. However, no reports have collectively discussed them as CRMs; hence, our knowledge about CRM and its physiological effects on the host remains fragmentary. This study is the first to present and collectively discuss the accumulative evidence of CRMs improving the gut environments for healthy lifespan extension, after enumerating the latest scientific findings related to the gut microbiome and CR. The conclusion drawn from this discussion is that CRM may partially extend the lifespan through its effect on the gut microbiota. CRMs increase beneficial bacteria abundance by decreasing harmful bacteria rather than increasing the diversity of the microbiome. Thus, the effect of CRMs on the gut could be different from that of conventional prebiotics and seemed similar to that of next-generation prebiotics.

From-Toilet-to-Freezer: A Review on Requirements for an Automatic Protocol to Collect and Store Human Fecal Samples for Research Purposes

The composition, viability and metabolic functionality of intestinal microbiota play an important role in human health and disease. Studies on intestinal microbiota are often based on fecal samples, because these can be sampled in a non-invasive way, although procedures for sampling, processing and storage vary. This review presents factors to consider when developing an automated protocol for sampling, processing and storing fecal samples: donor inclusion criteria, urine-feces separation in smart toilets, homogenization, aliquoting, usage or type of buffer to dissolve and store fecal material, temperature and time for processing and storage and quality control. The lack of standardization and low-throughput of state-of-the-art fecal collection procedures promote a more automated protocol. Based on this review, an automated protocol is proposed. Fecal samples should be collected and immediately processed under anaerobic conditions at either room temperature (RT) for a maximum of 4 h or at 4 °C for no more than 24 h. Upon homogenization, preferably in the absence of added solvent to allow addition of a buffer of choice at a later stage, aliquots obtained should be stored at either -20 °C for up to a few months or -80 °C for a longer period-up to 2 years. Protocols for quality control should characterize microbial composition and viability as well as metabolic functionality.

Therapeutic efficacy and underlying mechanisms of Gastrodia elata polysaccharides on dextran sulfate sodium-induced inflammatory bowel disease in mice: Modulation of the gut microbiota and improvement of metabolic disorders

Inflammatory bowel disease (IBD) is a chronic inflammatory gastrointestinal disease, and an imbalance in the gut microbiota is a critical factor in its development. Gastrodia elata (G. elata), an Orchidaceae plant, is recognized for its nutritional and medicinal value. Studies have shown that G. elata polysaccharides (GBP) have anti-inflammatory properties that may ameliorate IBD. However, the therapeutic effects of GBP on gut microbiota metabolism remain unknown. Therefore, we aimed to examine the therapeutic potential of G. elata extract and GBP in dextran sulfate sodium (DSS)-induced IBD mice. GBP demonstrated the best therapeutic effect by reducing IBD symptoms in mice to the greatest extent. Administering GBP resulted in significant increases in the relative abundances of bacteria with potential anti-inflammatory effects, such as Ligilactobacillus and Alloprevotella, and decreases in the levels of bacteria associated with proinflammatory responses, such as Bacteroides and Escherichia-Shigella. Furthermore, 36 significant differential metabolites between the model and GBP groups were identified in feces, which were mainly enriched in amino acid metabolism, including tryptophan and cysteine, vitamin B6 metabolism and steroid hormone biosynthesis. Consequently, investigating the metabolic regulation of the gut microbiota is a promising approach to evaluate the therapeutic effect of GBP on IBD.

Differences in gut microbiota and fecal bile acids between Caucasian and Hispanic children and young adults with ulcerative colitis

Ulcerative Colitis (UC) is an inflammatory bowel disease (IBD) that has been associated with gut dysbiosis. Changes in the gut microbiome lead to changes in bile acids (BA) metabolism, which changes the BA profiles in patients with UC. We conducted this study to investigate the differences in bile acids and gut microbiota between Hispanic and Caucasian children and young adults with UC. Twenty-seven Caucasian and 20 Hispanic children and young adults with UC were enrolled in the study. BAs were extracted from the subjects' stool samples and analyzed by liquid chromatography-mass spectrometry. Microbial DNA was also extracted from the stool samples to perform 16s rRNA amplicon sequencing. The median levels of cholic acid and taurolithocholic acid were found to be significantly higher in Hispanic children and young adults with UC compared to their Caucasian counterparts. The abundance of the gut microbiota that metabolizes BAs such as Proteobacteria, Pseudomonadaceae, Pseudomonas, Ruminococcus gnavus, and Escherichia coli were also all significantly higher in Hispanic children and young adults as well. The distinct BA profile that we found in Hispanic children and young adults with UC, in addition to the unique composition of their gut microbiome, provide them with a protective gut environment against inflammation, which is contrary to the common believe that Hispanics have worse IBD.

Causal relationship in gut microbiota and upper urinary urolithiasis using Mendelian randomization

Background

Several reports in recent years have found an association between gut microbiota and upper urinary urolithiasis. However, the causal relationship between them remains to be clarified.

Methods

Genetic variation is used as a tool in Mendelian randomization for inference of whether exposure factors have a causal effect on disease outcomes. We selected summary statistics from a large genome-wide association study of the gut microbiome published by the MiBioGen consortium with a sample size of 18,340 as an exposure factor and upper urinary urolithiasis data from FinnGen GWAS with 4,969 calculi cases and 213,445 controls as a disease outcome. Then, a two-sample Mendelian randomization analysis was performed by applying inverse variance-weighted, MR-Egger, maximum likelihood, and weighted median. In addition, heterogeneity and horizontal pleiotropy were excluded by sensitivity analysis.

Results

IVW results confirmed that class Deltaproteobacteria (OR = 0.814, 95% CI: 0.666-0.995, P = 0.045), order NB1n (OR = 0.833, 95% CI: 0.737-0.940, P = 3.15 × 10^-3), family Clostridiaceae1 (OR = 0.729, 95% CI: 0.581-0.916, P = 6.61 × 10^-3), genus Barnesiella (OR = 0.695, 95% CI: 0.551-0.877, P = 2.20 × 10^-3), genus Clostridium sensu_stricto_1 (OR = 0.777, 95% CI: 0.612-0.986, P = 0.0380), genus Flavonifractor (OR = 0.711, 95% CI: 0.536-0.944, P = 0.0181), genus Hungatella (OR = 0.829, 95% CI: 0.690-0.995, P = 0.0444), and genus Oscillospira (OR = 0.758, 95% CI: 0.577-0.996, P = 0.0464) had a protective effect on upper urinary urolithiasis, while Eubacterium xylanophilum (OR =1.26, 95% CI: 1.010-1.566, P = 0.0423) had the opposite effect. Sensitivity analysis did not find outlier SNPs.

