Interplay Between the Gut-Brain Axis, Obesity and Cognitive Function

Düşük veya Yüksek Karbonhidratlı Diyetlerin Beyin, Beyin-Bağırsak Aksı ve Bilişsel İşlevler Üzerine Etkisi

İntestinal mikrobiyota sağlığın korunmasında anahtar bir rol oynamaktadır. Mikrobiyota üzerine önemli etkileri olan beslenme, beyin-bağırsak aksındaki bozuklukları hafifletmek, nöroinflamasyonu ve bilişsel bozulmayı iyileştirmek için büyük önem taşımaktadır. Bağırsak bakterileri, diyetle alınan besin ögelerini kullanarak çeşitli metabolitleri (örn., kısa zincirli yağ asitleri, amino asitler, vitaminler) üretebilme yeteneğine sahiptir. Üretilen bu metabolitler, periferik sinir sistemi, enteroendokrin hücreler ve merkezi sinir sistemine sinyal gönderen immün hücreler aracılığıyla beyin fonksiyonlarını ve bilişsel davranış değişikliğini etkilemektedir. Karbonhidratlar, çoğu durumda intestinal mikrobiyota tarafından substrat olarak kullanılmakta ve fermente edilmektedir. Karbonhidratların bu etkileri kimyasal yapılarına, sindirilmeden kolona ulaşıp ulaşamamalarına ve konağın karbonhidratı enerji kaynağı olarak kullanabilme yeteneğine bağlıdır. Karbonhidratın türü ve miktarı mikrobiyota, beyin bağırsak aksı ve bilişsel işlevlerdeki etkiyi belirleyen ana faktörlerden biridir. Bu derlemede, düşük veya yüksek karbonhidrat içeren diyetlerin beyin-bağırsak aksı ve bilişsel fonksiyonlara olan etkilerinin güncel literatür verileri ışığında değerlendirilmesi amaçlanmıştır.

Recent Updates on Associations among Various Obesity Metrics and Cognitive Impairment: from Body Mass Index to Sarcopenic Obesity

Obesity and obesity-associated morbidity continues to be a major public health issue worldwide. Dementia is also a major health concern in aging societies and its prevalence has increased rapidly. Many epidemiologic studies have shown an association between obesity and cognitive impairment, but this relationship is not as well established as other comorbidities. Conflicting results related to the age and sex of participants, and the methodology used to define obesity and dementia may account for the uncertainty in whether obesity is a modifiable risk factor for dementia. More recently, sarcopenia and sarcopenic obesity have been reported to be associated with cognitive impairment. In addition, new mediators such as the muscle-myokine-brain axis and gut-microbiota-brain axis have been suggested and are attracting interest. In this review, we summarize recent evidence on the link between obesity and cognitive impairment, especially dementia. In particular, we focus on various metrics of obesity, from body mass index to sarcopenia and sarcopenic obesity.

Brain-gut axis and psychiatric disorders: A perspective from bibliometric and visual analysis

BACKGROUND

The Brain-Gut Axis, a bidirectional signaling pathway that connects the intestinal and central nervous systems, plays an important role in the development of psychiatric disorders. However, the overall research trends in this field are unclear. This study explored the patterns of research on the brain-gut axis and psychiatric disorders from a bibliometric perspective.

METHODS

Relevant data were retrieved from the Web of Science Core Collection, with search terms on psychiatric disorders and the brain-gut axis. R (version 4.2.0), VOSviewer (version 1.6.17), CiteSpace software, and the online bibliometric platform were used in the data analysis.

RESULTS

A total of 2,298 articles published between 1993 and 2022 were identified, showing an increasing trend over time. China (1,859; 20.70%) was the country that contributed the most publications. The journal Nutrients (95; 4.13%) published the most publications. Cryan JF (153; H-index=73) and University College Cork (559; 22.54%) were the most influential author and the most productive institution, respectively. The high-frequency keywords were clustered into six themes, including neurodegenerative diseases, stress-related diseases, immune, brain behavior, depression, and probiotic-related topics; of which, depression (880; 2019), anxiety (207; 2018) and autism (191; 2019) were the most studied psychiatric disorders in the past 5 years. "Depressive symptom" (2019-2020) and "probiotic treatment" (2019-2020) were the main areas addressed in recent years.

CONCLUSION

Research on the brain-gut axis and psychiatric disorders has attracted increasing attention in the past decade, with most publications originating from high-income level countries. This study provides a useful perspective on understanding the research trends, key hot topics, and research gaps in this expanding field.

Effects of autochthonous strains mixture on gut microbiota and metabolic profile in cobia (Rachycentron canadum)

The fish immune system is a topic or subject that offers a unique understanding of defensive system evolution in vertebrate heredity. While gut microbiota plays several roles in fish: well-being, promoting health and growth, resistance to bacterial invasion, regulation of energy absorption, and lipid metabolism. However, studies on fish gut microbiota face practical challenges due to the large number of fish varieties, fluctuating environmental conditions, and differences in feeding habits. This study was carried out to evaluate the impacts of supplemented three autochthonous strains, Bacillus sp. RCS1, Pantoea agglomerans RCS2, and Bacillus cereus RCS3 mixture diet on cobia fish (Rachycentron canadum). Also, chromatography, mass spectrometry and high throughput sequencing were combined to explore composition and metabolite profile of gut microbiota in juvenile cobia fed with supplemented diet. In the trial group, juvenile cobia received diets supplemented with 1 × 10¹² CFU mL^-1 autochthonous strains for ten weeks and a control diet without supplementation. Juvenile cobia receiving diets supplementation exhibited significantly improved growth than those without additives (control). Haematological indices, such as red blood cells, white blood cells, corpuscular haemoglobin concentration, mean corpuscular volume, haemoglobin, and mean corpuscular haemoglobin, were higher in the supplemented group. Similarly, digestive enzymes (trypsin, lipase, amylase, pepsin and cellulose, activities) activities were higher in supplemented diet with an indigenous isolates mixture. Serum biochemical parameters albumin, globulin, and total protein were significantly higher, while triglyceride, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and cholesterol showed no significant difference. On the other hand, glucose was significantly (P < 0.05) higher in the group without supplementation. On gene expression in the midgut, Immunoglobulin, Colony-stimulating factor receptor 1, major histocompatibility complex 1 were up-regulated by native isolates while T cell receptor beta, and Major histocompatibility complex 2 showed no significant difference. Gut bacterial composition was altered in fish receiving supplemented diet with autochthonous strains. Metabolomics also revealed that some metabolic pathways were considerably enriched in fish fed with supplemented diet; pathway analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment revealed that differentially expressed metabolites were involved in galactose metabolism, tryptophan metabolism, carbohydrate digestion and absorption, purine metabolism, and ABC transporters. Functional analysis of bacterial community showed that differences in enriched metabolic pathways generally comprised carbohydrate and its metabolites, nucleotide and its metabolites, amino acid and its metabolites, heterocyclic compounds, and tryptamines, cholines, pigments. The current investigation results showed that autochthonous strains mixture has significantly enhanced the growth, survival, and innate and adaptive immunities of juvenile cobia.

Association between Proximity to Food Sources and Dietary Behaviors in Black and White College Graduates

OBJECTIVES

Unequal access to healthy food environments is often implicated in racial inequities in health and behaviors that are largest among college graduates. The aim of this study was to determine associations between perceived proximity to food sources and dietary behaviors between black and white college graduates.

METHODS

In a cross-sectional online survey of dietary behaviors between black and white adults who have a ≥ 4-year bachelor's degree, respondents were asked how long it typically takes for them to get to grocery stores and fast-food restaurants from home. We used ordinal logit regression models to assess associations between perceived proximity to food sources and dietary behaviors.

