Parabacteroides distasonis induces depressive-like behavior in a mouse model of Crohn's disease

Multi-omic analyses of the development of obesity-related depression linked to the gut microbe Anaerotruncus colihominis and its metabolite glutamate

Emerging evidence implicates gut microbiota in the pathogenesis of obesity-related depression (OD); however, the underlying molecular mechanisms remain inadequately explored. This study compared the microbial and transcriptional profiles between patients with OD and healthy individuals. The results revealed an enrichment of Anaerotruncus colihominis (A. colihominis) and glutamate metabolism-related genes in the OD group. Fecal microbiota transplantation (FMT) from patients with OD induced weight gain, compromised barrier function, and intensified depression-like behaviors in high-fat diet (HFD) mice. Microbial analysis in the mice feces corroborated the clinical findings. Single-cell RNA sequencing highlighted the pivotal role of the Efnb2-Ephb2 interaction in cell communication among colon epithelial and hippocampal neuron subtypes in OD mice. Notably, A. colihominis correlated with glutamate levels in the OD mice and patients. It produced glutamate through a glutamic acid metabolism-related DNA sequence, verified in an engineered Escherichia coli MG1655 strain. Both A. colihominis and glutamate reduced barrier proteins in colon epithelial cells and modulated cognitive proteins in neurons. Finally, A. colihominis treatment induced the Efnb2-Ephb2 interaction, exacerbating depression-like behaviors in germ-free HFD mice. Collectively, these findings reveal that A. colihominis and glutamate are potential intervention targets for OD treatment.

Profiles of gut microbiota and metabolites for high risk of transgenerational depression-like behavior by paternal methamphetamine exposure

Parental substance abuse increases the risk of neurological and psychiatric disorders in offsprings. However, its underlying mechanism remains elusive. Our previous study demonstrated that long-term exposure to methamphetamine (Meth), a psychostimulant drug with high addiction potential, remarkably alters the gut microbiome and metabolites in male mice, which contribute to Meth-induced anxiety-like behaviors. The current study aimed to investigate whether gut microbiota and metabolism serve as potential peripheral targets for transgenerational mental problems by paternal Meth exposure. We found that paternal Meth exposure induced depression-like behaviors both in the first (F1) and the second (F2) generations of male mice. Further, the depletion of gut bacteria through antibiotic treatments normalized the depression-like behaviors to normal levels in both F1 and F2 male mice. Then, alterations in gut bacterial composition were observed in both F1 and F2 male mice. Specifically, Eubacterium_ruminantium_group, Enterorhabdus, Alloprevotella, and Parabacteroides were the commonly affected bacterial taxa in F1 and F2 male mice. In addition, the results of alterations in gut metabolism showed that LPC 14:1-SN1 emerged as the consistently altered metabolite in the colons of F1 and F2 male mice. Taken together, our findings provide the first evidence that paternal Meth exposure enhances depression-like behaviors in F1 and F2 male mice, potentially mediated by the gut microbiome and metabolism.

Therapeutic potential of Parabacteroides distasonis in gastrointestinal and hepatic disease

Increasing evidences indicate that the gut microbiota is involved in the development and therapy of gastrointestinal and hepatic disease. Imbalance of gut microbiota occurs in the early stages of diseases, and maintaining the balance of the gut microbiota provides a new strategy for the treatment of diseases. It has been reported that Parabacteroides distasonis is associated with multiple diseases. As the next-generation probiotics, several studies have demonstrated its positive regulation on the gastrointestinal and hepatic disease, including inflammatory bowel disease, colorectal cancer, hepatic fibrosis, and fatty liver. The function of P. distasonis and its metabolites mainly affect host immune system, intestinal barrier function, and metabolic networks. Manipulation of P. distasonis with natural components lead to the protective effect on enterohepatic disease. In this review, the metabolic pathways regulated by P. distasonis are summarized to illustrate its active metabolites and their impact on host metabolism, the role and action mechanism in gastrointestinal and hepatic disease are discussed. More importantly, the natural components can be used to manipulate P. distasonis as treatment strategies, and the challenges and perspectives of P. distasonis in clinical applications are discussed.

Gut commensal Parabacteroides distasonis exerts neuroprotective effects in acute ischemic stroke with hyperuricemia via regulating gut microbiota-gut-brain axis

BACKGROUND

Hyperuricemia is considered as an independent risk factor for acute ischemic stroke (AIS), and some AIS patients are accompanied by an increase in serum uric acid. Recent studies have highlighted the important role of gut microbiota in both hyperuricemia and AIS, but there is little available data on the relationship between gut microbiota and the pathogenesis of AIS with hyperuricemia (HAS).

METHODS

Here we profiled the gut microbiota composition in 63 HAS patients and 269 non-HAS patients through 16s rRNA sequencing. Male rat with hyperuricemia were subjected to middle cerebral artery occlusion (MCAO) to establish HAS model and were then treated with Parabacteroides distasonis. Subsequently, the neurological deficit, pathological damages and blood-brain barrier disruption were evaluated. Moreover, the levels of ROS, inflammatory cytokines, NF-𝜿B pathway related protein, and vascular density markers were determined.

RESULTS

There were significant differences of gut microbiota composition between HAS patients and non-HAS patients, and a significant decrease in the abundance of Parabacteroides in HAS patients compared to non-HAS patients. Animal experiments showed that supplementation with P. distasonis increased beneficial commensal bacteria, significantly improved neurological deficits, pathological damages and BBB disruption, as well as reduced the level of serum uric acid in HAS rats. We further demonstrated that P. distasonis treatment decreased ROS level and increased SOD2 level, thereby reducing oxidative stress. Meanwhile, P. distasonis effectively inhibited NF-𝜿B signal pathway and reduced the production of inflammatory cytokines, including TNF-α and IL-1β, alleviating the inflammatory response. Notably, P. distasonis treatment increased the levels of vascular density markers including cluster of differentiation 31 (CD31) and alpha-smooth muscle actin (α-SMA), ameliorating vascular damage in HAS rats.

CONCLUSIONS

Together, these findings highlighted the important role of P. distasonis in the pathogenesis of HAS, and its mechanism was involved in the regulation of gut microbiota-gut-brain axis, which implied a novel strategy against HAS.

Alcohol consumption during pregnancy differentially affects the fecal microbiota of dams and offspring

Microbiota imbalances are linked to inflammation and disease, as well as neurodevelopmental conditions where they may contribute to behavioral, physiological, and central nervous system dysfunction. By contrast, the role of the microbiota in Fetal Alcohol Spectrum Disorder (FASD), the group of neurodevelopmental conditions that can occur following prenatal alcohol exposure (PAE), has not received similar attention. Here we utilized a rodent model of alcohol consumption during pregnancy to characterize the impact of alcohol on the microbiota of dam-offspring dyads. Overall, bacterial diversity decreased in alcohol-consuming dams and community composition differed from that of controls in alcohol-consuming dams and their offspring. Bacterial taxa and predicted biochemical pathway composition were also altered with alcohol consumption/exposure; however, there was minimal overlap between the changes in dams and offspring. These findings illuminate the potential importance of the microbiota in the pathophysiology of FASD and support investigation into novel microbiota-based interventions.