Conclusion

In summary, a causal relationship was found between several genera and upper urinary urolithiasis. However, we still need further randomized controlled trials to validate.

Effects of cadmium and diethylhexyl phthalate on skin microbiota of Rana chinensis tadpoles

Skin microbiotas play a crucial role in the health, homeostasis, and immune function of amphibians. The contaminants in water could affect the structure and composition of microbial communities. The effects of coexisting pollutants on frogs cannot be adequately explained by a single exposure due to the coexistence of Cd and DEHP in the environment. Following exposure to Cd and/or DEHP, we examined the histological characteristics of Rana chensinensis tadpoles. We also used the 16S rRNA gene sequencing technique to assess the relative abundance of skin microbial communities among tadpoles from each treatment group. Our findings indicate that R. chensinensis' skin experienced some degree of injury due to exposure to Cd and DEHP, which led to the imbalance of their skin microbial community homeostasis and thus interfered with the normal trial status of the host. That may eventually lead to the decline of the amphibian population.

Potential of Gut Microbe-Derived Extracellular Vesicles to Differentiate Inflammatory Bowel Disease Patients from Healthy Controls

Background/Aims

This study aimed to evaluate the potential of the stool microbiome and gut microbe-derived extracellular vesicles (EVs) to differentiate between patients with inflammatory bowel disease (IBD) and healthy controls, and to predict relapse in patients with IBD.

Methods

Metagenomic profiling of the microbiome and bacterial EVs in stool samples of controls (n=110) and patients with IBD (n=110) was performed using 16S rRNA sequencing and then compared. Patients with IBD were divided into two enterotypes based on their microbiome, and the cumulative risk of relapse was evaluated.

Results

There was a significant difference in the composition of the stool microbiome and gut microbe-derived EVs between patients with IBD and controls. The alpha diversity of the microbiome in patients with IBD was significantly lower than that in controls, while the beta diversity also differed significantly between the two groups. These findings were more prominent in gut microbe-derived EVs than in the stool microbiome. The survival curve tended to be different for enterotypes based on the gut microbe-derived EVs; however, this difference was not statistically significant (log-rank test, p=0.166). In the multivariable analysis, elevated fecal calprotectin (>250 mg/kg) was the only significant risk factor associated with relapse (adjusted hazard ratio, 3.147; 95% confidence interval, 1.545 to 6.408; p=0.002).

Conclusions

Analysis of gut microbe-derived EVs is better at differentiating patients with IBD from healthy controls than stool microbiome analysis.

Intestine microbiota and SCFAs response in naturally Cryptosporidium-infected plateau yaks

Diarrhea is a severe bovine disease, globally prevalent in farm animals with a decrease in milk production and a low fertility rate. Cryptosporidium spp. are important zoonotic agents of bovine diarrhea. However, little is known about microbiota and short-chain fatty acids (SCFAs) changes in yaks infected with Cryptosporidium spp. Therefore, we performed 16S rRNA sequencing and detected the concentrations of SCFAs in Cryptosporidium-infected yaks. Results showed that over 80,000 raw and 70,000 filtered sequences were prevalent in yak samples. Shannon (p<0.01) and Simpson (p<0.01) were both significantly higher in Cryptosporidium-infected yaks. A total of 1072 amplicon sequence variants were shared in healthy and infected yaks. There were 11 phyla and 58 genera that differ significantly between the two yak groups. A total of 235 enzymes with a significant difference in abundance (p<0.001) were found between healthy and infected yaks. KEGG L3 analysis discovered that the abundance of 43 pathways was significantly higher, while 49 pathways were significantly lower in Cryptosporidium-infected yaks. The concentration of acetic acid (p<0.05), propionic acid (p<0.05), isobutyric acid (p<0.05), butyric acid (p<0.05), and isovaleric acid was noticeably lower in infected yaks, respectively. The findings of the study revealed that Cryptosporidium infection causes gut dysbiosis and results in a significant drop in the SCFAs concentrations in yaks with severe diarrhea, which may give new insights regarding the prevention and treatment of diarrhea in livestock.

Crosstalk between microbial biofilms in the gastrointestinal tract and chronic mucosa diseases

The gastrointestinal (GI) tract is the largest reservoir of microbiota in the human body; however, it is still challenging to estimate the distribution and life patterns of microbes. Biofilm, as the predominant form in the microbial ecosystem, serves ideally to connect intestinal flora, molecules, and host mucosa cells. It gives bacteria the capacity to inhabit ecological niches, communicate with host cells, and withstand environmental stresses. This study intends to evaluate the connection between GI tract biofilms and chronic mucosa diseases such as chronic gastritis, inflammatory bowel disease, and colorectal cancer. In each disease, we summarize the representative biofilm makers including Helicobacter pylori, adherent-invasive Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. We address biofilm's role in causing inflammation and the pro-carcinogenic stage in addition to discussing the typical resistance, persistence, and recurrence mechanisms seen in vitro. Biofilms may serve as a new biomarker for endoscopic and pathologic detection of gastrointestinal disease and suppression, which may be a useful addition to the present therapy strategy.

Probiotic-fermented Pueraria lobata (Willd.) Ohwi alleviates alcoholic liver injury by enhancing antioxidant defense and modulating gut microbiota

BACKGROUND

Pueraria lobata (Willd.) Ohwi (PL) has been used in China to detoxify alcohol and protect the liver for millennia, though its mechanism of liver protection has not been elucidated. However, fermentation is considered to be one of the effective ways to enhance the efficacy of traditional Chinese medicine. The aim of this study was to investigate the hepatoprotective mechanism of probiotic-fermented PL (FPL). Sprague Dawley rats were administered with FPL followed by gavage of alcohol for seven consecutive days; following that, liver injury levels were evaluated in rats.

