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

Functional Outcome Prediction of Acute Ischemic Stroke Based on the Oral and Gut Microbiota

Although several studies have identified a distinct gut microbiota in individuals with acute ischemic stroke (AIS), there is a limited amount of research that has simultaneously investigated alterations in the oral and intestinal microbiota in AIS patients and their correlation with clinical prognosis. This was a prospective and observational single-center cohort study in which we included 160 AIS patients who were admitted within 24 h after a stroke event. We collected oral and rectal swab samples for analysis using 16S rRNA high-throughput sequencing. Our study revealed that patients with unfavorable outcomes after AIS showed early disruptions in their oral and intestinal microbiota. Rectal swabs showed increased levels of facultatively anaerobic bacteria in patients with a poor prognosis, while the oral cavity exhibited higher levels of anaerobic and opportunistic pathogenic bacteria. By employing machine learning analysis, we found that the microbiota composition at both rectal and oral sites could predict early and long-term outcomes. Moreover, patients with a poor prognosis displayed increased oral bacterial colonization in the rectal microbiota and altered interactions between the oral and gut microbiota. This study reveals distinct rectal and oral bacteria that could predict unfavorable outcomes for AIS patients. Monitoring the microbiota of various body sites during the early stages after admission may hold prognostic value and inform personalized treatment strategies. The presence of oral bacteria colonizing the intestines during the acute phase of stroke could serve as an early indication of poor outcomes for AIS patients.

Recent advances in therapeutic probiotics: insights from human trials

SUMMARYRecent advances in therapeutic probiotics have shown promising results across various health conditions, reflecting a growing understanding of the human microbiome's role in health and disease. However, comprehensive reviews integrating the diverse therapeutic effects of probiotics in human subjects have been limited. By analyzing randomized controlled trials (RCTs) and meta-analyses, this review provides a comprehensive overview of key developments in probiotic interventions targeting gut, liver, skin, vaginal, mental, and oral health. Emerging evidence supports the efficacy of specific probiotic strains and combinations in treating a wide range of disorders, from gastrointestinal (GI) and liver diseases to dermatological conditions, bacterial vaginosis, mental disorders, and oral diseases. We discuss the expanding understanding of microbiome-organ connections underlying probiotic mechanisms of action. While many clinical trials demonstrate significant benefits, we acknowledge areas requiring further large-scale studies to establish definitive efficacy and optimal treatment protocols. The review addresses challenges in standardizing probiotic research methodologies and emphasizes the importance of considering individual variations in microbiome composition and host genetics. Additionally, we explore emerging concepts such as the oral-gut-brain axis and future directions, including high-resolution microbiome profiling, host-microbe interaction studies, organoid models, and artificial intelligence applications in probiotic research. Overall, this review offers a comprehensive update on the current state of therapeutic probiotics across multiple domains of human health, providing insights into future directions and the potential for probiotics to revolutionize preventive and therapeutic medicine.

Exploring the acute and chronic effects of a multi-strain probiotic supplement on cognitive function and mood in healthy older adults: A randomised controlled trial

BACKGROUND

Ageing, is associated with a decline in cognitive function and vulnerability to depression. Probiotic supplements have shown beneficial effects on cognition and mood in clinical populations, but the potential benefit for healthy older adults experiencing age-related decline in cognition remains unclear.

OBJECTIVES

The primary aim of the present work was to explore the effect of a chronic (long-term) multi-species probiotic intervention on cognition in healthy ageing adults. Secondary aims included exploring the chronic effect on mood outcomes and gut microbiota community, as well as a novel investigation into the acute effect of supplementation on cognition and mood.

METHOD

The study employed a randomised, placebo-controlled, cross-over trial in 30 healthy older adults to explore the acute (1 day) and chronic (8 weeks) effects of a probiotic supplement on cognitive domains of memory and executive function, alongside mood measures of stress, anxiety, depression, and cognitive reactivity to sad mood. 16s rRNA sequencing of stool samples was also performed pre- and post- chronic intervention to assess potential effects on the gut microbiota.

RESULTS

Acute probiotic supplementation was associated with faster reaction times on cognitively demanding trials during a task of executive function [-64.91ms, CI -115.70, -14.15]. Chronic supplementation was associated with improvement in cognitive biases such as hopelessness [-0.97, CI -1.72, -0.23], rumination [-1.58, CI -2.86, -0.29] and aggression [-1.57, CI -2.63, -0.51] that contribute to reactivity to sad mood and therefore vulnerability to depression, and may improve executive function under higher cognitive demand [0.43%, CI -0.53%, 1.38%].

CONCLUSIONS

The current work provides novel evidence for an acute effect of probiotics on reaction times during executive function, which should be replicated in future work. Additionally, this work replicates previous findings of improved cognitive reactivity to sad mood following chronic probiotic supplementation, indicating probiotics may reduce the risk of developing depression in a healthy ageing population. This trial was registered at https://clinicaltrials.gov/study/NCT04951687.

Dynamic changes in the gut microbiota play a critical role in age-associated cognitive dysfunction via SCFAs and LPS synthesis metabolic pathways during brain aging

BACKGROUND

Gut microbiota plays an essential role in cognitive dysfunction during aging. The aim of this study was to investigate the dynamic alterations in the gut microbiota and screen for key gut bacterial taxa correlated with age-associated cognitive dysfunction during natural aging.

METHODS

16S rRNA gene sequencing was performed to determine the composition of the gut microbiota in faecal samples from SAMR1 and SAMP8 mice, cognitively normal controls (NC), and patients with amnestic mild cognitive impairment (aMCI). Faecal microbiota transplantation (FMT) and GMrepo database were used to screen key gut microbiota associated with cognitive decline in aging mice and humans.

RESULTS

The composition of the gut microbiota dynamically changed during natural aging in SAMR1 and SAMP8 mice, as well as in healthy subjects of different ages extracted from the GMrepo database. FMT from SAMR1 to SAMP8 mice altered the gut microbiota composition and improved the cognitive impairment in SAMP8 mice. Key gut bacterial taxa, including Lactobacillus, Akkermansia, Clostridium, Oscillospira and Dorea, were screened and validated to correlate with aging-associated cognitive decline. The function of the key gut bacterial taxa predicted by PICRUSt2 indicated that the metabolic pathways related to short-chain fatty acids (SCFAs) and lipopolysaccharide (LPS) synthesis were involved in age-associated cognitive dysfunction during natural aging.

CONCLUSION

These results demonstrate that the composition of the gut microbiota changes dynamically during brain aging, with some key gut bacterial taxa playing critical roles in age-associated cognitive dysfunction through SCFAs and LPS synthesis metabolic pathways.

Draft genome sequences of eight strains isolated from homemade yogurts and cheeses from Bulgaria

Here, we report draft genome sequences of eight strains isolated from naturally processed, homemade dairy foods or human milk in Bulgaria; strains Lactobacillus gasseri AM-LG-29, Lactiplantibacillus plantarum AM-LP-81, Lactobacillus helveticus AM-LH-32, Lactobacillus delbrueckii subsp. bulgaricus AM-LB-13, Streptococcus thermophilus AM-ST-89, Lactobacillus acidophilus AM-LA-19, Bifidobacterium longum AM-BL-55, and Lacticaseibacillus rhamnosus AM-LR-51.

