Flavonoids from Seabuckthorn (Hippophae rhamnoides L.) restore CUMS-induced depressive disorder and regulate the gut microbiota in mice

Sea buckthorn polyphenols on gastrointestinal health and the interactions with gut microbiota

The potential health benefits of sea buckthorn polyphenols (SBP) have been extensively studied, attracting increasing attention from researchers. This paper reviews the composition of SBP, the effects of processing on SBP, its interactions with nutrients, and its protective role in the gastrointestinal tract. Polyphenols influence nutrient absorption and metabolism by regulating the intestinal flora, thereby enhancing bioavailability, protecting the gastrointestinal tract, and altering nutrient structures. Additionally, polyphenols exhibit anti-inflammatory and immunomodulatory effects, promoting intestinal health. The interaction between polyphenols and intestinal flora plays a significant role in gastrointestinal health, supporting the composition and diversity of the gut microbiota. However, further research is needed to emphasize the importance of human trials and to explore the intricate relationship between SBP and gut microbiota, as these insights are crucial for understanding the mechanisms underlying SBP's benefits for the gastrointestinal tract (GIT).

The Functions of Major Gut Microbiota in Obesity and Type 2 Diabetes

Background: Gut microbiomes play a vital role in maintaining whole-body metabolic homeostasis. It has gained significant attention in recent years due to advancements in genome sequencing technologies and a deeper understanding of its relationship with obesity. However, the specific ways in which different microorganisms directly or indirectly influence host obesity, as well as the underlying mechanisms, remain uncertain because of the complexity of gut microbiota composition. Methods: In this review, we summarize the roles of the major gut microbiota phyla such as Bacteroidetes, Firmicutes, Proteobacteria, and Verrucomicrobia in obesity and type 2 diabetes based on studies published in the past five years on PubMed and Google Scholar. The current therapeutic strategies associated with gut microbiota are also explored from clinical trials, and challenges and future directions are discussed. Results and Conclusions: This review will provide a deeper understanding of the functions of major gut microbiota in obesity and type 2 diabetes, which could lead to more individualized and effective treatments for metabolic diseases.

Sea buckthorn berries alleviate ulcerative colitis via regulating gut Faecalibaculum rodentium-mediated butyrate biosynthesis

BACKGROUND

The gut microbiota is firmly associated with the progression of ulcerative colitis (UC). Beneficial microbial metabolites, such as butyrate, exert vital roles in maintaining intestinal homeostasis. The Sea buckthorn berry is a traditional Chinese medicine homologous to food and medicine which is widely applied in the prevention and treatment of UC in clinic practice. Recent studies have exhibited the potential function of Sea buckthorn on regulating the gut microbiota, however, the mechanism underlying its anti-colitis effects and the key gut microbes mediating its efficacy are still unclear.

PURPOSE

This study is intended to explore the pharmacological mechanism of the efficacy of Sea buckthorn berries extract (SBE) in alleviating UC from the perspective of the gut microbial regulation.

METHODS

The effect of SBE on UC was evaluated on dextran sulfate sodium (DSS)-induced murine model by assessing the body weight change, colon length, disease activity index (DAI), histopathological staining and the transcriptional expression of genes associated with inflammation and mucosal integrity. The dependence of the gut microbiota in the therapeutical effects of SBE on UC was confirmed by pseudo-germ-free mice and the co-housing experiment. The differential gut microbes altered by SBE were discovered by 16S rRNA sequencing and qPCR. The levels of short chain fatty acids (SCFAs) in bacterial medium and colonic contents were determined by GC-MS/MS. Bacterial colonization was conducted to estimate the effects of the bacteria on UC and to verify the involvement of the functional bacteria in the efficacy of SBE. A butyrate receptor G protein-coupled receptor (GPR)109A antagonist mepenzolate bromide (MPN) was used to validate the important role of butyrate and GPR109A in the anti-colitis effects of SBE and functional bacteria on UC. Two-way ANOVA was employed for multiple curve comparison and One-way ANOVA and Brown-Forsythe ANOVA test were used for multiple group comparison. Statistical significance was defined as p< 0.05.