RESULTS

Among black men, perceiving that a grocery store was ≥ 10 minutes from their home was associated with lower fruit consumption (beta=-0.94, SE=0.48). Perceiving that a grocery store was ≥ 10 minutes from their home was associated with more frequent fast-food consumption among black men (beta=1.21, SE=0.39), Black women (beta=0.98, SE=0.34), and white men (beta=0.74, SE=0.30).

CONCLUSIONS

The associations between perceived proximity to food sources and dietary behaviors differ by race and sex among college graduates with important implications for racial disparities in diet quality and obesity across SES.

(-)-Epicatechin exerts positive effects on anxiety in high fat diet-induced obese mice through multi-genomic modifications in the hippocampus

Obesity is associated with increased occurrence of cognitive and mood disorders. While consumption of high-fat diets (HFD) and associated obesity could have a detrimental impact on the brain, dietary bioactives may mitigate these harmful effects. We previously observed that (-)-epicatechin (EC) can mitigate HFD-induced anxiety-associated behaviors in mice. The aim of our study is to investigate the molecular mechanisms of EC actions in the hippocampus which underlies its anti-anxiety effects in HFD-fed mice using a multi-genomic approach. Healthy eight-week old male C57BL/6J mice were fed for 24 weeks either: (A) a control diet containing 10% total calories from fat; (B) a HFD containing 45% total calories from fat; or (C) the HFD supplemented with 20 mg EC per kg body weight. Hippocampi were isolated for genomic analysis using Affymetrix arrays, followed by in-depth bioinformatic analyses. Genomic analysis demonstrated that EC induced significant changes in mouse hippocampal global gene expression. We observed changes in the expression of 1001 protein-coding genes, 241 miRNAs, and 167 long non-coding RNAs. Opposite gene expression profiles were observed when the gene expression profile obtained upon EC supplementation was compared to the profile obtained after consumption of the HFD. Functionality analysis revealed that the differentially expressed genes regulate processes involved in neurofunction, inflammation, endothelial function, cell-cell adhesion, and cell signaling. In summary, the capacity of EC to mitigate anxiety-related behaviors in HFD-induced obese mice can be in part explained by its capacity to exert complex genomic modifications in the hippocampus, counteracting changes driven by consumption of the HFD and/or associated obesity.

Zinc Supplementation Partially Decreases the Harmful Effects of a Cafeteria Diet in Rats but Does Not Prevent Intestinal Dysbiosis

Zinc (Zn) plays an important role in metabolic homeostasis and may modulate neurological impairment related to obesity. The present study aimed to evaluate the effect of Zn supplementation on the intestinal microbiota, fatty acid profile, and neurofunctional parameters in obese male Wistar rats. Rats were fed a cafeteria diet (CAF), composed of ultra-processed and highly caloric and palatable foods, for 20 weeks to induce obesity. From week 16, Zn supplementation was started (10 mg/kg/day). At the end of the experiment, we evaluated the colon morphology, composition of gut microbiota, intestinal fatty acids, integrity of the intestinal barrier and blood-brain barrier (BBB), and neuroplasticity markers in the cerebral cortex and hippocampus. Obese rats showed dysbiosis, morphological changes, short-chain fatty acid (SCFA) reduction, and increased saturated fatty acids in the colon. BBB may also be compromised in CAF-fed animals, as claudin-5 expression is reduced in the cerebral cortex. In addition, synaptophysin was decreased in the hippocampus, which may affect synaptic function. Our findings showed that Zn could not protect obese animals from intestinal dysbiosis. However, an increase in acetate levels was observed, which suggests a partial beneficial effect of Zn. Thus, Zn supplementation may not be sufficient to protect from obesity-related dysfunctions.

Different oral and gut microbial profiles in those with Alzheimer's disease consuming anti-inflammatory diets

The number of people living with Alzheimer's disease (AD) is increasing alongside with aging of the population. Systemic chronic inflammation and microbial imbalance may play an important role in the pathogenesis of AD. Inflammatory diets regulate both the host microbiomes and inflammatory status. This study aimed to explore the impact of inflammatory diets on oral-gut microbes in patients with AD and the relationship between microbes and markers of systemic inflammation. The dietary inflammatory properties and the oral and gut microorganisms were analyzed using the dietary inflammatory index (DII) and 16S RNA in 60 patients with AD. The α-diversity was not related to the DII (p > 0.05), whereas the β-diversity was different in the oral microbiomes (R² = 0.061, p = 0.013). In the most anti-inflammatory diet group, Prevotella and Olsenella were more abundant in oral microbiomes and Alistipes, Ruminococcus, Odoribacter, and unclassified Firmicutes were in the gut microbiomes (p < 0.05). Specific oral and gut genera were associated with interleukin-6 (IL)-6, complement 3 (C3), high-sensitivity C-reactive protein (hs-CRP), IL-1β, IL-4, IL-10, IL-12, and tumor necrosis factor-α (TNF-α) (p < 0.05). In conclusion, anti-inflammatory diets seem to be associated with increased abundance of beneficial microbes, and specific oral and gut microbial composition was associated with inflammatory markers.

Deletion of ghrelin alters tryptophan metabolism and exacerbates experimental ulcerative colitis in aged mice

A major component of aging is chronic, low-grade inflammation, attributable in part by impaired gut barrier function. We previously reported that deletion of ghrelin, a peptidergic hormone released mainly from the gut, exacerbates experimental muscle atrophy in aged mice. In addition, ghrelin has been shown to ameliorate colitis in experimental models of inflammatory bowel disease (IBD), although the role of endogenous ghrelin in host-microbe interactions is less clear. Here, we showed that 22-month-old global ghrelin knockout (Ghrl^-/-) mice exhibited significantly increased depressive-like behaviors, while anxiety levels and working memory were similar to littermate wild-type (WT) mice. Furthermore, old Ghrl^-/- mice showed significantly increased intestinal permeability to fluorescein isothiocyanate (FITC)-dextran, significantly higher colonic interleukin (IL-1β) levels, and trends for higher colonic IL-6 and tumor necrosis factor-α (TNF-α) compared to WT mice. Interestingly, young Ghrl^-/- and WT mice showed comparable depressive-like behavior and gut permeability, suggesting age-dependent exacerbation in gut barrier dysfunction in Ghrl^-/- mice. While fecal short-chain fatty acids levels were comparable between old Ghrl^-/- and WT mice, serum metabolome revealed alterations in metabolic cascades including tryptophan metabolism. Specifically, tryptophan and its microbial derivatives indole-3-acetic acid and indole-3-lactic acid were significantly reduced in old Ghrl^-/-mice. Furthermore, in an experimental model of dextran sulfate sodium (DSS)-induced colitis, Ghrl^-/- mice showed exacerbated disease symptoms, and higher levels of chemoattractant and pro-inflammatory cytokines in the colon. Overall, these data demonstrated that ghrelin deficiency is associated with gut barrier dysfunction, alterations in microbially derived tryptophan metabolites, and increased susceptibility to colitis. These data suggested that endogenous ghrelin contributes to maintaining a healthy host-microbe environment, ultimately impacting on brain function.