Uncovering the characteristics of the gut microbiota in patients with ischemic stroke and hemorrhagic stroke

This study aimed to explore the gut microbiota characteristics of ischemic and hemorrhagic stroke patients. A case-control study was conducted, and high-throughput sequencing of the V4-V5 region of 16S rRNA was used to analyze the differences in gut microbiota. The results showed that Proteobacteria was significantly increased in the ischemic stroke group compared with the healthy control group, while Fusobacteria was significantly increased in the hemorrhagic stroke group. In the ischemic stroke group, Butyricimonas, Alloprevotella, and Escherichia were significantly more abundant than in the healthy control group. In the hemorrhagic stroke group, Atopobium, Hungatella, Eisenbergiella, Butyricimonas, Odonbacter, Lachnociostridium, Alistipes, Parabacteroides, and Fusobacterium were significantly more abundant than in the healthy control group. Additionally, Alloprevotella, Ruminococcus, and Prevotella were significantly more abundant in the ischemic stroke group than in the hemorrhagic stroke group. The gut microbiota of ischemic and hemorrhagic stroke patients has significant diversity characteristics. These results provide new theoretical basis for exploring the prevention and treatment of different types of stroke through gut microbiota research.

Alternations in the human skin, gut and vaginal microbiomes in perimenopausal or postmenopausal Vulvar lichen sclerosus

Vulvar lichen sclerosus (VLS) is a chronic and progressive dermatologic condition that can cause physical dysfunction, disfigurement, and impaired quality of life. However, the etiology of VLS remains unknown. The vulvar skin, intestinal and vaginal microbiomes have been postulated to play important roles in the pathogenesis of this disease. The aim of this study was to compare the compositional characteristics of the vulvar skin, vagina, and gut microbiota between perimenopausal or postmenopausal VLS patients and healthy controls. The study involved six perimenopausal or postmenopausal VLS patients which were based on characteristic clinical manifestations and histologic confirmation and five healthy controls. The pruritus severity of each patient was evaluated using the NRS scale, and the dermatology-specific health-related quality of life was assessed using the Skindex-16. Metagenomic sequencing was performed, and the results were analyzed for alpha and beta diversity. LEfSe analysis were used to investigate the microbial alterations in vulvar skin, gut and vagina. KEGG databases were used to analyze differences in functional abundance. The study found significant differences in alpha diversity between the two groups in stool and vaginal samples (P < 0.05). Patients with VLS had a higher abundance of Enterobacter cloacae, Flavobacterium_branchiophilum, Mediterranea_sp._An20, Parabacteroides_johnsoniiand Streptococcus_bovimastitidis on the vulvar skin, while Corynebacterium_sp._zg-913 was less abundant compared to the control group. The relative abundance of Sphingomonas_sp._SCN_67_18, Sphingobium_sp._Ant17, and Pontibacter_sp_BT213 was significantly higher in the gut samples of patients with VLS.Paenibacillus_popilliae,Gemella_asaccharolytica, and Coriobacteriales_bacterium_DNF00809 compared to the control group. Additionally, the vaginal samples of patients with VLS exhibited a significantly lower relative abundance of Bacteroidales_bacterium_43_8, Bacteroides_sp._CAG:20, Blautia_sp._AM28-10, Fibrobacter_sp._UWB16, Lachnospiraceae_bacterium_AM25-39, Holdemania_filiformis, Lachnospiraceae_bacterium_GAM79, and Tolumonas_sp. Additionally, the butyrate-producing bacterium SS3/4 showed a significant difference compared to the controls. The study found a negative relationship between Sphingobium_sp._Ant17 in stool and Skindex-16 (P < 0.05), while Mediterranea_sp._An20 had a positive correlation with Skindex-16 (P < 0.05) in the skin. Additionally, our functional analysis revealed alterations in Aminoacyl_tRNA_biosynthesis, Glutathione_metabolism, the pentose phosphate pathway, and Alanine__aspartate_and_glutamate_metabolism in the VLS patient group. The study suggests that perimenopausal or postmenopausal patients with VLS have a modified microbiome in the vulvar skin, gut, and vagina. This modification is linked to abnormal energy metabolism, increased oxidative stress, and abnormal amino acid metabolism.

Zhi Zi Chi decoction (Gardeniae fructus and semen Sojae Praeparatum) attenuates anxious depression via modulating microbiota-gut-brain axis in corticosterone combined with chronic restraint stress-induced mice

BACKGROUND

The microbiota-gut-brain axis plays a critical role in neuropsychiatric disorders, particularly anxious depression, and attracts more attention gradually. Zhi Zi Chi decoction (ZZCD) consisting of Gardenia jasminoides J. Ellis and Glycine max (L.) Merr, is a classic formula in clinic and widely applied in anxiety and depression treatment. However, the underlying mechanisms of regulating microbiota-gut-brain axis in the treatment of anxious depression by oral administration of ZZCD remain elusive.

MATERIALS AND METHODS

In this project, we clarified the origin and preparation methods of the Gardenia jasminoides J. Ellis and Glycine max (L.) Merr and examined the chemical ingredients of ZZCD by liquid chromatograph mass spectrometer. Then, corticosterone combined with chronic restraint stress was applied to establish an anxious depression model. After treated with ZZCD standard decoction, based on enzyme-linked immunosorbent assay (ELISA), 16S rRNA technology, high-throughput sequencing, quantitative RT-PCR and fecal microbiota transplantation (FMT), the multiple associations between nucleus accumbens and intestinal flora in anxious depression mice were determined to clarify the mechanism of ZZCD in the treatment of anxiety and depression disorder.

RESULTS

We found various substances with antidepressant and antianxiety properties in ZZCD such as rosiridin and oleanolic acid. ZZCD could alleviate depressive and anxiety behaviors in anxious depression mice via regulating the disturbance of gut microbiota. Meanwhile, the bioactive compounds of ZZCD might directly active on neurodevelopment and neuroimmune-related genes. Furthermore, the secretion of prolactin and estrogen, and interfering with mitogen-activated protein kinase (MAPK) and tumor necrosis factor (TNF) signaling pathways were mainly involved in the multi-target therapeutic effects of ZZCD against anxiety and depression.

CONCLUSIONS

These findings suggested that ZZCD exerts antidepressant effects pleiotropically through modulating the microbiota-gut-brain.

Effects of postweaning cadmium exposure on socioemotional behaviors in adolescent male mice

Exposure to cadmium (Cd), a toxic heavy metal classified as an environmental endocrine disruptor, can exert significant toxicity in both animals and humans. However, the potential effects of Cd exposure on socioemotional behaviors are still poorly understood, as are the underlying mechanisms. In the present study, employing a series of behavioral tests as well as 16 S rRNA sequencing analysis, we investigated the long-term effects of Cd exposure on socioemotional behaviors and their associated mechanisms in mice based on the brain-gut interaction theory. The results showed that postweaning exposure to Cd reduced the ability to resist depression, decreased social interaction, subtly altered sexual preference, and changed the composition of the gut microbiota in male mice during adolescence. These findings provided direct evidence for the deleterious effects of exposure to Cd in the postweaning period on socioemotional behaviors later in adolescence, and suggested that these effects of Cd exposure may be linked to changes in the gut microbiota.