Drinking pattern and sex modulate the impact of ethanol consumption on the mouse gut microbiome

Gut microbiota impacts host homeostasis and diseases. Chronic plus binge ethanol consumption has been linked to increased injuries than chronic or binge ethanol intake alone. We hypothesized that distinct shapes in gut microbiota composition are induced by chronic, binge, and the association of these treatments, thereby affecting host functions and contributing to sex-based differences in alcohol use disorders. Male and female C57BL/6J mice were submitted to chronic, binge, or chronic plus binge ethanol feeding. DNA was extracted from fecal microbiota, followed by analysis of the V3-V4 region of the 16S rRNA gene and sequencing on an Illumina platform. Gut microbiome analysis was performed using QIIME v2022.2.0. Functional profiling of the gut microbiome was performed using PICRUSt2. Ethanol differentially affected the gut microbiota of female and male mice. Decreased α diversity was observed in male and female mice from the chronic plus binge and chronic groups, respectively. The genera Faecalibaculum, Lachnospiraceae, and Alistipes were identified as major potential biomarkers for gut dysbiosis induced by ethanol consumption. In addition, ethanol-induced gut dysbiosis altered several metabolic pathways. Ethanol consumption modifies the mouse gut microbiome in a drinking pattern- and sex-dependent manner, potentially leading to different susceptibility to ethanol-related diseases. Chronic plus binge ethanol intake induces a more pronounced gut dysbiosis in male mice. Conversely, chronic ethanol is linked to a greater degree of gut dysbiosis in female mice. The changed gut microbiome may be potentially targeted to prevent, mitigate, or treat alcohol use disorders.NEW & NOTEWORTHY Ethanol alters the mouse gut microbiome in a drinking pattern- and sex-dependent manner. Chronic plus binge ethanol intake induces a more severe gut dysbiosis in male mice, whereas chronic ethanol consumption appears to be a more potent inductor of gut dysbiosis in female mice. Ethanol-induced gut dysbiosis alters several pathways linked to metabolism, genetic and environmental information processing, cellular processes, organism systems, and neurological human diseases.

Achieving healthy aging through gut microbiota-directed dietary intervention: Focusing on microbial biomarkers and host mechanisms

BACKGROUND

Population aging has become a primary global public health issue, and the prevention of age-associated diseases and prolonging healthy life expectancies are of particular importance. Gut microbiota has emerged as a novel target in various host physiological disorders including aging. Comprehensive understanding on changes of gut microbiota during aging, in particular gut microbiota characteristics of centenarians, can provide us possibility to achieving healthy aging or intervene pathological aging through gut microbiota-directed strategies.

AIM OF REVIEW

This review aims to summarize the characteristics of the gut microbiota associated with aging, explore potential biomarkers of aging and address microbiota-associated mechanisms of host aging focusing on intestinal barrier and immune status. By summarizing the existing effective dietary strategies in aging interventions, the probability of developing a diet targeting the gut microbiota in future is provided.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review is focused on three key notions: Firstly, gut microbiota has become a new target for regulating health status and lifespan, and its changes are closely related to age. Thus, we summarized aging-associated gut microbiota features at the levels of key genus/species and important metabolites through comparing the microbiota differences among centenarians, elderly people and younger people. Secondly, exploring microbiota biomarkers related to aging and discussing future possibility using dietary regime/components targeted to aging-related microbiota biomarkers promote human healthy lifespan. Thirdly, dietary intervention can effectively improve the imbalance of gut microbiota related to aging, such as probiotics, prebiotics, and postbiotics, but their effects vary among.

Bifidobacterium infantis and Bifidobacterium breve Improve Symptomatology and Neuronal Damage in Neurodegenerative Disease: A Systematic Review

Background/Objectives: This systematic review focused on collecting the most significant findings on the impact of the administration of Bifidobacterium infantis (or Bifidobacterium longum subps. infantis) and Bifidobacterium breve, alone, in conjunction, or in combination with other strains, in the treatment of neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD). These diseases are characterized by the progressive degeneration of neurons, resulting in a broad spectrum of clinical manifestations. AD is typified by a progressive decline in cognitive abilities, while PD is marked by motor symptoms associated with the loss of dopamine (DA). Methods: Five different databases, ScienceDirect, Scopus, Wiley, PubMed, and Web of Science (WoS), were reviewed and the studies were screened for inclusion by the following criteria: (i) studies that specifically evaluated the use of Bifidobacterium infantis, Bifidobacterium longum subsp. infantis, or Bifidobacterium breve as a therapeutic intervention, either in human or animal models, in the context of neurodegenerative diseases; (ii) the studies were required to address one or more of the pathologies examined in this article, and the pathologies included, but were not limited to, neurodegeneration, Alzheimer's disease, Parkinson's disease, and oxidative stress; (iii) the full text was accessible online; and (iv) the article was written in English. Results: The data suggest that these probiotics have neuroprotective effects that may delay disease progression. Conclusions: This study provides updated insights into the use of these Bifidobacterium strains in neurodegenerative diseases like AD and PD, with the main limitation being the limited number of clinical trials available.

The interplay between gut microbiota composition and dementia

Recently, researchers have been interested in the potential connection between gut microbiota composition and various neuropsychological disorders. Dementia significantly affects the socioeconomics of families. Gut microbiota is considered as a probable factor in its pathogenesis. Multiple bacterial metabolites such as short-chain fatty acids, lipopolysaccharides, and various neurotransmitters that are responsible for the incidence and progression of dementia can be produced by gut microbiota. Various bacterial species such as Bifidobacterium breve, Akkermansia muciniphila, Streptococcus thermophilus, Escherichia coli, Blautia hydrogenotrophica, etc. are implicated in the pathogenesis of dementia. Gut microbiota can be a great target for imitating or inhibiting their metabolites as an adjunctive therapy based on their role in its pathogenesis. Therefore, some diets can prevent or decelerate dementia by altering the gut microbiota composition. Moreover, probiotics can modulate gut microbiota composition by increasing beneficial bacteria and reducing detrimental species. These therapeutic modalities are considered novel methods that are probably safe and effective. They can enhance the efficacy of traditional medications and improve cognitive function.

The gut core microbial species Bifidobacterium longum: Colonization, mechanisms, and health benefits

Bifidobacterium longum (B. longum) is a species of the core microbiome in the human gut, whose abundance is closely associated with host age and health status. B. longum has been shown to modulate host gut microecology and have the potential to alleviate various diseases. Comprehensive understanding on the colonization mechanism of B. longum and mechanism of the host-B. longum interactions, can provide us possibility to prevent and treat human diseases through B. longum-directed strategies. In this review, we summarized the gut colonization characteristics of B. longum, discussed the diet factors that have ability/potential to enrich indigenous and/or ingested B. longum strains, and reviewed the intervention mechanisms of B. longum in multiple diseases. The key findings are as follows: First, B. longum has specialized colonization mechanisms, like a wide carbohydrate utilization spectrum that allows it to adapt to the host's diet, species-level conserved genes encoding bile salt hydrolase (BSHs), and appropriate bacterial surface structures. Second, dietary intervention (e.g., anthocyanins) could effectively improve the gut colonization of B. longum, demonstrating the feasibility of diet-tuned strain colonization. Finally, we analyzed the skewed abundance of B. longum in different types of diseases and summarized the main mechanisms by which B. longum alleviates digestive (repairing the intestinal mucosal barrier by stimulating Paneth cell activity), immune (up-regulating the regulatory T cell (Treg) populations and maintaining the balance of Th1/Th2), and neurological diseases (regulating the kynurenine pathway and quinolinic acid levels in the brain through the gut-brain axis).