Immunohistochemical analysis of caspase expression in the brains of individuals with obesity or overweight

Mechanisms underlying the negative effects of obesity on the brain are still unknown. Obesity is associated with oxidative stress in the brain and neuroinflammation that promotes neurodegenerative diseases. Chronic low-grade neuroinflammation in obesity could be associated with lower volumes of gray matter and lower neuronal density. If neuroinflammation mediated by the expression of cytokines and chemokines leads to apoptosis, this can be assessed by examining caspase expression. The aim of this study was to compare the expression of caspases in the 16 brains of donors with obesity/overweight (n = 8; Body Mass Index [BMI] = 31.6 ± 4.35 kg/m²; 2 females; Age = 52.9 ± 4.76 years) and normal weight (n = 8; BMI = 21.8 ± 1.5 kg/m²; 3 females; Age = 37.8 ± 19.2 years). Sixteen human brain samples were processed. Serial paraffin sections were examined by anti-caspase immunochemistry (caspase-3, caspase-4, caspase-6, caspase-1, caspase-8, and caspase-9 antibodies). Postmortem samples of cerebral cortex tissue were captured as photomicrographs and the images obtained were analyzed using ImageJ software to obtain the percentage of positive caspase expression. Nonparametric Mann-Whitney U tests were performed to compare caspase expression between samples from donors with obesity/overweight and normal weight. Taking into consideration the immunohistochemistry results, the Search Tool for the Retrieval of Interacting Genes was used to model molecular interactions. Results showed that brain samples from individuals with obesity/overweight exhibited significantly greater values of positive expression for Caspase-1 (U = 16.5, p = 0.05, Cohen d = 0.89) and -8 (U = 15, p = 0.03, Cohen d = 0.99) than those from donors with normal weight. This study contributes to the knowledge about the inflammatory effects of obesity/overweight on brain, suggesting the activation of the alternative inflammasome pathway in which interact caspase-1 and -8.

Bidirectional prediction between weight status and executive function in children and adolescents: A systematic review and meta-analysis of longitudinal studies

This study examined the predictability of child weight status on executive function (EF) and vice versa. We searched PubMed, CINAHL, Web of Science, and EMBASE for longitudinal studies conducted in children and adolescents on October 31, 2021. A pairwise meta-analysis was performed using a frequentist random-effects approach. The quality of all included studies was evaluated using Newcastle-Ottawa Scale and GRADE assessments. This study included 18 longitudinal studies (N = 30,101). Overall executive functioning was a significant negative predictor of child weight status (pooled beta coefficient = -0.14; 95% confidence interval [CI] [-0.22 to -0.07]; I²  = 97%). The pooled odds ratio also revealed that high EF children had a significant lower risk for developing overweight/obesity (odds ratio [OR] = 0.72; 95% CI [0.59 to 0.87]; I²  = 72%). Conversely, child weight status was a significant negative predictor of overall executive functioning (pooled beta coefficient = -0.06; 95% CI [-0.12 to -0.01]; I²  = 81%). These results suggest a bidirectional prediction between child weight status and EF. These predictabilities are low but potentially beneficial for implementation in childcare systems.

Interactions between emotions and eating behaviors: Main issues, neuroimaging contributions, and innovative preventive or corrective strategies

Emotional eating is commonly defined as the tendency to (over)eat in response to emotion. Insofar as it involves the (over)consumption of high-calorie palatable foods, emotional eating is a maladaptive behavior that can lead to eating disorders, and ultimately to metabolic disorders and obesity. Emotional eating is associated with eating disorder subtypes and with abnormalities in emotion processing at a behavioral level. However, not enough is known about the neural pathways involved in both emotion processing and food intake. In this review, we provide an overview of recent neuroimaging studies, highlighting the brain correlates between emotions and eating behavior that may be involved in emotional eating. Interaction between neural and neuro-endocrine pathways (HPA axis) may be involved. In addition to behavioral interventions, there is a need for a holistic approach encompassing both neural and physiological levels to prevent emotional eating. Based on recent imaging, this review indicates that more attention should be paid to prefrontal areas, the insular and orbitofrontal cortices, and reward pathways, in addition to regions that play a major role in both the cognitive control of emotions and eating behavior. Identifying these brain regions could allow for neuromodulation interventions, including neurofeedback training, which deserves further investigation.

Inflammatory Signatures of Maternal Obesity as Risk Factors for Neurodevelopmental Disorders: Role of Maternal Microbiota and Nutritional Intervention Strategies

Obesity is a main risk factor for the onset and the precipitation of many non-communicable diseases. This condition, which is associated with low-grade chronic systemic inflammation, is of main concern during pregnancy leading to very serious consequences for the new generations. In addition to the prominent role played by the adipose tissue, dysbiosis of the maternal gut may also sustain the obesity-related inflammatory milieu contributing to create an overall suboptimal intrauterine environment. Such a condition here generically defined as “inflamed womb” may hold long-term detrimental effects on fetal brain development, increasing the vulnerability to mental disorders. In this review, we will examine the hypothesis that maternal obesity-related gut dysbiosis and the associated inflammation might specifically target fetal brain microglia, the resident brain immune macrophages, altering neurodevelopmental trajectories in a sex-dependent fashion. We will also review some of the most promising nutritional strategies capable to prevent or counteract the effects of maternal obesity through the modulation of inflammation and oxidative stress or by targeting the maternal microbiota.

Impact of Environmental Pollutants on Gut Microbiome and Mental Health via the Gut–Brain Axis

Over the last few years, the microbiome has emerged as a high-priority research area to discover missing links between brain health and gut dysbiosis. Emerging evidence suggests that the commensal gut microbiome is an important regulator of the gut–brain axis and plays a critical role in brain physiology. Engaging microbiome-generated metabolites such as short-chain fatty acids, the immune system, the enteric nervous system, the endocrine system (including the HPA axis), tryptophan metabolism or the vagus nerve plays a crucial role in communication between the gut microbes and the brain. Humans are exposed to a wide range of pollutants in everyday life that impact our intestinal microbiota and manipulate the bidirectional communication between the gut and the brain, resulting in predisposition to psychiatric or neurological disorders. However, the interaction between xenobiotics, microbiota and neurotoxicity has yet to be completely investigated. Although research into the precise processes of the microbiota–gut–brain axis is growing rapidly, comprehending the implications of environmental contaminants remains challenging. In these milieus, we herein discuss how various environmental pollutants such as phthalates, heavy metals, Bisphenol A and particulate matter may alter the intricate microbiota–gut–brain axis thereby impacting our neurological and overall mental health.

Effect of Tanshinone IIA on Gut Microbiome in Diabetes-Induced Cognitive Impairment

Diabetes-induced cognitive impairment (DCI) presents a major public health risk among the aging population. Previous clinical attempts on known therapeutic targets for DCI, such as depleted insulin secretion, insulin resistance, and hyperglycaemia have delivered poor patient outcomes. However, recent evidence has demonstrated that the gut microbiome plays an important role in DCI by modulating cognitive function through the gut–brain crosstalk. The bioactive compound tanshinone IIA (TAN) has shown to improve cognitive and memory function in diabetes mellitus models, though the pharmacological actions are not fully understood. This study aims to investigate the effect and underlying mechanism of TAN in attenuating DCI in relation to regulating the gut microbiome. Metagenomic sequencing analyses were performed on a group of control rats, rats with diabetes induced by a high-fat/high-glucose diet (HFD) and streptozotocin (STZ) (model group) and TAN-treated diabetic rats (TAN group). Cognitive and memory function were assessed by the Morris water maze test, histopathological assessment of brain tissues, and immunoblotting of neurological biomarkers. The fasting blood glucose (FBG) level was monitored throughout the experiments. The levels of serum lipopolysaccharide (LPS) and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunoassays to reflect the circulatory inflammation level. The morphology of the colon barrier was observed by histopathological staining. Our study confirmed that TAN reduced the FBG level and improved the cognitive and memory function against HFD- and STZ-induced diabetes. TAN protected the endothelial tight junction in the hippocampus and colon, regulated neuronal biomarkers, and lowered the serum levels of LPS and TNF-α. TAN corrected the reduced abundance of Bacteroidetes in diabetic rats. At the species level, TAN regulated the abundance of B. dorei, Lachnoclostridium sp. YL32 and Clostridiodes difficile. TAN modulated the lipid metabolism and biosynthesis of fatty acids in related pathways as the main functional components. TAN significantly restored the reduced levels of isobutyric acid and butyric acid. Our results supported the use of TAN as a promising therapeutic agent for DCI, in which the underlying mechanism may be associated with gut microbiome regulation.