Radix Bupleuri aqueous extract attenuates MK801-induced schizophrenia-like symptoms in mice: Participation of intestinal flora

Schizophrenia (SCZ) is a psychotic mental disorder characterized by cognitive, behavioral, and social impairments. However, current pharmacological treatment regimens are subpar in terms of effectiveness. This study aimed to investigate the function of Radix Bupleuri aqueous extract in SCZ in mouse models. The SCZ mouse model was established by MK-801 injection and feeding of Radix Bupleuri aqueous extract or combined antibiotics. Radix Bupleuri aqueous extract significantly improved the aberrant behaviors and neuronal damage in SCZ mice, upregulated SYP and PSD-95 expression and BDNF levels in hippocampal homogenates, down-regulated DA and 5-HT levels, and suppressed microglial activation in SCZ mice. Moreover, Radix Bupleuri aqueous extract improved the integrity of the intestinal tract barrier. The 16 S rRNA sequencing of feces showed that Radix Bupleuri extract modulated the composition of gut flora. Lactobacillus abundance was decreased in SCZ mice and reversed by Radix Bupleuri aqueous extract administration which exhibited a significant negative correlation with IL-6, IL-1β, DA, and 5-HT, and a significant positive correlation with BDNF levels in hippocampal tissues. The abundance of Parabacteroides and Alloprevotella was increased in SCZ mice. It was reversed by Radix Bupleuri aqueous extract administration, which exhibited a positive correlation with IL-6, IL-1β, and 5-HT and a negative correlation with BDNF. In conclusion, Radix Bupleuri aqueous extract attenuates the inflammatory response in hippocampal tissues and modulates neurotransmitter levels, exerting its neuroprotective effect in SCZ. Meanwhile, the alteration of intestinal flora may be involved in this process, which is expected to be an underlying therapeutic option in treating SCZ.

A Gpr35-tuned gut microbe-brain metabolic axis regulates depressive-like behavior

Gene-environment interactions shape behavior and susceptibility to depression. However, little is known about the signaling pathways integrating genetic and environmental inputs to impact neurobehavioral outcomes. We report that gut G-protein-coupled receptor, Gpr35, engages a microbe-to-brain metabolic pathway to modulate neuronal plasticity and depressive behavior in mice. Psychological stress decreases intestinal epithelial Gpr35, genetic deletion of which induces depressive-like behavior in a microbiome-dependent manner. Gpr35-/- mice and individuals with depression have increased Parabacteroides distasonis, and its colonization to wild-type mice induces depression. Gpr35-/- and Parabacteroides distasonis-colonized mice show reduced indole-3-carboxaldehyde (IAld) and increased indole-3-lactate (ILA), which are produced from opposing branches along the bacterial catabolic pathway of tryptophan. IAld and ILA counteractively modulate neuroplasticity in the nucleus accumbens, a brain region linked to depression. IAld supplementation produces anti-depressant effects in mice with stress or gut epithelial Gpr35 deficiency. Together, these findings elucidate a gut microbe-brain signaling mechanism that underlies susceptibility to depression.

Dietary supplementation with inulin improves burn-induced skeletal muscle atrophy by regulating gut microbiota disorders

Inulin, as a prebiotic, could modulate the gut microbiota. Burn injury leads to gut microbiota disorders and skeletal muscle catabolism. Therefore, whether inulin can improve burn-induced muscle atrophy by regulating microbiota disorders remains unknown. This study aimed to clarify that inulin intake alleviates gut microbiota disorders and skeletal muscle atrophy in burned rats. Rats were divided into the sham group, burn group, prebiotic inulin intervention group, and pseudo-aseptic validation group. A 30% total body surface area (TBSA) third-degree burn wound on dorsal skin was evaluated in all groups except the sham group. Animals in the intervention group received 7 g/L inulin. Animals in the validation group received antibiotic cocktail and inulin treatment. In our study inulin intervention could significantly alleviate the burn-induced skeletal muscle mass decrease and skeletal myoblast cell apoptosis. Inulin intake increased the abundances of Firmicutes and Actinobacteria but decreased the abundance of Proteobacteria. The biosynthesis of amino acids was the most meaningful metabolic pathway distinguishing the inulin intervention group from the burn group, and further mechanistic studies have shown that inulin can promote the phosphorylation of the myogenesis-related proteins PI3K, AKT and P70S6K and activate PI3K/AKT signaling for protein synthesis. In conclusion, inulin alleviated burn induced muscle atrophy through PI3K/AKT signaling and regulated gut microbiota dysbiosis.

Alterations of gut microbiota and its correlation with the liver metabolome in the process of ameliorating Parkinson's disease with Buyang Huanwu decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Buyang Huanwu decoction (BHD), a famous traditional Chinese medicine (TCM) formula, was first recorded in Qing Dynasty physician Qingren Wang's Yi Lin Gai Cuo. BHD has been widely utilized in the treatment of patients with neurological disorders, including Parkinson's disease (PD). However, the underlying mechanism has not been fully elucidated. In particular, little is known about the role of gut microbiota.

AIM OF THE STUDY

We aimed to reveal the alterations and functions of gut microbiota and its correlation with the liver metabolome in the process of improving PD with BHD.

MATERIALS AND METHODS

The cecal contents were collected from PD mice treated with or without BHD. 16S rRNA gene sequencing was performed on an Illumina MiSeq-PE250 platform, and the ecological structure, dominant taxa, co-occurrence patterns, and function prediction of the gut microbial community were analyzed by multivariate statistical methods. The correlation between differential microbial communities in the gut and differentially accumulated metabolites in the liver was analyzed using Spearman's correlation analysis.

RESULTS

The abundance of Butyricimonas, Christensenellaceae, Coprococcus, Peptococcaceae, Odoribacteraceae, and Roseburia was altered significantly in the model group, which was by BHD. Ten genera, namely Dorea, unclassified_Lachnospiraceae, Oscillospira, unidentified_Ruminococcaceae, unclassified_Clostridiales, unidentified_Clostridiales, Bacteroides, unclassified_Prevotellaceae, unidentified_Rikenellaceae, and unidentified_S24-7, were identified as key bacterial communities. According to the function prediction of differential genera, the mRNA surveillance pathway might be a target of BHD. Integrated analysis of gut microbiota and the liver metabolome revealed that several gut microbiota genera such as Parabacteroides, Ochrobactrum, Acinetobacter, Clostridium, and Halomonas, were positively or negatively correlated with some nervous system-related metabolites, such as L-carnitine, L-pyroglutamic acid, oleic acid, and taurine.

CONCLUSIONS

Gut microbiota might be a target of BHD in the process of ameliorating PD. Our findings provide novel insight into the mechanisms underlying the effects of BHD on PD and contribute to the development of TCM.

Cryptotanshinone regulates gut microbiota and PI3K-AKT pathway in rats to alleviate CUMS induced depressive symptoms

Cryptotanshinone (CPT), a bioactive compound derived from the traditional Chinese herb Salvia miltiorrhiza, exhibits promising antidepressant properties. Employing a rat model subjected to Chronic Unpredictable Mild Stress (CUMS), behavioral analyses (open field experiment, elevated cross maze experiment, sugar water preference experiment, forced swimming experiment) and inflammatory factor assessments were conducted to assess the efficacy of CPT in alleviating depressive symptoms and inflammatory responses induced by CUMS. Moreover, 16 S rDNA analysis revealed alterations in the gut microbiota of rats exposed to both CUMS and CPT administration. Notably, CPT administration was found to mitigate harmful bacterial shifts associated with depression. Preliminary exploration of the molecular mechanism underlying CPT's antidepressant effects via transcriptomics analysis and molecular docking indicated that CPT might exert its influence by regulating the PI3K-AKT pathway. This study sheds light on the potential therapeutic role of CPT in managing depressive disorders, offering a comprehensive understanding of its impact on behavior, inflammation, gut microbiota, and molecular pathways.