Probiotics as Potential Treatments for Neurodegenerative Diseases: a Review of the Evidence from in vivo to Clinical Trial

Neurodegenerative diseases (NDDs), characterized by the progressive deterioration of the structure and function of the nervous system, represent a significant global health challenge. Emerging research suggests that the gut microbiota plays a critical role in regulating neurodegeneration via modulation of the gut-brain axis. Probiotics, defined as live microorganisms that confer health benefits to the host, have garnered significant attention owing to their therapeutic potential in NDDs. This review examines the current research trends related to the microbiome-gut-brain axis across various NDDs, highlighting key findings and their implications. Additionally, the effects of specific probiotic strains, including Lactobacillus plantarum, Bifidobacterium breve, and Lactobacillus rhamnosus, on neurodegenerative processes were assessed, focusing on their potential therapeutic benefits. Overall, this review emphasizes the potential of probiotics as promising therapeutic agents for NDDs, underscoring the importance of further investigation into this emerging field.

Effects of non-pharmacological interventions on gut microbiota and intestinal permeability in older adults: A systematic review: Non-pharmacological interventions on gut microbiota/barrier

This systematic review appraised previous findings of non-pharmacological interventions on gut microbiota and/ or intestinal permeability in older adults. A literature search was performed using PubMed, Scopus, ScienceDirect and the Cochrane Library. Relevant studies were shortlisted based on the inclusion and exclusion criteria, and evaluated for risks of bias using the "Cochrane Collaboration's Risk of Bias 2" and the "NIH Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group". The primary outcomes were the effects of non-pharmacological interventions on gut microbiota diversity and composition, and intestinal permeability in older adults. Out of 85,114 studies, 38 were shortlisted. Generally, the non-pharmacological interventions were beneficial against dysbiosis and the leaky gut in older adults. Considering specific interventions with two or more studies that reported consistent outcomes, a pattern was observed amongst the Mediterranean diet (MD), polyphenol-rich (PR) diet and supplements (i.e., probiotics, prebiotics and synbiotics). As for the other interventions, the very few studies that have been conducted did not allow a strong conclusion to be made just yet. The MD (single and multidomain interventions) restored gut microbiota by increasing species richness (alpha diversity) and reduced intestinal permeability (zonulin) and inflammation (CRP). The PR diet only showed slight changes in the gut microbiota but improved the gut barrier by reducing zonulin, CRP and IL-6. Probiotics, prebiotics and synbiotics increased the genus Bifidobacterium spp. which are considered beneficial bacteria. This review has uncovered insights into the relationship between gut microbiota and intestinal epithelial barriers of specific non-pharmacological interventions in older adults.

Efficacy of Sophora japonica L. Pill in Subjective Memory Complaints in Healthy Adults: a protocol of randomized, double-blind, placebo-controlled, parallel-group, clinical trial

Objectives

Subjective memory complaints, increasingly common among older adults, may indicate early cognitive decline or dementia. Sophora japonica L., a herbal medicine in Korean medicine, has shown potential cognitive benefits in preclinical studies through neuroprotective and anti-inflammatory properties. Given limited efficacy of current pharmacological treatments for cognitive impairment and growing interest in natural products, investigating S. japonica extract in humans is warranted.

Methods

This randomized, double-blind, placebo-controlled trial will involve 100 participants aged 40-70 years with subjective memory complaints but without diagnosed cognitive impairment. Participants will receive either S. japonica extract (1,250 mg) or placebo daily for 8 weeks. The primary outcome is change in digit span test score, assessing short-term memory and attention. Secondary outcomes include changes in other cognitive function tests (visual short-term memory, visual learning, and verbal learning), as well as measures of depression (Beck Depression Inventory-II), anxiety (State-Trait Anxiety Inventory-Y), stress (Stress Response Inventory), heart rate variability, and quality of life (EuroQol 5-Dimension-3L). Assessments will be conducted at baseline and after 8 weeks, with safety monitoring throughout the study period.

Conclusion

This study will provide evidence on the efficacy and safety of S. japonica extract for improving cognitive function in adults with subjective memory complaints. If proven effective, this supplement could offer a new approach for supporting cognitive health in aging populations. The comprehensive assessment of cognitive, mood, and quality of life outcomes will allow thorough evaluation of its potential benefits.

The Bifidogenic Effect of 2'Fucosyllactose Is Driven by Age-Specific Bifidobacterium Species, Demonstrating Age as an Important Factor for Gut Microbiome Targeted Precision Medicine

BACKGROUND

The human gut microbiota develops in concordance with its host over a lifetime, resulting in age-related shifts in community structure and metabolic function. Little is known about whether these changes impact the community's response to microbiome-targeted therapeutics. Providing critical information on this subject, faecal microbiomes of subjects from six age groups, spanning from infancy to 70-year-old adults (n = six per age group) were harvested. The responses of these divergent communities to treatment with the human milk oligosaccharide 2'-fucosyllactose (2'FL), fructo-oligosaccharides (FOS), and lactose was investigated using the Ex vivo SIFR® technology that employs bioreactor fermentation and is validated to be predictive of clinical findings. Additionally, it was evaluated whether combining faecal microbiomes of a given age group into a single pooled microbiome produced similar results as the individual microbiomes.

RESULTS

First, marked age-dependent changes in community structure were identified. Bifidobacterium levels strongly declined as age increased, and Bifidobacterium species composition was age-dependent: B. longum, B. catenulatum/pseudocatenulatum, and B. adolescentis were most prevalent for breastfed infants, toddlers/children, and adults, respectively. Metabolomic analyses (LA-REIMS) demonstrated that these age-dependent differences particularly impacted treatment effects of 2'FL (more than FOS/lactose). Further analysis revealed that while 2'FL enhanced production of short-chain fatty acids (SCFAs) and exerted potent bifidogenic effects, regardless of age, the specific Bifidobacterium species enhanced by 2'FL, as well as subsequent cross-feeding interactions, were highly age-dependent. Furthermore, single-pooled microbiomes produced results that were indicative of the average treatment response for each age group. Nevertheless, pooled microbiomes had an artificially high diversity, thus overestimating treatment responses (especially for infants), did not recapitulate interindividual variation, and disallowed for the correlative analysis required to unravel mechanistic actions.

CONCLUSIONS

Age is an important factor in shaping the gut microbiome, with the dominant taxa and their metabolites changing over a lifetime. This divergence affects the response of the microbiota to therapeutics, demonstrated in this study using 2'FL. These results evidence the importance of screening across multiple age groups separately to provide granularity of how therapeutics impact the microbiome and, consequently, human health.

