Protective Effects of a Novel Probiotic Bifidobacterium pseudolongum on the Intestinal Barrier of Colitis Mice via Modulating the Pparγ/STAT3 Pathway and Intestinal Microbiota

Targeted modulation of intestinal barrier and mucosal immune-related microbiota attenuates IgA nephropathy progression

IgA nephropathy (IgAN) is related to the balance of gut microbiota. However, it is unclear whether changes in the gut microbiota can cause IgAN or attenuate its progression. This study employed IgAN and human microbiota-associated (HMA)-IgAN models to investigate the impact of IgAN on gut microbiota alteration and the mechanisms by which gut microbiota might trigger IgAN. Furthermore, this study examined the effects of chitooligosaccharides (COS) and COS formulation (COSF) with microbiota-targeting function on enhancing intestinal barrier and renal functions. These results revealed that IgAN led to a reduction in α-diversity and structural alterations in the gut microbiota, characterized by an increase in Shigella sonnei, Streptococcus danieliae, Desulfovibrio fairfieldensis, and a decrease in Bifidobacterium pseudolongum and Clostridium leptum. There was also an imbalance in intestinal B-cell immunity and a decrease in the level of tight junction proteins (ZO-1 and Occludin). Intestinal barrier and mucosal immune-related microbiota (Clostridium leptum, unclassified Lachnospiraceae NK4Al36 group, unclassified Clostridia vadinBB60 group, unclassified Oscillospiraceae, and unclassified Roseburia) were enriched through targeted modulation with COS/COSF, enhancing intestinal ZO-1 expression and reducing APRIL/BAFF overexpression, thereby reducing renal damage in IgAN. In conclusion, this study clarified the kidney-gut crosstalk between gut microbiota and IgAN, providing scientific evidence for developing microbiota-targeted food interventions to improve IgAN outcomes.

Time-restricted feeding mitigates Alzheimer's disease-associated cognitive impairments via a B. pseudolongum-propionic acid-FFAR3 axis

Time-restricted feeding (TRF) holds promise for alleviating cognitive decline in aging, albeit the precise mechanism via the gut-brain axis remains elusive. In a clinical trial, we observed, for the first time, that a 4-month TRF ameliorated cognitive impairments among Alzheimer's disease (AD) patients. Experiments in 5xFAD mice corroborated the gut microbiota-dependent effect of TRF on mitigating cognitive dysfunction, amyloid-beta deposition, and neuroinflammation. Multi-omics integration linked Bifidobacterium pseudolongum (B. pseudolongum) and propionic acid (PA) with key genes in AD pathogenesis. Oral supplementation of B. pseudolongum or PA mimicked TRF's protective effects. Positron emission tomography imaging confirmed PA's blood-brain barrier penetration, while knockdown of the free fatty acid receptor 3 (FFAR3) diminished TRF's cognitive benefits. Notably, we observed a positive correlation between fecal PA and improved cognitive function in an AD cohort, further indicating that TRF enhanced PA production. These findings highlight the microbiota-metabolites-brain axis as pivotal in TRF's cognitive benefits, proposing B. pseudolongum or PA as potential AD therapies.

Alleviation effects of Lactobacillus plantarum in colitis aggravated by a high-salt diet depend on intestinal barrier protection, NF-κB pathway regulation, and oxidative stress improvement

A high-salt diet (HSD) can result in numerous health issues, including exacerbation of intestinal inflammation. Therefore, there is an immediate necessity of developing dietary supplements that can mitigate colitis exacerbated by a HSD. This study examined the impact of Lactobacillus plantarum HGD228 on colitis exacerbated by a HSD and the mechanisms underlying its alleviation. HGD228 treatment significantly enhanced colonic goblet cells and MUC2, upregulated ZO-1 and occludin, inhibited epithelial cell apoptosis, and mitigated colitis exacerbated by a HSD. Moreover, HGD228 significantly regulated oxidative stress-related enzymes, including SOD, GSH-PX, and CAT. HGD228 treatment significantly suppressed the NF-κB pathway induced by a HSD and regulated the levels of cytokines, including TNF-α, IL-10, and IL-1β. Furthermore, HGD228 reestablished the gut microbiota altered by HSDDSS, increasing Bifidobacterium while decreasing Escherichia-Shigella and Clostridium sensu stricto 1. HGD228 treatment also enhanced the production of butyric acid and acetic acid, suppressed pro-inflammatory cytokines, and strengthened the intestinal mucosal barrier. Therefore, HGD228 enhanced the production of beneficial metabolites by regulating inflammatory cytokines and oxidative stress, preserving the mucosal barrier, and enhancing gut microbiota, and mitigated colitis aggravated by a HSD. These results will aid in clinical trials of probiotics and the development of dietary supplements for colitis, with promising application value.

To explore the potential combined treatment strategy for colorectal cancer: Inhibition of cancer stem cells and enhancement of intestinal immune microenvironment

BACKGROUND

The antibiotic salinomycin, a well-known cancer stem cell inhibitor, may impact the diversity of the intestinal microbiota in colorectal cancer (CRC) mice, which plays a pivotal role in shaping the immune system. This study explores the anti-cancer effects and mechanisms of combining salinomycin and fecal microbiota transplantation (FMT) in treating CRC.

METHODS

FMT was given via enema, while salinomycin was injected intraperitoneally into the CRC mouse model induced by azoxymethane/dextran sodium sulfate.

RESULTS

In CRC mice, a large number of LGR5-labeled cancer stem cells and severe disturbances in the intestinal microbiota were observed. Interestingly, salinomycin inhibited the proliferation of cancer stem cells without exacerbating the microbial disorder as expected. In comparison to salinomycin treatment, the combination of salinomycin and FMT significantly improved pathological damage and restored intestinal microbial diversity, which is responsible for shaping the anti-cancer immune microenvironment. The supplementation of FMT significantly increased the levels of propionic acid and butyric acid while also promoting the infiltration of CD8+ T cells and Ly6G+ neutrophils, as well as reducing F4/80+ macrophage recruitment. Notably, cytokines that were not impacted by salinomycin exhibited robust reactions to alterations in the gut microbiota. These included pro-inflammatory factors (IL6, IL12b, IL17, and IL22), chemokine-like protein OPN, and immunosuppressive factor PD-L1.

CONCLUSIONS

Salinomycin plays the role of "eliminating pathogenic qi," targeting cancer stem cells; FMT plays the role of "strengthening vital qi," reversing the intestinal microbiota disorder and enhancing anti-cancer immunity. They have a synergistic effect on the development of CRC.

Dietary supplement of Acanthopanax senticosus decoction formula improves immune response via intestine flora of rabbits

Young rabbits are sensitive to surrounding changes and conditioned pathogens in intestine which might result in slow inflammation and diarrhea after microbial invasion. Traditional medicine herbs could provide efficacious treatment on slow infection and inflammation. The present research designed an Acanthopanax senticosus (ACS) formula consisted of five types of Chinese herbs including Acanthopanax senticosus (Rupr & Maxim) Harms (Ciwujia in Chinese), Astragalus membranceus (Fisch) Bge (Huangqi in Chinese), Indigo naturalis (Qingdai in Chinese), Houttuynia cordata Thunb (Yuxingcao in Chinese), and Glycyrrhizae radix et Rhizoma (Gancao in Chinese). The effects of ACS decoction supplement were investigated via determination of cytokines and growth performances of young rabbits, and the flora in intestinal digesta from six fragments were further explored using 16S rRNA gene sequencing technology. Compared to the control group, rabbits supplied with different doses of ACS decoction possessed lower diarrhea and death rates, together with the IL-10 concentration, while the declined IL-1β and IL-12 levels and inflammatory factor gene expressions in intestinal tissues. Additionally, ACS addition changed the diversity of flora in each segments of intestine. Functional prediction on abundances of genera enriched to seven KEGG immunity pathways. Moreover, strong correlations were determined between the abundance of bacteria with interleukins contents, and the predictive immune signaling abundances, respectively. Especially, ACS exhibited anti-inflammation effects via decreasing the abundances of Bacteroides, Clostridia_vadinBB60_group, NK4A214_group, and dgA_11_gut_group in intestine of young rabbits. In conclusion, dietary supplement with ACS exerted diarrhea-reducing effects, and improved immunity homeostasis by modulating intestinal flora diversity in young rabbits.

The Prebiotic Effect of Kaempferol in Regulating Bile Acid Metabolism

Kaempferol (Kae), as a homologous flavonoid, plays a pivotal role in human nutrition and disease treatment. This study endeavors to elucidate the in vivo metabolism of Kae and its potential to modulate the interplay between bile acids (BAs) and gut microbiota (GM). After Kae administration, we analyzed pharmacokinetics, BA levels, and drug metabolic enzymes (DMEs) amount using LC-MS/MS. Subsequently, we checked the gene and protein expression with qRT-PCR and western blot and studied the changes in GM using 16S rRNA sequencing, accompanying in-depth data analysis. Finally, molecular docking was employed to explore Kae's interaction with the Farnesoid X receptor (FXR). Kae enhances its own absorption and metabolic circulation in vivo by upregulating the UDP-Glucuronosyltransferases (UGTs) expression. Furthermore, Kae significantly suppressed the expression of cholesterol 7α-hydroxylase (CYP7A1) while concurrently elevating the sterol 27-hydroxylase (CYP27A1) expression, by activating the liver FXR, a nuclear transcription factor involved in the regulation of CYPs and UGTs enzymes. For BA analysis, Kae induced the upregulation of tauro-BAs by attenuating the activity of bile salt hydrolases (BSH), which correlated with shifts in the GM composition. Specifically, Kae increased the abundance of beneficial bacteria such as Bacteroides acidifaciens and Bifidobacterium choerinum, while reduced populations of species associated with BSH deconjugation. The study indicates that Kae may serve as a prebiotic, modulating the BA-GM interaction to confer nutritional and therapeutic advantages.