Landscape of gut microbiota and metabolites and their interaction in comorbid heart failure and depressive symptoms: a random forest analysis study

IMPORTANCE

There is increasing evidence that alterations in gut microbial composition and function are associated with cardiovascular or psychiatric disease. Therefore, it is meaningful to investigate the taxonomic and functional characterization of the microbiota in HF patients who also have depressive symptoms. In this cross-sectional study, Cloacibacillus and alpha-tocopherol were determined as new diagnostic markers. Furthermore, intestinal microecosystem disorders are closely linked to depressive symptoms in HF patients, providing a new reference viewpoint for understanding the gut-heart/brain axis.

Bacteroides acidifaciens and its derived extracellular vesicles improve DSS-induced colitis

Introduction

"Probiotic therapy" to regulate gut microbiota and intervene in intestinal diseases such as inflammatory bowel disease (IBD) has become a research hotspot. Bacteroides acidifaciens, as a new generation of probiotics, has shown beneficial effects on various diseases.

Methods

In this study, we utilized a mouse colitis model induced by dextran sodium sulfate (DSS) to investigate how B. acidifaciens positively affects IBD. We evaluated the effects ofB. acidifaciens, fecal microbiota transplantation, and bacterial extracellular vesicles (EVs) on DSS-induced colitis in mice. We monitored the phenotype of mouse colitis, detected serum inflammatory factors using ELISA, evaluated intestinal mucosal barrier function using Western blotting and tissue staining, evaluated gut microbiota using 16S rRNA sequencing, and analyzed differences in EVs protein composition derived from B. acidifaciens using proteomics to explore how B. acidifaciens has a positive impact on mouse colitis.

Results

We confirmed that B. acidifaciens has a protective effect on colitis, including alleviating the colitis phenotype, reducing inflammatory response, and improving intestinal barrier function, accompanied by an increase in the relative abundance of B. acidifaciens and Ruminococcus callidus but a decrease in the relative abundance of B. fragilis. Further fecal bacterial transplantation or fecal filtrate transplantation confirmed the protective effect of eosinophil-regulated gut microbiota and metabolites on DSS-induced colitis. Finally, we validated that EVs derived from B. acidifaciens contain rich functional proteins that can contribute to the relief of colitis.

Conclusion

Therefore, B. acidifaciens and its derived EVs can alleviate DSS-induced colitis by reducing mucosal damage to colon tissue, reducing inflammatory response, promoting mucosal barrier repair, restoring gut microbiota diversity, and restoring gut microbiota balance in mice. The results of this study provide a theoretical basis for the preclinical application of the new generation of probiotics.

Bazi Bushen maintains intestinal homeostasis through inhibiting TLR4/NFκB signaling pathway and regulating gut microbiota in SAMP6 mice

BACKGROUND

Bazi Bushen is a Chinese patented medicine with multiple health benefits and geroprotective effects, yet, no research has explored its effects on intestinal homeostasis. In this study, we aimed to investigate the effect of Bazi Bushen on intestinal inflammation and the potential mechanism of gut microbiota dysbiosis and intestinal homeostasis in senescence-accelerated mouse prone 6 (SAMP6). The hematoxylin and eosin (H&E) staining and immunohistochemistry were performed to assess the function of the intestinal mucosal barrier. The enzyme-linked immunosorbent assay (ELISA) and Western blotting were used to determine the level of intestinal inflammation. The aging-related β-galactosidase (SA-β-gal) staining and Western blotting were used to measure the extent of intestinal aging. The 16S ribosomal RNA (16S rRNA) was performed to analyze the change in gut microbiota composition and distribution.

RESULTS

Bazi Bushen exerted remarkable protective effects in SAMP6, showing a regulated mucosal barrier and increased barrier integrity. It also suppressed intestinal inflammation through down-regulating pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) and inhibiting TLR4/NFκB signaling pathway (MYD88, p-p65, and TLR4). Bazi Bushen improved intestinal aging by reducing the area of SA-β-gal-positive cells and the expression of senescence markers p16, p21, and p53. In addition, Bazi Bushen effectively rebuilt the gut microbiota ecosystem by decreasing the abundance of Bacteroides and Klebsiella, whiles increasing the ratio of Lactobacillus/Bacteroides and the abundance of Akkermansia.

CONCLUSION

Our study shows that Bazi Bushen could serve as a potential therapy for maintaining intestinal homeostasis. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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

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

The microglial innate immune receptors TREM-1 and TREM-2 in the anterior cingulate cortex (ACC) drive visceral hypersensitivity and depressive-like behaviors following DSS-induced colitis

Inflammatory bowel disease (IBD) is a chronic condition with a high recurrence rate. To date, the clinical treatment of IBD mainly focuses on inflammation and gastrointestinal symptoms while ignoring the accompanying visceral pain, anxiety, depression, and other emotional symptoms. Evidence is accumulating that bi-directional communication between the gut and the brain is indispensable in the pathophysiology of IBD and its comorbidities. Increasing efforts have been focused on elucidating the central immune mechanisms in visceral hypersensitivity and depression following colitis. The triggering receptors expressed on myeloid cells-1/2 (TREM-1/2) are newly identified receptors that can be expressed on microglia. In particular, TREM-1 acts as an immune and inflammatory response amplifier, while TREM-2 may function as a molecule with a putative antagonist role to TREM-1. In the present study, using the dextran sulfate sodium (DSS)-induced colitis model, we found that peripheral inflammation induced microglial and glutamatergic neuronal activation in the anterior cingulate cortex (ACC). Microglial ablation mitigated visceral hypersensitivity in the inflammation phase rather than in the remission phase, subsequently preventing the emergence of depressive-like behaviors in the remission phase. Moreover, a further mechanistic study revealed that overexpression of TREM-1 and TREM-2 remarkably aggravated DSS-induced neuropathology. The improved outcome was achieved by modifying the balance of TREM-1 and TREM-2 via genetic and pharmacological means. Specifically, a deficiency of TREM-1 attenuated visceral hyperpathia in the inflammatory phase, and a TREM-2 deficiency improved depression-like symptoms in the remission phase. Taken together, our findings provide insights into mechanism-based therapy for inflammatory disorders and establish that microglial innate immune receptors TREM-1 and TREM-2 may represent a therapeutic target for the treatment of pain and psychological comorbidities associated with chronic inflammatory diseases by modulating neuroinflammatory responses.

Effect of Probiotic Yogurt Supplementation(Bifidobacterium animalis ssp. lactis BB-12) on Gut Microbiota of Female Taekwondo Athletes and Its Relationship with Exercise-Related Psychological Fatigue

OBJECTIVE

The gut microbiota plays a critical role in regulating human health and athletic performance. Probiotic supplementation has been shown to modulate gut microbiota composition and improve exercise performance. This study aimed to investigate the effect of probiotic yogurt supplementation on gut microbiota and its relationship with exercise-related psychological fatigue in female taekwondo athletes.