Correlation of Autoimmune Pancreatitis and Malignancy: Systematic Review and Meta-Analysis

BACKGROUND

There is conflicting evidence regarding autoimmune pancreatitis (AIP) association with pancreatic and non-pancreatic cancers. Literature lacks data on overall prevalence of malignancies in autoimmune pancreatitis.

AIM

Given the lack of definite evidence, we aimed to pool and summarize data from available literature regarding prevalence of different malignancies in AIP.

METHODS

We conducted a systematic search of MEDLINE, EMBASE, Cochrane Register of Controlled Trials, and Web of Science through February 16, 2021, to include observational studies assessing the incidence of cancer in AIP. We used the DerSimonian-Laird method with random effects for meta-analysis. Pooled prevalence, 95% confidence interval (CI), and I² statistic are reported.

RESULTS

A total of 17 studies with 2746 patients were included assessing the prevalence of cancer in AIP. The overall prevalence of cancer in AIP was 9.6% [95% confidence interval (CI), 5.7-13.5%]. The cancers with the highest prevalence in AIP population were gastric and colorectal cancer, with prevalence of 1.3% (95% CI, 0.5-2.1%) and 1.2% (95% CI, 0.6-1.8%), respectively.

CONCLUSION

We demonstrate the prevalence of different cancers in AIP. Inflammatory surge in AIP and subsequent carcinogenesis is one explanation for this association. Moreover, AIP can be a paraneoplastic syndrome manifestation of malignancies.

Dietary Supplement of Anoectochilus roxburghii (Wall.) Lindl. Polysaccharides Ameliorates Cognitive Dysfunction Induced by High Fat Diet via “Gut-Brain” Axis

Purpose

Anoectochilus roxburghii (Wall.) Lindl. polysaccharides (ARPs) have been reported to exhibit multiple pharmacological activities including anti-inflammatory and anti-hyperglycemia. This study aims to investigate the effect of ARPs on cognitive dysfunction induced by high fat diet (HFD).

Methods

Six-week-old male mice were treated with ARPs by dietary supplementation for 14 weeks. The effect of ARPs on cognitive function was determined by assessing the changes in spatial learning and memory ability, neurotrophic factors in hippocampus, inflammatory parameters, intestinal barrier integrity, and gut microbiota.

Results

ARPs supplementation can effectively ameliorate cognitive dysfunction, decrease the phosphorylation levels of Tau protein in hippocampus. Meanwhile, the increased body weight, plasma glucose, total cholesterol, inflammatory factors induced by HFD were abolished by ARPs treatment. Furthermore, ARPs treatment restored the intestinal epithelial barrier as evidenced by upregulation of intestinal tight junction proteins. Additionally, ARPs supplementation significantly decreased the relative abundance of several bacteria genus such as Parabacteroides, which may play regulatory roles in cognitive function.

Conclusion

These results suggest that ARPs might be a promising strategy for the treatment of cognitive dysfunction induced by HFD. Mechanistically, alleviation of cognitive dysfunction by ARPs might be associated with the “gut-brain” axis.

Adipokines Level and Cognitive Function-Disturbance in Homeostasis in Older People with Poorly Managed Hypertension: A Pilot Study

Aim: To explore the network relationship between cognitive function, depressive symptom intensity, body composition, proxies of cognitive reserve, trophic factor, adipokines and myokines, physical performance and blood pressure in a group of older people with poorly managed hypertension (PMHTN) compared to a normotensive (NTN) group. Materials and methods: History of hypertension and blood pressure level were examined in older participants. Thirty-one subjects diagnosed with PMHTN (history of hypertension diagnosis and values of sBP or dBP over 140/90 mmHg) and eighteen NTN (lack of history of hypertension and sBP and dBP lower than 140/90 mmHg) participated. Participants completed physical and cognitive function assessments: including the Mini–Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and its two subtests Delayed Recall (DR) and Verbal Fluency (VF) and Trail Making Test Part B (TMT B). Factors associated with cognitive functioning: age, years of education, cognitive and travel activity were assessed using a questionnaire. Visceral fat was determined by bioimpedance testing and gait velocity and agility assessed using an Up and Go test. To summarize the strength and direction (negative or positive) of a relationship between two variables, Spearman’s rank correlation coefficient was used. Then, network graphs were created to illustrate the relationship between variables. Node strength (number of edges per node), neighbourhood connectivity (the average connectivity of all the neighbours of a node), stress (the number of shortest paths passing through each node) were compared in network from PMHTN group to network from NTN group. Results: Neighbourhood connectivity and stress were significantly higher in of the PMHTN network compared to NTN (6.03 ± 1.5 vs. 4.23 ± 2.5, p = 0.005 and 118.21 ± 137.6 vs. 56.87 ± 101.5, p = 0.02, accordingly). Conclusion: In older subjects with poorly managed hypertension, dyshomeostasis was observed, compared to normotensive subjects.

Morbid Obesity in Women Is Associated with an Altered Intestinal Expression of Genes Related to Cancer Risk and Immune, Defensive, and Antimicrobial Response

Background: Little is known about the relation between morbid obesity and duodenal transcriptomic changes. We aimed to identify intestinal genes that may be associated with the development of obesity regardless of the degree of insulin resistance (IR) of patients. Material and Methods: Duodenal samples were assessed by microarray in three groups of women: non-obese women and women with morbid obesity with low and high IR. Results: We identified differentially expressed genes (DEGs) associated with morbid obesity, regardless of IR degree, related to digestion and lipid metabolism, defense response and inflammatory processes, maintenance of the gastrointestinal epithelium, wound healing and homeostasis, and the development of gastrointestinal cancer. However, other DEGs depended on the IR degree. We mainly found an upregulation of genes involved in the response to external organisms, hypoxia, and wound healing functions in women with morbid obesity and low IR. Conclusions: Regardless of the degree of IR, morbid obesity is associated with an altered expression of genes related to intestinal defenses, antimicrobial and immune responses, and gastrointestinal cancer. Our data also suggest a deficient duodenal immune and antimicrobial response in women with high IR.

