Lactobacillus plantarum ST-III culture supernatant ameliorates alcohol-induced cognitive dysfunction by reducing endoplasmic reticulum stress and oxidative stress

The impact of gut microbiota on the occurrence, treatment, and prognosis of ischemic stroke

Ischemic stroke (IS) is a cerebrovascular disease that predominantly affects middle-aged and elderly populations, exhibiting high mortality and disability rates. At present, the incidence of IS is increasing annually, with a notable trend towards younger affected individuals. Recent discoveries concerning the "gut-brain axis" have established a connection between the gut and the brain. Numerous studies have revealed that intestinal microbes play a crucial role in the onset, progression, and outcomes of IS. They are involved in the entire pathophysiological process of IS through mechanisms such as chronic inflammation, neural regulation, and metabolic processes. Although numerous studies have explored the relationship between IS and intestinal microbiota, comprehensive analyses of specific microbiota is relatively scarce. Therefore, this paper provides an overview of the typical changes in gut microbiota following IS and investigates the role of specific microorganisms in this context. Additionally, it presents a comprehensive analysis of post-stroke microbiological therapy and the relationship between IS and diet. The aim is to identify potential microbial targets for therapeutic intervention, as well as to highlight the benefits of microbiological therapies and the significance of dietary management. Overall, this paper seeks to provide key strategies for the treatment and management of IS, advocating for healthy diets and health programs for individuals. Meanwhile, it may offer a new perspective on the future interdisciplinary development of neurology, microbiology and nutrition.

ISRIB ameliorates spatial learning and memory impairment induced by adolescent intermittent ethanol exposure in adult male rats

Alcohol exposure in adolescence is considered a major cause of cognitive impairments later in life including spatial learning and memory. Integrated stress response (ISR), a program of conservative translation and transcription, is crucial in synaptic plasticity and memory. Although previous studies have elucidated ISR in different brain areas involved in learning and memory disorders, the impact of ISR on learning and memory following adolescent alcohol exposure remains unclear. Here, we demonstrated that adolescent intermittent ethanol (AIE) exposure caused spatial learning and memory impairment, combined with neuronal damage in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc) and hippocampus (HIP) in adult rats. Moreover, integrated stress response inhibitor (ISRIB) administration not only improved spatial learning and memory impairment and neuronal damage but also inhibited the endoplasmic reticulum stress (ER) and reversed changes in synaptic proteins. These findings suggested that ISRIB ameliorates AIE exposure-induced spatial learning and memory deficits by improving neural morphology and synaptic function through inhibiting ER stress signaling pathway in the mPFC, NAc and HIP in adulthood. Our findings may enhance comprehension of cognitive function and neuronal effects of adolescent ethanol exposure and ISRIB treatment may be an underlying potential option for addressing alcohol-induced learning and memory deficits.

Lactobacilli Cell-Free Supernatants Modulate Inflammation and Oxidative Stress in Human Microglia via NRF2-SOD1 Signaling

Microglia are macrophage cells residing in the brain, where they exert a key role in neuronal protection. Through the gut-brain axis, metabolites produced by gut commensal microbes can influence brain functions, including microglial activity. The nuclear factor erythroid 2-related factor 2 (NRF2) is a key regulator of the oxidative stress response in microglia, controlling the expression of cytoprotective genes. Lactobacilli-derived cell-free supernatants (CFSs) are postbiotics that have shown antioxidant and immunomodulatory effects in several in vitro and in vivo studies. This study aimed to explore the effects of lactobacilli CFSs on modulating microglial responses against oxidative stress and inflammation. HMC3 microglia were exposed to lipopolysaccaride (LPS), as an inflammatory trigger, before and after administration of CFSs from three human gut probiotic species. The NRF2 nuclear protein activation and the expression of NRF2-controlled antioxidant genes were investigated by immunoassay and quantitative RT-PCR, respectively. Furthermore, the level of pro- and anti-inflammatory cytokines was evaluated by immunoassay. All CFSs induced a significant increase of NRF2 nuclear activity in basal conditions and upon inflammation. The transcription of antioxidant genes, namely heme oxygenase 1, superoxide dismutase (SOD), glutathione-S transferase, glutathione peroxidase, and catalase also increased, especially after inflammatory stimulus. Besides, higher SOD1 activity was detected relative to inflamed microglia. In addition, CFSs pre-treatment of microglia attenuated pro-inflammatory TNF-α levels while increasing anti-inflammatory IL-10 levels. These findings confirmed that gut microorganisms' metabolites can play a relevant role in adjuvating the microglia cellular response against neuroinflammation and oxidative stress, which are known to cause neurodegenerative diseases.