RESULTS

FPL ameliorated lipid accumulation and inflammation levels in rats. Meanwhile, the levels of ethanol dehydrogenase, acetaldehyde dehydrogenase, and cytochrome P4502E1 were elevated by FPL treatment. It was observed that the levels of catalase, superoxide dismutase, and glutathione peroxidase were elevated, and the expression of nuclear transcriptional factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 genes and proteins were increased by FPL treatment, demonstrating that the Nrf2-mediated signal pathway was activated. Furthermore, FPL restored the composition of the gut microbiota with an increase in the abundances of Firmicutes and Lactobacillus and a decrease in the abundances of Bacteroidota and Akkermansia. Additionally, a strong correlation was found between the gut microbiota and the antioxidant parameters.

CONCLUSION

The results indicate that FPL possesses an excellent protective effect in alcoholic liver injury. Our findings are beneficial to the development of hepatoprotective nutraceuticals for alcoholics. © 2022 Society of Chemical Industry.

Different Effects of Different Lactobacillus acidophilus Strains on DSS-Induced Colitis

Inflammatory bowel disease (IBD) is a worldwide chronic intestinal inflammatory immune-related disease. In this study, mice with dextran sulfate sodium (DSS)-induced colitis were used to evaluate the effect of Lactobacillus acidophilus on colitis. The results revealed that L. acidophilus CCFM137 and FAHWH11L56 show potential for relieving colitis symptoms, while L. acidophilus FGSYC48L79 did not show a protective effect. Moreover, L. acidophilus NCFM and FAHWH11L56 showed similar effects on various indicators of DSS-induced colitis, increasing the IL-10 and IL-17 in the colon, and modifying the CCL2/CCR2 axis and CCL3/CCR1 axis. For L. acidophilus CCFM137, its effects on colitis were different from the above two strains. Moreover, L. acidophilus FGSYC48L79 had negative effects on colitis by increasing the abundance of harmful bacteria in the gut microbiota and may promote the signaling of chemokines and their receptors. This may be related to its special genome compared to the other strains.

Dietary Moringa oleifera leaf powder improves jejunal permeability and digestive function by modulating the microbiota composition and mucosal immunity in heat stressed rabbits

Heat stress (HS) has detrimental effects on intestinal health by altering digestive and immune responses in animals. Dietary Moringa oleifera leaf powder (MOLP) has been implicated in ameliorating the impact of HS, but its effects in terms of intestinal function improvement under HS remain poorly characterized. Therefore, the current study investigated the impact of HS and MOLP supplementation on tight junction barriers, intestinal microbiota (jejunal digesta), and differentially expressed genes (DEGs) in jejunal mucosa of heat-stressed rabbits by using the next-generation sequencing techniques. A total of 21 male New Zealand White rabbits (32 weeks old mean body weight of 3318 ± 171 g) were divided into three groups (n = 7/group) as control (CON, 25 °C), heat stress (HS, 35 °C for 7 h daily), and HS with MOLP supplementation (HSM, 35 °C for 7 h daily) gavage at 200 mg/kg body weight per day for 4 weeks. The results indicated that MOLP supplementation increased mRNA expression of tight junction proteins and glutathione transferase activity, while the malonaldehyde concentration was decreased in the jejunal mucosa compared to HS group (P < 0.05). Furthermore, MOLP decreased the concentrations of lipopolysaccharide, pro-inflammatory cytokines, and myeloperoxidase compared with HS group (P < 0.05). Intestinal microbiota analysis revealed that at phyla level, the relative abundance of Bacteroidetes was higher in HSM group compared to CON and HS groups. MOLP supplementation also resulted in higher abundance of putatively health-associated genera such as Christensenellaceae R-7 gut group, Ruminococcaceae NK4A214 group, Ruminococcus 2, Lachnospiraceae NK4A136 group, and Lachnospiraceae unclassified along with higher butyrate levels in HSM group as compared to HS group. The analysis of DEGs revealed that MOLP reversed inflammatory response by downregulation of genes, such as TNFRSF13C, LBP, and COX2 in enriched KEGG pathway of NF-kβ pathway. MOLP supplementation also significantly upregulated the expression of genes in protein digestion and absorption pathway, including PRSS2, LOC100349163, CPA1, CPB1, SLC9A3, SLC1A1, and SLC7A9 in HSM group. Three genes of fibrillar collagens, i.e., COL3A1, COL5A3, and COL12A1 in protein digestion were also down-regulated in HSM group. In conclusion, MOLP supplementation could improve jejunal permeability and digestive function, positively modulate microbiota composition and mucosal immunity in heat-stressed rabbits.

Topical issues of prevention of stomach cancer: A review

Prevention of gastric cancer, both primary and secondary, is an extremely important component of the management of gastroenterological patients. The correct collection of anamnesis with an assessment of the hereditary (family) cancer risk, the action of risk factors (eating disorders, habitual/chronic intoxication, obesity, Helicobacter pylori infection, etc.), as well as the use of gastroprotectors (in particular, the drug Regastim Gastro), especially in persons with potentially precancerous the condition is chronic atrophic gastritis. According to the data of a double-blind placebo-controlled randomized study Regastim Gastro (active ingredient alpha-glutamyl tryptophan) in the treatment of chronic atrophic gastritis, it was found that this drug has a powerful anti-inflammatory effect and regenerative activity. Taking the drug Regastim Gastro, compared with placebo, statistically significantly contributed to a decrease in the number of inflammatory infiltration cells per 1 mm2 of the gastric mucosa. Regastim Gastro decreases in eosinophilic (3 times) and neutrophilic (4 times) infiltration of the gastric mucosa and also reduced the number of macrophages, lymphocytes and plasmocytes. In addition to anti-inflammatory properties, the drug also had a pronounced regenerative effect. Taking of Regastim Gastro statistically significant (p=0.028) increases in the number of glands per 1 mm2 of the gastric mucosa by 26.1% compared with the initial screening indicators. In the group of patients taking placebo, on the contrary, there was a further progression of the pathological process, accompanied by a decrease in the number of glands per 1 mm2 of the gastric mucosa after the end of treatment in comparison with the initial indicators. After the course of therapy, the number of glands per 1 mm2 of the gastric mucosa in patients taking the drug Regastim Gastro was statistically significantly higher in comparison with the results in the placebo group (p=0.013). After the course of Regastim Gastro, there was an improvement in acid production: a shift in the acidic side of the average pH value (1.6 times) and an increase in the value of the acidity index, both when compared with the initial values (5.4 times) and in comparison with the placebo group (2.9 times). The intake of Regastim Gastro to patients with gastritis, both H. pylori (+) and H. pylori (-) before the development of atrophy of the gastric mucosa can reduce the inflammatory factor, prevent the occurrence of atrophy and may have maximum anti-carcinogenic action.