Dialdehyde starch-epicatechin gallate conjugate alleviates inflammation in lipopolysaccharide-stimulated RAW264.7 cells and dextran sulfate sodium-induced colitis mice

In this study, epicatechin gallate (ECG), a natural anti-inflammatory agent, was conjugated onto dialdehyde starch (DAS) to achieve high physiological stability. The anti-inflammatory effect of DAS-ECG conjugate was evaluated by lipopolysaccharide (LPS)-stimulated RAW264.7 cells and dextran sulfate sodium (DSS)-induced colitis mice models. Results showed that 25-800 μg/mL of DAS-ECG conjugate was non-cytotoxic to RAW264.7 cells. DAS-ECG conjugate effectively inhibited the abnormal morphology, the production of nitric oxide, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and reactive oxygen species, and the apoptosis of LPS-stimulated RAW264.7 cells in a dose-dependent manner. DAS-ECG conjugate significantly reduced the disease activity index, thymus atrophy, spleen enlargement, colon shortening and colon damage of DSS-induced colitis mice. Meanwhile, DAS-ECG conjugate remarkably reduced the levels of TNF-α, IL-6, IL-1β and malondialdehyde but increased the levels of superoxide dismutase and glutathione in the colon tissue of DSS-induced colitis mice. Moreover, DAS-ECG conjugate increased the relative abundance of beneficial bacteria (Akkermansia, Candidatus_Saccharimonas, unclassified_f_Muribaculaceae, Alistipes and Parabacteroides), promoted the production of short-chain fatty acids, and decreased the relative abundance of harmful bacterium (norank_f_Ruminococcaceae) in DSS-induced colitis mice. Therefore, DAS-ECG conjugate could be considered as a promising anti-inflammatory agent.

Wolfberry Honey and Its Extract Alleviate Dextran Sodium Sulfate-Induced Ulcerative Colitis by Improving Intestinal Barrier Function and Reducing Oxidative Stress and Inflammation

Inflammatory bowel disease (IBD) is a chronic condition characterized by gut inflammation causing persistent diarrhea and abdominal pain. Despite the nutritional benefits of wolfberry honey (from Lycium barbarum L.), its potential to alleviate IBD remains underexplored. This study evaluated the protective effects of wolfberry honey and its extract (wolfberry honey extract [WHE]) against dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) using in vivo and in vitro models. Mice pretreated with wolfberry honey showed significant symptom improvement in DSS-induced UC, linked to reduced expression of proinflammatory markers (Il-1β, Il-6, Tnf-α, and Mcp-1) and increased antioxidant genes (Nrf2, Sod2). Increased Occludin levels indicated improved intestinal barrier function. In vitro, WHE protected DSS-treated Caco-2 cells by lowering reactive oxygen species (ROS), stabilizing mitochondrial membrane potential, and inhibiting TLR4/NF-κB signaling. It enhanced the expression of antioxidant genes and tight junction proteins (ZO-1, Occludin, and Claudin-1). Metabolomic analysis revealed that WHE modulated glycerophospholipid metabolism, increasing phosphatidylcholine and choline levels and decreasing lysophosphatidylcholine levels. These results highlight the potential of wolfberry honey and its extract as nutraceuticals for managing UC through their effects on inflammation, oxidative stress, and intestinal barrier function. Further research is warranted to elucidate their mechanisms of action and assess their long-term therapeutic benefits in IBD management.

Mesenchymal stem cells: a novel therapeutic approach for feline inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) poses a significant and growing global health challenge, affecting both humans and domestic cats. Research on feline IBD has not kept pace with its widespread prevalence in human populations. This study aimed to develop a model of feline IBD by incorporating dextran sulfate sodium (DSS) to evaluate the therapeutic potential of MSCs and to elucidate the mechanisms that enhance their action.

METHODS

We conducted a comprehensive clinical assessment, including magnetic resonance imaging (MRI), endoscopy, and histopathological examination. Additionally, alterations in intestinal microbiota were characterized by 16 S rDNA sequencing, and the influence of MSCs on IBD-related gene expression was investigated through transcriptome analysis.

RESULTS

According to our findings, MSC treatment significantly mitigated DSS-induced clinical manifestations, reduced inflammatory cell infiltration, decreased the production of inflammatory mediators, and promoted mucosal repair. Regarding the intestinal microbiota, MSC intervention effectively corrected the DSS-induced dysbiosis, increasing the presence of beneficial bacteria and suppressing the proliferation of harmful bacteria. Transcriptome analysis revealed the ability of MSCs to modulate various inflammatory and immune-related signaling pathways, including cytokine-cytokine receptor interactions, TLR signaling pathways, and NF-κB pathways.

CONCLUSION

The collective findings indicate that MSCs exert multifaceted therapeutic effects on IBD, including the regulation of intestinal microbiota balance, suppression of inflammatory responses, enhancement of intestinal barrier repair, and modulation of immune responses. These insights provide a solid scientific foundation for employing MSCs as an innovative therapeutic strategy for IBD and pave the way for future clinical explorations.

Association of the gut microbiome and different phenotypes of COPD and asthma: a bidirectional Mendelian randomization study

Mounting evidence has revealed the association between gut microbiota and both chronic obstructive pulmonary disease (COPD) and asthma; however, the causal association between gut microbiota and specific disease phenotypes remains to be determined. This study employed bidirectional two-sample Mendelian randomization (MR) analyses to investigate the potential causal relationship between gut microbiota and these conditions. The research utilized genome-wide association study (GWAS) data from the MiBioGen consortium for gut microbiota and the integrative epidemiology unit (IEU) Open GWAS for these conditions. Four MR analysis methods were employed: the inverse variance weighted (IVW) test, MR-Egger, weighted median, and weighted mode methods. The IVW method results are considered the primary findings. Sensitivity analyses, including heterogeneity tests, horizontal pleiotropy analysis, and leave-one-out analysis, were used to enhance robustness. Our MR study identified eight gut microbiota taxa potentially associated with the risk of different types of COPD and asthma. These include two taxa for early-onset COPD: Streptococcaceae [odds ratio (OR) = 1.315, 95% confidence interval (CI) = 1.071-1.616, P = 0.009] and Holdemanella (OR = 1.199, 95% CI = 1.063-1.352, P = 0.003); three for later-onset COPD: Acidaminococcaceae (OR = 1.312, 95% CI = 1.098-1.567, P = 0.003), Holdemania (OR = 1.165, 95% CI = 1.039-1.305, P = 0.009), and Marvinbryantia (OR = 0.814, 95% CI = 0.697-0.951, P = 0.009); one for allergic asthma: Butyricimonas (OR = 0.794, 95% CI = 0.693-0.908, P = 0.001); and two for non-allergic asthma: Clostridia (OR = 1.255, 95% CI = 1.043-1.511, P = 0.016) and Clostridiales (OR = 1.256, 95% CI = 1.048-1.506, P = 0.014).IMPORTANCEIndividuals with diverse phenotypes of chronic obstructive pulmonary disease (COPD) and asthma exhibit different responses to the conventional "one treatment fits all" approach. Recent research has revealed the significant role of the gut-lung axis in both COPD and asthma. However, the specific impact of gut microbiota on different subtypes of these conditions remains poorly understood. Our study has identified eight gut microbiota that may be associated with the risk of different types of COPD and asthma. These findings provide evidence suggesting a potential causal relationship between gut microbiota and various phenotypes of COPD and asthma. This offers a new perspective on the origins of different disease phenotypes and points toward future exploration of phenotype-specific and personalized therapies.

Metabolomics reveals the potential metabolic mechanism of infliximab against DSS-induced acute and chronic ulcerative colitis

Inflammatory bowel disease (IBD) is often accompanied by metabolic imbalance, and infliximab (IFX) can alleviate IBD symptoms, but its metabolic mechanisms remain unclear. To investigate the relationship between IBD, metabolism, and IFX, an acute and chronic ulcerative colitis (UC) model induced by dextran sulfate sodium (DSS) was established. Plasma samples were analyzed using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry, followed by multivariate statistical analysis. The results showed that IFX could alleviate colonic shortening and reduce colonic pathological damage in acute and chronic mouse colitis, improve acute and chronic UC, and ameliorate metabolic disturbances. Among the 104 elevated metabolites and 170 decreased metabolites, these metabolites mainly belonged to amino acids, glucose, and purines. The changes in these metabolites were mainly associated with drug metabolism-other enzymes, riboflavin metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, phosphonate and phosphinate metabolism, and phenylalanine metabolism. In summary, this study provides a valuable approach to explore the metabolic mechanisms of IFX in treating acute and chronic UC from a metabolomics perspective.

Multi-omics revealed anti-fatigue property of polyphenol from areca nut

BACKGROUND

Areca nut polyphenols (AP) that extracted from areca nut, have been demonstrated for their potential of anti-fatigue effects. However, the underlying mechanisms for the anti-fatigue properties of AP has not been fully elucidated to date. Previous studies have predominantly concentrated on single aspects, such as antioxidation and anti-inflammation, yet have lacked comprehensive multi-dimensional analyses.

PURPOSE

To explore the underlying mechanism of AP in exerting anti-fatigue effects.

METHODS

In this study, we developed a chronic sleep deprivation-induced fatigue model and used physiological, hematological, and biochemical indicators to evaluate the anti- fatigue efficacy of AP. Additionally, a multi-omics approach was employed to reveal the anti-fatigue mechanisms of AP from the perspective of microbiome, metabolome, and proteome.

RESULTS

The detection of physiology, hematology and biochemistry index indicated that AP markedly alleviate mice fatigue state induced by sleep deprivation. The 16S rRNA sequencing showed the AP promoted the abundance of probiotics (Odoribacter, Dubosiella, Marvinbryantia, and Eubacterium) and suppressed harmful bacteria (Ruminococcus). On the other hand, AP was found to regulate the expression of colonic proteins, such as increases of adenosine triphosphate (ATP) synthesis and mitochondrial function related proteins, including ATP5A1, ATP5O, ATP5L, ATP5H, NDUFA, NDUFB, NDUFS, and NDUFV. Serum metabolomic analysis revealed AP upregulated the levels of anti-fatigue amino acids, such as taurine, leucine, arginine, glutamine, lysine, and l-proline. Hepatic proteins express levels, especially tricarboxylic acid (TCA) cycle (CS, SDHB, MDH2, and DLST) and redox-related proteins (SOD1, SOD2, GPX4, and PRDX3), were significantly recovered by AP administration. Spearman correlation analysis uncovered the strong correlation between microbiome, metabolome and proteome, suggesting the anti-fatigue effects of AP is attribute to the energy homeostasis and redox balance through gut-liver axis.

CONCLUSION

AP increased colonic ATP production and improve mitochondrial function by regulating gut microbiota, and further upregulated anti-fatigue amino acid levels in the blood. Based on the gut-liver axis, AP upregulated the hepatic tricarboxylic acid cycle and oxidoreductase-related protein expression, regulating energy homeostasis and redox balance, and ultimately exerting anti-fatigue effects. This study provides insights into the anti-fatigue mechanisms of AP, highlighting its potential as a therapeutic agent.