Gut–brain Axis: Impact of Intestinal Inflammation and Micronutrient Deficiency on Psychomotor Development and Cognitive Functions in Egyptian Children with UndernutritionGut–brain Axis: Impact of Intestinal Inflammation and Micronutrient Deficiency on Psychomotor Development and Cognitive Functions in Egyptian Children with Undernutrition

Cognitive impairment, growth faltering and stunting are pervasive in many countries. mostly causes are unknown. Role of intestinal inflammation in such cases should be minded especially in low- and middle-income countries. We assessed serum markers of inflammation, fecal markers of intestinal inflammation and serum micronutrients in cases with aged 1 to 10 years who suffer from moderate or severe malnutrition “weight-for-age z-score and height-for-age z- Score (WAZ or HAZ) less than -2 SD”. Cognitive abilities were assessed using Wechsler intelligence scale for preschool and school children, Bayley scale III. 55.6% of preschool cases were below average or had mild or moderate intelligence retardation while 24.5% of school cases and 5% of children below 2 years were below average regarding cognitive functions. Cases showed statistically significant reduction of vitamin D, zinc and iron as compared to control. Serum markers of inflammation (alpha 1- glycoprotein (a1-AGP), endotoxin core protein (EndoCAB)) and fecal markers of intestinal inflammation (alpha 1 antitrypsin (AAT) and neopterin (NEOP)) were significant higher in cases than controls. School children showed negative correlation between processing functions and( a1-AGP), positive correlation between perceptual reasoning and serum vitamin A. Children below 2 years, showed negative correlations between motor function and (AAT), (a1-AGP), tumor necrosis factor- alpha (TNF-a) and (EndoCAB), positive correlation between language and serum zinc. In conclusion, our study showed impaired neurocognitive and psychomotor functions in malnourished stunted children. Also, vitamins and minerals deficiency and increased markers of intestinal inflammation were observed in cases compared to healthy control.

Obesity and gut-microbiota-brain axis: A narrative review

Introduction

Obesity is a major health problem that is associated with many physiological and mental disorders, such as diabetes, stroke, and depression. Gut microbiota has been affirmed to interact with various organs, including the brain. Intestinal microbiota and their metabolites might target the brain directly via vagal stimulation or indirectly through immune‐neuroendocrine mechanisms, and they can regulate metabolism, adiposity, homoeostasis and energy balance, and central appetite and food reward signaling, which together have crucial roles in obesity. Studies support the concept of bidirectional signaling within the gut–brain axis (GBA) in the pathophysiology of obesity, mediated by metabolic, endocrine, neural, and immune system mechanisms.

Materials and methods

Scopus, PubMed, Google Scholar, and Web of Science databases were searched to find relevant studies.

Results

The gut–brain axis (GBA), a bidirectional connection between the gut microbiota and brain, influences physiological function and behavior through three different pathways. Neural pathway mainly consists of the enteric nervous system (ENS) and vagus nerve. Endocrine pathway, however, affects the neuroendocrine system of the brain, particularly the hypothalamus–pituitary–adrenal (HPA) axis and immunological pathway. Several alterations in the gut microbiome can lead to obesity, by modulating metabolic pathways and eating behaviors of the host through GBA. Therefore, novel therapies targeting the gut microbiome, i.e., fecal microbiota transplantation and supplementation with probiotics and prebiotics, can be a potential treatment for obesity.

Conclusion

This study corroborates the effect of gut microbiome on physiological function and body weight. The results show that the gut microbiota is becoming a target for new antiobesity therapies.

Dietary fatty acids affect learning and memory ability via regulating inflammatory factors in obese mice

OBJECTIVE

High-fat diets are linked to obesity, contributing to the alterations in inflammatory signaling pathways, which is associated with cognitive function. We aim to investigate the mechanisms by which various different types of dietary fatty acids affecting cognitive function in obese mice through the gut/brain axis-inflammatory signaling pathway.

METHODS AND RESULTS

Eight-week-old male C57BL/6 mice were fed with basal diet (control group), lard high-fat diet (containing long-chain saturated fatty acid (LCSFA group)), coconut oil high-fat diet (containing medium-chain saturated fatty acid (MCSFA group)), linseed oil high-fat diet (containing n-3 polyunsaturated fatty acid (n-3 PUFA group)), soybean oil high-fat diet (containing n-6 polyunsaturated fatty acid (n-6 PUFA group)), olive oil high-fat diet (containing monounsaturated fatty acid (MUFA group)) and 8% hydrogenated soybean oil high-fat diet (containing trans fatty acid (TFA group)) respectively for 16 weeks. Our results revealed that the mean escape latency was significantly prolonged in LCSFA group, and the latency to cross the platform location of n-6 PUFA and TFA groups were increased significantly. The differences of inflammatory markers and toll-like receptor-myeloid differentiation factor-88-nuclear factor kappa-B (TLR-MyD88-NF-κB) inflammatory signaling pathway expressions among all groups reached statistical significances.

CONCLUSION

Compared to basal diet, high-fat diets enriched in LCSFA, MCSFA, n-6 PUFA, MUFA, and TFA might exert detrimental effects on cognitive function in obese mice via regulating the inflammatory markers and inflammatory signaling pathway in brain and intestine. High-fat diet enriched in n-3 PUFA might exhibit different effect on modulating inflammatory responses in different tissues and might benefit to cognitive function.

Investigating the potential of fish oil as a nutraceutical in an animal model of early life stress

Background: Early life stress is a key predisposing factor for depression and anxiety disorders. Selective serotonin re-uptake inhibitors (SSRI) are frequently used as the first line of pharmacology treatment for depression but have several negative qualities, i.e. a delay or absence of effectiveness and negative side-effects. Therefore, there is a growing need for new nutraceutical-based strategies to blunt the effects of adverse-life events.Objectives: This study aimed to use the maternal separation model in rats to test the efficacy of fish oil dietary supplementation, on its own and in conjunction with the SSRI anti-depressant fluoxetine, as a treatment for depressive and anxiety-like symptoms associated with early life stress.Methods: Behavioural tests (open field test, elevated plus maze test and forced swim test) and biochemical markers (corticosterone, BDNF, brain fatty acids and short chain fatty acids) were used to analyse the effects of the dietary treatments. Gut microbial communities and relating metabolites (SCFA) were analysed to investigate possible changes in the microbiota-gut-brain axis.Results: Maternally separated rats showed depressive-like behaviours in the forced swim and open field tests. These behaviours were prevented significantly by fluoxetine administration and in part by fish oil supplementation. Associated biochemical changes reported include altered brain fatty acids, significantly lower plasma corticosterone levels (AUC) and reduced brain stem serotonin turnover, compared to untreated, maternally separated (MS) rats. Untreated MS animals had significantly lower ratios of SCFA producers such as Caldicoprobacteraceae, Streptococcaceae, Rothia, Lachnospiraceae_NC2004_group, and Ruminococcus_2, along with significantly reduced levels of total SCFA compared to non-separated animals. Compared to untreated MS animals, animals fed fish oil had significantly higher Bacteroidetes and Prevotellaceae and reduced levels of butyrate, while fluoxetine treatment resulted in significantly higher levels of Neochlamydia, Lachnoclostridium, Acetitomaculum and Stenotrophomonas and, acetate and propionate.Conclusion: Despite the limitations in extrapolating from animal behavioural data and the notable differences in pharmacokinetics between rodents and humans, the results of this study provide a further advancement into the understanding of some of the complex systems within which nutraceuticals and pharmaceuticals effect the microbiota-gut-brain axis.

Potential role of gut microbiota in patients with COVID-19, its relationship with lung axis, central nervous system (CNS) axis, and improvement with probiotic therapy

Coronavirus Disease 2019 (COVID-19) is a pandemic disease caused by a new corona virus. COVID-19 affects different people in different ways. COVID-19 could affect the gastrointestinal system via gut microbiota impairment. Gut microbiota could affect lung health through a relationship between gut and lung microbiota, which is named gut-lung axis. Gut microbiota impairment plays a role in pathogenesis of various pulmonary disease states, so GI diseases were found to be associated with respiratory diseases. Moreover, most infected people will develop mild to moderate gastrointestinal (GI) symptoms such as diarrhea, vomiting, and stomachache, which is caused by impairment in gut microbiota. Therefore, the current study aimed to review potential role of gut microbiota in patients with COVID-19, its relation with lung axis, Central Nervous System (CNS) axis and improvement with probiotic therapy. Also, this review can be a guide for potential role of gut microbiota in patients with COVID-19.