Intestine-Specific NHE3 Deletion in Adulthood Causes Microbial Dysbiosis

In the intestine, the Na⁺/H⁺ exchanger 3 (NHE3) plays a critical role for Na⁺ and fluid absorption. NHE3 deficiency predisposes patients to inflammatory bowel disease (IBD). In mice, selective deletion of intestinal NHE3 causes various local and systemic pathologies due to dramatic changes in the intestinal environment, which can influence microbiota colonization. By using metagenome shotgun sequencing, we determined the effect of inducible intestinal epithelial cell-specific deletion of NHE3 (NHE3^IEC-KO) in adulthood on the gut microbiome in mice. Compared with control mice, NHE3^IEC-KO mice show a significantly different gut microbiome signature, with an unexpected greater diversity. At the phylum level, NHE3^IEC-KO mice showed a significant expansion in Proteobacteria and a tendency for lower Firmicutes/Bacteroidetes (F/B) ratio, an indicator of dysbiosis. At the family level, NHE3^IEC-KO mice showed significant expansions in Bacteroidaceae, Rikenellaceae, Tannerellaceae, Flavobacteriaceae and Erysipelotrichaceae, but had contractions in Lachnospiraceae, Prevotellaceae and Eubacteriaceae. At the species level, after removing those with lowest occurrence and abundance, we identified 23 species that were significantly expanded (several of which are established pro-inflammatory pathobionts); whereas another 23 species were found to be contracted (some of which are potential anti-inflammatory probiotics) in NHE3^IEC-KO mice. These results reveal that intestinal NHE3 deletion creates an intestinal environment favoring the competitive advantage of inflammophilic over anti-inflammatory species, which is commonly featured in conventional NHE3 knockout mice and patients with IBD. In conclusion, our study emphasizes the importance of intestinal NHE3 for gut microbiota homeostasis, and provides a deeper understanding regarding interactions between NHE3, dysbiosis, and IBD.

The effect of a hydrolyzed protein diet on the fecal microbiota in cats with chronic enteropathy

The effect of a hydrolyzed protein diet on the fecal microbiota has not been studied in feline chronic enteropathy (CE). Our study aimed to (1) compare the fecal microbiota of cats with CE to control cats with no gastrointestinal signs and (2) determine the effect of a hydrolyzed protein diet on the fecal microbiota of cats with CE and whether this differs between dietary responders and non-responders. The fecal microbiome of cats with CE (n = 36) showed decreased α-diversity in terms of genus richness (P = 0.04) and increased β-diversity in terms of Bray-Curtis Dissimilarity (P < 0.001) compared to control cats (n = 14). Clostridium was the only genera significantly over-represented in cats with CE compared to control cats (adjusted P < 0.1). After 6-weeks of feeding the diet, fifteen cats were classified as responders and 18 as non-responders, based on clinical signs. At the genus level, α-diversity was increased in non-responders versus responders at diagnosis, but decreased after dietary intervention in both groups (P < 0.05). At the family level, non-responders became increasingly dissimilar after dietary intervention (P = 0.012). In general, the abundance of bacteria decreased with feeding a hydrolyzed diet, with the genera most significantly affected being more frequently observed in non-responders. Bifidobacterium was the only genus that increased significantly in abundance post-diet and this effect was observed in both responders and non-responders. Both Oscillibacter and Desulfovibrionaceae_unclassified were most abundant in non-responders at diagnosis but were rarely observed post diet in neither responders nor non-responders. Cats with CE had similar microbiota changes to those described in human inflammatory bowel disease. Whether the presence of Oscillibacter and Desulfovibrionaceae_unclassified are indicators of non-response to the diet at diagnosis requires further investigation. Despite the hydrolyzed diet reducing α-diversity in all cats with CE, this did not resolve gastrointestinal signs in some cats. However, responders metabolized the diet in a similar manner, reflected by sustained β-diversity, while the microbiome of non-responders became increasingly dissimilar compared to diagnosis at the family level. Therefore, the microbiome may not be as tightly regulated in cats with CE that are non-responders and therefore, these cats would require additional therapy for remission of clinical signs.

Acteoside, the Main Bioactive Compound in Osmanthus fragrans Flowers, Palliates Experimental Colitis in Mice by Regulating the Gut Microbiota

The present study investigated the effects of Osmanthus fragrans flowers and acteoside on murine colitis and the underlying mechanisms. The O. fragrans flower extract (OFE) and acteoside were administrated to chemically induced colitic mice. The results showed that OFE or acteoside ameliorates intestinal inflammation, oxidative stress, and activation of nuclear factor-κB (NF-κB) in colitic mice. The dysbiosis of the gut microbiome in colitic mice was also partly restored by OFE or acteoside, which was characterized by the alteration of the gut microbiome structure and the enrichment of beneficial bacteria (Akkermansia muciniphila and Bacteroides thetaiotaomicron). Dextran sulfate sodium (DSS)-induced gut metabolome dysfunctions (e.g., sphingosine metabolism and amino acids metabolism) in colitic mice were also partly restored by OFE and acteoside. A fecal microbiota (FM) transplantation study suggested that, compared with the FM from the normal diet-dosed donor mice, the FM from the OFE- or acteoside-dosed donor mice significantly suppressed colitic symptoms.

Potential Biomarkers Associated with Differential Manifestations of Ulcerative Colitis (UC) in Uyghur and Han Population in China

BACKGROUND

Ulcerative colitis (UC) is one of the main subtypes of inflammatory bowel disease (IBD). The incidence of UC in the Xinjiang region is relatively high in China and the manifestations of UC in Uyghur and Han patients are usually differential. This study aimed to identify potential biomarkers of UC.