Bacteroides salyersiae Is a Candidate Probiotic Species with Potential Anti-Colitis Properties in the Human Colon: First Evidence from an In Vivo Mouse Model

Previous studies have indicated a critical role of intestinal bacteria in the pathogenesis of ulcerative colitis (UC). B. salyersiae is a commensal species from the human gut microbiota. However, what effect it has on UC development has not been investigated. In the present study, we explored this issue and demonstrated for the first time that oral administration of B. salyersiae CSP6, a bacterium previously isolated from the fecal sample of a healthy individual, protected against dextran sulfate sodium (DSS)-induced colitis in C57BL/6J mice. In particular, B. salyersiae CSP6 improved mucosal damage and attenuated gut dysbiosis in the colon of DSS-fed mice. Specifically, B. salyersiae CSP6 decreased the population of pathogenic Escherichia-Shigella spp. and increased the abundance of probiotic Dubosiella spp. and Bifidobacterium pseudolongum. Additionally, by reshaping the colonic microbiota, B. salyersiae CSP6 remarkably increased the fecal concentrations of equol, 8-deoxylactucin, and tiglic acid, three beneficial metabolites that have been well documented to exert strong anti-inflammatory effects. Altogether, our study provides novel evidence that B. salyersiae is a candidate probiotic species with potential anti-colitis properties in the human colon, which has applications for the development of next-generation probiotics.

The prophylaxis functions of Lactobacillus fermentum GLF-217 and Lactobacillus plantarum FLP-215 on ulcerative colitis via modulating gut microbiota of mice

BACKGROUND

The strong connection between gut microbes and human health has been confirmed by an increasing number of studies. Although probiotics have been found to relieve ulcerative colitis, the mechanism varies by the species involved. In this study, the physiological, immune and pathological factors of mice were measured and shotgun metagenomic sequencing was conducted to investigate the potential mechanisms in preventing ulcerative colitis.

RESULTS

The results demonstrated that ingestion of Lactobacillus fermentum GLF-217 and Lactobacillus plantarum FLP-215 significantly alleviated ulcerative colitis induced by dextran sulfate sodium (DSS), as evidenced by the increase in body weight, food intake, water intake and colon length as well as the decrease in disease activity index, histopathological score and inflammatory factor. Both strains not only improved intestinal mucosa by increasing mucin-2 and zonula occludens-1, but also improved the immune system response by elevating interleukin-10 levels and decreasing the levels of interleukin-1β, interleukin-6, tumor necrosis factor-α and interferon-γ. Moreover, L. fermentum GLF-217 and L. plantarum FLP-215 play a role in preventing DSS-induced colitis by regulating the structure of gut microbiota and promoting the formation of short-chain fatty acids.

CONCLUSIONS

This study may provide a reference for the prevention strategy of ulcerative colitis. © 2024 Society of Chemical Industry.

Multistrain Probiotics with Fructooligosaccharides Improve Middle Cerebral Artery Occlusion-Driven Neurological Deficits by Revamping Microbiota-Gut-Brain Axis

Recent burgeoning literature unveils the importance of gut microbiota in the neuropathology of post-stroke brain injury and recovery. Indeed, ingestion of prebiotics/probiotics imparts positive effects on post-stroke brain injury, neuroinflammation, gut dysbiosis, and intestinal integrity. However, information on the disease-specific preference of selective prebiotics/probiotics/synbiotics and their underlying mechanism is yet elusive. Herein, we examined the effect of a new synbiotic formulation containing multistrain probiotics (Lactobacillus reuteri UBLRu-87, Lactobacillus plantarum UBLP-40, Lactobacillus rhamnosus UBLR-58, Lactobacillus salivarius UBLS-22, and Bifidobacterium breve UBBr-01), and prebiotic fructooligosaccharides using a middle cerebral artery occlusion (MCAO) model of cerebral ischemia in female and male rats. Three weeks pre-MCAO administration of synbiotic rescinded the MCAO-induced sensorimotor and motor deficits on day 3 post-stroke in rotarod, foot-fault, adhesive removal, and paw whisker test. We also observed a decrease in infarct volume and neuronal death in the ipsilateral hemisphere of synbiotic-treated MCAO rats. The synbiotic treatment also reversed the elevated levels/mRNA expression of the glial fibrillary acidic protein (GFAP), NeuN, IL-1β, TNF-α, IL-6, matrix metalloproteinase-9, and caspase-3 and decreased levels of occludin and zonula occludens-1 in MCAO rats. 16S rRNA gene-sequencing data of intestinal contents indicated an increase in genus/species of Prevotella (Prevotella copri), Lactobacillus (Lactobacillus reuteri), Roseburia, Allobaculum, and Faecalibacterium prausnitzii, and decreased abundance of Helicobacter, Desulfovibrio, and Akkermansia (Akkermansia muciniphila) in synbiotic-treated rats compared to the MCAO surgery group. These findings confer the potential benefits of our novel synbiotic preparation for MCAO-induced neurological dysfunctions by reshaping the gut-brain-axis mediators in rats.

Effects of Early Life Exposures to the Aryl Hydrocarbon Receptor Ligand TCDF on Gut Microbiota and Host Metabolic Homeostasis in C57BL/6J Mice

BACKGROUND

Exposure to persistent organic pollutants (POPs) and disruptions in the gastrointestinal microbiota have been positively correlated with a predisposition to factors such as obesity, metabolic syndrome, and type 2 diabetes; however, it is unclear how the microbiome contributes to this relationship.

OBJECTIVE

This study aimed to explore the association between early life exposure to a potent aryl hydrocarbon receptor (AHR) agonist and persistent disruptions in the microbiota, leading to impaired metabolic homeostasis later in life.

METHODS

This study used metagenomics, nuclear magnetic resonance (NMR)- and mass spectrometry (MS)-based metabolomics, and biochemical assays to analyze the gut microbiome composition and function, as well as the physiological and metabolic effects of early life exposure to 2,3,7,8-tetrachlorodibenzofuran (TCDF) in conventional, germ-free (GF), and Ahr-null mice. The impact of TCDF on Akkermansia muciniphila (A. muciniphila) in vitro was assessed using optical density (OD 600), flow cytometry, transcriptomics, and MS-based metabolomics.

RESULTS

TCDF-exposed mice exhibited lower abundances of A. muciniphila, lower levels of cecal short-chain fatty acids (SCFAs) and indole-3-lactic acid (ILA), as well as lower levels of the gut hormones glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), findings suggestive of disruption in the gut microbiome community structure and function. Importantly, microbial and metabolic phenotypes associated with early life POP exposure were transferable to GF recipients in the absence of POP carry-over. In addition, AHR-independent interactions between POPs and the microbiota were observed, and they were significantly associated with growth, physiology, gene expression, and metabolic activity outcomes of A. muciniphila, supporting suppressed activity along the ILA pathway.

CONCLUSIONS

These data obtained in a mouse model point to the complex effects of POPs on the host and microbiota, providing strong evidence that early life, short-term, and self-limiting POP exposure can adversely impact the microbiome, with effects persisting into later life with associated health implications. https://doi.org/10.1289/EHP13356.

Integrated analysis of gut microbiome and its metabolites in ACE2-knockout and ACE2-overexpressed mice

Background

Aberrant activation of the classic renin-angiotensin system (RAS) and intestinal micro dysbiosis adversely affect insulin resistance (IR), dyslipidemia, and other metabolic syndrome markers. However, the action of angiotensin-converting enzyme 2 (ACE2) and gut health in systemic homeostasis vary, and their interaction is not completely understood.

Methods

We adopted a combinatory approach of metabolomics and fecal 16S rRNA analysis to investigate gut microbiota and metabolite in two different mouse models, ACE2 knockout (ACE2 KO) mice and the ACE2-overexpressing obese mice.

Results

16S rRNA gene sequencing revealed that ACE2 influences microbial community composition and function, and ACE2 KO mice had increased Deferribacteres, Alcaligenaceae, Parasutterella, Catenibacterium, and Anaerotruncus, with decreased short-chain fatty acid (SCFA)-producing bacteria (Marvinbryantia and Alistipes). In contrast, ACE2-overexpressed mice exhibited increased anti-inflammatory probiotic (Oscillospiraceae, Marinifilaceae, and Bifidobacteriaceae) and SCFA-producing microbes (Rikenellaceae, Muribaculaceae, Ruminococcaceae, Odoribacter, and Alistipes) and decreased Firmicutes/Bacteroidetes, Lactobacillaceae, Erysipelotrichaceae, and Lachnospiraceae. Metabolome analysis indicated differential metabolites in ACE2 KO and ACE2-overexpression mice, especially the glucolipid metabolism-related compounds. Furthermore, correlation analysis between gut microbiota and metabolites showed a dynamic mutual influence affecting host health.

Conclusion

Our study confirms for the first time a significant association between ACE2 status and gut microbiome and metabolome profiles, providing a novel mechanism for the positive effect of ACE2 on energy homeostasis.

An inhibitory immunoreceptor Allergin-1 regulates the intestinal dysbiosis and barrier function in mice

The intestinal barrier consists of mucosal, epithelial, and immunological barriers and serves as a dynamic interface between the host and its environment. Disruption of the intestinal barrier integrity is a leading cause of various gastrointestinal diseases, such as inflammatory bowel disease. The homeostasis of the intestinal barrier is tightly regulated by crosstalk between gut microbes and the immune system; however, the implication of the immune system on the imbalance of gut microbes that disrupts barrier integrity remains to be fully elucidated. An inhibitory immunoglobulin-like receptor, Allergin-1, is expressed on mast cells and dendritic cells and inhibits Toll-like receptor (TLR)-2 and TLR-4 signaling in these cells. Since TLRs are major sensors of microbiota and are involved in local epithelial homeostasis, we investigated the role of Allergin-1 in maintaining intestinal homeostasis. Allergin-1-deficient (Milr1-/-) mice exhibited more severe dextran sulfate sodium (DSS)-induced colitis than did wild-type (WT) mice. Milr1-/- mice showed an enhanced intestinal permeability compared with WT mice even before DSS administration. Treatment of Milr1-/- mice with neomycin, but not ampicillin, restored intestinal barrier integrity. The 16S rRNA gene sequencing analysis demonstrated that Bifidobacterium pseudolongum was the dominant bacterium in Milr1-/- mice after treatment with ampicillin. Although the transfer of B. pseudolongum to germ-free WT mice had no effect on intestinal permeability, its transfer into ampicillin-treated WT mice enhanced intestinal permeability. These results demonstrated that Allergin-1 deficiency enhanced intestinal dysbiosis with expanded B. pseudolongum, which contributes to intestinal barrier dysfunction in collaboration with neomycin-sensitive and ampicillin-resistant microbiota.