METHODS

Twenty female taekwondo athletes were randomly assigned to either a dietary intervention group (DK) or a control group (CK). The athletes' exercise-related psychological fatigue was measured using the Athlete Burnout Questionnaire (ABQ) before and after an 8-week intervention. High-throughput sequencing was used to profile the gut microbiota, and functional prediction of the microbial community was performed. The effect of the dietary intervention on the athletes' exercise-related psychological fatigue clearance rate and its relationship with the gut microbiota were explored.

RESULTS

(1) The probiotic supplementation of Bifidobacterium animalis ssp. lactis BB-12 for 8 weeks significantly increased the ABQ scores of the DK group compared to the CK group (p < 0.05). (2) The abundances of Bifidobacterium, Bacteroides, Lachnospiraceae, family _Lactobacillaceae, and genus _Lactobacillus were significantly higher in the DK group than in the CK group after probiotic supplementation, while Escherichia coli was significantly lower in the DK group than in the CK group. (3) The ABQa scores were positively correlated with Proteus; ABQb scores were positively correlated with Streptococcus and Enterococcus; and ABQc scores were positively correlated with Klebsiella, Bacteroides, and Streptomyces. (4) The DK group had significantly higher levels of L-arginine biosynthesis I (via L-ornithine), fatty acid biosynthesis and oxidation, and L-isoleucine biosynthesis III pathways compared to the CK group. Tyrosine degradation I (via 2,3-dihydroxyphenylpropionate) was significantly lower in the DK group than in the CK group.

CONCLUSIONS

Probiotic yogurt supplementation of Bifidobacterium animalis ssp. lactis can promote the clearance of exercise-related psychological fatigue in female taekwondo athletes by upregulating beneficial gut microbiota, inhibiting harmful gut microbiota, and regulating relevant metabolic pathways.

Bacillus licheniformis prevents and reduces anxiety-like and depression-like behaviours

As common mental disorders, depression and anxiety impact people all around the world. Recent studies have found that the gut microbiome plays an important role in mental health. It is becoming possible to treat mental disorders by regulating the composition of the gut microbiota. Bacillus licheniformis is a probiotic used to treat gut diseases through balancing the gut microbiome during lasting years. Considering the role of gut microbiota in the gut-brain axis, this study used chronic unpredictable mild stress (CUMS) model rats to explore whether Bacillus licheniformis can prevent and treat depression and anxiety. We found that B. licheniformis reduced the depressive-like and anxiety-like behaviours of the rats during the CUMS process. Meanwhile, B. licheniformis changed the gut microbiota composition; increased the short chain fatty acids (SCFAs) in the colon, decreased kynurenine, norepinephrine, and glutamate levels; and increased the tryptophan, dopamine, epinephrine, and γ-aminobutyric acid (GABA) in the brain. After correlation analysis, we found Parabacteroides, Anaerostipes, Ruminococcus-2, and Blautia showed significant correlation with neurotransmitters and SCFAs, indicating the gut microbiome plays an important role in B. licheniformis reducing depressive-like behaviours. Therefore, this study suggested B. licheniformis may prevent depressive-like and anxiety-like behaviours while regulating the gut microbiota composition and increasing the SCFA levels in the colon to alter the levels of the neurotransmitters in the brain. KEY POINTS: • B. licheniformis reduced depressive-like and anxiety-like behaviours induced by the chronic unpredictable mild stress. • GABA levels in the brain are assonated with B. licheniformis regulating depressive-like and anxiety-like behaviours. • Gut microbiota composition alteration followed by metabolic changes may play a role in the GABA levels increase.

Neuroinflammation, Microbiota-Gut-Brain Axis, and Depression: The Vicious Circle

Depression is the leading cause of disability worldwide, contributing to the global disease burden. From above, it is a priority to investigate models that fully explain its physiopathology to develop new treatments. In the last decade, many studies have shown that gut microbiota (GM) dysbiosis influences brain functions and participate, in association with immunity, in the pathogenesis of depression. Thereby, GM modulation could be a novel therapeutic target for depression. This review aims to evidence how the GM and the immune system influence mental illness, particularly depression. Here, we focus on the communication mechanisms between the intestine and the brain and the impact on the development of neuroinflammation contributing to the development of Major Depressive Disorder (MDD). However, most of the current findings are in animal models, suggesting the need for studies in humans. In addition, more analysis of metabolites and cytokines are needed to identify new pathophysiological mechanisms improving anti-depression treatments.

Parabacteroides distasonis ameliorates hepatic fibrosis potentially via modulating intestinal bile acid metabolism and hepatocyte pyroptosis in male mice

Parabacteroides distasonis (P. distasonis) plays an important role in human health, including diabetes, colorectal cancer and inflammatory bowel disease. Here, we show that P. distasonis is decreased in patients with hepatic fibrosis, and that administration of P. distasonis to male mice improves thioacetamide (TAA)- and methionine and choline-deficient (MCD) diet-induced hepatic fibrosis. Administration of P. distasonis also leads to increased bile salt hydrolase (BSH) activity, inhibition of intestinal farnesoid X receptor (FXR) signaling and decreased taurochenodeoxycholic acid (TCDCA) levels in liver. TCDCA produces toxicity in mouse primary hepatic cells (HSCs) and induces mitochondrial permeability transition (MPT) and Caspase-11 pyroptosis in mice. The decrease of TCDCA by P. distasonis improves activation of HSCs through decreasing MPT-Caspase-11 pyroptosis in hepatocytes. Celastrol, a compound reported to increase P. distasonis abundance in mice, promotes the growth of P. distasonis with concomitant enhancement of bile acid excretion and improvement of hepatic fibrosis in male mice. These data suggest that supplementation of P. distasonis may be a promising means to ameliorate hepatic fibrosis.

Poria cocos Polysaccharide Ameliorated Antibiotic-Associated Diarrhea in Mice via Regulating the Homeostasis of the Gut Microbiota and Intestinal Mucosal Barrier

Poria cocos polysaccharides (PCP) have been validated for several biological activities, including antitumor, anti-inflammatory, antioxidant, immunomodulatory, hepatoprotective and modulation on gut microbiota. In this research, we aim to demonstrate the potential prebiotic effects and the therapeutic efficacies of PCP in the treatment of antibiotic-associated diarrhea (AAD), and confirm the beneficial effects of PCP on gut dysbiosis. Antibiotic-associated diarrhea mice models were established by treating them with broad-spectrum antibiotics in drinking water for seven days. Mice in two groups treated with probiotics and polysaccharide were given Bifico capsules (4.2 g/kg/d) and PCP (250 mg/kg/d) for seven days using intragastric gavage, respectively. To observe the regulatory effects of PCP on gut microbiota and intestinal mucosal barrier, we conducted the following experiments: intestinal flora analysis (16S rDNA sequencing), histology (H&E staining) and tight junction proteins (immunofluorescence staining). The levels of mRNA expression of receptors associated with inflammation and gut metabolism were assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR). The study revealed that PCP can comprehensively improve the clinical symptoms of AAD mice, including fecal traits, mental state, hair quality, etc., similar to the effect of probiotics. Based on histology observation, PCP significantly improved the substantial structure of the intestine of AAD mice by increasing the expression levels of colonic tight junction protein zonula-occludens 1 (ZO-1) and its mRNA. Moreover, PCP not only increased the abundance of gut microbiota, but also increased the diversity of gut microbiota in AAD mice, including alpha diversity and beta diversity. Further analysis found that PCP can modulate seven characteristic species of intestinal flora in AAD mice, including Parabacteroides_distasonis, Akkermansia_muciniphila, Clostridium_saccharolyticum, Ruminoc-occus_gnavus, Lactobacillus_salivarius, Salmonella_enterica and Mucispirillum_schaedleri. Finally, enrichment analysis predicted that PCP may affect intestinal mucosal barrier function, host immune response and metabolic function by regulating the microbiota. RT-PCR experiments showed that PCP can participate in immunomodulatory and modulation on metabolic by regulating the mRNA expression of forkhead-box protein 3 (FOXP3) and G protein-coupled receptor 41 (GPR41). These results indicated that Poria cocos polysaccharide may ameliorate antibiotic-associated diarrhea in mice by regulating the homeostasis of the gut microbiota and intestinal mucosal barrier. In addition, polysaccharide-derived changes in intestinal microbiota were involved in the immunomodulatory activities and modulation of the metabolism.