The effects of heavy metal exposure on brain and gut microbiota: A systematic review of animal studies

The gut-brain axis is a crucial interface between the central nervous system and the gut microbiota. Recent evidence shows that exposure to environmental contaminants, such as heavy metals, can cause dysbiosis in gut microbiota, which may affect the gut-brain communication, impacting aspects of brain function and behavior. This systematic review of the literature aims to evaluate whether deleterious effects on brain function due to heavy metal exposure could be mediated by changes in the gut microbiota profile. Animal studies involving exposure to heavy metals and a comparison with a control group that evaluated neuropsychological outcomes and/or molecular outcomes along with the analysis of microbiota composition were reviewed. The authors independently assessed studies for inclusion, extracted data and assessed risk of bias using the protocol of Systematic Review Center for Laboratory Animal Experimentation (SYRCLE) for preclinical studies. A search in 3 databases yielded 16 eligible studies focused on lead (n = 10), cadmium (n = 1), mercury (n = 3), manganese (n = 1), and combined exposure of lead and manganese (n = 1). The animal species were rats (n = 7), mice (n = 4), zebrafish (n = 3), carp (n = 1) and fruit fly (n = 1). Heavy metals were found to adversely affect cognitive function, behavior, and neuronal morphology. Moreover, heavy metal exposure was associated with changes in the abundance of specific bacterial phyla, such as Firmicutes and Proteobacteria, which play crucial roles in gut health. In some studies, these alterations were correlated with learning and memory impairments and mood disorders. The interplay of heavy metals, gut microbiota, and brain suggests that heavy metals can induce direct brain alterations and indirect effects through the microbiota, contributing to neurotoxicity and the development of neuropsychological disorders. However, the small number of papers under review makes it difficult to draw definitive conclusions. Further research is warranted to unravel the underlying mechanisms and evaluate the translational implications for human health.

Mechanism Explanation on Improved Cognitive Ability of D-Gal Inducing Aged Mice Model by Lactiplantibacillus plantarum MWFLp-182 via the Microbiota-Gut-Brain Axis

Gut microbiota can influence cognitive ability via the gut-brain axis. Lactiplantibacillus plantarum MWFLp-182 (L. plantarum MWFLp-182) was obtained from feces of long-living individuals and could exert marked antioxidant ability. Interestingly, this strain reduced the D-galactose-induced impaired cognitive ability in BALB/c mice. To comprehensively elucidate the underlying mechanism, we evaluated the colonization, antioxidant, and anti-inflammatory activities of L. plantarum MWFLp-182, along with the expression of potential genes associated with cognitive ability influenced and gut microbiota. L. plantarum MWFLp-182 enhanced the expression of anti-inflammatory cytokines, reduced the expression of proinflammatory cytokines, and increased tight junction protein expression in the colon. Moreover, L. plantarum MWFLp-182 could modify the gut microbiota. Notably, treatment with L. plantarum MWFLp-182 upregulated the expression of postsynaptic density protein-95, nuclear factor erythroid 2-related factor, nerve growth factor, superoxide dismutase, and brain-derived neurotrophic factor/neuronal nuclei, while downregulating the expression of bcl-2-associated X and malondialdehyde in the hippocampus and upregulating short-chain fatty acids against D-galactose-induced mouse brain deficits. Accordingly, L. plantarum MWFLp-182 could improve cognitive ability in a D-galactose-inducing mouse model.

Apoptosis Due to After-effects of Acute Ethanol Exposure in Brain Cortex: Intrinsic and Extrinsic Signaling Pathways

Alcohol hangover is the combination of negative mental and physical symptoms which can be experienced after a single episode of alcohol consumption, starting when blood alcohol concentration approaches zero. We previously demonstrated that hangover provokes mitochondrial dysfunction, oxidative stress, imbalance in antioxidant defenses, and impairment in cellular bioenergetics. Chronic and acute ethanol intake induces neuroapoptosis but there are no studies which evaluated apoptosis at alcohol hangover. The aim of the present work was to study alcohol residual effects on intrinsic and extrinsic apoptotic signaling pathways in mice brain cortex. Male Swiss mice received i.p. injection of ethanol (3.8 g/kg) or saline. Six hours after injection, at alcohol hangover onset, mitochondria and tissue lysates were obtained from brain cortex. Results indicated that during alcohol hangover a loss of granularity of mitochondria and a strong increment in mitochondrial permeability were observed, indicating the occurrence of swelling. Alcohol-treated mice showed a significant 35% increase in Bax/Bcl-2 ratio and a 5-fold increase in the ratio level of cytochrome c between mitochondria and cytosol. Caspase 3, 8 and 9 protein expressions were 32%, 33% and 20% respectively enhanced and the activity of caspase 3 and 6 was 30% and 20% increased also due to the hangover condition. Moreover, 38% and 32% increments were found in PARP1 and p53 protein expression respectively and on the contrary, SIRT-1 was almost 50% lower than controls due to the hangover condition. The present work demonstrates that alcohol after-effects could result in the activation of mitochondrial and non-mitochondrial apoptosis pathways.