Mangaba pulp fermented with Lacticaseibacillus casei 01 has improved chemical, technological, and sensory properties and positively impacts the colonic microbiota of vegan adults

This study aimed to evaluate the functional, technological, and sensory aspects of mangaba (Hancornia speciosa Gomes) fruit pulp fermented with the probiotic Lacticaseibacillus casei 01 (LC1) during refrigerated storage (7 °C, 28 days). The effects of the fermented mangaba pulp on the modulation of the intestinal microbiota of healthy vegan adults were also assessed. Mangaba pulp allowed high viability of LC1 during storage and after simulated gastrointestinal conditions (≥7 log CFU/g). The fermented mangaba pulp showed lower pH and total soluble solids, and higher titratable acidity, and concentrations of lactic, acetic, citric, and propionic acids during storage compared to non-fermented pulp. Also, it presented a higher concentration of bioaccessible phenolics and volatiles, and improved sensory properties (yellow color, brightness, fresh appearance, and typical aroma and flavor). Fermented mangaba pulp added to in vitro cultured colonic microbiota of vegan adults decreased the pH values and concentrations of maltose, glucose, and citric acid while increasing rhamnose and phenolic contents. Fermented mangaba pulp promoted increases in the abundance of Dorea, Romboutsia, Faecalibacterium, Lachnospira, and Lachnospiraceae ND3007 genera and positively impacted the microbial diversity. Findings indicate that mangaba pulp fermented with LC1 has improved chemical composition and functionality, inducing changes in the colonic microbiota of vegan adults associated with potential benefits for human health.

Studies of the Impact of the Bifidobacterium Species on Inducible Nitric Oxide Synthase Expression and Nitric Oxide Production in Murine Macrophages of the BMDM Cell Line

Bifidobacterium species are one of the most important probiotic microorganisms which are present in both, infants and adults. Nowadays, growing data describing their healthy properties arise, indicating they could act at the cellular and molecular level. However, still little is known about the specific mechanisms promoting their beneficial effects. Nitric oxide (NO), produced by inducible nitric oxide synthase (iNOS), is involved in the protective mechanisms in the gastrointestinal tract, where it can be provided by epithelial cells, macrophages, or bacteria. The present study explored whether induction of iNOS-dependent NO synthesis in macrophages stems from the cellular action of Bifidobacterium species. The ability of ten Bifidobacterium strains belonging to 3 different species (Bifidobacterium longum, Bifidobacterium adolescentis, and Bifidobacterium animalis) to activate MAP kinases, NF-κB factor, and iNOS expression in a murine bone-marrow-derived macrophages cell line was determined by Western blotting. Changes in NO production were determined by the Griess reaction. It was performed that the Bifidobacterium strains were able to induce NF-қB-dependent iNOS expression and NO production; however, the efficacy depends on the strain. The highest stimulatory activity was observed for Bifidobacterium animalis subsp. animals CCDM 366, whereas the lowest was noted for strains Bifidobacterium adolescentis CCDM 371 and Bifidobacterium longum subsp. longum CCDM 372. Both TLR2 and TLR4 receptors are involved in Bifidobacterium-induced macrophage activation and NO production. We showed that the impact of Bifidobacterium on the regulation of iNOS expression is determined by MAPK kinase activity. Using pharmaceutical inhibitors of ERK 1/2 and JNK, we confirmed that Bifidobacterium strains can activate these kinases to control iNOS mRNA expression. Concluding, the induction of iNOS and NO production may be involved in the protective mechanism of action observed for Bifidobacterium in the intestine, and the efficacy is strain-dependent.

Probiotics induce intestinal IgA secretion in weanling mice potentially through promoting intestinal APRIL expression and modulating the gut microbiota composition

Intestinal infections are strongly associated with infant mortality, and intestinal immunoglobulin A (IgA) is important to protect infants from intestinal infections after weaning. This study aims to screen probiotics that can promote the production of intestinal IgA after weaning and further explore their potential mechanisms of action. In this study, probiotics promoting intestinal IgA production were screened in weanling mouse models. The results showed that oral administration of Bifidobacterium bifidum (B. bifidum) FL228.1 and Bifidobacterium bifidum (B. bifidum) FL276.1 significantly enhanced IgA levels in the small intestine and upregulated the expression of a proliferation-inducing ligand (APRIL) and its upstream regulatory factor toll-like receptor 4 (TLR4). Furthermore, B. bifidum FL228.1 upregulated the relative abundance of Lactobacillus, while B. bifidum FL276.1 increased the relative abundance of Marvinbryantia and decreased Mucispirillum, further elevating intestinal IgA levels. In summary, B. bifidum FL228.1 and B. bifidum FL276.1 can induce IgA production in the intestinal tract of weanling mice by promoting intestinal APRIL expression and mediating changes in the gut microbiota, thus playing a significant role in enhancing local intestinal immunity in infants.

Coated sodium butyrate and vitamin D3 supplementation improve gut health through influencing intestinal immunity, barrier, and microflora in early-stage broilers

BACKGROUND

Intestinal development and function are critical to maintaining sustained broiler growth. The present study aimed to evaluate the effects of coated sodium butyrate (CSB) and vitamin D3 (VD3) on the intestinal immunity, barrier, oxidative stress and microflora in early-stage broilers. In total, 192 one-day-old broilers were assigned to a 2 × 2 factorial design including two dietary supplements at two different levels, in which the main effects were VD3 (3000 or 5000 IU kg-1) and CSB (0 or 1 g kg-1).

RESULTS

The results showed that CSB supplementation increased ileal goblet cells (GCs) numbers, villus height and decreased crypt depth in broilers. CSB increased ileal proliferating cell nuclear antigen expression and high-level VD3 decreased cluster of differentiation 3 expression. CSB reduced serum d-lactate, endotoxin (ET), adrenocorticotropic hormone, corticosterone and malondialdehyde (MDA) concentrations and increased total antioxidant capacity (T-AOC) level. Meanwhile, high-level VD3 decreased serum ET concentration. Furthermore, CSB increased ileal T-AOC, lysozyme (LYZ) and transforming growth factor (TGF)-β and decreased MDA, whereas high-level VD3 decreased ileal MDA and increased secretory immunoglobulin A. CSB up-regulated ileal claudin1, superoxide dismutase 1, TGF-β and LYZ mRNA expression and down-regulated interleukin-1β mRNA expression. CSB combined with high-level VD3 increased ileal Faecalibaculum abundance. Spearman correlation analysis showed that Faecalibaculum was related to the immune and barrier function.

CONCLUSION

Dietary supplementation with CSB and high-level VD3 improved early gut health in broilers by promoting intestinal development, enhancing antioxidant capacity, strengthening barrier function and enhancing the favorable composition of the gut bacterial flora. © 2024 Society of Chemical Industry.

Anthocyanins from Lycium ruthenicum Murray attenuates high-fat diet-induced hypercholesterolemia in ApoE-/- mice are related to the modulation of gut microbiota and the ratio of conjugated to unconjugated bile acids in fecal bile acid profile

Previous findings showed that anthocyanins from Lycium ruthenicum Murray (ACN) reduced HFD-induced hypercholesterolemia by regulating gut microbiota, but the mechanism has not been fully understood. The objective of this research was to know whether the cholesterol-lowering impact of ACN in HFD-induced ApoE-/- mice is related to the gut microbiota-bile acid (BA) metabolism. Twenty-four male ApoE-/- mice were divided into three groups: the Control group, the HFD group, and the HFD + ACN group. Here, we showed that ACN intervention reduced HFD-induced body weight serum concentrations of TC and LDL-C and ameliorated lipid accumulation in the liver and adipose tissues. Besides, ACN altered gut microbiota composition in HFD-fed ApoE-/- mice. Moreover, UHPLC-MS/MS analysis revealed that ACN intervention significantly increased the ratio of conjugated to unconjugated BAs in feces induced by HFD, attributed to the increase in conjugated BAs and decrease in unconjugated BAs. Finally, the correlation analysis indicated that the above changes in fecal BA profile were linked with an increase in Bifidobacterium, Allobaculum and a decrease in Ileibacterium, Helicobacter, Rikenellaceae_RC9_gut_group, Blautia, Odoribacter, and Colidextribacter. In summary, ACN could alleviate HFD-induced hypercholesterolemia in ApoE-/- mice, which was associated with the improvement of gut microbiota and modulation of fecal BA profile.

Assessing the causal relationship between gut microbiota and diabetic nephropathy: insights from two-sample Mendelian randomization

Background

The causal association between gut microbiota (GM) and the development of diabetic nephropathy (DN) remains uncertain. We sought to explore this potential association using two-sample Mendelian randomization (MR) analysis.

Methods

Genome-wide association study (GWAS) data for GM were obtained from the MiBioGen consortium. GWAS data for DN and related phenotypes were collected from the FinngenR9 and CKDGen databases. The inverse variance weighted (IVW) model was used as the primary analysis model, supplemented by various sensitivity analyses. Heterogeneity was assessed using Cochran's Q test, while horizontal pleiotropy was evaluated through MR-Egger regression and the MR-PRESSO global test. Reverse MR analysis was conducted to identify any reverse causal effects.

Results

Our analysis identified twenty-five bacterial taxa that have a causal association with DN and its related phenotypes (p < 0.05). Among them, only the g_Eubacterium_coprostanoligenes_group showed a significant causal association with type 1 DN (p < Bonferroni-adjusted p-value). Our findings remained consistent regardless of the analytical approach used, with all methods indicating the same direction of effect. No evidence of heterogeneity or horizontal pleiotropy was observed. Reverse MR analysis did not reveal any causal associations.

Conclusions

This study established a causal association between specific GM and DN. Our findings contribute to current understanding of the role of GM in the development of DN, offering potential insights for the prevention and treatment strategies for this condition.

Lacticaseibacillus paracasei CCFM1222 Ameliorated the Intestinal Barrier and Regulated Gut Microbiota in Mice with Dextran Sulfate Sodium-Induced Colitis

Lacticaseibacillus paracasei has been regarded as a probiotic bacterium because of its role in anti-inflammatory properties and maintenance of intestinal barrier permeability. Here, we explored the anticolitic effects and mechanism of L. paracasei CCFM1222. The results showed that L. paracasei CCFM1222 supplementation could suppress the disease activity index (DAI) and colon length shortening in colitis mice, accompanied by a moderate increase in colonic tight junction proteins (ZO-1, occludin and claudin-1). L. paracasei CCFM1222 intervention significantly suppressed the levels of inflammatory cytokines (TNF-α, IL-1β, and IL-6) and significantly elevated the activities of antioxidant enzymes (including SOD, GSH-Px, and CAT) in the colon by regulating the TLR4/MyD88/NF-κB and Nrf2 signaling pathways in colitis mice. In addition, L. paracasei CCFM1222 significantly shifted the gut microbiota, including elevating the abundance of Catabacter, Ruminiclostridium 9, Alistipes, and Faecalibaculum, as well as reducing the abundance of Mucispirillum, Escherichia-Shigella, and Salmonella, which was associated with the improvement of colonic barrier damage. Overall, these results suggest that L. paracasei CCFM1222 is a good candidate for probiotic of improving colonic barrier damage and associated diseases.