Fecal microbiome transplant from patients with lactation mastitis promotes mastitis in conventional lactating mice

Introduction

Lactation mastitis seriously severely affects the health of lactating females and their infants, yet the underlying causes of clinical lactation mastitis remain unclear.

Methods

In this study, we used microbiota-humanized mice as a model to investigate the role of gut microbiota in lactation mastitis. We compared the fecal microbiota of lactation mastitis patients and healthy individuals and conducted fecal microbiota transplantation (FMT) experiments in an antibiotic-pretreated mouse model to test whether gut microbes contribute to human lactation mastitis.

Results

Our results showed that gut microbiota diversity was reduced and dysbiosis was present in lactating mastitis patients. FMT from lactation mastitis patients (M-FMT), but not from healthy individuals (H-FMT), to antibiotic-treated mice resulted in lactation mastitis. The inflammation in mice caused by gut microbiota from lactating mastitis patients appears to be pervasive, as hepatocytes from mice that received feces from lactating mastitis patients showed marked swelling. In addition, serum pro-inflammatory factors, including IL-4, IL-17, MPO, IL-6, IL-1β, and TNF-α, were significantly increased in the M-FMT group. The Firmicutes/Bacteroidetes ratio (F/B), a biomarker of gut dysbiosis, was significantly increased in the M-FMT group. At the phylum level, Actinobacteria were significantly increased, and Verrucomicrobia were significantly decreased in the M-FMT group. At the genus level, Ruminococcus and Faecalibacterium were significantly reduced, while Parabacteroides were significantly increased in the feces of both patients with lactation mastitis and M-FMT mice. Moreover, our study revealed an "amplification effect" on microbiota differences and mastitis disease following human-to-mouse FMT.

Conclusion

Collectively, our findings demonstrate that the gut microbiota in lactating mastitis patients is dysbiotic and contributes to the pathogenesis of mastitis.

The role of gut microbiota in T cell immunity and immune mediated disorders

Gut microbiota was only considered as a commensal organism that aids in digestion, but recent studies revealed that the microbiome play a critical role in both physiological and pathological immune system. The gut microbiome composition is altered by environmental factors such as diet and hygiene, and the alteration affects immune cells, especially T cells. Advanced genomic techniques in microbiome research defined that specific microbes regulate T cell responses and the pathogenesis of immune-mediated disorders. Here, we review features of specific microbes-T cell crosstalk and relationship between the microbes and immunopathogenesis of diseases including in cancers, autoimmune disorders and allergic inflammations. We also discuss the limitations of current experimental animal models, cutting-edge developments and current challenges to overcome in the field, and the possibility of considering gut microbiome in the development of new drug.

Probiotic Bifidobacterium longum BB68S Improves Cognitive Functions in Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial

Probiotics could improve cognitive functions in patients with neurological disorders such as Alzheimer’s disease, but the effects on cognitive function in healthy older adults without cognitive impairment need further study. The purpose of this study was to investigate the effect of Bifidobacterium longum BB68S (BB68S) on cognitive functions among healthy older adults without cognitive impairment. A randomized, double-blind, placebo-controlled trial was conducted with 60 healthy older adults without cognitive impairment who were divided into probiotic or placebo groups and required to consume either a sachet of probiotic (BB68S, 5 × 1010 CFU/sachet) or placebo once daily for 8 weeks. The Montreal Cognitive Assessment (MoCA) was used as an inclusion screening tool to screen elderly participants with healthy cognitive function in our study, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognitive function in subjects before and after intervention as an assessment tool. BB68S significantly improved subjects’ cognitive functions (total RBANS score increased by 18.89 points after intervention, p < 0.0001), especially immediate memory, visuospatial/constructional, attention, and delayed memory domains. BB68S intervention increased the relative abundances of beneficial bacteria Lachnospira, Bifidobacterium, Dorea, and Cellulosilyticum, while decreasing those of bacteria related to cognition impairment, such as Collinsella, Parabacteroides, Tyzzerella, Bilophila, unclassified_c_Negativicutes, Epulopiscium, Porphyromonas, and Granulicatella. In conclusion, BB68S could improve cognitive functions in healthy elderly adults without cognitive impairment, along with having beneficial regulatory effects on their gut microbiota. This study supports probiotics as a strategy to promote healthy aging and advances cognitive aging research.

Multi-cohort analysis of depression-associated gut bacteria sheds insight on bacterial biomarkers across populations

Gut microbes are associated with the development of depression based on extensive evidence. However, previous studies have led to conflicting reports on this association, posing challenges to the application of gut bacteria in the diagnostics and treatment of depression. To minimise heterogenicity in data analysis, the present meta-analysis adopted a standardised bioinformatics and statistical pipeline to analyse 16S rRNA sequences of 1827 samples from eight different cohorts. Although changes in the overall bacterial community were identified by our meta-analysis, depressive-correlated changes in alpha-diversity were absent. Enrichment of Bacteroidetes, Parabacteroides, Barnesiella, Bacteroides, and Bacteroides vulgatus, along with depletion in Firmicutes, Dialister, Oscillospiraceae UCG 003 and UCG 002, and Bacteroides plebeius, were observed in depressive-associated bacteria. By contrast, elevated L-glutamine degradation, and reduced L-glutamate and L-isoleucine biosynthesis were identified in depressive-associated microbiomes. After systemically reviewing the data of these collected cohorts, we have established a bacterial classifier to identify depressive symptoms with AUC 0.834 and 0.685 in the training and external validation dataset, respectively. Moreover, a low-risk bacterial cluster for depressive symptoms was identified, which was represented by a lower abundance of Escherichia-Shigella, and a higher abundance of Faecalibacterium, Oscillospiraceae UCG 002, Ruminococcus, and Christensenellaceae R.7 group.