RESULTS

SBE treatment significantly alleviated DSS-induced UC and its therapeutical effects was impaired in pseudo-germ-free mice. Moreover, the co-housing experiment exhibited that SBE-altered microbiota could effectively ameliorate UC. Further research demonstrated that Faecalibaculum rodentium was obviously increased by SBE and could be transferable by co-housing. Moreover, butyrate, a product of F. rodentium, dramatically decreased in UC mice while could be recovered by SBE administration. Abolishment of F. rodentium using vancomycin deprived the efficacy of SBE, but this could be reversed by recolonization of F. rodentium. Finally, blockage of the butyrate's receptor GPR109A weakened the effects of F. rodentium, indicating the indispensability of butyrate and GPR109A in the anti-colitis effects of F. rodentium.

CONCLUSION

SBE has potent therapeutical efficacy on UC including relieving inflammation and enhancing intestinal epithelial integrity, which is mediated by the gut F. rodentium-regulated butyrate-GPR109A axis.

Administration time modify the anxiolytic and antidepressant effects of inulin via gut-brain axis

An imbalance in the microbiota-gut-brain axis exerts an essential effect on the pathophysiology of depressive and anxiety disorders. Our previous research revealed that the timing of inulin administration altered its effects on chronic unpredictable mild stress (CUMS)-induced anxiety and depression. However, it is still unclear if the gut-brain axis is primarily responsible for these effects. In this study, fecal microbiota transplantation (FMT) confirmed that inulin administration at different times alleviated CUMS-induced anxiety- and depression-like behaviors via the gut-brain axis. The time of administration seemed to modify the anxiolytic and antidepressant effects of inulin, and inulin intervention in the evening was more pronounced in inhibiting the inflammatory responses than that of morning inulin intervention. Serum metabolomics analysis showed that the main differential metabolites, including fenofibric acid, 4'-Hydroxyfenoprofen glucuronide and 5-(4-Hydroxybenzyl)thiazolidine-2,4-dione may be vital for the anxiolytic and antidepressant effects of different inulin treatment times. Our results suggested that inulin administration in the evening was more effective in alleviating the inflammatory responses and improving amino acids metabolism. This study provides a new potential link between the microbiota-gut-brain axis and chrono-nutrition, demonstrating that a more appropriate administration time results in a better intervention effect.

A systematic review of preclinical studies targeted toward the management of co-existing functional gastrointestinal disorders, stress, and gut dysbiosis

Modern dietary habits and stressed lifestyle have escalated the tendency to develop functional gastrointestinal disorders (FGIDs) through alteration in the gut-brain-microbiome axis. Clinical practices use symptomatic treatments, neglect root causes, and prolong distress in patients. The past decade has seen the evolution of various interventions to attenuate FGIDs. But clinical translation of such studies is very rare mostly due to lack of awareness. The aim of this review is to meticulously integrate different studies and bridge this knowledge gap. Literature between 2013 and 2023 was retrieved from PubMed, ProQuest, and Web of Science. The data was extracted based on the PRISMA guidelines and using the SYRCLE's risk of bias and the Cochrane Risk of Bias tools, quality assessment was performed. The review has highlighted molecular insights into the coexistence of FGIDs, stress, and gut dysbiosis. Furthermore, novel interventions focusing on diet, probiotics, herbal formulations, and phytoconstituents were explored which mostly had a multitargeted approach for the management of the diseases. Scientific literature implied positive interactions between the interventions and the gut microbiome by increasing the relative abundance of beneficial bacteria and reducing stress-related hormones. Moreover, the interventions reduced intestinal inflammation and regulated the expression of epithelial tight junction proteins in different in vivo models. This systematic review delves deep into the preclinical interventions to manage coexisting FGIDs, stress, and gut dysbiosis. However, in most of the discussed studies, long-term risks and toxicity profile of the interventions are lacking. So, it is necessary to highlight them for improved clinical outcomes.