Comparison Between Two Divergent Diets, Mediterranean and Western, on Gut Microbiota and Cognitive Function in Young Sprague Dawley Rats

Clinical studies strongly suggest the importance of diet quality on cognition in youth populations (15-24 years). The Mediterranean diet (MeDi) has been shown to improve cognition in contrast to the commonly consumed Western diet (WD). The gut microbiota may serve as a mechanism for diet-induced changes in cognition. Ten-week-old male Sprague Dawley rats were assigned a MeDi or WD (n=10/group) for 14 weeks. Prior to neurobehavior assessments, microbiota community composition was assessed. At the genus level, the relative abundance of four bacteria increased with the MeDi and five decreased compared to the WD. Rats in the MeDi group demonstrated cognitive flexibility and improvement in reference and working memory relative to the WD group. At the end of the study, serum cytokines were increased, and low-density lipoproteins were decreased in the MeDi group. Markers for neuroinflammation, blood-brain barrier, glial cells, and synaptic plasticity in brain regions did not differ between groups. Overall, the MeDi modulated gut microbiota, cognitive function, and serum lipid and cytokines but not gene expression in the brain compared to the WD. Further studies are needed to determine causality between diet-modulated gut microbiota, cognitive function, and immune function.

Maternal Gut Microbiome-Mediated Epigenetic Modifications in Cognitive Development and Impairments: A New Frontier for Therapeutic Innovation

Cognitive impairment in various mental illnesses, particularly neuropsychiatric disorders, has adverse functional and clinical consequences. While genetic mutations and epigenetic dysregulations of several genes during embryonic and adult periods are linked to cognitive impairment in mental disorders, the composition and diversity of resident bacteria in the gastrointestinal tract-shaped by environmental factors-also influence the brain epigenome, affecting behavior and cognitive functions. Accordingly, many recent studies have provided evidence that human gut microbiota may offer a potential avenue for improving cognitive deficits. In this review, we provide an overview of the relationship between cognitive impairment, alterations in the gut microbiome, and epigenetic alterations during embryonic and adult periods. We examine how various factors beyond genetics-such as lifestyle, age, and maternal diet-impact the composition, diversity, and epigenetic functionality of the gut microbiome, consequently influencing cognitive performance. Additionally, we explore the potential of maternal gut microbiome signatures and epigenetic biomarkers for predicting cognitive impairment risk in older adults. This article also explores the potential roles of nutritional deficiencies in programming cognitive disorders during the perinatal period in offspring, as well as the promise of gut microbiome-targeted therapeutics with epigenetic effects to prevent or alleviate cognitive dysfunctions in infants, middle-aged adults, and older adults. Unsolved challenges of gut microbiome-targeted therapeutics in mitigating cognitive dysfunctions for translation into clinical practice are discussed, lastly.

Plant Extracts and ω-3 Improve Short-Term Memory and Modulate the Microbiota-Gut-Brain Axis in D-galactose Model Mice

BACKGROUND

Aging, characterized by a slow and progressive alteration of cognitive functions, is associated with gut microbiota dysbiosis, low-grade chronic inflammation, as well as increased oxidative stress and neurofunctional alterations. Some nutrients, such as polyphenols, carotenoids, and omega (ω)-3 (n-3), are good candidates to prevent age-related cognitive decline, because of their immunomodulatory, antioxidant, and neuroprotective properties.

OBJECTIVES

The objective of this study was to demonstrate the preventive effect of a combination of plant extracts (PE) containing Memophenol™ (grapes and blueberries polyphenols) and a patented saffron extract (saffron carotenoids and safranal) and ω-3 on cognitive function in a mouse model of accelerated aging and to understand the biological mechanisms involved.

METHODS

We used an accelerated-aging model by injecting 3-mo-old male C57Bl6/J mice with D-galactose for 8 wk, during which they were fed with a balanced control diet and supplemented or not with PE and/or ω-3 (n = 15-16/group). Short-term memory was evaluated by Y-maze test, following analyses of hippocampal and intestinal RNA expressions, brain fatty acid and oxylipin amounts, and gut microbiota composition (16S rRNA gene sequencing). Statistical analyses were performed (t test, analysis of variance, and Pearson correlation).

RESULTS

Our results showed that oral administration of PE, ω-3, or both (mix) prevented hippocampus-dependent short-term memory deficits induced by D-galactose (P < 0.05). This effect was accompanied by the modulation of gut microbiota, altered by the treatment. PE and the mix increased the expression of antioxidative and neurogenesis markers, such as catalase and doublecortin, in hippocampus (P < 0.05 for both). Moreover, ω-3 and the mix showed a higher ω-3 amounts (P < 0.05) and EPA-derived 18- hydroxyeicosapentaenoic acid (P < 0.001) in prefrontal cortex. These changes may contribute to the improvement in memory.

CONCLUSIONS

These results suggest that the mix of PE and ω-3 could be more efficient at attenuating age-related cognitive decline than individual supplementations because it targeted, in mice, the different pathways impaired with aging.

Gut microbiota and healthy longevity

Recent progress on the underlying biological mechanisms of healthy longevity has propelled the field from elucidating genetic modification of healthy longevity hallmarks to defining mechanisms of gut microbiota influencing it. Importantly, the role of gut microbiota in the healthy longevity of the host may provide unprecedented opportunities to decipher the plasticity of lifespan on a natural evolutionary scale and shed light on using microbiota-targeted strategies to promote healthy aging and combat age-related diseases. This review investigates how gut microbiota affects healthy longevity, focusing on the mechanisms through which gut microbiota modulates it. Specifically, we focused on the ability of gut microbiota to enhance the intestinal barrier integrity, provide protection from inflammaging, ameliorate nutrientsensing pathways, optimize mitochondrial function, and improve defense against age-related diseases, thus participating in enhancing longevity and healthspan.

Inflammation-related abnormal dynamic brain activity correlates with cognitive impairment in first-episode, drug-naïve major depressive disorder

BACKGROUND

Cognitive impairment is common in major depressive disorder (MDD) and potentially linked to inflammation-induced alterations in brain function. However, the relationship between inflammation, dynamic brain activity, and cognitive impairment in MDD remains unclear.

METHODS

Fifty-seven first-episode, drug-naïve MDD patients and sixty healthy controls underwent fMRI scanning. Dynamic amplitude of low-frequency fluctuations (dALFF) and dynamic functional connectivity (dFC) were measured using the sliding window method. Plasma IL - 6 levels and cognitive function were assessed using enzyme-linked immunosorbent assay (ELISA) and the Repeated Battery for Assessment of Neuropsychological Status (RBANS), respectively.

RESULTS

MDD patients exhibited decreased dALFF in the bilateral inferior temporal gyrus (ITG), right inferior frontal gyrus, opercular part (IFGoperc), and bilateral middle occipital gyrus (MOG). Regions of dALFF associated with IL-6 included right ITG (r = -0.400/p = 0.003), left ITG (r = -0.381/p = 0.004), right IFGoperc (r = -0.342/p = 0.011), and right MOG (r = -0.327/p = 0.016). Furthermore, IL-6-related abnormal dALFF (including right ITG: r = 0.309/p = 0.023, left ITG: r = 0.276/p = 0.044) was associated with attention impairment. These associations were absent entirely in MDD patients without suicidal ideation. Additionally, IL-6 levels were correlated with dFC of specific brain regions.

LIMITATIONS

Small sample size and cross-sectional study design.

CONCLUSIONS

Inflammation-related dALFF was associated with attention impairment in MDD patients, with variations observed among MDD subgroups. These findings contribute to the understanding of the intricate relationship between inflammation, dynamic brain activity and cognitive impairments in MDD.

Gut microbiota dysbiosis in patients with Alzheimer's disease and correlation with multiple cognitive domains

Background

Accumulating evidence suggested that Alzheimer's disease (AD) was associated with altered gut microbiota. However, the relationships between gut microbiota and specific cognitive domains of AD patients have yet been fully elucidated. The aim of this study was to explore microbial signatures associated with global cognition and specific cognitive domains in AD patients and to determine their predictive value as biomarkers.