Dynamics of Gut Microbiota and Clinical Variables after Ketogenic and Mediterranean Diets in Drug-Naïve Patients with Type 2 Diabetes Mellitus and Obesity

Type 2 diabetes mellitus (T2DM), the most common form of diabetes, is a progressive chronic metabolic disease that has increasingly spread worldwide, enhancing the mortality rate, particularly from cardiovascular diseases (CVD). Lifestyle improvement through diet and physical activity is, together with drug treatment, the cornerstone of T2DM management. The Mediterranean diet (MD), which favors a prevalence of unprocessed vegetable foods and a reduction in red meats and industrial foods, without excluding any food category, is usually recommended. Recently, scientific societies have promoted a very low-calorie ketogenic diet (VLCKD), a multiphasic protocol that limits carbohydrates and then gradually re-introduces them, with a favorable outcome on body weight and metabolic parameters. Indeed, gut microbiota (GM) modifications have been linked to overweight/obesity and metabolic alterations typical of T2DM. Diet is known to affect GM largely, but only a few studies have investigated the effects of VLCKD on GM, especially in T2DM. In this study, we have compared anthropometric, biochemical, lifestyle parameters, the quality of life, and the GM of eleven patients with recently diagnosed T2DM and overweight or obesity, randomly assigned to two groups of six and five patients who followed the VLCKD (KETO) or hypocaloric MD (MEDI) respectively; parameters were recorded at baseline (T0) and after two (T2) and three months (T3). The results showed that VLCKD had more significant beneficial effects than MD on anthropometric parameters, while biochemical improvements did not statistically differ. As for the GM, despite the lack of significant results regarding the alpha and beta diversity, and the Firmicutes/Bacteroidota ratio between the two groups, in the KETO group, a significant increase in beneficial microbial taxa such as Verrucomicrobiota phylum with its members Verrucomicrobiae, Verrucomicrobiales, Akkermansiaceae, and Akkermansia, Christensenellaceae family, Eubacterium spp., and a reduction in microbial taxa previously associated with obesity (Firmicutes and Actinobacteriota) or other diseases (Alistipes) was observed both at T2 and T3. With regards to the MEDI group, variations were limited to a significant increase in Actinobacteroidota phylum at T2 and T3 and Firmicutes phylum at T3. Moreover, a metagenomic alteration linked to some metabolic pathways was found exclusively in the KETO group. In conclusion, both dietary approaches allowed patients to improve their state of health, but VLCKD has shown better results on body composition as well as on GM profile.

Chaihu-shugan-san alleviates depression-like behavior in mice exposed to chronic unpredictable stress by altering the gut microbiota and levels of the bile acids hyocholic acid and 7-ketoDCA

Chaihu-Shugan-San (CSS) is a traditional botanical drug formula often prescribed to treat depression in oriental countries, but its pharmacotherapeutic mechanism remains unknown. It was recently reported that CSS alters the composition of intestinal microflora and related metabolites such as bile acids (BAs). Since the intestinal microflora affects physiological functions of the brain through the gut-microbiota-brain axis, herein we investigated whether CSS altered BA levels, gut microflora, and depression-like symptoms in chronic unpredictable mild stress (CUMS) mice, a well-established mouse model of depression. Furthermore, we determined whether BA manipulation and fecal microbiota transplantation altered CSS antidepressant actions. We found that the BA chelator cholestyramine impaired the antidepressant effects of CSS, which was partially rescued by dietary cholic acid. CSS increased the relative abundance of Parabacteroides distasonis in the colon of CUMS mice, and increased serum levels of various BAs including hyocholic acid (HCA) and 7-ketodeoxycholic acid (7-ketoDCA). Furthermore, gut bacteria transplantation from CSS-treated mice into untreated or cholestyramine-treated CUMS mice restored serum levels of HCA and 7-ketoDCA, alleviating depression-like symptoms. In the hippocampus, CSS-treated mice had decreased expression of genes associated with BA transport (Bsep and Fxr) and increased expression of brain-derived neurotrophic factor and its receptor, TrkB. Overall, CSS increases intestinal P. distasonis abundance, leading to elevated levels of secondary BAs in the circulation and altered expression of hippocampal genes implicated in BA transport and neurotrophic signaling. Our data strongly suggest that the gut microbiota-brain axis contributes to the potent antidepressant action of CSS by modulating BA metabolism.

Chronic stress induces colonic tertiary lymphoid organ formation and protection against secondary injury through IL-23/IL-22 signaling

Psychological stress has been previously reported to worsen symptoms of inflammatory bowel disease (IBD). Similarly, intestinal tertiary lymphoid organs (TLOs) are associated with more severe inflammation. While there is active debate about the role of TLOs and stress in IBD pathogenesis, there are no studies investigating TLO formation in the context of psychological stress. Our mouse model of Crohn's disease-like ileitis, the SAMP1/YitFc (SAMP) mouse, was subjected to 56 consecutive days of restraint stress (RS). Stressed mice had significantly increased colonic TLO formation. However, stress did not significantly increase small or large intestinal inflammation in the SAMP mice. Additionally, 16S analysis of the stressed SAMP microbiome revealed no genus-level changes. Fecal microbiome transplantation into germ-free SAMP mice using stool from unstressed and stressed mice replicated the behavioral phenotype seen in donor mice. However, there was no difference in TLO formation between recipient mice. Stress increased the TLO formation cytokines interleukin-23 (IL-23) and IL-22 followed by up-regulation of antimicrobial peptides. SAMP × IL-23r-/- (knockout [KO]) mice subjected to chronic RS did not have increased TLO formation. Furthermore, IL-23, but not IL-22, production was increased in KO mice, and administration of recombinant IL-22 rescued TLO formation. Following secondary colonic insult with dextran sodium sulfate, stressed mice had reduced colitis on both histology and colonoscopy. Our findings demonstrate that psychological stress induces colonic TLOs through intrinsic alterations in IL-23 signaling, not through extrinsic influence from the microbiome. Furthermore, chronic stress is protective against secondary insult from colitis, suggesting that TLOs may function to improve the mucosal barrier.

Inhibition of GABAAR or Application of Lactobacillus casei Zhang Alleviates Ulcerative Colitis in Mice: GABAAR as a Potential Target for Intestinal Epithelial Renewal and Repair

Emerging evidence indicates that the gamma−aminobutyric acid type A receptor (GABA_AR) and Lactobacillus casei Zhang regulate colitis in a variety of ways, such as by participating in host immune and inflammatory responses, altering the gut microbiota, and influencing intestinal barrier function. However, not much is known about the mechanisms by which GABA_AR and L. casei affect colon epithelial cell renewal and the interaction between GABA_AR and L. casei during this process. To elucidate this, we established a dextran sulfate sodium (DSS)−induced model and measured the mouse body weights, colon length, the disease activity index (DAI), and histological scores. Our results indicated that inhibition of GABA_AR alleviated the DSS−induced colitis symptoms, resulting in less weight loss and more intact colon tissue. Moreover, treatment with bicuculline (Bic, a GABA_AR inhibitor) increased the levels of PCNA, β−catenin, and TCF4 in mice with colitis. Interestingly, open field test performances showed that inhibition of GABA_AR also attenuated colitis−related anxiety−like behavior. By 16S RNA gene sequencing analysis, we showed that inhibition of GABA_AR partially reversed the gut dysbacteriosis of DSS−induced mice and increased the abundance of beneficial bacteria. Additionally, L. casei Zhang supplementation inhibited the expression of GABA_AR in mice with colitis, promoted the proliferation and renewal of colon epithelial cells, and alleviated anxiety−like behavior and intestinal microflora disorder in mice. Thus, GABA_AR plays a key role in the beneficial effects of L. casei on DSS−induced colitis in mice.