Sodium oligomannate alters gut microbiota, reduces cerebral amyloidosis and reactive microglia in a sex-specific manner

It has recently become well-established that there is a connection between Alzheimer's disease pathology and gut microbiome dysbiosis. We have previously demonstrated that antibiotic-mediated gut microbiota perturbations lead to attenuation of Aβ deposition, phosphorylated tau accumulation, and disease-associated glial cell phenotypes in a sex-dependent manner. In this regard, we were intrigued by the finding that a marine-derived oligosaccharide, GV-971, was reported to alter gut microbiota and reduce Aβ amyloidosis in the 5XFAD mouse model that were treated at a point when Aβ burden was near plateau levels. Utilizing comparable methodologies, but with distinct technical and temporal features, we now report on the impact of GV-971 on gut microbiota, Aβ amyloidosis and microglial phenotypes in the APPPS1-21 model, studies performed at the University of Chicago, and independently in the 5X FAD model, studies performed at Washington University, St. Louis.Methods To comprehensively characterize the effects of GV-971 on the microbiota-microglia-amyloid axis, we conducted two separate investigations at independent institutions. There was no coordination of the experimental design or execution between the two laboratories. Indeed, the two laboratories were not aware of each other's experiments until the studies were completed. Male and female APPPS1-21 mice were treated daily with 40, 80, or 160 mg/kg of GV-971 from 8, when Aβ burden was detectable upto 12 weeks of age when Aβ burden was near maximal levels. In parallel, and to corroborate existing published studies and further investigate sex-related differences, male and female 5XFAD mice were treated daily with 100 mg/kg of GV-971 from 7 to 9 months of age when Aβ burden was near peak levels. Subsequently, the two laboratories independently assessed amyloid-β deposition, metagenomic, and neuroinflammatory profiles. Finally, studies were initiated at the University of Chicago to evaluate the metabolites in cecal tissue from vehicle and GV-971-treated 5XFAD mice.Results These studies showed that independent of the procedural differences (dosage, timing and duration of treatment) between the two laboratories, cerebral amyloidosis was reduced primarily in male mice, independent of strain. We also observed sex-specific microbiota differences following GV-971 treatment. Interestingly, GV-971 significantly altered multiple overlapping bacterial species at both institutions. Moreover, we discovered that GV-971 significantly impacted microbiome metabolism, particularly by elevating amino acid production and influencing the tryptophan pathway. The metagenomics and metabolomics changes correspond with notable reductions in peripheral pro-inflammatory cytokine and chemokine profiles. Furthermore, GV-971 treatment dampened astrocyte and microglia activation, significantly decreasing plaque-associated reactive microglia while concurrently increasing homeostatic microglia only in male mice. Bulk RNAseq analysis unveiled sex-specific changes in cerebral cortex transcriptome profiles, but most importantly, the transcriptome changes in the GV-971-treated male group revealed the involvement of microglia and inflammatory responses.Conclusions In conclusion, these studies demonstrate the connection between the gut microbiome, neuroinflammation, and Alzheimer's disease pathology while highlighting the potential therapeutic effect of GV-971. GV-971 targets the microbiota-microglia-amyloid axis, leading to the lowering of plaque pathology and neuroinflammatory signatures in a sex-dependent manner when given at the onset of Aβ deposition or when given after Aβ deposition is already at higher levels.

Structural elucidation of a highly branched α-D-glucan from Huangjiu and its hepatoprotective activity via gut microbiome regulation and intestinal barrier repairment

Polysaccharides in Huangjiu, a traditional fermented food, are expected to be potentially effective ingredients in protecting against alcoholic liver disease (ALD). Elucidating their precise structural and functional characteristics is essential for in-depth understanding of structure-activity relationships of hepatoprotective polysaccharides. Herein, a major polysaccharide component HJPS1-2 was purified from Huangjiu with an average molecular weight of 3.49 kDa. Structural analyses inferred that HJPS1-2 backbone was composed of (1 → 4)-linked α-D-Glcp and a single α(1 → 6)-D-Glcp-α(1 → 6)-D-Glcp branched unit for every three α(1 → 4)-D-Glcp. An ALD mouse model was further established to clarify the underlying effect of HJPS1-2 on ALD alleviation. Biochemical detection and histopathological assessment revealed that HJPS1-2 intervention remarkably improved ethanol-induced hepatic dysfunction and steatosis. HJPS1-2 treatment ameliorated gut microbiota dysbiosis of ALD mice in a dose-dependent manner, mainly manifested as restoration of microbial diversities, community structure and bacterial interaction patterns. Compared with ethanol group, the strikingly elevated intestinal short-chain fatty acids' levels and enhanced intestinal barrier function after HJPS1-2 intake might contribute to reduced serum and liver lipopolysaccharide levels and subsequently suppressed release of hepatic inflammatory cytokines, thus mitigating ALD. Collectively, this research supports the potential of food-derived polysaccharides to hinder the early formation and progression of ALD through maintaining intestinal homeostasis.

Polystyrene microplastics induce size-dependent multi-organ damage in mice: Insights into gut microbiota and fecal metabolites

Particle size is one of the most important factors in determining the biological toxicity of microplastics (MPs). In this study, we attempted to examine the systemic toxicity of polystyrene MPs of different sizes (0.5 µm MP1 and 5 µm MP2) in C57BL/6 J mice. After the mice were given oral gavage of MPs for 8 consecutive weeks, histopathology and molecular biology assays, 16 S rRNA sequencing of the gut microbiota, and untargeted metabolomics were performed. The results showed that MPs were distributed in the organs in a size-dependent manner, with smaller particles demonstrating greater biodistribution. Further analysis indicated that exposure to MPs caused multi-organ damage through distinct toxicity pathways. Specifically, exposure to 0.5 µm MP1 led to excessive accumulation and induced more serious inflammation and mechanical damage in the spleen, kidney, heart, lung, and liver. However, 5 µm MP2 led to more severe intestinal barrier dysfunction, as well as gut dysbiosis and metabolic disorder in association with neuroinflammation. These results are helpful in expanding our knowledge of the toxicity of MPs of different sizes in mammalian models.

Indole-3-acetic acid alleviates DSS-induced colitis by promoting the production of R-equol from Bifidobacterium pseudolongum

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by immune-mediated, chronic inflammation of the intestinal tract. The occurrence of IBD is driven by the complex interactions of multiple factors. The objective of this study was to evaluate the therapeutic effects of IAA in colitis.

METHOD

C57/BL6 mice were administered 2.5% DSS in drinking water to induce colitis. IAA, Bifidobacterium pseudolongum, and R-equol were administered by oral gavage and fed a regular diet. The Disease Activity Index was used to evaluate disease activity. The degree of colitis was evaluated using histological morphology, RNA, and inflammation marker proteins. CD45+ CD4+ FOXP3+ Treg and CD45+ CD4+ IL17A+ Th17 cells were detected by flow cytometry. Analysis of the gut microbiome in fecal content was performed using 16S rRNA gene sequencing. Gut microbiome metabolites were analyzed using Untargeted Metabolomics.

RESULT

In our study, we found IAA alleviates DSS-induced colitis in mice by altering the gut microbiome. The abundance of Bifidobacterium pseudolongum significantly increased in the IAA treatment group. Bifidobacterium pseudolongum ATCC25526 alleviates DSS-induced colitis by increasing the ratio of Foxp3+T cells in colon tissue. R-equol alleviates DSS-induced colitis by increasing Foxp3+T cells, which may be the mechanism by which ATCC25526 alleviates DSS-induced colitis in mice.

CONCLUSION

Our study demonstrates that IAA, an indole derivative, alleviates DSS-induced colitis by promoting the production of Equol from Bifidobacterium pseudolongum, which provides new insights into gut homeostasis regulated by indole metabolites other than the classic AHR pathway.

Prescription opioids induced microbial dysbiosis worsens severity of chronic pancreatitis and drives pain hypersensitivity

Opioids, such as morphine and oxycodone, are widely used for pain management associated with chronic pancreatitis (CP); however, their impact on the progression and pain sensitivity of CP has never been evaluated. This report investigates the impact of opioid use on the severity of CP, pain sensitivity, and the gut microbiome. C57BL/6 mice were divided into control, CP, CP with morphine/oxycodone, and either morphine or oxycodone alone groups. CP was induced by administration of caerulein (50ug/kg/h, i.p. hourly x7, twice a week for 10 weeks). The mouse-to-pancreas weight ratio, histology, and Sirius red staining were performed to measure CP severity. Tail flick and paw pressure assays were used to measure thermal and mechanical pain. DNA was extracted from the fecal samples and subjected to whole-genome shotgun sequencing. Germ-free mice were used to validate the role of gut microbiome in sensitizing acute pancreatic inflammation. Opioid treatment exacerbates CP by increasing pancreatic necrosis, fibrosis, and immune-cell infiltration. Opioid-treated CP mice exhibited enhanced pain hypersensitivity and showed distinct clustering of the gut microbiome compared to untreated CP mice, with severely compromised gut barrier integrity. Fecal microbiota transplantation (FMT) from opioid-treated CP mice into germ-free mice resulted in pancreatic inflammation in response to a suboptimal caerulein dose. Together, these analyses revealed that opioids worsen the severity of CP and induce significant alterations in pain sensitivity and the gut microbiome in a caerulein CP mouse model. Microbial dysbiosis plays an important role in sensitizing the host to pancreatic inflammation.

Novel Lauric Acid-Butyric Structural Lipid Inhibits Inflammation: Small Intestinal Microbes May Be Important Mediators

SCOPE

Butyric acid (C4) and lauric acid (C12) are recognized as functional fatty acids, while the health benefits of the structural lipids they constitute remain unclear.