Methods

A total of 64 subjects (18 mild AD, 23 severe AD and 23 healthy control) were recruited in the study. 16 s rDNA sequencing was performed for the gut bacteria composition, followed by liquid chromatography electrospray ionization tandem mass spectrometry (LC/MS/MS) analysis of short-chain fatty acids (SCFAs). The global cognition, specific cognitive domains (abstraction, orientation, attention, language, etc.) and severity of cognitive impairment, were evaluated by Montreal Cognitive Assessment (MoCA) scores. We further identified characteristic bacteria and SCFAs, and receiver operating characteristic (ROC) curve was used to determine the predictive value.

Results

Our results showed that the microbiota dysbiosis index was significantly higher in the severe and mild AD patients compared to the healthy control (HC). Linear discriminant analysis (LDA) showed that 12 families and 17 genera were identified as key microbiota among three groups. The abundance of Butyricicoccus was positively associated with abstraction, and the abundance of Lachnospiraceae_UCG-004 was positively associated with attention, language, orientation in AD patients. Moreover, the levels of isobutyric acid and isovaleric acid were both significantly negatively correlated with abstraction, and level of propanoic acid was significantly positively associated with the attention. In addition, ROC models based on the characteristic bacteria Lactobacillus, Butyricicoccus and Lachnospiraceae_UCG-004 could effectively distinguished between low and high orientation in AD patients (area under curve is 0.891), and Butyricicoccus and Agathobacter or the combination of SCFAs could distinguish abstraction in AD patients (area under curve is 0.797 and 0.839 respectively).

Conclusion

These findings revealed the signatures gut bacteria and metabolite SCFAs of AD patients and demonstrated the correlations between theses characteristic bacteria and SCFAs and specific cognitive domains, highlighting their potential value in early detection, monitoring, and intervention strategies for AD patients.

Isomalto-Oligosaccharide Potentiates Alleviating Effects of Intermittent Fasting on Obesity-Related Cognitive Impairment during Weight Loss and the Rebound Weight Gain

Obesity-related cognitive dysfunction poses a significant threat to public health. The present study demonstrated mitigating effects of intermittent fasting (IF) and its combination with isomalto-oligosaccharides and IF (IF + IMO) on cognitive impairments induced by a high-fat-high-fructose (HFHF) diet in mice, with IF + IMO exhibiting superior effects. Transcriptomic analysis of the hippocampus revealed that the protective effects on cognition might be attributed to the suppression of toll-like receptor 4 (TLR4)/NFκB signaling, oxidative phosphorylation, and neuroinflammation. Moreover, both IF and IF + IMO modulated the gut microbiome and promoted the production of short-chain fatty acids, with IF + IMO displaying more pronounced effects. IF + IMO-modulated gut microbiota, metabolites, and molecular targets associated with cognitive impairments were further corroborated using human data from public databases Gmrepo and gutMgene. Furthermore, the fecal microbiome transplantation confirmed the direct impacts of IF + IMO-derived microbiota on improving cognition functions by suppressing TLR4/NFκB signaling and increasing BDNF levels. Notably, prior exposure to IF + IMO prevented weight-regain-induced cognitive decline, suppressed TLR4/NFκB signaling and inflammatory cytokines in the hippocampus, and mitigated weight regain-caused gut dysbacteriosis without altering body weight. Our study underscores that IMO-augmented alleviating effects of IF on obesity-related cognitive impairment particularly during weight-loss and weight-regain periods, presenting a novel nutritional strategy to tackle obesity-related neurodegenerative disorders.

Exerkine irisin mitigates cognitive impairment by suppressing gut-brain axis-mediated inflammation

INTRODUCTION

Exercise has been recognized to improve cognitive performance by optimizing gut flora and up-regulating exerkine irisin.

OBJECTIVE

Although exercise-induced irisin is beneficial to cognitive improvement, whether this benefit is achieved by optimizing gut microbiota and metabolites is not fully explored.

METHODS

After aerobic exercise and exogenous irisin interventions for 12 weeks, the 16S rRNA and metabolites in feces of 21-month-old mice were analyzed. Meanwhile, the differential miRNAs and mRNAs in hippocampal tissues were screened by high-throughput sequencing. Relevant mRNAs and proteins were evaluated by RT-PCR, Western blot, and immunofluorescence.

RESULTS

Compared with the young control mice, irisin levels and cognitive capacity of aged mice revealed a significant reduction, while aerobic exercise and intraperitoneal injection of exogenous irisin reversed aging-induced cognitive impairment. Similarly, 147 up-regulated and 173 down-regulated metabolites were detected in aged mice, while 64 and 45 up-regulated and 225 and 187 down-regulated metabolites were detected in aged mice with exercise and irisin interventions, respectively. Moreover, during hippocampal miRNA and mRNA sequencing analysis, 9 differential gut flora and 35 differential genes were identified to be correlated with the inflammatory signaling mediated by the TLR4/MyD88 signal pathway.

CONCLUSION

Aging-induced cognitive impairment is due to insulin resistance induced by TLR4/MyD88 signaling activation in hippocampal tissues mediated by gut microbiota and metabolite changes. Myokine irisin may be an important mediator in optimizing gut microbiota and metabolism for an improved understanding of mitigated aging process upon exercise interventions.

The effect of probiotics on select cognitive domains in mild cognitive impairment and Alzheimer's disease: A systematic review and meta-analysis

Background

Mild cognitive impairment (MCI) and Alzheimer's disease (AD) are progressive neurodegenerative disorders, and probiotics may offer therapeutic benefits by modulating gut microbiota and reducing inflammation.

Objective

This study systematically evaluated the impact of probiotics on cognitive function in MCI and AD through a meta-analysis of randomized controlled trials (RCTs).

Methods

A systematic review and meta-analysis were performed following PRISMA 2020 guidelines. PubMed, Embase, EBSCO, and Cochrane databases were searched for RCTs (January 2000-January 2024) on probiotic interventions lasting 8-24 weeks. Cognitive outcomes included Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), language, naming, visual-spatial, memory, and attention. Data were analyzed using R with a random-effects model to calculate pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs). Risk of bias was rigorously assessed.

Results

Out of 2000 articles, 500 full texts were screened, and 10 studies were included. The meta-analysis showed varied effect sizes: MMSE (SMD: 0.28, 95%CI -0.35-0.91, p = 0.38), MoCA (SMD: 0.51, 95%CI -0.49-1.52, p = 0.33), language (SMD: -0.12, 95% CI -0.54-0.29, p = 0.56), naming (SMD: 0.02, 95%CI -0.69-0.74, p = 0.95), visual-spatial (SMD: 0.38, 95%CI -0.13-0.88, p = 0.14), memory (SMD: 0.20, 95%CI -0.15-0.55, p = 0.26), and attention (SMD: -0.07, 95%CI -0.44-0.30, p = 0.71). Positive SMDs suggest cognitive improvement, while non-significant negative SMDs indicate trends toward decline, inclined by probiotic strains, duration, and participant characteristics.

Conclusions

Probiotics did not significantly improve cognitive function in MCI and AD patients, with variability in effects across cognitive domains, suggesting the need for tailored interventions and future studies.