METHODS

All miRNA and mRNA were extracted from the tissue samples obtained from participants in Xinjiang. Differential expression analysis was performed on all mRNAs and miRNAs. The target genes of miRNAs were predicted via three databases. The clusterProfiler package was used for GO and KEGG pathway enrichment analysis.

RESULTS

Preliminarily, four miRNAs and 15 genes were associated with the differential manifestations of UC in Uyghur and Han patients. Through the co-expression network construction and further screening in more samples, two miRNAs (hsa-miR-141-5p and hsa-miR-378a-5p) and three genes (ARNTL2, CLDN1 and SLC6A14) were found to be more crucial. These 15 genes were enriched in tight junction, NF-κB, and several other pathways.

CONCLUSION

Two miRNAs (hsa-miR-141-5p and hsa-miR-378a-5p) and three genes (ARNTL2, CLDN1, and SLC6A14) associated with the differential manifestations of UC in Uyghur and Han population were identified, which were potential biomarkers.

Effect of Long-Term and Short-Term Imbalanced Zn Manipulation on Gut Microbiota and Screening for Microbial Markers Sensitive to Zinc Status

Zinc (Zn) imbalance is a common single-nutrient disorder worldwide, but little is known about the short-term and long-term effects of imbalanced dietary zinc in the intestinal microbiome. Here, 3-week-old C57BL/6 mice were fed diets supplemented with Zn at the doses of 0 (low Zn), 30 (control Zn), 150 (high Zn), and 600 mg/kg of body weight (excess Zn) for 4 weeks (short term) and 8 weeks (long term). The gut bacterial composition at the phyla, genus, and species levels were changed as the result of the imbalanced Zn diet (e.g., Lactobacillus reuteri and Akkermansia muciniphila). Moreover, pathways including carbohydrate, glycan, and nucleotide metabolism were decreased by a short-term low-Zn diet. Valeriate production was suppressed by a long-term low-Zn diet. Pathways such as drug resistance and infectious diseases were upregulated in high- and excess-Zn diets over 4-week and 8-week intervals. Long-term zinc fortification doses, especially at the high-Zn level, suppressed the abundance of short-chain fatty acids (SCFAs)-producing genera as well as the concentrations of metabolites. Finally, Melainabacteria (phylum) and Desulfovibrio sp. strain ABHU2SB (species) were identified to be potential markers for Zn status with high accuracy (area under the curve [AUC], >0.8). Collectively, this study identified significant changes in gut microbial composition and its metabolite concentration in altered Zn-fed mice and the relevant microbial markers for Zn status. IMPORTANCE Zn insufficiency is an essential health problem in developing countries. To prevent the occurrence of zinc deficit, zinc fortification and supplementation are widely used. However, in developed countries, the amounts of Zn consumed often exceed the tolerable upper intake limit. Our results demonstrated that dietary Zn is an essential mediator of microbial community structure and that both Zn deficiency and Zn overdose can generate a dysbiosis in the gut microbiota. Moreover, specific microbial biomarkers of Zn status were identified and correlated with serum Zn level. Our study found that a short-term low-Zn diet (0 mg/kg) and a long-term high-zinc diet (150 mg/kg) had obvious negative effects in a mouse model. Thus, these results indicate that the provision and duration of supplemental Zn should be approached with caution.

Identification of a gut microbiota member that ameliorates DSS-induced colitis in intestinal barrier enhanced Dusp6-deficient mice

Strengthening the gut epithelial barrier is a potential strategy for management of gut microbiota-associated illnesses. Here, we demonstrate that dual-specificity phosphatase 6 (Dusp6) knockout enhances baseline colon barrier integrity and ameliorates dextran sulfate sodium (DSS)-induced colonic injury. DUSP6 mutation in Caco-2 cells enhances the epithelial feature and increases mitochondrial oxygen consumption, accompanied by altered glucose metabolism and decreased glycolysis. We find that Dusp6-knockout mice are more resistant to DSS-induced dysbiosis, and the cohousing and fecal microbiota transplantation experiments show that the gut/fecal microbiota derived from Dusp6-knockout mice also confers protection against colitis. Further culturomics and mono-colonialization experiments show that one gut microbiota member in the genus Duncaniella confers host protection from DSS-induced injury. We identify Dusp6 deficiency as beneficial for shaping the gut microbiota eubiosis necessary to protect against gut barrier-related diseases.

Daily ingestion of Akkermansia mucciniphila for one month promotes healthy aging and increases lifespan in old female mice

The ingestion of certain probiotics has been suggested as a promising nutritional strategy to improve aging. The objective of this work was to evaluate the effects of the daily intake, for a month, of a new probiotic Akkermansia muciniphila (AKK) (2 × 10⁸ cfu/100µL PBS) on behavior, as well as function and redox state of immune cells of old female ICR-CD1 mice (OA group). For this, several behavioral tests were performed, and function and oxidative-inflammatory stress parameters of peritoneal leukocytes were analyzed in OA group, in a group of the same age that did not take AKK (old control, OC group) and in another adult control (AC) group. The results showed, in OA group, a significant improvement of several behavioral responses (coordination, balance, neuromuscular vigor, exploratory ability and anxiety like-behaviors), as well as in immune functions (chemotaxis, phagocytosis, NK activity and lymphoproliferation) and in oxidative stress parameters (glutathione peroxidase and reductase activities, oxidized glutathione and lipid oxidation concentrations) of the peritoneal leukocytes in comparison to those observed in OC group. In addition, peritoneal immune cells from the OA group released lower basal concentrations of pro-inflammatory cytokines (IL-2, IL-6 and TNF-α) compared to those from the OC group. The values of parameters in OA were similar to those in AC group. These improvements in the old mice receiving the probiotic were reflected in an increase in their lifespan. In conclusion, our data indicate that AKK supplementation for a short period could be a good nutritional strategy to promote healthy longevity.

Eicosapentaenoic and docosahexaenoic acids attenuate hyperglycemia through the microbiome-gut-organs axis in db/db mice

BACKGROUND

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been suggested to prevent the development of metabolic disorders. However, their individual role in treating hyperglycemia and the mechanism of action regarding gut microbiome and metabolome in the context of diabetes remain unclear.