METHODS AND RESULTS

In this study, lauric acid-butyric structural lipid (SLBL ) is synthesized through ultrasound-assisted enzyme-catalyzed acidolysis and its health benefits are evaluated in a high-fat diet-induced obesity mouse model. SLBL and its physical mixture (MLBL ) do not significantly inhibit obesity in mice. However, SLBL treatment increases the ratio of n3/n6 fatty acids in the liver and improves obesity-induced hepatic lipid metabolism disorders. Furthermore, the expression of liver pro-inflammatory cytokines (interleukin [IL]-6, IL-1β, TNF-α) are significantly suppressed by SLBL , while the expression of anti-inflammatory cytokine (IL-10) is increased. Moreover, SLBL ameliorates the dysbiosis of small intestinal microbes induced by high-fat diet and regulates microbial community structure to be close to the control group. Especially, SLBL significantly alleviates the high-fat diet-induced decrease in Dubosiella and Bifidobacterium abundance. Correlation analysis reveals that SLBL treatment increases the abundance of microorganisms with potential anti-inflammatory function and decreases the abundance of potentially pathogenic bacteria.

CONCLUSION

In all, small intestinal microbes may be a significant bridge for the positive anti-inflammatory effects of SLBL , while the exact mechanism remains to be clarified.

Dietary fiber guar gum-induced shift in gut microbiota metabolism and intestinal immune activity enhances susceptibility to colonic inflammation

With an increasing interest in dietary fibers (DFs) to promote intestinal health and the growth of beneficial gut bacteria, there is a continued rise in the incorporation of refined DFs in processed foods. It is still unclear how refined fibers, such as guar gum, affect the gut microbiota activity and pathogenesis of inflammatory bowel disease (IBD). Our study elucidated the effect and underlying mechanisms of guar gum, a fermentable DF (FDF) commonly present in a wide range of processed foods, on colitis development. We report that guar gum containing diet (GuD) increased the susceptibility to colonic inflammation. Specifically, GuD-fed group exhibited severe colitis upon dextran sulfate sodium (DSS) administration, as evidenced by reduced body weight, diarrhea, rectal bleeding, and shortening of colon length compared to cellulose-fed control mice. Elevated levels of pro-inflammatory markers in both serum [serum amyloid A (SAA), lipocalin 2 (Lcn2)] and colon (Lcn2) and extensive disruption of colonic architecture further affirmed that GuD-fed group exhibited more severe colitis than control group upon DSS intervention. Amelioration of colitis in GuD-fed group pre-treated with antibiotics suggest a vital role of intestinal microbiota in GuD-mediated exacerbation of intestinal inflammation. Gut microbiota composition and metabolite analysis in fecal and cecal contents, respectively, revealed that guar gum primarily enriches Actinobacteriota, specifically Bifidobacterium. Guar gum also altered multiple genera belonging to phyla Bacteroidota and Firmicutes. Such shift in gut microbiota composition favored luminal accumulation of intermediary metabolites succinate and lactate in the GuD-fed mice. Colonic IL-18 and tight junction markers were also decreased in the GuD-fed group. Importantly, GuD-fed mice pre-treated with recombinant IL-18 displayed attenuated colitis. Collectively, unfavorable changes in gut microbiota activity leading to luminal accumulation of lactate and succinate, reduced colonic IL-18, and compromised gut barrier function following guar gum feeding contributed to increased colitis susceptibility.

Ginkgo biloba Extract Drives Gut Flora and Microbial Metabolism Variation in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a complex neurodegenerative disease. Numerous investigations have demonstrated that medications that regulate the "brain-gut" axis can ameliorate disease symptoms of AD. Studies have shown that Ginkgo biloba extract (EGb) is involved in intestinal metabolism to meet the goal of illness treatment. EGb is currently utilized extensively in the clinical prevention and treatment of cardiovascular and cerebrovascular diseases. However, the regulatory effect of EGb on intestinal flora and its metabolites in AD pathology remains largely speculative. In this study, the Morris water maze test showed a significant improvement of spatial memory in the AD mouse model (APP/PS1 mice) after EGb treatment. We next confirmed the positive effects of EGb on the gut flora and metabolites of APP/PS1 mice and further showed that EGb treatment reshaped the disturbed gut microbiome, in particular by reducing the Firmicutes/Bacteroides ratio and increasing the abundance of Bacteroidetes, Uroviricota, Streptophyta, and Spirochaetes. Meanwhile, a non-targeted metabolomics analysis showed that EGb treatment significantly reversed the dysfunction of the microbial metabolic phenotype by altering Limosilactobacillus and Parvibacte, with 300 differential metabolites modulated (131 up-regulated, 169 down-regulated). Our findings highlight the significant regulatory impact of EGb on intestinal microflora and microbial metabolism in AD mice models and provide a potential therapeutic strategy for AD.

Bifidobacterium pseudolongum-generated acetate suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma

BACKGROUND & AIMS

Recent studies have highlighted the role of the gut microbiota and their metabolites in non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). We aimed to identify specific beneficial bacterial species that could be used prophylactically to prevent NAFLD-HCC.

METHODS

The role of Bifidobacterium pseudolongum was assessed in two mouse models of NAFLD-HCC: diethylnitrosamine + a high-fat/high-cholesterol diet or + a choline-deficient/high-fat diet. Germ-free mice were used for the metabolic study of B. pseudolongum. Stool, portal vein and liver tissues were collected from mice for non-targeted and targeted metabolomic profiles. Two human NAFLD-HCC cell lines (HKCI2 and HKCI10) were co-cultured with B. pseudolongum-conditioned media (B.p CM) or candidate metabolites.

RESULTS

B. pseudolongum was the top depleted bacterium in mice with NAFLD-HCC. Oral gavage of B. pseudolongum significantly suppressed NAFLD-HCC formation in two mouse models (p < 0.01). Incubation of NAFLD-HCC cells with B.p CM significantly suppressed cell proliferation, inhibited the G1/S phase transition and induced apoptosis. Acetate was identified as the critical metabolite generated from B. pseudolongum in B.p CM, an observation that was confirmed in germ-free mice. Acetate inhibited cell proliferation and induced cell apoptosis in NAFLD-HCC cell lines and suppressed NAFLD-HCC tumor formation in vivo. B. pseudolongum restored heathy gut microbiome composition and improved gut barrier function. Mechanistically, B. pseudolongum-generated acetate reached the liver via the portal vein and bound to GPR43 (G coupled-protein receptor 43) on hepatocytes. GPR43 activation suppressed the IL-6/JAK1/STAT3 signaling pathway, thereby preventing NAFLD-HCC progression.

CONCLUSIONS

B. pseudolongum protected against NAFLD-HCC by secreting the anti-tumor metabolite acetate, which reached the liver via the portal vein. B. pseudolongum holds potential as a probiotic for the prevention of NAFLD-HCC.

IMPACT AND IMPLICATIONS

Non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC) is an increasing healthcare burden worldwide. There is an urgent need to develop effective agents to prevent NAFLD-HCC progression. Herein, we show that the probiotic Bifidobacterium pseudolongum significantly suppressed NAFLD-HCC progression by secreting acetate, which bound to hepatic GPR43 (G coupled-protein receptor 43) via the gut-liver axis and suppressed the oncogenic IL-6/JAK1/STAT3 signaling pathway. Bifidobacterium pseudolongum holds potential as a novel probiotic for NAFLD-HCC prevention.

Investigation of the anti-inflammatory effects of native potential probiotics as supplementary therapeutic agents in an in-vitro model of inflammation

BACKGROUND

IBD is considered an inflammatory disease with abnormal and exaggerated immune responses. To control the symptoms, different theraputic agents could be used, however, utilizing the agents with the least side effects could be important. Probiotics as beneficial microorganisms are one of the complementory theraputic agents that could be used to modulate inflammatory signaling pathways. In the current study, we aimed to identify the precise molecular effects of potential probiotics on signaling pathways involved in the development of inflammation.

METHODS

A quantitative real-time polymerase chain reaction (qPCR) assay was used to analyze the expression of JAK /STAT (JAK1, JAK2, JAK3, TYK2, STAT1, STAT2, STAT3, STAT4, STAT5 and STAT6) and inflammatory genes (NEMO, TIRAP, IRAK, and RIP) after the HT -29 cell line treatment with the sonicated pathogens and potential probiotics. A cytokine assay was also used to evaluate IL -6 and IL -1β production after potential probiotic treatment.

RESULTS

The potential probiotic cocktail downregulated the JAK genes and TIRAP, IRAK4, NEMO, and RIP genes in the NF-kB pathway compared with cells that were treated with sonicated gram negative pathogens. The expression of STAT genes was different after potential probiotic treatment. The production of IL -6 and IL -1β decreased after potential probiotic treatment.

CONCLUSIONS

Considering the importance of controlling the symptoms of IBD to improve the life quality of the patients, using probiotic could be crucial. In the current study the studied native potential probiotic cocktails showed anti-inflammatory effects via modulation of JAK /STAT and NF-kB signaling pathways. This observation suggests that our native potential probiotics consumption could be useful in reducing intestinal inflammation.

Mitigation of Dextran-Sodium-Sulfate-Induced Colitis in Mice through Oral Administration of Microbiome-Derived Inosine and Its Underlying Mechanisms

BACKGROUND

Colonic and serum inosine are significantly reduced in patients with inflammatory bowel disease (IBD).

METHODS

This study aimed to explore whether microbiome-derived inosine alleviates colitis and its underlying mechanisms.

RESULTS

An inosine intervention effectively improved the clinical signs in colitis mice, suppressed inflammatory cytokines (tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1β) by regulating the nuclear factor-kappa B (NF-κB) pathway, and elevated the activities of anti-oxidative enzymes (including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px)) by regulating the nuclear factor erythroid-2 related factor 2 (Nrf2) pathway. Additionally, the inosine intervention significantly elevated the expression of tight junction proteins (ZO-1, occudin, and claudin-1) in mice with colitis. High-throughput sequencing revealed that the inosine intervention also prevented gut microbiota disorder by increasing the abundance of beneficial bacteria (Lachnospiraceae NK4A136 group, Romboutsia, Marvinbryantia, Clostridium sensu stricto 1, and Bifidobacterium) and reducing the abundance of harmful bacteria (Pseudomonas, Acinetobacter, and Tyzzerella) in mice with colitis.

CONCLUSIONS

Inosine played a significant role in mitigating colitis-related intestinal barrier injury and could potentially be used for therapy in clinical practice.