Flavonoids and the gut microbiome: a powerful duo for brain health

Flavonoids, a class of polyphenolic compounds, are widely distributed in plant-based foods and have been recognized for their potential to promote overall health and well-being. Flavonoids in fruits and vegetables offer various beneficial effects such as anti-aging, anticancer, and anti-inflammatory properties. Flavonoids have been extensively studied for their neuroprotective properties, which are attributed to their ability to cross the blood-brain barrier and interact with neural cells. Factors like gut microbiota composition, age, genetics, and diet can impact how well flavonoids are absorbed in the gut. The gut microbiota can enhance the absorption of flavonoids through enzymatic processes, making microbiota composition a key factor influenced by age, genetics, and diet. Flavonoids can modulate the gut microbiota through prebiotic and antimicrobial effects, affecting the production of beneficial microbial metabolites like short-chain fatty acids (SCFAs) such as butyrate, which play a role in brain function and health. The gut microbiome also modulates the immune system, which is critical for preventing neuroinflammation. Additionally, flavonoids can benefit mental and psychological health by influencing anti-inflammatory signaling pathways in brain cells and increasing the absorption of tyrosine and tryptophan, precursors to neurotransmitters like serotonin, dopamine, norepinephrine, adrenaline, and gamma-aminobutyric acid (GABA). The flavonoid-gut microbiome axis is a complex and multifaceted relationship that has significant implications for neurological health. This review will explore how genetic and environmental factors can impact flavonoid absorption and the positive effects of flavonoids on brain health and the gut microbiota network.

Microbiota-gut-brain axis: Natural antidepressants molecular mechanism

BACKGROUND

Major depressive disorder (MDD) is a severe mental health condition characterized by persistent depression, impaired cognition, and reduced activity. Increasing evidence suggests that gut microbiota (GM) imbalance is closely linked to the emergence and advancement of MDD, highlighting the potential significance of regulating the "Microbiota-Gut-Brain" (MGB) axis to impact the development of MDD. Natural products (NPs), characterized by broad biological activities, low toxicity, and multi-target characteristics, offer unique advantages in antidepressant treatment by regulating MGB axis.

PURPOSE

This review was aimed to explore the intricate relationship between the GM and the brain, as well as host responses, and investigated the mechanisms underlying the MGB axis in MDD development. It also explored the pharmacological mechanisms by which NPs modulate MGB axis to exert antidepressant effects and addressed current research limitations. Additionally, it proposed new strategies for future preclinical and clinical applications in the MDD domain.

METHODS

To study the effects and mechanism by which NPs exert antidepressant effects through mediating the MGB axis, data were collected from Web of Science, PubMed, ScienceDirect from initial establishment to March 2024. NPs were classified and summarized by their mechanisms of action.

RESULTS

NPs, such as flavonoids,alkaloids,polysaccharides,saponins, terpenoids, can treat MDD by regulating the MGB axis. Its mechanism includes balancing GM, regulating metabolites and neurotransmitters such as SCAFs, 5-HT, BDNF, inhibiting neuroinflammation, improving neural plasticity, and increasing neurogenesis.

CONCLUSIONS

NPs display good antidepressant effects, and have potential value for clinical application in the prevention and treatment of MDD by regulating the MGB axis. However, in-depth study of the mechanisms by which antidepressant medications affect MGB axis will also require considerable effort in clinical and preclinical research, which is essential for the development of effective antidepressant treatments.

Impact of Altered Gut Microbiota on Ketamine-Induced Conditioned Place Preference in Mice

Objects

Ketamine is a drug of abuse worldwide and current treatments for ketamine abuse are inadequate. It is an urgent need to develop novel anti-addictive strategy. Since gut microbiota plays a crucial role in drug abuse, the present study investigates the impact and mechanisms of the gut microbiota in addictive behaviors induced by ketamine addiction.

Methods

Conditioned place preference (CPP) was employed to assess addiction, followed by 16S rRNA gene sequencing to elucidate alterations in the gut microbiota. Furthermore, qRT-PCR, ELISA, and immunohistochemistry were conducted to evaluate the expression levels of crucial genes and proteins associated with the gut-brain axis. Additionally, we investigated whether ketamine addiction is regulated through the gut microbiota by orally administering antibiotics to establish pseudo-germ-free mice.