The microbiota-gut-brain axis: pathways to better brain health. Perspectives on what we know, what we need to investigate and how to put knowledge into practice

The gut and brain link via various metabolic and signalling pathways, each with the potential to influence mental, brain and cognitive health. Over the past decade, the involvement of the gut microbiota in gut-brain communication has become the focus of increased scientific interest, establishing the microbiota-gut-brain axis as a field of research. There is a growing number of association studies exploring the gut microbiota's possible role in memory, learning, anxiety, stress, neurodevelopmental and neurodegenerative disorders. Consequently, attention is now turning to how the microbiota can become the target of nutritional and therapeutic strategies for improved brain health and well-being. However, while such strategies that target the gut microbiota to influence brain health and function are currently under development with varying levels of success, still very little is yet known about the triggers and mechanisms underlying the gut microbiota's apparent influence on cognitive or brain function and most evidence comes from pre-clinical studies rather than well controlled clinical trials/investigations. Filling the knowledge gaps requires establishing a standardised methodology for human studies, including strong guidance for specific focus areas of the microbiota-gut-brain axis, the need for more extensive biological sample analyses, and identification of relevant biomarkers. Other urgent requirements are new advanced models for in vitro and in vivo studies of relevant mechanisms, and a greater focus on omics technologies with supporting bioinformatics resources (training, tools) to efficiently translate study findings, as well as the identification of relevant targets in study populations. The key to building a validated evidence base rely on increasing knowledge sharing and multi-disciplinary collaborations, along with continued public-private funding support. This will allow microbiota-gut-brain axis research to move to its next phase so we can identify realistic opportunities to modulate the microbiota for better brain health.

Pelzer B, Khodamoradi Y, Vehreschild MJGT. The role of the human gut microbiota in colonization and infection with multidrug-resistant bacteria

About 100 years ago, the first antibiotic drug was introduced into health care. Since then, antibiotics have made an outstanding impact on human medicine. However, our society increasingly suffers from collateral damage exerted by these highly effective drugs. The rise of resistant pathogen strains, combined with a reduction of microbiota diversity upon antibiotic treatment, has become a significant obstacle in the fight against invasive infections worldwide.Alternative and complementary strategies to classical "Fleming antibiotics" comprise microbiota-based treatments such as fecal microbiota transfer and administration of probiotics, live-biotherapeutics, prebiotics, and postbiotics. Other promising interventions, whose efficacy may also be influenced by the human microbiota, are phages and vaccines. They will facilitate antimicrobial stewardship, to date the only globally applied antibiotic resistance mitigation strategy.In this review, we present the available evidence on these nontraditional interventions, highlight their interaction with the human microbiota, and discuss their clinical applicability.

Obesity in adolescents may be associated with limitations in daily activities and an increased level of anxiety in patients and their parents - preliminary results of a pilot study

Obesity is a chronic disease, that in adolescents may lead to serious consequences affecting somatic and mental health. This study aimed to assess the prevalence of depressive symptoms and anxiety in adolescents with obesity and their parents. The relationships between depressive and anxiety symptoms and the somatic consequences of obesity were also analyzed.

MATERIAL AND METHODS

19 patients with obesity (BMI Z-SCORE 2.1-5.5), at the age 16-17, and their parents answered validated questionnaires (Children's Depression Inventory 2, The State-Trait Anxiety Inventory), and a survey assessing everyday functioning.

RESULTS

There were no significant differences in the occurrence of symptoms of depression in children and their parents: for the overall scale score of T-score (p=0.331), for the emotional problems (p=0.281) subscale, and the functional problems (p=0.147) subscale. The comparison of the results between boys and girls revealed no significant differences. A significantly higher level of anxiety was found in parents of children who gained weight in the year preceding the study (p = 0.046), and both in children and parents of children with metabolic-associated fatty liver disease - MAFLD (p=0.022 and p=0.007). According to adolescents, obesity affects the most leisure activities.

CONCLUSION

Obesity, like any chronic disease, can have a significant impact on the emotional state of children and adolescents as well as the possibility of realizing interests and spending free time. Much more important than depressive disorders are anxiety disorders concerning both patients and their parents.

Obesity status and obesity-associated gut dysbiosis effects on hypothalamic structural covariance

BACKGROUND

Functional connectivity alterations in the lateral and medial hypothalamic networks have been associated with the development and maintenance of obesity, but the possible impact on the structural properties of these networks remains largely unexplored. Also, obesity-related gut dysbiosis may delineate specific hypothalamic alterations within obese conditions. We aim to assess the effects of obesity, and obesity and gut-dysbiosis on the structural covariance differences in hypothalamic networks, executive functioning, and depressive symptoms.

METHODS

Medial (MH) and lateral (LH) hypothalamic structural covariance alterations were identified in 57 subjects with obesity compared to 47 subjects without obesity. Gut dysbiosis in the subjects with obesity was defined by the presence of high (n = 28) and low (n = 29) values in a BMI-associated microbial signature, and posthoc comparisons between these groups were used as a proxy to explore the role of obesity-related gut dysbiosis on the hypothalamic measurements, executive function, and depressive symptoms.

RESULTS

Structural covariance alterations between the MH and the striatum, lateral prefrontal, cingulate, insula, and temporal cortices are congruent with previously functional connectivity disruptions in obesity conditions. MH structural covariance decreases encompassed postcentral parietal cortices in the subjects with obesity and gut-dysbiosis, but increases with subcortical nuclei involved in the coding food-related hedonic information in the subjects with obesity without gut-dysbiosis. Alterations for the structural covariance of the LH in the subjects with obesity and gut-dysbiosis encompassed increases with frontolimbic networks, but decreases with the lateral orbitofrontal cortex in the subjects with obesity without gut-dysbiosis. Subjects with obesity and gut dysbiosis showed higher executive dysfunction and depressive symptoms.

CONCLUSIONS

Obesity-related gut dysbiosis is linked to specific structural covariance alterations in hypothalamic networks relevant to the integration of somatic-visceral information, and emotion regulation.

Non-alcoholic fatty liver disease in irritable bowel syndrome: More than a coincidence?

Irritable bowel syndrome (IBS) and non-alcoholic fatty liver disease (NAFLD) are amongst the most common gastrointestinal and liver conditions encountered in primary and secondary care. Recently, there has been interest in the apparent co-incidence of NAFLD in patients with IBS mainly driven by improved understanding of their shared risk factors and pathophysiology. In this paper we summarize the shared risk factors which include; overlapping nutritional and dietary factors as well as shared putative mechanisms of pathophysiology. These include changes in the gut microbiome, gut permeability, immunity, small bowel bacterial overgrowth and bile acid metabolism. This paper describes how these shared risk factors and etiological factors may have practical clinical implications for these highly prevalent conditions. It also highlights some of the limitations of current epidemiological data relating to estimates of the overlapping prevalence of the two conditions which have resulted in inconsistent results and, therefore the need for further research. Early recognition and management of the overlap could potentially have impacts on treatment outcomes, compliance and morbidity of both conditions. Patients with known IBS who have abnormal liver function tests or significant risk factors for NAFLD should be investigated appropriately for this possibility. Similarly, IBS should be considered in patients with NAFLD and symptoms of abdominal pain associated with defecation, an altered bowel habit and bloating.

Model Integration: Can Understanding Biopsychosocial Gut-Brain Axis Mechanistic Pathways Improve our Clinical Reasoning in Primary Care?

Introduction

Most NPs practice in primary care settings. Cognitive tools to inform and advance NP understanding of biopsychosocial mechanisms can support early recognition, interdisciplinary collaboration, interventions, and prevention of negative outcomes.