Gut microbiota metabolites: potential therapeutic targets for Alzheimer's disease?

Background

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive decline in cognitive function, which significantly increases pain and social burden. However, few therapeutic interventions are effective in preventing or mitigating the progression of AD. An increasing number of recent studies support the hypothesis that the gut microbiome and its metabolites may be associated with upstream regulators of AD pathology.

Methods

In this review, we comprehensively explore the potential mechanisms and currently available interventions targeting the microbiome for the improvement of AD. Our discussion is structured around modern research advancements in AD, the bidirectional communication between the gut and brain, the multi-target regulatory effects of microbial metabolites on AD, and therapeutic strategies aimed at modulating gut microbiota to manage AD.

Results

The gut microbiota plays a crucial role in the pathogenesis of AD through continuous bidirectional communication via the microbiota-gut-brain axis. Among these, microbial metabolites such as lipids, amino acids, bile acids and neurotransmitters, especially sphingolipids and phospholipids, may serve as central components of the gut-brain axis, regulating AD-related pathogenic mechanisms including β-amyloid metabolism, Tau protein phosphorylation, and neuroinflammation. Additionally, interventions such as probiotic administration, fecal microbiota transplantation, and antibiotic use have also provided evidence supporting the association between gut microbiota and AD. At the same time, we propose an innovative strategy for treating AD: a healthy lifestyle combined with targeted probiotics and other potential therapeutic interventions, aiming to restore intestinal ecology and microbiota balance.

Conclusion

Despite previous efforts, the molecular mechanisms by which gut microbes act on AD have yet to be fully described. However, intestinal microorganisms may become an essential target for connecting the gut-brain axis and improving the symptoms of AD. At the same time, it requires joint exploration by multiple centers and multiple disciplines.

Influence of human gut microbiome on the healthy and the neurodegenerative aging

The gut microbiome plays a crucial role in host health throughout the lifespan by influencing brain function during aging. The microbial diversity of the human gut microbiome decreases during the aging process and, as a consequence, several mechanisms increase, such as oxidative stress, mitochondrial dysfunction, inflammatory response, and microbial gut dysbiosis. Moreover, evidence indicates that aging and neurodegeneration are closely related; consequently, the gut microbiome may serve as a novel marker of lifespan in the elderly. In this narrative study, we investigated how the changes in the composition of the gut microbiome that occur in aging influence to various neuropathological disorders, such as mild cognitive impairment (MCI), dementia, Alzheimer's disease (AD), and Parkinson's disease (PD); and which are the possible mechanisms that govern the relationship between the gut microbiome and cognitive impairment. In addition, several studies suggest that the gut microbiome may be a potential novel target to improve hallmarks of brain aging and to promote healthy cognition; therefore, current and future therapeutic interventions have been also reviewed.

Live and pasteurized Akkermansia muciniphila ameliorates diabetic cognitive impairment by modulating gut microbiota and metabolites in db/db mice

The established role of disturbances in the microbiota-gut-brain axis in the development of diabetic cognitive impairment (DCI) has long been recognized. It has shown the potential of Akkermansia muciniphila (A. muciniphila) in improving metabolic disorders and exerting anti-inflammatory effects. However, there remains a lack of comprehensive understanding regarding the specific effects and mechanisms underlying the treatment of DCI with A. muciniphila. This study aimed to evaluate the potential of A. muciniphila in alleviating DCI in db/db mice. Eleven-week-old db/db mice were administered either live or pasteurized A. muciniphila (5 × 109 CFU/200 μL) for a duration of eight weeks. Administering live A. muciniphila significantly ameliorated cognitive impairments, improved the synaptic ultrastructure, and inhibited hippocampal neuron loss in the CA1 and CA3 subregions in db/db mice. Both live and pasteurized A. muciniphila effectively mitigated neuroinflammation. Moreover, live A. muciniphila increased the relative abundance of Lactococcus and Staphylococcus, whereas pasteurized A. muciniphila increased the relative abundance of Lactobacillus, Prevotellaceae_UCG_001, and Alistipes. Supplementation of A. muciniphila also induced alterations in serum and brain metabolites, with a particular enrichment observed in tryptophan metabolism, glyoxylate and dicarboxylate metabolism, nitrogen metabolism, and pentose and glucuronate interconversions. Correlation analysis further demonstrated a direct and substantial correlation between the altered gut microbiota and the metabolites in the serum and brain tissue. In conclusion, the results indicate that live A. muciniphila demonstrated greater efficacy compared to pasteurized A. muciniphila. The observed protective effects of A. muciniphila against DCI are likely mediated through the neuroinflammation and microbiota-metabolites-brain axis.

Vagus Nerve Suppression in Ischemic Stroke by Carotid Artery Occlusion: Implications for Metabolic Regulation, Cognitive Function, and Gut Microbiome in a Gerbil Model

The vagus nerve regulates metabolic homeostasis and mediates gut-brain communication. We hypothesized that vagus nerve dysfunction, induced by truncated vagotomy (VGX) or carotid artery occlusion (AO), would disrupt gut-brain communication and exacerbate metabolic dysregulation, neuroinflammation, and cognitive impairment. This study aimed to test the hypothesis in gerbils fed a high-fat diet. The gerbils were divided into four groups: AO with VGX (AO_VGX), AO without VGX (AO_NVGX), no AO with VGX (NAO_VGX), and no AO without VGX (NAO_NVGX). After 5 weeks on a high-fat diet, the neuronal cell death, neurological severity, hippocampal lipids and inflammation, energy/glucose metabolism, intestinal morphology, and fecal microbiome composition were assessed. AO and VGX increased the neuronal cell death and neurological severity scores associated with increased hippocampal lipid profiles and lipid peroxidation, as well as changes in the inflammatory cytokine expression and brain-derived neurotrophic factor (BDNF) levels. AO and VGX also increased the body weight, visceral fat mass, and insulin resistance and decreased the skeletal muscle mass. The intestinal morphology and microbiome composition were altered, with an increase in the abundance of Bifidobacterium and a decrease in Akkermansia and Ruminococcus. Microbial metagenome functions were also impacted, including glutamatergic synaptic activity, glycogen synthesis, and amino acid biosynthesis. Interestingly, the effects of VGX were not significantly additive with AO, suggesting that AO inhibited the vagus nerve activity, partly offsetting the effects of VGX. In conclusion, AO and VGX exacerbated the dysregulation of energy, glucose, and lipid metabolism, neuroinflammation, and memory deficits, potentially through the modulation of the gut-brain axis. Targeting the gut-brain axis by inhibiting vagus nerve suppression represents a potential therapeutic strategy for ischemic stroke.

Lactobacillus rhamnosus 069 and Lactobacillus brevis 031: Unraveling Strain-Specific Pathways for Modulating Lipid Metabolism and Attenuating High-Fat-Diet-Induced Obesity in Mice

Obesity is a global health crisis, marked by excessive fat in tissues that function as immune organs, linked to microbiota dysregulation and adipose inflammation. Investigating the effects of Lactobacillus rhamnosus SG069 (LR069) and Lactobacillus brevis SG031 (LB031) on obesity and lipid metabolism, this research highlights adipose tissue's critical immune-metabolic role and the probiotics' potential against diet-induced obesity. Mice fed a high-fat diet were treated with either LR069 or LB031 for 12 weeks. Administration of LB031 boosted lipid metabolism, indicated by higher AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) phosphorylation, and increased the M2/M1 macrophage ratio, indicating LB031's anti-inflammatory effect. Meanwhile, LR069 administration not only led to significant weight loss by enhancing lipolysis which evidenced by increased phosphorylation of hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) but also elevated Akkermansia and fecal acetic acid levels, showing the gut microbiota's pivotal role in its antiobesity effects. LR069 and LB031 exhibit distinct effects on lipid metabolism and obesity, underscoring their potential for precise interventions. This research elucidates the unique impacts of these strains on metabolic health and highlights the intricate relationship between gut microbiota and obesity, advancing our knowledge of probiotics' therapeutic potential.