Effects of acupuncture on gut microbiota and short-chain fatty acids in patients with functional constipation: a randomized placebo-controlled trial

Objective: To comprehensively evaluate the effect of acupuncture on gut microbiota, identify specific microbes closely related to the clinical efficacy of acupuncture, and explored the role of short-chain fatty acids (SCFAs). Methods: A randomized placebo-controlled trial was conducted with 80 FC patients and 28 healthy controls (HCs). FC patients randomly received 16 acupuncture (n = 40) or sham acupuncture (n = 40) sessions over 4 weeks; HCs received no treatment. The change in the proportion of patients with mean weekly complete spontaneous bowel movements (CSBMs) was considered as the primary outcome measure. Moreover, the composition and the predictive metabolic function of the gut microbiota from feceal samples were analyzed by 16S rRNA gene sequencing, while feceal SCFAs were identified via gas chromatography-mass spectrometry (GC-MS). Results: Compared to sham acupuncture, acupuncture significantly increased the proportion of CSBM responders, and improved spontaneous bowel movements (SBMs), straining, stool consistency, and quality of life. Moreover, Sequencing of 16S rRNA genes revealed that acupuncture improved β-diversity and restored the composition of gut microbiota. Specifically, the abundance of beneficial bacteria such as g_Lactobacillus increased while that of pathogenic bacteria such as g_Pseudomonas decreased after acupuncture, which were significantly correlated with alleviated symptoms. Moreover, ten microbes including g_Coprobacter, g_Lactobacillus, and g_Eubacterium_coprostanoligenes_group might be considered acupuncture-specific microbes, and formed a stable interaction network. Additionally, GC-MS analysis indicated that acupuncture increased the content of butyrate acid in the gut, which was positively correlated with an increase in defecation frequency and a decrease in acupuncture-related pathogens. Finally, acupuncture specific-microbes including g_Coprobacter, g_Lactobacillus, g_Pseudomonas, g_Eubacterium_coprostanoligenes_group, g_Erysipelotrichaceae_UCG.003, g_Prevotellaceae_UCG.001, and g_Rolstonia could accurately predict the clinical efficacy of acupuncture (AUC = 0.918). Conclusion: Acupuncture could effectively improve clinical symptoms in FC patients, and was associated with gut microbiota reshaping and increased butyrate acid levels. Moreover, key microbial genera such as g_Coprobacter and g_Lactobacillus was predictive of acupuncture efficacy in treating FC. Future studies are required to validate the causal relationship between key microbial genera and acupuncture clinical efficacy, and should explore further metabolic pathways for designing personalized treatment strategies. Clinical Trial Registration: http://www.chictr.org.cn, Identifier: ChiCTR2100048831.

Rosmarinic acid alleviates intestinal inflammatory damage and inhibits endoplasmic reticulum stress and smooth muscle contraction abnormalities in intestinal tissues by regulating gut microbiota

The host-bacterial interactions play the key role in inflammatory bowel disease (IBD). Dysbiosis of the intestinal flora can lead to pathological changes in the intestine. Rosmarinic acid (RA) is a natural phenolic acid compound with antioxidant, anti-cancer, anti-inflammatory, anti-apoptotic, anti-fibrotic, and anti-bacterial activities that has a palliative effect on acute IBD. We have established an in vivo model for mice. Histological staining was performed to directly observe RA alterations in the intestinal tract. The alteration of RA on mouse intestinal flora was observed by 16S rRNA high-throughput sequencing, and the effect of RA on intestinal mechanism of action was detected by qPCR and western blot. The results showed that RA had a significant protective effect on the intestine. RA upregulated the abundance of Lactobacillus johnsonii and Candidatus Arthromitus sp SFB-mouse-NL and downregulated the abundance of Bifidobacterium pseudolongum, Escherichia coli, and Romboutsia ilealis. RA downregulated the expressions of ROCK, RhoA, CaM, MLC, MLCK, ZEB1, ZO-1, ZO-2, occludin, E-cadherin, IL-1β, IL-6, TNF-α, GRP78, PERK, IRE1, ATF6, CHOP, Caspase12, Caspase9, Caspase3, Bax, Cytc, RIPK1, RIPK3, MLKL, and upregulated the expression of IL-10 and Bcl-2. These results displayed that RA inhibited the inflammation, which is caused by tight junction damage, by repairing intestinal flora dysbiosis, relieved endoplasmic reticulum stress, inhibited cell death, and corrected smooth muscle contractile dysregulation. The results of this study revealed RA could have a protective effect on the small intestine of mice by regulating intestinal flora. IMPORTANCE Inflammatory bowel disease (IBD) is a chronic, relapsing, remitting disorder of the gastrointestinal system. In this study, we investigated the protective effects of rosmarinic acid on the intestinal tract. The results showed that RA was effective in reducing inflammatory damage, endoplasmic reticulum stress, smooth muscle contraction abnormalities, and regulating intestinal flora disorders.

Chlorella vulgaris Modulates Gut Microbiota and Induces Regulatory T Cells to Alleviate Colitis in Mice

Chlorella vulgaris (C. vulgaris) is unicellular green algae consumed worldwide as a functional food. The immune stimulatory function of C. vulgaris is known; however, no study has elucidated its immune regulatory potential and associated microbiome modulation. In the current study, we aimed to validate the immune regulatory role of C. vulgaris mediated through two mechanisms. Initially, we assessed its ability to promote the expansion of the regulatory T cell (Treg) population. Subsequently, we investigated its impact on gut microbiota composition and associated metabolites. The supplementation of C. vulgaris altered the gut microbiota composition, accompanied by increased short-chain fatty acid (SCFAs) production in mice at homeostasis. We later used C. vulgaris in the treatment of a DSS-induced colitis model. C. vulgaris intervention alleviated the pathological symptom of colitis in mice, with a corresponding increase in Treg levels. As C. vulgaris is a safe and widely used food supplement, it can be a feasible strategy to instigate cross-talk between the host immune system and the intestinal flora for the effective management of inflammatory bowel disease (IBD).

Microbiome diversity in African American, European American, and Egyptian colorectal cancer patients

Purpose

Although there is an established role for microbiome dysbiosis in the pathobiology of colorectal cancer (CRC), CRC patients of various race/ethnicities demonstrate distinct clinical behaviors. Thus, we investigated microbiome dysbiosis in Egyptian, African American (AA), and European American (EA) CRC patients.

Patients and methods

CRCs and their corresponding normal tissues from Egyptian (n = 17) patients of the Alexandria University Hospital, Egypt, and tissues from AA (n = 18) and EA (n = 19) patients at the University of Alabama at Birmingham were collected. DNA was isolated from frozen tissues, and the microbiome composition was analyzed by 16S rRNA sequencing. Differential microbial abundance, diversity, and metabolic pathways were identified using linear discriminant analysis (LDA) effect size analyses. Additionally, we compared these profiles with our previously published microbiome data derived from Kenyan CRC patients.

Results

Differential microbiome analysis of CRCs across all racial/ethnic groups showed dysbiosis. There were high abundances of Herbaspirillum and Staphylococcus in CRCs of Egyptians, Leptotrichia in CRCs of AAs, Flexspiria and Streptococcus in CRCs of EAs, and Akkermansia muciniphila and Prevotella nigrescens in CRCs of Kenyans (LDA score >4, adj. p-value <0.05). Functional analyses showed distinct microbial metabolic pathways in CRCs compared to normal tissues within the racial/ethnic groups. Egyptian CRCs, compared to normal tissues, showed lower l-methionine biosynthesis and higher galactose degradation pathways.

Conclusions

Our findings showed altered mucosa-associated microbiome profiles of CRCs and their metabolic pathways across racial/ethnic groups. These findings provide a basis for future studies to link racial/ethnic microbiome differences with distinct clinical behaviors in CRC.

Preventive effect of tilapia skin collagen hydrolysates on ulcerative colitis mice based on metabonomic and 16 S rRNA gene sequencing

BACKGROUND

Tilapia skin collagen hydrolysates (TSCHs) are the product of enzymatic hydrolysis of collagen, which is mainly extracted from tilapia skin. The components of TSCHs have recently been reported to play a preventive role in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). However, it has not been illustrated whether TSCHs can prevent against DSS-induced UC via the gut microbiota and its derived metabolites.

RESULTS

TSCHs are mainly composed of amino acids, which have similar characteristics to collagen, with most having a molecular weight below 5 kDa. In a mouse model of UC, TSCHs had no toxic effect at a dose of 60 g kg^-1 and could reduce body weight changes, colon length, histopathological changes and score, and the level of the serum inflammatory cytokine interleukin (IL)-6. Concurrently, 16 S rRNA sequencing showed that TSCHs significantly reduced the abundance of Bacteroidetes and Proteobacteria at the phylum level and norank_f__Muribaculaceae and Escherichia-Shigella at the genus level, while they increased the abundance of Firmicutes at the phylum level and Lachnoclostridium, Allobaculum, Enterorhabdus, and unclassified__f__Ruminococcaceae at the genus level. Target metabolomic analysis showed that TSCHs elevated the concentration of total acid, acetic acid, propanoic acid, and butanoic acid, but reduced isovaleric acid concentrations. Moreover, Pearson correlation analysis revealed that Allobaculum, unclassified_Ruminococcaceae, and Enterorhabdus were positively correlated with acetic acid and butyric acid, but not Escherichia-Shigella.

CONCLUSION

These findings suggest that TSCHs can prevent UC by modulating gut microbial and microbiota-derived metabolites. © 2023 Society of Chemical Industry.

Ginkgo biloba Extract Preventively Intervenes in Citrobacter Rodentium-Induced Colitis in Mice

Inflammatory bowel disease (IBD) represents a highly recurrent gastrointestinal disorder and global public health issue. However, it lacks effective and safe strategies for its control. Although Ginkgo biloba extract (GBE) has been suggested to exhibit preventive and therapeutic activity for the control of IBD, whether its activity is associated with its ability to modulate intestinal microbiota remains to be addressed. To investigate the effect of GBE on controlling IBD, a Citrobacter Rodentium (CR)-induced mouse colitis model was used, and then histopathological examinations, biochemical assays, immunohistochemistry, and immunoblotting were performed to detect histological changes, cytokines, and tight junction (TJ) proteins in the intestine samples. We also studied 16s rRNA to detect changes in intestinal microbiota and used GC-MS to determine the microbiota-related metabolites short chain fatty acids (SCFAs). The results of our studies revealed that pre-treatment with GBE was sufficient for protecting the animals from CR-induced colitis. As a mechanism for GBE activity, GBE treatment was able to modulate the intestinal microbiota and increase the SCFAs capable of decreasing the pro-inflammatory factors and up-regulating the anti-inflammatory factors while elevating the intestinal-barrier-associated proteins to maintain the integrity of the intestines. Accordingly, our results led to a strong suggestion that GBE should be seriously considered in the preventive control of CR-induced colitis and in the development of effective and safe therapeutic strategies for controlling IBD.

Corylin ameliorates chronic ulcerative colitis via regulating the gut-brain axis and promoting 5-hydroxytryptophan production in the colon

BACKGROUND

Chronic ulcerative colitis (UC) is a lifelong disease, patients with chronic UC have a high prevalence of common mental disorders. The increasing interest in the role of gut-brain axis is seen in inflammatory bowel diseases.