Theory and Methods

We describe the development of a model to support NP consideration of gut-brain axis (GBA) evidence-based pathways, contributing variables, and related health outcomes.

Results

The model's outcomes are factors associated with homeostasis or disruption of biological, psychological, and social systems.

Discussion/conclusion

This cognitive tool aims to support NP awareness of multi-domain GBA relationships to consider with differential diagnoses and clinical treatment of the "whole body system".

Non-Alcoholic Fatty Liver Disease (NAFLD) and Potential Links to Depression, Anxiety, and Chronic Stress

Non-alcoholic fatty liver disease (NAFLD) constitutes the most common liver disease worldwide, and is frequently linked to the metabolic syndrome. The latter represents a clustering of related cardio-metabolic components, which are often observed in patients with NAFLD and increase the risk of cardiovascular disease. Furthermore, growing evidence suggests a positive association between metabolic syndrome and certain mental health problems (e.g., depression, anxiety, and chronic stress). Given the strong overlap between metabolic syndrome and NAFLD, and the common underlying mechanisms that link the two conditions, it is probable that potentially bidirectional associations are also present between NAFLD and mental health comorbidity. The identification of such links is worthy of further investigation, as this can inform more targeted interventions for patients with NAFLD. Therefore, the present review discusses published evidence in relation to associations of depression, anxiety, stress, and impaired health-related quality of life with NAFLD and metabolic syndrome. Attention is also drawn to the complex nature of affective disorders and potential overlapping symptoms between such conditions and NAFLD, while a focus is also placed on the postulated mechanisms mediating associations between mental health and both NAFLD and metabolic syndrome. Relevant gaps/weaknesses of the available literature are also highlighted, together with future research directions that need to be further explored.

Effects of semi-purified diet on depressive behaviors in aged mice

Diet is a key modifiable factor influencing the composition of gut microbiota. There are two types of commercially available diets for experimental animals: non-purified and semi-purified diets. Non-purified diets are composed of complex ingredients from multiple sources, while semi-purified diets are formulated with refined ingredients. Accumulating evidence has demonstrated a link between the gut microbiota and depression, and feed ingredients may influence depressive physiology and behaviors. To test this hypothesis, we examined how chronic non-purified (CRF-1) and semi-purified (AIN-93G) diets affected phenotypes, including depressive behaviors, plasma corticosterone levels, and small-intestine microbiota in young (2 months old) and aged (22 months old) inbred C57BL/JJcl mice. In young mice, similar phenotypes were associated with non-purified and semi-purified diets. However, in aged mice, semi-purified diets increased depressive behaviors in the tail suspension (P < 0.05) and forced swimming tests (P < 0.01). The corticosterone levels were similar between the two diets under normal rearing conditions. However, immediately after exposure to the stressful conditions of the forced swimming test, the corticosterone levels in the aged mice fed the semi-purified diet were higher than those of mice fed the non-purified diet (P < 0.05). There were fewer Lactobacillales in the small intestines of aged mice fed the semi-purified diet compared to those fed the non-purified diet (P < 0.01). Further, α-diversity was lower in aged mice fed the semi-purified versus non-purified diet (P < 0.01). Our results indicate that host physiology and gut microbiota differed according to whether the aged mice were fed a non-purified or semi-purified diet. Specifically, those fed the semi-purified diet were more vulnerable to stress than age-matched mice fed the non-purified diet. Our findings indicate that researchers should consider the effects of feed ingredients on depressive physiology and behaviors, and select diets that are appropriate for their particular research design. Further, identification of the ingredients in non-purified diets could facilitate examination of the mechanisms by which gut microbiota composition might increase resistance to stress and depression.

Gut commensal-derived butyrate reverses obesity-induced social deficits and anxiety-like behaviors via regulation of microglial homeostasis

Neuropsychiatric dysfunction and reactive microglia are hallmarks of high-fat diet (HFD)-induced obesity, yet whether these reactive microglia contribute to HFD-induced obesity-related behavioral abnormalities and the underlying mechanisms remain unclear. Here, we show that HFD feeding causes social deficits and anxiety-like behaviors with impaired neuronal activity and alters the gut microbiota, particularly by depleting Lactobacillus reuteri (L. reuteri), in mice. The profiles of microbiome and metabolome in HFD-fed mice predict that specific microbial taxa and their metabolites regulate HFD-induced obesity-related behavioral abnormalities. Oral treatment with the L. reuteri reduces microglial activation and increases dendritic spine density, thus ameliorates social deficits and anxiety in HFD-fed mice. HFD-fed mice that are administered L. reuteri are also found to accumulate butyrate in their gut, sera and brain. Moreover, supplementation of butyrate improves behavioral abnormalities and modulates microglial homeostasis in HFD-fed mice. In addition, selectively removal of microglia through a pharmacologic approach can rescue dendritic spine loss and increase neuronal activity that profoundly alleviates social deficits and anxiety arising from HFD-induced obesity. Overall, this study reveals an unexpected pivotal role of gut commensal-derived butyrate in HFD-induced social deficits and anxiety-like behaviors through regulation of microglial homeostasis and identifies a potential probiotic treatment for HFD-induced obesity-related behavioral abnormalities.

Maintaining the Balance of Intestinal Flora through the Diet: Effective Prevention of Illness

The human body is home to a complex community of dynamic equilibrium microbiota, including bacteria, fungi, parasites, and viruses. It is known that the gut microbiome plays a crucial role in regulating innate and adaptive immune responses, intestinal peristalsis, intestinal barrier homeostasis, nutrient uptake, and fat distribution. The complex relationship between the host and microbiome suggests that when this relationship is out of balance, the microbiome may contribute to disease development. The brain-gut-microbial axis is composed of many signal molecules, gastrointestinal mucosal cells, the vagus nerve, and blood-brain barrier, which plays an essential role in developing many diseases. The microbiome can influence the central nervous system function through the brain-gut axis; the central nervous system can also affect the composition and partial functions of the gut microbiome in the same way. Different dietary patterns, specific dietary components, and functional dietary factors can significantly affect intestinal flora's structure, composition, and function, thereby affecting human health. Based on the above, this paper reviewed the relationship between diet, intestinal flora, and human health, and the strategies to prevent mental illness through the dietary modification of intestinal microorganisms.

Effect of Eicosapentaenoic Acid Supplementation on Murine Preadipocytes 3T3-L1 Cells Activated with Lipopolysaccharide and/or Tumor Necrosis Factor-α

The beneficial effect of n-3 fatty acids can be related to anti-inflammatory properties. The aim of the study was to analyzed the effect of eicosapentaenoic acid (EPA) on 3T3-L1 cells (murine embryonic fibroblasts‒preadipocytes) activated with inflammatory factors (IF). Cells were incubated with 50 µmol of EPA for 48 h, and then activated with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α). The level of cycloxygenase-2 (Prostaglandin-Endoperoxide Synthase 2, PTGS2, COX-2), cytosolic prostaglandin synthase E2 (cPGES), fatty acid binding protein 4 (FABP4), toll-like receptor 4 (TLR4), glucose receptor type 4 (GLUT-4), and cannabinoid receptor 2 (CB2) was determined using Western blot analysis. The phospholipase A2 (Pla2g4a), and prostaglandin-Endoperoxide Synthase 2 (Ptgs2) gene expression was analyzed by real-time qPCR. After EPA and IF activation, a significant decrease in the COX-2, cPGES, and TRL4 protein levels was observed. Incubation of cells with EPA and IF resulted in a decrease in Ptgs2 and an increase in the Pla2g4a gene. A significant increase in the CB2 protein was observed in adipocytes co-treated with EPA and IF. The results indicated an anti-inflammatory properties of EPA. Interestingly, the activation of the GLUT4 receptor by EPA suggests an unique role of this FA in the regulation of the adipocyte metabolism and prevention of insulin resistance.