Results

We found that repeated ketamine administration (20 mg/kg) induced CPP and significantly altered gut microbiota diversity and composition, as revealed by 16S rRNA gene sequencing. Compared to the control group, ketamine exposure exhibited differences in the relative abundance of 5 microbial families, with 4 (Lachnospiraceae, Ruminococcaceae, Desulfovibrionaceae and Family-XIII) showing increases, while one (Prevotellaceae) displayed a decrease. At the genus level, five genera were upregulated, while one was downregulated. Furthermore, COG analysis revealed significant differences in protein functionality between the two groups. Additionally, axis series studies showed that ketamine dependence reduced levels of tight junction proteins, GABA and GABRA1, while increasing BDNF and 5-HT. Moreover, an oral antibiotic cocktail simulating pseudo germ-free conditions in mice did not enhance the addictive behavior induced by ketamine.

Conclusion

Our study supports the hypothesis that ketamine-induced CPP is mediated through the gut microbiota. The present study provides new insights into improvement of efficient strategy for addiction treatment.

A Dual Emission Fluorescence Probe Based on Silicon Nanoparticles and Rhodamine B for Ratiometric Detection of Kaempferol

In this paper, blue fluorescent silicon nanoparticles (SiNPs) with outstanding optical properties and robust stability were synthesized by a simple one-step hydrothermal method. By introducing red emissive rhodamine B (RhB) into SiNPs solution, a dual emission nanoprobe (SiNPs@RhB) was constructed, which showed excellent pH stability, salt resistance and photobleaching resistance. The SiNPs@RhB probe could emit two peaks at 444 nm and 583 nm under 365 nm excitation. It was found that the fluorescence intensity of the two emission peaks decreased in different degrees with the addition of different concentrations of kaempferol (Kae). According to this phenomenon, a novel ratiometric fluorescence method was established for the detection of Kae via utilizing SiNPs@RhB as nanoprobe. The detection range and limit of detection (LOD) were 0.5 ~ 150 µM and 0.24 µM, respectively. The ratiometric fluorescence method exhibited the superiority of rapid detection, excellent stability, wide linear range and high sensitivity. The detection mechanism was studied by ultraviolet visible absorption spectra, fluorescence spectra and fluorescence lifetime. Furthermore, the method was applied to the detection of Kae in real samples (kaempferia powder, sea buckthorn granules and sea buckthorn dry emulsion).

Effects of Sea-Buckthorn Flavonoids on Growth Performance, Serum Inflammation, Intestinal Barrier and Microbiota in LPS-Challenged Broilers

The experiment investigated the effects of sea-buckthorn flavonoids (SF) on lipopolysaccharide (LPS)-challenged broilers. A total of 288 one-day-old male broilers were randomly assigned to 4 groups, with 6 replicates of 12 broilers each. The experiment lasted for 20 days. The diet included two levels of SF (0 or 1000 mg/kg) and broilers intraperitoneally injected with 500 μg/kg LPS on 16, 18, and 20 days, or an equal amount of saline. LPS challenge decreased final body weight, average daily gain, and average daily feed intake, increased feed-to-gain ratio, and elevated serum IL-1β, IL-2, TNF-α, D-LA, and endotoxin levels. Moreover, it resulted in a reduction in the IL-10 level. LPS impaired the intestinal morphology of the duodenum, jejunum, and ileum, down-regulated the mRNA relative expression of Occludin, ZO-1, and MUC-2 in the jejunum mucosa, up-regulated the mRNA relative expression of TLR4, MyD88, NF-κB, and IL-1β, and increased the relative abundance of Erysipelatoclostridium in broilers (p < 0.05). However, SF supplementation mitigated the decrease in growth performance, reduced serum IL-1β, IL-2, and D-LA levels, increased IL-10 levels, alleviated intestinal morphological damage, up-regulated mRNA expression of Occludin and ZO-1, down-regulated the mRNA expression of TLR4, NF-κB, and IL-lβ in jejunum mucosal (p < 0.05), and SF supplementation presented a tendency to decrease the relative abundance of proteobacteria (0.05 < p < 0.1). Collectively, incorporating SF can enhance the growth performance, alleviate serum inflammation, and improve the intestinal health of broilers, effectively mitigating the damage triggered by LPS-challenges.