Co-administration of probiotic and vitamin D significantly improves cognitive function in schizophrenic patients: A double-blinded randomized controlled trial

AIM

Manipulation of the intestinal microbiome and supplying vitamin D can attenuate psychiatric symptoms in schizophrenic patients. The current study tried to evaluate the effects of probiotic/vitamin D supplementation on the cognitive function and disease severity of schizophrenic patients.

METHODS

In the present study, 70 patients (aged 18-65) with schizophrenia were recruited. Participants were randomly allocated to the placebo (n = 35) and intervention (probiotic supplements+400 IU vitamin D, n = 35) groups. Severity of disease and cognitive function (primary outcomes) were evaluated by Positive and Negative Syndrome Scale (PANSS) and Montreal Cognitive Assessment (MoCA) tests, respectively. Moreover, lipid profile, body mass index (BMI), gastrointestinal (GI) problems, serum C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were evaluated as secondary outcomes.

RESULTS

A total of 69 patients completed the study. The MoCA score was increased by 1.96 units in the probiotic-containing supplement group compared to the placebo (p = 0.004). Also, the percentage of subjects with MoCA score ≥ 26 rose significantly in the intervention group (p = 0.031). Moreover, TC (p = 0.011), FBS (p = 0.009), and CRP (p < 0.001) significantly decreased in the supplement group compared to the placebo. Although the probiotic supplement reduced PANSS score by 2.82 units, the difference between the study groups was not statistically significant (p = 0.247).

CONCLUSION

Co-administration of probiotics and vitamin D has beneficial effects on the improvement of cognitive function in schizophrenic patients.

Probiotics, prebiotics, synbiotics and other microbiome-based innovative therapeutics to mitigate obesity and enhance longevity via the gut-brain axis

The global prevalence of obesity currently exceeds 1 billion people and is accompanied by an increase in the aging population. Obesity and aging share many hallmarks and are leading risk factors for cardiometabolic disease and premature death. Current anti-obesity and pro-longevity pharmacotherapies are limited by side effects, warranting the development of novel therapies. The gut microbiota plays a major role in human health and disease, with a dysbiotic composition evident in obese and aged individuals. The bidirectional communication system between the gut and the central nervous system, known as the gut-brain axis, may link obesity to unhealthy aging. Modulating the gut with microbiome-targeted therapies, such as biotics, is a novel strategy to treat and/or manage obesity and promote longevity. Biotics represent material derived from living or once-living organisms, many of which have therapeutic effects. Pre-, pro-, syn- and post-biotics may beneficially modulate gut microbial composition and function to improve obesity and the aging process. However, the investigation of biotics as next-generation therapeutics has only just begun. Further research is needed to identify therapeutic biotics and understand their mechanisms of action. Investigating the function of the gut-brain axis in obesity and aging may lead to novel therapeutic strategies for obese, aged and comorbid (e.g., sarcopenic obese) patient populations. This review discusses the interrelationship between obesity and aging, with a particular emphasis on the gut microbiome, and presents biotics as novel therapeutic agents for obesity, aging and related disease states.

Microbiota-Gut-Brain Axis Dysregulation in Alzheimer's Disease: Multi-Pathway Effects and Therapeutic Potential

An essential regulator of neurodegenerative conditions like Alzheimer's disease (AD) is the gut microbiota. Alterations in intestinal permeability brought on by gut microbiota dysregulation encourage neuroinflammation, central immune dysregulation, and peripheral immunological dysregulation in AD, as well as hasten aberrant protein aggregation and neuronal death in the brain. However, it is unclear how the gut microbiota transmits information to the brain and how it influences brain cognition and function. In this review, we summarized the multiple pathways involved in the gut microbiome in AD and provided detailed treatment strategies based on the gut microbiome. Based on these observations, this review also discusses the problems, challenges, and strategies to address current therapeutic strategies.

Real-time PCR methods for identification and stability monitoring of Bifidobacterium longum subsp. longum UABl-14 during shelf life

Bifidobacterium longum subsp. longum UABl-14™ is an important probiotic strain that was found to support digestive health. Here we present the development and validation of real-time PCR methods for strain-specific identification and enumeration of this important strain. The identification method was evaluated for specificity using 22 target samples and 30 non-target samples. All target samples successfully amplified, while no amplification was observed from any non-target samples including other B. longum strains. The identification method was evaluated for sensitivity using three DNA dilution series and the limit of detection was 2 pg. of DNA. Coupled with a viability dye, the method was further validated for quantitative use to enumerate viable cells of UABl-14. The viability dye treatment (PMAxx) was optimized, and a final concentration of 50 μM was found as an effective concentration to inactivate DNA in dead cells from reacting in PCR. The reaction efficiency, linear dynamic range, repeatability, and reproducibility were also evaluated. The reaction efficiency was determined to be 97.2, 95.2, and 95.0% with R2 values of 99%, in three replicates. The linear dynamic range was 1.3 × 102 to 1.3 × 105 genomes. The relative standard deviation (RSD%) for repeatability ranged from 0.03 to 2.80, and for reproducibility ranged from 0.04 to 2.18. The ability of the validated enumeration method to monitor cell counts during shelf life was evaluated by determining the viable counts and total counts of strain UABl-14 in 18 multi-strain finished products. The viable counts were lower than label claims in seven products tested post-expiration and were higher than label claims in products tested pre-expiration, with a slight decrease in viable counts below label claim in three samples that were tested 2-3 months pre-expiration. Interestingly, the total counts of strain UABl-14 were consistently higher than label claims in all 18 products. Thus, the method enables strain-specific stability monitoring in finished products during shelf life, which can be difficult or impossible to achieve using the standard plate count method. The validated methods allow for simultaneous and cost-effective identification and enumeration of strain UABl-14 and represent an advancement in the quality control and quality assurance of probiotics.

Exploring the Influence of Gut-Brain Axis Modulation on Cognitive Health: A Comprehensive Review of Prebiotics, Probiotics, and Symbiotics

Recent research exploring the relationship between the gut and the brain suggests that the condition of the gut microbiota can influence cognitive health. A well-balanced gut microbiota may help reduce inflammation, which is linked to neurodegenerative conditions. Prebiotics, probiotics, and symbiotics are nutritional supplements and functional food components associated with gastrointestinal well-being. The bidirectional communication of the gut-brain axis is essential for maintaining homeostasis, with pre-, pro-, and symbiotics potentially affecting various cognitive functions such as attention, perception, and memory. Numerous studies have consistently shown that incorporating pre-, pro-, and symbiotics into a healthy diet can lead to improvements in cognitive functions and mood. Maintaining a healthy gut microbiota can support optimal cognitive function, which is crucial for disease prevention in our fast-paced, Westernized society. Our results indicate cognitive benefits in healthy older individuals with probiotic supplementation but not in healthy older individuals who have good and adequate levels of physical activity. Additionally, it appears that there are cognitive benefits in patients with mild cognitive impairment and Alzheimer's disease, while mixed results seem to arise in younger and healthier individuals. However, it is important to acknowledge that individual responses may vary, and the use of these dietary supplements should be tailored to each individual's unique health circumstances and needs.