RESULTS

Supplementation of DHA and EPA attenuated hyperglycemia and insulin resistance without changing body weight in db/db mice while the ameliorative effect appeared to be more pronounced for EPA. DHA/EPA supplementation reduced the abundance of the lipopolysaccharide-containing Enterobacteriaceae whereas elevated the family Coriobacteriaceae negatively correlated with glutamate level, genera Barnesiella and Clostridium XlVa associated with bile acids production, beneficial Bifidobacterium and Lactobacillus, and SCFA-producing species. The gut microbiome alterations co-occurred with the shifts in the metabolome, including glutamate, bile acids, propionic/butyric acid, and lipopolysaccharide, which subsequently relieved β cell apoptosis, suppressed hepatic gluconeogenesis, and promoted GLP-1 secretion, white adipose beiging, and insulin signaling. All these changes appeared to be more evident for EPA. Furthermore, transplantation with DHA/EPA-mediated gut microbiota mimicked the ameliorative effect of DHA/EPA on glucose homeostasis in db/db mice, together with similar changes in gut metabolites. In vitro, DHA/EPA treatment directly inhibited the growth of Escherichia coli (Family Enterobacteriaceae) while promoted Coriobacterium glomerans (Family Coriobacteriaceae), demonstrating a causal effect of DHA/EPA on featured gut microbiota.

CONCLUSIONS

DHA and EPA dramatically attenuated hyperglycemia and insulin resistance in db/db mice, which was mediated by alterations in gut microbiome and metabolites linking gut to adipose, liver and pancreas. These findings shed light into the gut-organs axis as a promising target for restoring glucose homeostasis and also suggest a better therapeutic effect of EPA for treating diabetes. Video abstract.

A Review of the Role of the Intestinal Microbiota in Age-Related Macular Degeneration

Blindness from age-related macular degeneration (AMD) is an escalating problem, yet AMD pathogenesis is incompletely understood and treatments are limited. The intestinal microbiota is highly influential in ocular and extraocular diseases with inflammatory components, such as AMD. This article reviews data supporting the role of the intestinal microbiota in AMD pathogenesis. Multiple groups have found an intestinal dysbiosis in advanced AMD. There is growing evidence that environmental factors associated with AMD progression potentially work through the intestinal microbiota. A high-fat diet in apo-E-/- mice exacerbated wet and dry AMD features, presumably through changes in the intestinal microbiome, though other independent mechanisms related to lipid metabolism are also likely at play. AREDS supplementation reversed some adverse intestinal microbial changes in AMD patients. Part of the mechanism of intestinal microbial effects on retinal disease progression is via microbiota-induced microglial activation. The microbiota are at the intersection of genetics and AMD. Higher genetic risk was associated with lower intestinal bacterial diversity in AMD. Microbiota-induced metabolite production and gene expression occur in pathways important in AMD pathogenesis. These studies suggest a crucial link between the intestinal microbiota and AMD pathogenesis, thus providing a novel potential therapeutic target. Thus, the need for large longitudinal studies in patients and germ-free or gnotobiotic animal models has never been more pressing.

Silicon-containing water intake confers antioxidant effect, gastrointestinal protection, and gut microbiota modulation in the rodents

We explored the effects of silicon-containing water (BT) intake on gastrointestinal function and gut microbiota. BT was obtained by pressuring tap water through silicon minerals (mullite, Al₆Si₂O₁₃) column. BT decreased H₂O₂ chemiluminescence counts, indicating its antioxidant activity. Four weeks of BT drinking increased H₂O₂ scavenging activity and glutathione peroxidase activity of plasma. BT drinking did not affect the body weight but significantly reduced the weight of feces and gastrointestinal motility. BT drinking significantly suppressed pylorus ligation enhanced gastric juice secretion, gastric reactive oxygen species amount, erythrocyte extravasation, IL-1β production by infiltrating leukocyte, and lipid peroxidation within gastric mucosa. Data from 16S rRNA sequencing revealed BT drinking significantly increased beneficial flora including Ruminococcaceae UCG-005, Prevotellaceae NK3B31, Weissella paramesenteroides, Lactobacillus reuteri, and Lactobacillus murinus and decreased harmful flora including Mucispirillum, Rodentibacter, and Staphylococcus aureus. This study pioneerly provided scientific evidences for the potential effects of water-soluble forms of silicon intake on antioxidant activity, gastrointestinal function, and gut microbiota modulation.

Role of HCA2 in Regulating Intestinal Homeostasis and Suppressing Colon Carcinogenesis

Hydroxycarboxylic acid receptor 2 (HCA₂) is vital for sensing intermediates of metabolism, including β-hydroxybutyrate and butyrate. It also regulates profound anti-inflammatory effects in various tissues, indicating that HCA₂ may serve as an essential therapeutic target for mediating inflammation-associated diseases. Butyrate and niacin, endogenous and exogenous ligands of HCA₂, have been reported to play an essential role in maintaining intestinal homeostasis. HCA₂, predominantly expressed in diverse immune cells, is also present in intestinal epithelial cells (IECs), where it regulates the intricate communication network between diet, microbiota, and immune cells. This review summarizes the physiological role of HCA₂ in intestinal homeostasis and its pathological role in intestinal inflammation and cancer.

Altered Gut Microbiota Related to Inflammatory Responses in Patients With Huntington's Disease

Emerging evidence indicates that gut dysbiosis may play a regulatory role in the onset and progression of Huntington’s disease (HD). However, any alterations in the fecal microbiome of HD patients and its relation to the host cytokine response remain unknown. The present study investigated alterations and host cytokine responses in patients with HD. We enrolled 33 HD patients and 33 sex- and age- matched healthy controls. Fecal microbiota communities were determined through 16S ribosomal DNA gene sequencing, from which we analyzed fecal microbial richness, evenness, structure, and differential abundance of individual taxa between HD patients and healthy controls. HD patients were evaluated for their clinical characteristics, and the relationships of fecal microbiota with these clinical characteristics were analyzed. Plasma concentrations of interferon gamma (IFN-γ), interleukin 1 beta (IL-1β), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and tumor necrosis factor alpha were measured by Meso Scale Discovery (MSD) assays, and relationships between microbiota and cytokine levels were analyzed in the HD group. HD patients showed increased α-diversity (richness), β-diversity (structure), and altered relative abundances of several taxa compared to those in healthy controls. HD-associated clinical characteristics correlated with the abundances of components of fecal microbiota at the genus level. Genus Intestinimonas was correlated with total functional capacity scores and IL-4 levels. Our present study also revealed that genus Bilophila were negatively correlated with proinflammatory IL-6 levels. Taken together, our present study represents the first to demonstrate alterations in fecal microbiota and inflammatory cytokine responses in HD patients. Further elucidation of interactions between microbial and host immune responses may help to better understand the pathogenesis of HD.