Influence of microorganisms on flavor substances and functional components of sojae semen praeparatum during fermentation: A study integrating comparative metabolomics and high-throughput sequencing

Sojae semen praeparatum (SSP), a fermented product known for its distinctive flavor and medicinal properties, undergoes a complex fermentation process due to the action of various microorganisms. Despite its widespread use, the effect of these microorganisms on the flavor compounds and functional components of SSP remains poorly understood. This study aimed to shed light on this aspect by identifying 20 metabolites as potential key flavor substances in SSP. Moreover, glycine and lysine were identified as crucial flavor substances. Additionally, 24 metabolites were identified as key functional components. The dominant microorganisms involved in the fermentation process were examined, revealing six genera of fungi and 12 genera of bacteria. At the species level, 16 microorganisms were identified as dominant through metagenome sequencing. Spearman correlation analysis demonstrated a strong association between dominant microorganisms and both flavor substances and functional components. Furthermore, the study validated the significance of four core functional microorganisms in improving the flavor and quality of SSP. This comprehensive exploration of functional microorganisms of SSP on key flavor substances/functional components during SSP fermentation. The study findings serve as a valuable reference for enhancing the overall flavor and quality of SSP.

Exploration of the mechanism of Traditional Chinese Medicine for anxiety and depression in patients with diarrheal irritable bowel syndrome based on network pharmacology and meta-analysis

Background

The efficacy of Chinese herbal medicine (CHM) in managing irritable bowel syndrome with diarrhea (IBS-D) accompanied by anxiety and depression remains uncertain. Thus, a systematic review was carried out employing meta-analysis and network pharmacology to ascertain the efficacy and underlying mechanisms of CHM therapy.

Methods

By conducting a systematic review, including literature search, screening, and data extraction, we identified 25 randomized controlled trials to assess CHM's effectiveness in treating irritable bowel syndrome alongside anxiety and depression. Network pharmacology was utilized to scrutinize the metabolite utility of CHM in addressing this condition. Potential primary mechanisms were synthesized using information sourced from the PubMed database.

Results

Twenty-five studies, including 2055 patients, were analyzed, revealing significant treatment efficacy for IBS-D in the trial group compared to controls [OR = 4.01, 95% CI (2.99, 5.36), I2 = 0%] Additionally, treatment for depression [SMD = -1.08, 95% CI (-1.30, -0.86), p < 0.00001, I2 = 68%; SDS: SMD = -1.69, 95% CI (-2.48, -0.90), p < 0.0001, I2 = 96%] and anxiety [HAMA: SMD = -1.29, 95% CI (-1.68, -0.91), p < 0.00001, I2 = 89%; SAS: SMD = -1.75, 95% CI (-2.55, -0.95), p < 0.00001, I2 = 96%] significantly improved in the trial group. Furthermore, the trial group exhibited a significantly lower disease relapse rate [OR = 0.30, 95% CI (0.20, 0.44), p < 0.00001, I2 = 0%]. CHM treatment consistently improved IBS severity (IBS-SSS) and symptom scores. Network pharmacology analysis identified key chemical metabolites in traditional Chinese medicine formulations, including Beta-sitosterol, Stigmasterol, Quercetin, Naringenin, Luteolin, Kaempferol, Nobiletin, Wogonin, Formononetin, and Isorhamnetin. Utilizing the STRING database and Cytoscape v3.9.0 software, a protein-protein interaction (PPI) network revealed the top eight key targets: IL-6, TNF, PPARG, PTGS2, ESR1, NOS3, MAPK8, and AKT1, implicated in anti-inflammatory responses, antioxidant stress modulation, and neurotransmitter homeostasis maintenance.

Conclusion

Chinese Herbal Medicine (CHM) offers a promising and safe treatment approach for patients dealing with Diarrheal Irritable Bowel Syndrome (IBS-D) accompanied by anxiety and depression; thus, indicating its potential for practical implementation. The most active metabolites of CHM could simultaneously act on the pathological targets of IBS-D, anxiety, and depression.The diverse scope of CHM's therapeutic role includes various aspects and objectives, underscoring its potential for broad utilization.