Fecal microbiota transplantation treatment for type 1 diabetes mellitus with malnutrition: a case report

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease. Not only genetics, but the intestinal environment affected by gut microbiota is also the key to pathogenesis. Besides the occurrence of diabetes, gut microbiota dysbiosis may also contribute to the development of diabetes-related complications. Fecal microbiota transplantation (FMT) is an emerging technique that had shown its potential as a treatment for metabolic disease. Here, we report the first case of T1DM with malnutrition and gastrointestinal symptoms treated with FMT. A 24-year-old T1DM patient suffered from poor blood glucose control, recurrent nausea and vomiting, severe malnutrition, and intractable constipation after insulin treatment. The clinical response of the patients after FMT was well, especially nausea and vomiting were significantly relieved. In addition, constipation, nutritional status, and blood glucose control (fasting blood glucose, HbA1c) gradually improved. A degree of similarity was found in gut microbiota composition between the patient and healthy donor after FMT while it was totally different before the treatment. Furthermore, pathway function analysis of MetaCYC database implies that the potential mechanism of the response of FMT may be driven by specific bacteria involved in several metabolic pathways that need further exploration. To sum up, we believe that the reconstruction of intestinal flora by FMT may be a new choice for the treatment of T1DM patients with malnutrition.

Abnormal bile acid metabolism is an important feature of gut microbiota and fecal metabolites in patients with slow transit constipation

Destructions in the intestinal ecosystem are implicated with changes in slow transit constipation (STC), which is a kind of intractable constipation characterized by colonic motility disorder. In order to deepen the understanding of the structure of the STC gut microbiota and the relationship between the gut microbiota and fecal metabolites, we first used 16S rRNA amplicon sequencing to evaluate the gut microbiota in 30 STC patients and 30 healthy subjects. The α-diversity of the STC group was changed to a certain degree, and the β-diversity was significantly different, which indicated that the composition of the gut microbiota of STC patients was inconsistent with healthy subjects. Among them, Bacteroides, Parabacteroides, Desulfovibrionaceae, and Ruminiclostridium were significantly upregulated, while Subdoligranulum was significantly downregulated. The metabolomics showed that different metabolites between the STC and the control group were involved in the process of bile acids and lipid metabolism, including taurocholate, taurochenodeoxycholate, taurine, deoxycholic acid, cyclohexylsulfamate, cholic acid, chenodeoxycholate, arachidonic acid, and 4-pyridoxic acid. We found that the colon histomorphology of STC patients was significantly disrupted, and TGR5 and FXR were significantly downregulated. The differences in metabolites were related to changes in the abundance of specific bacteria and patients’ intestinal dysfunction. Analysis of the fecal genomics and metabolomics enabled separation of the STC from controls based on random forest model prediction [STC vs. control (14 gut microbiota and metabolite biomarkers)—Sensitivity: 1, Specificity: 0.877]. This study provided a perspective for the diagnosis and intervention of STC related with abnormal bile acid metabolism.

A Prebiotic Diet Alters the Fecal Microbiome and Improves Sleep in Response to Sleep Disruption in Rats

Sleep disruption is a challenging and exceedingly common physiological state that contributes to a wide range of biochemical and molecular perturbations and has been linked to numerous adverse health outcomes. Modern society exerts significant pressure on the sleep/wake cycle via myriad factors, including exposure to electric light, psychological stressors, technological interconnection, jet travel, shift work, and widespread use of sleep-affecting compounds. Interestingly, recent research has identified a link between the microbiome and the regulation of sleep, suggesting that interventions targeting the microbiome may offer unique therapeutic approaches to challenges posed by sleep disruption. In this study, we test the hypothesis that administration of a prebiotic diet containing galactooligosaccharides (GOS) and polydextrose (PDX) in adult male rats improves sleep in response to repeated sleep disruption and during recovery sleep. We found that animals fed the GOS/PDX prebiotic diet for 4 weeks exhibit increased non-rapid eye movement (NREM) and rapid eye movement (REM) sleep during 5 days of sleep disruption and increased total sleep time during 24 h of recovery from sleep disruption compared to animals fed a control diet, despite similar baseline sleep characteristics. Further, the GOS/PDX prebiotic diet led to significant changes in the fecal microbiome. Consistent with previous reports, the prebiotic diet increased the relative abundance of the species Parabacteroides distasonis, which positively correlated with sleep parameters during recovery sleep. Taken together, these findings suggest that the GOS/PDX prebiotic diet may offer an approach to improve resilience to the physiologic challenge of sleep disruption, in part through impacts on the microbiome.

Investigating local and systemic intestinal signalling in health and disease with Drosophila

Whole-body health relies on complex inter-organ signalling networks that enable organisms to adapt to environmental perturbations and to changes in tissue homeostasis. The intestine plays a major role as a signalling centre by producing local and systemic signals that are relayed to the body and that maintain intestinal and organismal homeostasis. Consequently, disruption of intestinal homeostasis and signalling are associated with systemic diseases and multi-organ dysfunction. In recent years, the fruit fly Drosophila melanogaster has emerged as a prime model organism to study tissue-intrinsic and systemic signalling networks of the adult intestine due to its genetic tractability and functional conservation with mammals. In this Review, we highlight Drosophila research that has contributed to our understanding of how the adult intestine interacts with its microenvironment and with distant organs. We discuss the implications of these findings for understanding intestinal and whole-body pathophysiology, and how future Drosophila studies might advance our knowledge of the complex interplay between the intestine and the rest of the body in health and disease.

Summary: We outline work in the fruit fly Drosophila melanogaster that has contributed knowledge on local and whole-body signalling coordinated by the adult intestine, and discuss its implications in intestinal pathophysiology and associated systemic dysfunction.

The effect of COVID-19 lockdown on mental health, gut microbiota composition and serum cortisol levels

The aim of this study was to assess changes in mental health, gut microbiota composition, and stress marker serum cortisol due to COVID-19 lockdown in asymptomatic individuals. Healthy adults participated in anthropometric measurements, blood and stool sample collection pre-lockdown and post-lockdown (n = 38, 63.2% females), lifestyle and psychological questionnaires were included in pre-lockdown measurement and lockdown survey (n = 46, 67.4% females). Subjects reported significantly higher body dissatisfaction (p = 0.007) and anxiety (p = 0.002), and significantly lower positive affect (p = 0.001) during lockdown compared with pre-lockdown. According to perceived stress, 51.6% of females and 20% of males experienced moderate to high stress. This was reflected in serum cortisol levels that significantly increased only in females (p = 0.006) post-lockdown and correlated with perceived stress (p = 0.037) and anxiety (p = 0.031). In addition to psychological measures, changes in gut microbiota composition were observed. Gut microbial alpha diversity significantly decreased (p = 0.033), whereas relative abundance of Proteobacteria significantly increased (p = 0.043) post-lockdown. Depression during lockdown was moderately positively correlated with changes in Bacteroidetes abundance (p = 0.015) and negatively with changes in Firmicutes abundance (p = 0.008). Alistipes abundance post-lockdown was moderately positively correlated with anxiety (p = 0.004) and negative affect (p = 0.005) during lockdown. Despite a small sample size and not being able to perform objective measurements during lockdown, the results confirm the effect of lockdown on mental health and gut microbiota composition that could have a great impact on our health (ClinicalTrials identifier: NCT04347213).