Berberine improves colitis by triggering AhR activation by microbial tryptophan catabolites

Inflammatory bowel diseases (IBD) are kind of recurrent inflammatory issues that occur in the gastrointestinal tract, and currently clinical treatment is still unideal due to the complex pathogenesis of IBD. Basically, gut barrier dysfunction is triggered by gut microbiota dysbiosis that is closely associated with the development of IBD, we thus investigated the therapeutic capacity of berberine (BBR) to improve the dysregulated gut microbiota, against IBD in rats, using a combinational strategy of targeted metabolomics and 16 s rDNA amplicon sequencing technology. Expectedly, our data revealed that BBR administration could greatly improve the pathological phenotype, gut barrier disruption, and the colon inflammation in rats with dextran sulfate sodium (DSS)-induced colitis. In addition, 16S rDNA-based microbiota analysis demonstrated that BBR could alleviate gut dysbiosis in rats. Furthermore, our targeted metabolomics analysis illustrated that the levels of microbial tryptophan catabolites in the gastrointestinal tract were significantly changed during the development of the colitis in rats, and BBR treatment can significantly restore such changes of the tryptophan catabolites accordingly. At last, our in vitro mechanism exploration was implemented with a Caco-2 cell monolayer model, which verified that the modulation of the dysregulated gut microbiota to change microbial metabolites coordinated the improvement effect of BBR on gut barrier disruption in the colitis, and we also confirmed that the activation of AhR induced by microbial metabolites is indispensable to the improvement of gut barrier disruption by BBR. Collectively, BBR has the capacity to treat DSS-induced colitis in rats through the regulation of gut microbiota associated tryptophan metabolite to activate AhR, which can greatly improve the disrupted gut barrier function. Importantly, our finding elucidated a novel mechanism of BBR to improve gut barrier function, which holds the expected capacity to promote the BBR derived drug discovery and development against the colitis in clinic setting.

Lactobacillus paracasei KBL382 administration attenuates atopic dermatitis by modulating immune response and gut microbiota

Administration of probiotics has been linked to immune regulation and changes in gut microbiota composition, with effects on atopic dermatitis (AD). In this study, we investigated amelioration of the symptoms of AD using Lactobacillus paracasei KBL382 isolated from the feces of healthy Koreans. Mice with Dermatophagoides farinae extract (DFE)-induced AD were fed 1 × 109 CFU d-1 of L. paracasei KBL382 for 4 weeks. Oral administration of L. paracasei KBL382 significantly reduced AD-associated skin lesions, epidermal thickening, serum levels of immunoglobulin E, and immune cell infiltration. L. paracasei KBL382-treated mice showed decreased production of T helper (Th)1-, Th2-, and Th17-type cytokines, including thymic stromal lymphopoietin, thymus, and activation-regulated chemokine, and macrophage-derived chemokine, and increased production of the anti-inflammatory cytokine IL-10 and transforming growth factor-β in skin tissue. Intake of L. paracasei KBL382 also increased the proportion of CD4+ CD25+ Foxp3+ regulatory T cells in mesenteric lymph nodes. In addition, administration of L. paracasei KBL382 dramatically changed the composition of gut microbiota in AD mice. Administration of KBL382 significantly ameliorates AD-like symptoms by regulating the immune response and altering the composition of gut microbiota.

Lactobacillus paracasei KBL382 administration attenuates atopic dermatitis by modulating immune response and gut microbiota

Administration of probiotics has been linked to immune regulation and changes in gut microbiota composition, with effects on atopic dermatitis (AD). In this study, we investigated amelioration of the symptoms of AD using Lactobacillus paracasei KBL382 isolated from the feces of healthy Koreans. Mice with Dermatophagoides farinae extract (DFE)-induced AD were fed 1 × 10⁹ CFU d^-1 of L. paracasei KBL382 for 4 weeks. Oral administration of L. paracasei KBL382 significantly reduced AD-associated skin lesions, epidermal thickening, serum levels of immunoglobulin E, and immune cell infiltration. L. paracasei KBL382-treated mice showed decreased production of T helper (Th)1-, Th2-, and Th17-type cytokines, including thymic stromal lymphopoietin, thymus, and activation-regulated chemokine, and macrophage-derived chemokine, and increased production of the anti-inflammatory cytokine IL-10 and transforming growth factor-β in skin tissue. Intake of L. paracasei KBL382 also increased the proportion of CD4+ CD25+ Foxp3+ regulatory T cells in mesenteric lymph nodes. In addition, administration of L. paracasei KBL382 dramatically changed the composition of gut microbiota in AD mice. Administration of KBL382 significantly ameliorates AD-like symptoms by regulating the immune response and altering the composition of gut microbiota.

Fish Oil, Cannabidiol and the Gut Microbiota: An Investigation in a Murine Model of Colitis