Dietary (Poly)phenols and the Gut-Brain Axis in Ageing

As the population ages, the incidence of age-related neurodegenerative diseases is rapidly increasing, and novel approaches to mitigate this soaring prevalence are sorely needed. Recent studies have highlighted the importance of gut microbial homeostasis and its impact on brain functions, commonly referred to as the gut-brain axis, in maintaining overall health and wellbeing. Nonetheless, the mechanisms by which this system acts remains poorly defined. In this review, we will explore how (poly)phenols, a class of natural compounds found in many plant-based foods and beverages, can modulate the gut-brain axis, and thereby promote neural health. While evidence indicates a beneficial role of (poly)phenol consumption as part of a balanced diet, human studies are scarce and mechanistic insight is still lacking. In this regard, we make the case that dietary (poly)phenols should be further explored to establish their therapeutic efficacy on brain health through modulation of the gut-brain axis, with much greater emphasis on carefully designed human interventions.

Microbiome-based precision nutrition: Prebiotics, probiotics and postbiotics

Microorganisms have been used in nutrition and medicine for thousands of years worldwide, long before humanity knew of their existence. It is now known that the gut microbiota plays a key role in regulating inflammatory, metabolic, immune and neurobiological processes. This text discusses the importance of microbiota-based precision nutrition in gut permeability, as well as the main advances and current limitations of traditional probiotics, new-generation probiotics, psychobiotic probiotics with an effect on emotional health, probiotic foods, prebiotics, and postbiotics such as short-chain fatty acids, neurotransmitters and vitamins. The aim is to provide a theoretical context built on current scientific evidence for the practical application of microbiota-based precision nutrition in specific health fields and in improving health, quality of life and physiological performance.

Polyherbal and Multimodal Treatments: Kaempferol- and Quercetin-Rich Herbs Alleviate Symptoms of Alzheimer's Disease

Alzheimer's Disease (AD) is a progressive neurodegenerative disorder impairing cognition and memory in the elderly. This disorder has a complex etiology, including senile plaque and neurofibrillary tangle formation, neuroinflammation, oxidative stress, and damaged neuroplasticity. Current treatment options are limited, so alternative treatments such as herbal medicine could suppress symptoms while slowing cognitive decline. We followed PRISMA guidelines to identify potential herbal treatments, their associated medicinal phytochemicals, and the potential mechanisms of these treatments. Common herbs, including Ginkgo biloba, Camellia sinensis, Glycyrrhiza uralensis, Cyperus rotundus, and Buplerum falcatum, produced promising pre-clinical results. These herbs are rich in kaempferol and quercetin, flavonoids with a polyphenolic structure that facilitate multiple mechanisms of action. These mechanisms include the inhibition of Aβ plaque formation, a reduction in tau hyperphosphorylation, the suppression of oxidative stress, and the modulation of BDNF and PI3K/AKT pathways. Using pre-clinical findings from quercetin research and the comparatively limited data on kaempferol, we proposed that kaempferol ameliorates the neuroinflammatory state, maintains proper cellular function, and restores pro-neuroplastic signaling. In this review, we discuss the anti-AD mechanisms of quercetin and kaempferol and their limitations, and we suggest a potential alternative treatment for AD. Our findings lead us to conclude that a polyherbal kaempferol- and quercetin-rich cocktail could treat AD-related brain damage.

Bioactive Components in Fruit Interact with Gut Microbes

Fruits contain many bioactive compounds, including polysaccharides, oligosaccharides, polyphenols, anthocyanins, and flavonoids. All of these bioactives in fruit have potentially beneficial effects on gut microbiota and host health. On the one hand, fruit rich in active ingredients can act as substrates to interact with microorganisms and produce metabolites to regulate the gut microbiota. On the other hand, gut microbes could promote health effects in the host by balancing dysbiosis of gut microbiota. We have extensively analyzed significant information on bioactive components in fruits based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Although the deep mechanism of action of bioactive components in fruits on gut microbiota needs further study, these results also provide supportive information on fruits as a source of dietary active ingredients to provide support for the adjunctive role of fruits in disease prevention and treatment.