PURPOSE

Corylin is a representative flavonoid compound isolated from the Psoraleae Fructus. This study aimed to identify the effects and mechanism of corylin on the inflammation interactions and 5-HT synthesis between the gut and brain in chronic UC.

METHODS

Dextran sulfate sodium (DSS) induced chronic UC mouse model was established to assess the therapeutic effect of corylin on chronic UC symptoms. The expression of inflammatory cytokines was detected in the colon and brain. The expression of tight junction (TJ) proteins of intestinal mucosal barrier and blood-brain barrier (BBB) and the ionized calcium-binding adaptor molecule 1 (Iba1) in the hippocampus were determined by western blotting and immunofluorescence staining. In addition, several tryptophan (Trp) metabolites and related neurotransmitters in faeces, colon, serum, and brain were detected by UPLC-MS/MS. The interaction between corylin and 5-hydroxytryptophan decarboxylase (5-HTPDC) was performed by molecular docking and surface plasmon resonance (SPR). Finally, the changes of gut microbiota composition were analyzed by 16S rRNA sequencing.

RESULTS

Corylin significantly alleviated colitis symptoms and inhibited inflammatory response in the colon and brain of DSS-induced chronic UC mice. The TJ proteins of intestinal mucosal barrier and BBB were improved and the expression of Iba1 in the hippocampus was normalized after corylin treatment. In addition, corylin treatment increased the expression of neurotransmitters in the brain, especially 5-hydroxytryptamine (5-HT) and 5-hydroxytryptophan (5-HTP), but the expression of 5-HT in the colon was inhibited. Further study firstly proved that corylin could bind to the 5-HTDPC, and then inhibit the expression of 5-HTDPC and VB₆, resulting in the 5-HT reduction and 5-HTP accumulation in the colon. Moreover, the intake of corylin transformed the diversity and composition of intestinal microbiota, Bacteroides, Escherichia-Shigella, and Turicibacter were decreased but Dubosiella, Enterorhabdus, and Candidatus_Stoquefichus were increased.

CONCLUSION

Corylin administration ameliorated DSS-induced colitis and inhibited intestinal inflammation and neuroinflammation via regulating the inflammation interactions across gut-brain axis and increasing 5-HTP generation in the colon.

Bifidobacterium longum CCFM1206 Promotes the Biotransformation of Glucoraphanin to Sulforaphane That Contributes to Amelioration of Dextran-Sulfate-Sodium-Induced Colitis in Mice

Glucoraphanin, rich in broccoli seed extract (BSE), is generally inert but can be biotransformed into active sulforaphane by gut bacteria. This study aimed to screen probiotics with glucoraphanin-metabolizing ability and explore the effect of a combination of strain and BSE on colitis induced by dextran sulfate sodium (DSS) in mice. Bifidobacterium longum CCFM1206 was isolated from healthy adult feces. Ultra-high-performance liquid chromatography Q Exactive mass spectrometry analysis revealed the presence of sulforaphane, sulforaphane-l-cysteine, and erucin in the BSE supernatant fermented by B. longum CCFM1206 in vitro. Combined and individual interventions of BSE and B. longum CCFM1206 were applied to explore the effects on DSS-induced colitis. The results suggested that the combination of B. longum CCFM1206 and BSE could ameliorate colitis symptoms, relieve colonic inflammatory reactions and oxidative stress, and protect the intestinal barrier in DSS-induced mice. In comparison to the BSE intervention alone, the combined intervention of B. longum CCFM1206 and BSE promoted the generation of sulforaphane and sulforaphane-N-acetylcysteine in mice colon from 220.88 ± 19.81 to 333.99 ± 36.46 nmol/g and from 232.04 ± 26.48 to 297.50 ± 40.08 nmol/g dry weight feces, respectively. According to quantitative reverse transcription polymerase chain reaction and immunohistochemical analysis, B. longum CCFM1206 and BSE effectively activated the transcription and expression of genes related to the Nrf2 signaling pathway. These results were intended to elucidate that probiotics could elevate the bioactivity of dietary phytochemicals in vivo, and the combination had potential for therapeutic treatment of colitis.

Bifidobacterium longum, Lactobacillus plantarum and Pediococcus acidilactici Reversed ETEC-Inducing Intestinal Inflammation in Mice

Microecological preparation could relieve Enterotoxigenic Escherichia coli (ETEC) K88-induced diarrhea in piglets, but which bacteria play a key role and the mitigation mechanism have not been fully clarified. In this study, 36 male mice were randomly divided into six groups (CON, K88, BK (Bifidobacterium longum + K88), LK (Lactobacillus plantarum + K88), PK (Pediococcus acidilactici + K88), and MK (mixed strains + K88)) to explore the prevention mechanisms. Three probiotic strains and their mixtures (TPSM) significantly relieved the weight loss and restored the ratio of villus height to crypt depth in the jejunum. Except for Bifidobacterium longum, other strains significantly decreased interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in mice serum. The TPSM treatment significantly downregulated the mRNA expression of the inflammatory cytokines and the Toll-like receptor and downstream gene (TLR4, MyD88, NF-κB) in jejunum induced by ETEC. Furthermore, the TPSM could restore dysbiosis of the intestinal microbiota caused by ETEC. The intestinal microbiota analysis demonstrated that Bifidobacterium longum enriched the Bifidobacterium genus (p < 0.05), Lactobacillus plantarum enriched the Lactobacillus genus (p < 0.05), Pediococcus acidilactici enriched the Coriobacteriaceae_UCG-002 and Christensenellaceae_R-7_group genus (p < 0.05), mixed bacteria enriched the Akkermansia genus (p < 0.05), but ETEC enriched the Desulfovibrio genus (p < 0.05). Meanwhile, the starch and sucrose metabolism, galactose and fructose metabolism, mannose metabolism and ABC transporters were increased with probiotics pre-treatment (p < 0.05). To sum up, the microecological preparation alleviated ETEC-induced diarrhea by regulating the immune response, rebalancing intestinal microbiota and improving carbohydrate metabolism.

Prospects of Probiotic Adjuvant Drugs in Clinical Treatment

In modern society, where new diseases and viruses are constantly emerging, drugs are still the most important means of resistance. However, adverse effects and diminished efficacy remain the leading cause of treatment failure and a major determinant of impaired health-related quality of life for patients. Clinical studies have shown that the disturbance of the gut microbial structure plays a crucial role in the toxic and side effects of drugs. It is well known that probiotics have the ability to maintain the balance of intestinal microecology, which implies their potential as an adjunct to prevent and alleviate the adverse reactions of drugs and to make medicines play a better role. In addition, in the past decade, probiotics have been found to have excellent prevention and alleviation effects in drug toxicity side effects, such as liver injury. In this review, we summarize the development history of probiotics, discuss the impact on drug side effects of probiotics, and propose the underlying mechanisms. Probiotics will be a new star in the world of complementary medicine.

Lactobacillus paracasei CCFM1223 Protects against Lipopolysaccharide-Induced Acute Liver Injury in Mice by Regulating the “Gut–Liver” Axis

Background: Lactobacillus paracasei CCFM1223, a probiotic previously isolated from the healthy people’s intestine, exerts the beneficial influence of preventing the development of inflammation. Methods: The aim of this research was to explore the beneficial effects of L. paracasei CCFM1223 to prevent lipopolysaccharide (LPS)-induced acute liver injury (ALI) and elaborate on its hepatoprotective mechanisms. Results: L. paracasei CCFM1223 pretreatment remarkably decreased the activities of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in mice with LPS treatment and remarkably recovered LPS-induced the changes in inflammatory cytokines (tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), interleukin (IL)-1β, IL-6, IL-17, IL-10, and LPS) and antioxidative enzymes activities (total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT)). Metagenomic analysis showed that L. paracasei CCFM1223 pretreatment remarkably increased the relative abundance of Catabacter compared with the LPS group but remarkably reduced the relative abundance of [Eubacterium] xylanophilumgroup, ASF356, LachnospiraceaeNK4A136group, and Lachnoclostridium, which is closely associated with the inflammation cytokines and antioxidative enzymes. Furthermore, L. paracasei CCFM1223 pretreatment remarkably increased the colonic, serum, and hepatic IL-22 levels in ALI mice. In addition, L. paracasei CCFM1223 pretreatment remarkably down-regulated the hepatic Tlr4 and Nf-kβ transcriptions and significantly up-regulated the hepatic Tlr9, Tak1, Iκ-Bα, and Nrf2 transcriptions in ALI mice. Conclusions: L. paracasei CCFM1223 has a hepatoprotective function in ameliorating LPS-induced ALI by regulating the “gut–liver” axis.

Altered microbial biogeography in an innate model of colitis

Changes in the spatial organization, or biogeography, of colonic microbes have been observed in human inflammatory bowel disease (IBD) and mouse models of IBD. We have developed a mouse model of IBD that occurs spontaneously and consistently in the absence of adaptive immunity. Mice expressing tumor necrosis factor-induced protein 3 (TNFAIP3) in intestinal epithelial cells (villin-TNFAIP3) develop colitis when interbred with Recombination Activating 1-deficient mice (RAG1^-/-). The colitis in villin-TNFAIP3 × RAG1^-/- (TRAG) mice is prevented by antibiotics, indicating a role for microbes in this innate colitis. We therefore explored the biogeography of microbes and responses to antibiotics in TRAG colitis. Laser capture microdissection and 16S rRNA sequencing revealed altered microbial populations across the transverse axis of the colon as the inner mucus layer of TRAG, but not RAG1^-/-, mice was infiltrated by microbes, which included increased abundance of the classes Gammaproteobacteria and Actinobacteria. Along the longitudinal axis differences in the efficacy of antibiotics to prevent colitis were evident. Neomycin was most effective for prevention of inflammation in the cecum, while ampicillin was most effective in the proximal and distal colon. RAG1^-/-, but not TRAG, mice exhibited a structured pattern of bacterial abundance with decreased Firmicutes and Proteobacteria but increased Bacteroidetes along the proximal to distal axis of the gut. TRAG mice exhibited increased relative abundance of potential pathobionts including <i>Bifidobacterium animalis</i> along the longitudinal axis of the gut whereas others, like <i>Helicobacter hepaticus</i> were increased only in the cecum. Potential beneficial organisms including <i>Roseburia</i> were decreased in the proximal regions of the TRAG colon, while <i>Bifidobacterium pseudolongulum</i> was decreased in the TRAG distal colon. Thus, the innate immune system maintains a structured, spatially organized, gut microbiome along the transverse and longitudinal axis of the gut, and disruption of this biogeography is a feature of innate immune colitis.