A mediation analysis of the role of total free fatty acids on pertinence of gut microbiota composition and cognitive function in late life depression

BACKGROUND

Extensive evidence demonstrates correlations among gut microbiota, lipid metabolism and cognitive function. However, there is still a lack of researches in the field of late-life depression (LLD). This research targeted at investigating the relationship among gut microbiota, lipid metabolism indexes, such as total free fatty acids (FFAs), and cognitive functions in LLD.

METHODS

Twenty-nine LLD patients from the Cognitive Outcome Cohort Study of Depression in Elderly were included. Cognitive functions were estimated through the Chinese version of Montreal Cognitive Assessment (MoCA). Blood samples were collected to evaluate serum lipid metabolism parameters. Fecal samples were evaluated for gut microbiota determination via 16S rRNA sequencing. Spearman correlation, linear regression and mediation analysis were utilized to explore relationship among gut microbiota, lipid metabolism and cognitive function in LLD patients.

RESULTS

Spearman correlation analysis revealed significant correlations among Akkermansia abundance, total Free Fatty Acids (FFAs) and MoCA scores (P < 0.05). Multiple regression indicated Akkermansia and total FFAs significantly predicted MoCA scores (P < 0.05). Mediation analysis demonstrated that the correlation between decreased Akkermansia relative abundance and cognitive decline in LLD patients was partially mediated by total FFAs (Bootstrap 95%CI: 0.023-0.557), accounting for 43.0% of the relative effect.

CONCLUSION

These findings suggested a significant relationship between cognitive functions in LLD and Akkermansia, as well as total FFAs. Total FFAs partially mediated the relationship between Akkermansia and cognitive functions. These results contributed to understanding the gut microbial-host lipid metabolism axis in the cognitive function of LLD.

Probiotics as modulators of gut-brain axis for cognitive development

Various microbial communities reside in the gastrointestinal tract of humans and play an important role in immunity, digestion, drug metabolism, intestinal integrity, and protection from pathogens. Recent studies have revealed that the gut microbiota (GM) is involved in communication with the brain, through a bidirectional communication network known as the gut-brain axis. This communication involves humoral, immunological, endocrine, and neural pathways. Gut dysbiosis negatively impacts these communication pathways, leading to neurological complications and cognitive deficits. Both pre-clinical and clinical studies have demonstrated that probiotics can restore healthy GM, reduce intestinal pH, and reduce inflammation and pathogenic microbes in the gut. Additionally, probiotics improve cell-to-cell signaling and increase blood-brain-derived neurotrophic factors. Probiotics emerge as a potential approach for preventing and managing neurological complications and cognitive deficits. Despite these promising findings, the safety concerns and possible risks of probiotic usage must be closely monitored and addressed. This review article provides a brief overview of the role and significance of probiotics in cognitive health.

Analysis of intestinal flora and cognitive function in maintenance hemodialysis patients using combined 16S ribosome DNA and shotgun metagenome sequencing

BACKGROUND

Cognitive impairment is widely prevalent in maintenance hemodialysis (MHD) patients, and seriously affects their quality of life. The intestinal flora likely regulates cognitive function, but studies on cognitive impairment and intestinal flora in MHD patients are lacking.

METHODS

MHD patients (36) and healthy volunteers (18) were evaluated using the Montreal Cognitive Function Scale, basic clinical data, and 16S ribosome DNA (rDNA) sequencing. Twenty MHD patients and ten healthy volunteers were randomly selected for shotgun metagenomic analysis to explore potential metabolic pathways of intestinal flora. Both16S rDNA sequencing and shotgun metagenomic sequencing were conducted on fecal samples.

RESULTS

Roseburia were significantly reduced in the MHD group based on both 16S rDNA and shotgun metagenomic sequencing analyses. Faecalibacterium, Megamonas, Bifidobacterium, Parabacteroides, Collinsella, Tyzzerella, and Phascolarctobacterium were positively correlated with cognitive function or cognitive domains. Enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways included oxidative phosphorylation, photosynthesis, retrograde endocannabinoid signaling, flagellar assembly, and riboflavin metabolism.

CONCLUSION

Among the microbiota, Roseburia may be important in MHD patients. We demonstrated a correlation between bacterial genera and cognitive function, and propose possible mechanisms.

Human trials exploring anti-aging medicines

Here, we summarize the current knowledge on eight promising drugs and natural compounds that have been tested in the clinic: metformin, NAD+ precursors, glucagon-like peptide-1 receptor agonists, TORC1 inhibitors, spermidine, senolytics, probiotics, and anti-inflammatories. Multiple clinical trials have commenced to evaluate the efficacy of such agents against age-associated diseases including diabetes, cardiovascular disease, cancer, and neurodegenerative diseases. There are reasonable expectations that drugs able to decelerate or reverse aging processes will also exert broad disease-preventing or -attenuating effects. Hence, the outcome of past, ongoing, and future disease-specific trials may pave the way to the development of new anti-aging medicines. Drugs approved for specific disease indications may subsequently be repurposed for the treatment of organism-wide aging consequences.

Effect of Continuous Ingestion of Bifidobacteria and Dietary Fiber on Improvement in Cognitive Function: A Randomized, Double-Blind, Placebo-Controlled Trial

Bifidobacterium animalis subsp. lactis GCL2505 has been shown to have some positive effects on health, including improved defecation frequency and reduced visceral fat. These effects are thought to be due to GCL2505's unique ability to reach the intestine in a viable form and proliferate after a single intake. This leads to an increased number of intestinal bifidobacteria. This randomized, double-blind, placebo-controlled, parallel-group study was conducted to confirm that intake of GCL2505 and inulin (a prebiotic) improve cognitive function (n = 80). Participants consumed test drinks containing 1 × 1010 colony-forming units of GCL2505 per 100 g and 2.0 g of inulin per 100 g for 12 weeks. The change in cognitive function assessment scores was set as the primary endpoint. There were significant improvements in scores in the neurocognitive index domain, which is an assessment of overall cognitive function, in addition to overall attention, cognitive flexibility, and executive function domains. The intervention significantly increased the number of fecal bifidobacteria and affected the levels of several inflammatory markers. These results suggest that intake of GCL2505 and inulin improves cognitive function by improving the intestinal environment and alleviating inflammation.

Probiotics in the Sourdough Bread Fermentation: Current Status

Sourdough fermentation is an ancient technique to ferment cereal flour that improves bread quality, bringing nutritional and health benefits. The fermented dough has a complex microbiome composed mainly of lactic acid bacteria and yeasts. During fermentation, the production of metabolites and chemical reactions occur, giving the product unique characteristics and a high sensory quality. Mastery of fermentation allows adjustment of gluten levels, delaying starch digestibility, and increasing the bio-accessibility of vitamins and minerals. This review focuses on the main steps of sourdough fermentation, the microorganisms involved, and advances in bread production with functional properties. The impact of probiotics on human health, the metabolites produced, and the main microbial enzymes used in the bakery industry are also discussed.