Inflammatory bowel disorders can be associated with alterations in gut microbiota (dysbiosis) and behavioral disturbances. In experimental colitis, administration of fish oil (FO) or cannabinoids, such as cannabidiol (CBD), reduce inflammation. We investigated the effect of combined FO/CBD administration on inflammation and dysbiosis in the dextran sulphate sodium (DSS) model of mouse colitis, which also causes behavioral disturbances. Colitis was induced in CD1 mice by 4% w/v DSS in drinking water for five consecutive days followed by normal drinking water. FO (20–75 mg/mouse) was administered once a day starting two days after DSS, whereas CBD (0.3–30 mg/kg), alone or after FO administration, was administered once a day starting 3 days after DSS, until day 8 (d8) or day 14 (d14). Inflammation was assessed at d8 and d14 (resolution phase; RP) by measuring the Disease Activity Index (DAI) score, change in body weight, colon weight/length ratio, myeloperoxidase activity and colonic interleukin (IL)-1β (IL-1β), IL-10, and IL-6 concentrations. Intestinal permeability was measured with the fluorescein isothiocyanate-dextran. Behavioral tests (novel object recognition (NOR) and light/dark box test) were performed at d8. Fecal microbiota composition was determined by ribosomal 16S DNA sequencing of faecal pellets at d8 and d14. DSS-induced inflammation was stronger at d8 and accompanied by anxiety-like behavior and impaired recognition memory. FO (35, 50, 75 mg/mouse) alone reduced inflammation at d8, whereas CBD alone produced no effect at any of the doses tested; however, when CBD (3, 10 mg/kg) was co-administered with FO (75 mg/mouse) inflammation was attenuated. FO (20 mg/mouse) and CBD (1 mg/kg) were ineffective when given alone, but when co-administered reduced all inflammatory markers and the increased intestinal permeability at both d8 and d14, but not the behavioral impairments. FO, CBD, and their combination affected gut bacteria taxa that were not affected by DSS per se. Akkermansia muciniphila, a species suggested to afford anti-inflammatory action in colitis, was increased by DSS only at d14, but its levels were significantly elevated by all treatments at d8. FO and CBD co-administered at per se ineffective doses reduce colon inflammation, in a manner potentially strengthened by their independent elevation of Akkermansia muciniphila.

Ruminococcus gnavus bacteraemia in a patient with multiple haematological malignancies

We present a case of Ruminococcus gnavus sepsis in a woman suffering from multiple myeloma and myelodysplastic syndrome. R. gnavus, a Gram-positive coccus and a gut commensal, has been described in nine cases of infection in the literature, with most infections having occurred in patients with either gastrointestinal symptoms or prosthesis infections. In this case, R gnavus was identified by mass spectrometry, and showed susceptibility to penicillin, meropenem, tetracycline, metronidazole and clindamycin. The patient was successfully treated initially with intravenous piperacillin/tazobactam and metronidazole, and then switched to oral penicillin and metronidazole. The cause of infection is hypothesized to have been a shift in the gut microbiota towards an excess growth of R. gnavus caused by immunosuppression, and bacterial translocation across a vulnerable mucosal barrier due to prednisolone treatment and severe thrombocytopenia.

The role of gastric microbiota in gastric cancer

Gastric cancer represents one of the leading causes of cancer deaths worldwide. Helicobacter pylori (H. pylori) infection is the strongest risk factor associated with gastric cancer. Due to new molecular techniques allowing greater identification of stomach microbes, investigators are beginning to examine the role that bacteria other than H. pylori play in gastric cancer development. Recently, researchers have investigated how the composition of the gastric microbiota varies among individuals with various stages of gastric disease. Specific microbes residing in the stomach have been preferentially associated with gastric cancer patients compared to individuals with a healthy gastric mucosa. Studies conducted on the insulin-gastrin (INS-GAS) transgenic mouse model have provided additional insight into the association between the gastric microbiota and gastric cancer. The purpose of this article is to review the current state of literature on the relationship between the gastric microbiota and gastric cancer based on clinical studies performed to date.

Glyphosate exposure induces inflammatory responses in the small intestine and alters gut microbial composition in rats

Glyphosate is the most popular herbicide used worldwide. This study aimed to investigate the adverse effects of glyphosate on the small intestine and gut microbiota in rats. The rats were gavaged with 0, 5, 50, and 500 mg/kg of body weight glyphosate for 35 continuous days. The different segments of the small intestine were sampled to measure indicators of oxidative stress, ion concentrations and inflammatory responses, and fresh feces were collected for microbiota analysis. The results showed that glyphosate exposure decreased the ratio of villus height to crypt depth in the duodenum and jejunum. Decreased activity of antioxidant enzymes (T-SOD, GSH, GSH-Px) and elevated MDA content were observed in different segments of the small intestine. Furthermore, the concentrations of Fe, Cu, Zn and Mg were significantly decreased or increased. In addition, the mRNA expression levels of IL-1β, IL-6, TNF-α, MAPK3, NF-κB, and Caspase-3 were increased after glyphosate exposure. The 16 S rRNA gene sequencing results indicated that glyphosate exposure significantly increased α-diversity and altered bacterial composition. Glyphosate exposure significantly decreased the relative abundance of the phylum Firmicutes and the genus Lactobacillus, but several potentially pathogenic bacteria were enriched. In conclusion, this study provides important insight to reveal the negative influence of glyphosate exposure on the small intestine, and the altered microbial composition may play a vital role in the process.

Eicosapentaenoic and Docosahexaenoic Acids Differentially Alter Gut Microbiome and Reverse High-Fat Diet-Induced Insulin Resistance

SCOPE

To assess the individual effects of dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on insulin resistance (IR), gut microbiome, and gut metabolites in high-fat-diet-induced obese (DIO) mice.

METHODS AND RESULTS

DIO mice are fed an either high-fat diet (HFD), EPA (1% w/w) enriched HFD, or DHA (1% wt/wt) enriched HFD for 15 weeks. Both EPA and DHA supplements reverse hyperglycemia and IR but do not affect body weight in DIO mice while DHA exhibits a more pronounced ameliorative effect in male mice. Both EPA- and DHA-enriched Lactobacillus and short-chain fatty acids (SCFAs)-producing species from Lachnospiraceae while reduced lipopolysaccharide (LPS)-producing Bilophila and Escherichia/Shigella. Compared with EPA, DHA-supplemented mice have more abundant propionic/butyric acid-producing bacteria, including Coprococcus, Butyricimonas synergistica, Bacteroides acidifaciens, and Intestinimonas, and less-abundant LPS-correlated species Streptococcus and p-75-a5. The shifts in gut microbiome co-occurred with the changes in levels of propionic/butyric acid, circulating LPS, and serotonin. Additionally, EPA/DHA supplementation attenuates adipose inflammation with upregulated glucose transporter 4 and Akt phosphorylation, indicating the improvement of insulin signaling.

CONCLUSION

EPA and DHA differentially reverse IR and relieve adipose inflammation while modulating gut microbiome and SCFAs/LPS production, underscoring the gut-adipose axis as a primary target of EPA/DHA.