Modulation of gut microbiota with probiotics as a strategy to counteract endogenous and exogenous neurotoxicity

The existing data demonstrate that probiotic supplementation affords protective effects against neurotoxicity of exogenous (e.g., metals, ethanol, propionic acid, aflatoxin B1, organic pollutants) and endogenous (e.g., LPS, glucose, Aβ, phospho-tau, α-synuclein) agents. Although the protective mechanisms of probiotic treatments differ between various neurotoxic agents, several key mechanisms at both the intestinal and brain levels seem inherent to all of them. Specifically, probiotic-induced improvement in gut microbiota diversity and taxonomic characteristics results in modulation of gut-derived metabolite production with increased secretion of SFCA. Moreover, modulation of gut microbiota results in inhibition of intestinal absorption of neurotoxic agents and their deposition in brain. Probiotics also maintain gut wall integrity and inhibit intestinal inflammation, thus reducing systemic levels of LPS. Centrally, probiotics ameliorate neurotoxin-induced neuroinflammation by decreasing LPS-induced TLR4/MyD88/NF-κB signaling and prevention of microglia activation. Neuroprotective mechanisms of probiotics also include inhibition of apoptosis and oxidative stress, at least partially by up-regulation of SIRT1 signaling. Moreover, probiotics reduce inhibitory effect of neurotoxic agents on BDNF expression, on neurogenesis, and on synaptic function. They can also reverse altered neurotransmitter metabolism and exert an antiamyloidogenic effect. The latter may be due to up-regulation of ADAM10 activity and down-regulation of presenilin 1 expression. Therefore, in view of the multiple mechanisms invoked for the neuroprotective effect of probiotics, as well as their high tolerance and safety, the use of probiotics should be considered as a therapeutic strategy for ameliorating adverse brain effects of various endogenous and exogenous agents.

Lactiplantibacillus (Lactobacillus) plantarum as a Complementary Treatment to Improve Symptomatology in Neurodegenerative Disease: A Systematic Review of Open Access Literature

This systematic review addresses the use of Lactiplantibacillus (Lactobacillus) plantarum in the symptomatological intervention of neurodegenerative disease. The existence of gut microbiota dysbiosis has been associated with systemic inflammatory processes present in neurodegenerative disease, creating the opportunity for new treatment strategies. This involves modifying the strains that constitute the gut microbiota to enhance synaptic function through the gut-brain axis. Recent studies have evaluated the beneficial effects of the use of Lactiplantibacillus plantarum on motor and cognitive symptomatology, alone or in combination. This systematic review includes 20 research articles (n = 3 in human and n = 17 in animal models). The main result of this research was that the use of Lactiplantibacillus plantarum alone or in combination produced improvements in symptomatology related to neurodegenerative disease. However, one of the studies included reported negative effects after the administration of Lactiplantibacillus plantarum. This systematic review provides current and relevant information about the use of this probiotic in pathologies that present neurodegenerative processes such as Alzheimer's disease, Parkinson's disease and Multiple Sclerosis.

The association between neuropsychiatric effects of substance use and occurrence of endoplasmic reticulum and unfolded protein response: A systematic review

INTRODUCTION

This systematic review aimed to assess the association between neuropsychiatric effects of substance use and occurrence of ER stress and unfolded protein response (UPR) through comprehensive electronic search of existing literature and review of their findings.

METHODS

A comprehensive electronic literature search was carried out on research articles published between 1950 to July 2023 through major databases, such as Scopus, Web of Science, Google Scholar, PubMed, PsycINFO, EMBASE, Medline and Cochrane Library.