Diet and the Microbiota-Gut-Brain Axis: Sowing the Seeds of Good Mental Health

Over the past decade, the gut microbiota has emerged as a key component in regulating brain processes and behavior. Diet is one of the major factors involved in shaping the gut microbiota composition across the lifespan. However, whether and how diet can affect the brain via its effects on the microbiota is only now beginning to receive attention. Several mechanisms for gut-to-brain communication have been identified, including microbial metabolites, immune, neuronal, and metabolic pathways, some of which could be prone to dietary modulation. Animal studies investigating the potential of nutritional interventions on the microbiota-gut-brain axis have led to advancements in our understanding of the role of diet in this bidirectional communication. In this review, we summarize the current state of the literature triangulating diet, microbiota, and host behavior/brain processes and discuss potential underlying mechanisms. Additionally, determinants of the responsiveness to a dietary intervention and evidence for the microbiota as an underlying modulator of the effect of diet on brain health are outlined. In particular, we emphasize the understudied use of whole-dietary approaches in this endeavor and the need for greater evidence from clinical populations. While promising results are reported, additional data, specifically from clinical cohorts, are required to provide evidence-based recommendations for the development of microbiota-targeted, whole-dietary strategies to improve brain and mental health.

Bacteroides uniformis CECT 7771 Modulates the Brain Reward Response to Reduce Binge Eating and Anxiety-Like Behavior in Rat

Food addiction (FA) is characterized by behavioral and neurochemical changes linked to loss of food intake control. Gut microbiota may influence appetite and food intake via endocrine and neural routes. The gut microbiota is known to impact homeostatic energy mechanisms, but its role in regulating the reward system is less certain. We show that the administration of Bacteroides uniformis CECT 7771 (B. uniformis) in a rat FA model impacts on the brain reward response, ameliorating binge eating and decreasing anxiety-like behavior. These effects are mediated, at least in part, by changes in the levels of dopamine, serotonin, and noradrenaline in the nucleus accumbens and in the expression of dopamine D1 and D2 receptors in the prefrontal cortex and intestine. B. uniformis reverses the fasting-induced microbiota changes and increases the abundance of species linked to healthy metabolotypes. Our data indicate that microbiota-based interventions might help to control compulsive overeating by modulating the reward response.

The neurotherapeutic role of a selenium-functionalized quinoline in hypothalamic obese rats

RATIONALE

Obesity is considered one of the major global health problems and increases the risk of several medical complications, such as diabetes and mental illnesses.

OBJECTIVE

The present study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) on obesity parameters, behavioral and neurochemical alterations in hypothalamic obese rats.

METHODS

Male Wistar rats received subcutaneous neonatal injections of monosodium glutamate (MSG, 4g/kg) or saline. After the Lee Index evaluation, rats were divided into groups and treated with 4-PSQ (5 mg/kg, intragastric route) or canola oil once a day (post-natal days (PND) 60→76). Open-field, elevated plus-maze, forced swim task, object recognition/location memory, and stepdown inhibitory avoidance tasks were conducted from PND 66 to 74. On PND 76, rats were euthanized and epididymal fat, blood, cerebral cortex, andhippocampus were removed. Blood biochemical parameters and cortical/hippocampal acetylcholinesterase (AChE) and Na /K -ATPase activities were assessed.

RESULTS

MSG increased the Lee Index characterizing the chemically induced hypothalamic obesity model. 4-PSQ reversed the increases of epididymal fat, blood glucose, and triglyceride levels caused by MSG exposure. 4-PSQ attenuated anxiety-like and depression-like behaviors induced by neonatal administrations of MSG. Memory deficits found in MSG-obese rats were reversed by treatment with 4-PSQ. Neurochemical alterations produced by MSG evidenced by stimulation ofNa⁺/K⁺-ATPase and AChE activities in the cerebral cortex and hippocampus of rats were normalized by 4-PSQ treatment.

CONCLUSIONS

In brief, 4-PSQ therapy improved hypothalamic obesity-related parameters, as well as psychiatric symptoms, cognitive impairment, and neurochemical alterations found in obese rats.

The Link between Obesity, Microbiota Dysbiosis, and Neurodegenerative Pathogenesis

Current research in medicine in several parts of the world has attempted to establish a link between the occurrence of neurodegenerative pathologies, microbiota dysbiosis, and the incidence of obesity. The body’s response to different physicochemical factors has also been influenced by the proper assimilation of bioactive compounds contained in the food that is ingested. Oxidative stress is one of the major factors that directly affects the functioning of the human microbiota. The body’s reaction to this imbalance is crucial to the progression of inflammatory processes, which are based on molecular mechanisms. Microbial dysbiosis can result in a possibly permanent alteration in the physiological response. This review aims to highlight recent contributions made to alleviating human dysbiosis in degenerative diseases, especially for neurodegenerative pathologies based on the rising prevalence of obesity. We discuss the significance of both microbiota modulation and possible alleviations of pathologies by a modulatory function. We argue that pre- and probiotics (including phenolic compounds stimulating the favorable strain from the microbiota) are an effective alternative that can support the microbiota pattern’s modulation over time and the attenuation of indirect causes that determine dysbiosis. Molecular aspects are presented in support of the modulating role of the microbiota following the use of probiotics.

β-Elemene Suppresses Obesity-Induced Imbalance in the Microbiota-Gut-Brain Axis

As a kind of metabolically triggered inflammation, obesity influences the interplay between the central nervous system and the enteral environment. The present study showed that β-elemene, which is contained in various plant substances, had effects on recovering the changes in metabolites occurring in high-fat diet (HFD)-induced obese C57BL/6 male mice brains, especially in the prefrontal cortex (PFC) and hippocampus (HIP). β-elemene also partially reversed HFD-induced changes in the composition and contents of mouse gut bacteria. Furthermore, we evaluated the interaction between cerebral metabolites and intestinal microbiota via Pearson correlations. The prediction results suggested that Firmicutes were possibly controlled by neuron integrity, cerebral inflammation, and neurotransmitters, and Bacteroidetes in mouse intestines might be related to cerebral aerobic respiration and the glucose cycle. Such results also implied that Actinobacteria probably affected cerebral energy metabolism. These findings suggested that β-elemene has regulatory effects on the imbalanced microbiota-gut-brain axis caused by obesity and, therefore, would contribute to the future study in on the interplay between cerebral metabolites from different brain regions and the intestinal microbiota of mice.

In Pursuit of Healthy Aging: Effects of Nutrition on Brain Function

Consuming a balanced, nutritious diet is important for maintaining health, especially as individuals age. Several studies suggest that consuming a diet rich in antioxidants and anti-inflammatory components such as those found in fruits, nuts, vegetables, and fish may reduce age-related cognitive decline and the risk of developing various neurodegenerative diseases. Numerous studies have been published over the last decade focusing on nutrition and how this impacts health. The main objective of the current article is to review the data linking the role of diet and nutrition with aging and age-related cognitive decline. Specifically, we discuss the roles of micronutrients and macronutrients and provide an overview of how the gut microbiota-gut-brain axis and nutrition impact brain function in general and cognitive processes in particular during aging. We propose that dietary interventions designed to optimize the levels of macro and micronutrients and maximize the functioning of the microbiota-gut-brain axis can be of therapeutic value for improving cognitive functioning, particularly during aging.