RESULTS

A total of 21 research articles were selected for review, which were comprised of sixteen animal studies, four human studies and one study on postmortem human brain samples. The selected studies revealed that alcohol, methamphetamine, cocaine, opioid and kratom exposures contributed to neuropsychiatric effects: such as decline in learning and memory function, executive dysfunction, alcohol, methamphetamine, opioid, and kratom dependence. These effects were associated with activation and persistent of ER stress and UPR with elevation of BiP and CHOP expression and the direction of ER stress is progressing towards the PERK-eIF2α-ATF4-CHOP pathway and neuronal apoptosis and neurodegeneration at various regions of the brain. In addition, regular kratom use in humans also contributed to elevation of p-JNK expression, denoting progress of ER stress towards the IRE1-ASK1-JNK-p-JNK pathway which was linked to kratom use disorder. However, treatment with certain compounds or biological agents could reverse the activation of ER stress.

CONCLUSIONS

The neuropsychiatric effects of alcohol, methamphetamine, cocaine, opioid and kratom use may be associated with persistent ER stress and UPR.

Lactobacillus plantarum ST-III culture supernatant protects against acute alcohol-induced liver and intestinal injury

The beneficial effects of probiotics have been studied in inflammatory bowel disease, nonalcoholic steatohepatitis, and alcoholic liver disease (ALD). Probiotic supplements are safer and more effective; however, their potential mechanisms are unclear. An objective of the current study was to examine the effects of extracellular products of Lactobacillus plantarum on acute alcoholic liver injury. Mice on a standard chow diet were supplemented with Lactobacillus plantarum ST-III culture supernatant (LP-cs) for two weeks and administered alcohol at 6 g/kg body weight by gavage. Alcohol-induced liver injury was assessed by measuring plasma alanine aminotransferase activity levels and triglyceride content determined liver steatosis. Intestinal damage and tight junctions were assessed using histochemical staining. LP-cs significantly inhibited alcohol-induced fat accumulation, inflammation, and apoptosis by inhibiting oxidative stress and endoplasmic reticulum stress. LP-cs significantly inhibited alcohol-induced intestinal injury and endotoxemia. These findings suggest that LP-cs alleviates acute alcohol-induced liver damage by inhibiting oxidative stress and endoplasmic reticulum stress via one mechanism and suppressing alcohol-induced increased intestinal permeability and endotoxemia via another mechanism. LP-cs supplements are a novel strategy for ALD prevention and treatment.

Alcohol degradation, learning, and memory-enhancing effect of Acetobacter pasteurianus BP2201 in Caenorhabditis elegans model

AIMS

This study aimed to investigate the probiotic effects of Acetobacter pasteurianus BP2201, isolated from brewing mass, for the treatment of alcohol-induced learning and memory ability impairments in a Caenorhabditis elegans model.

METHODS AND RESULTS

Acetobacter pasteurianus BP2201 was examined for probiotic properties, including acid and bile salt resistance, ethanol degradation, antioxidant efficacy, hemolytic activity, and susceptibility to antibiotics. The strain displayed robust acid and bile salt tolerance, efficient ethanol degradation, potent antioxidant activity, and susceptibility to specific antibiotics. Additionally, in the C. elegans model, administering A. pasteurianus BP2201 significantly improved alcohol-induced learning and memory impairments.

CONCLUSIONS

Acetobacter pasteurianus BP2201 proves to be a promising candidate strain for the treatment of learning and memory impairments induced by alcohol intake.

Long-term LDR exposure may induce cognitive impairments: A possible association through targeting gut microbiota-gut-brain axis

Environmental and occupational low-dose radiation (LDR) exposure may be harmful for health but the previous reports regarding effect of LDR on cognition are contradictory. Here we investigated the effect of long-term LDR exposure on cognition. In this study, male Balb/c mice' cognitive functions were tested at 15 weeks after being exposed to 0.5 Gy LDR in 10 fractions at each dose of 0.05 Gy. The results demonstrated that long-term LDR exposure increases escape latency and the time spent in finding exits in mice compared with non LDR exposure. Meanwhile, the inflammation-related proteins including NFκB and p38 also increased. Lipopolysaccharide (LPS) increased and short-chain fatty acid (SCFA) levels decreased following long term LDR exposure. Treatment with microbiota-derived LPS and SCFAs reversed these effects in mice. Furthermore, the gut barrier integrity was damaged in a time-dependent manner with the decreased expression of intestinal epithelial-related biomarkers such as ZO-1 and occludin. Mechanistically, long after exposure to LDR, increased LPS levels may cause cognitive impairment through the regulation of Akt/mTOR signaling in the mouse hippocampus. These findings provide new insight into the clinical applications of LDR and suggest that the gut microbiota-plasma LPS and SCFAs-brain axis may underlie long-term LDR-induced cognition effects.