Psychobiotics, gut microbiota and fermented foods can help preserving mental health

Fermented, Freeze-Dried Snacks from Lactarius deliciosus as a Source of Functional Compounds and Lactic Acid Bacteria

Lactarius deliciosus is an edible, seasonal, wild-growing forest mushroom with significant functional properties and potential applications in health-promoting foods. The aim of the study was to compare the level of selected functional compounds (minerals, phenols, indoles, L-phenylalanine, lovastatin, ergothioneine, glucans, chitin, chitosan) and Lactic Acid Bacteria (LAB) in freeze-dried snacks made from the fermented caps of L. deliciosus mushrooms. The snacks were made from mushrooms blanched in water or microwave, and fermentation was carried out using one of the strains of probiotic bacteria: L. acidophilus (LA-5) or L. plantarum (SWA016). After 6 months of storage, mushroom products were a good source of functional compounds, especially LAB, minerals, indoles, lovastatin, antioxidants (phenolic compounds), and dietary fibre. Fermentation with added probiotic cultures enhanced indigenous lactobacilli levels, but after storage, only microwave-blanched snacks fermented with L. plantarum retained a high LAB count (7.3 log CFU/g). The selection of pre-treatment significantly influenced bioactive compound composition: water blanching enhanced lovastatin and 6-methyl-D,L-tryptophan contents, whereas microwave blanching maximised K, S, Rb, Fe, Se, Mn, Br, phenolic compounds, antioxidant activity, and soluble dietary fibre. In order to optimise the level of the most important bioactive compounds and LAB, microwave blanching with the addition of L. plantarum SWA016 should applied.

Limosilactobacillus reuteri fermented brown rice alleviates anxiety improves cognition and modulates gut microbiota in stressed mice

Chronic stress disrupts gut microbiota homeostasis, contributing to anxiety and depression. This study explored the effects of Limosilactobacillus reuteri fermented brown rice (FBR) on anxiety using an ICR mouse chronic mild stress (CMS) model. Anxiety was assessed through body weight, corticosterone levels, neurotransmitter profiles, and behavioral tests. A four-week FBR regimen reduced corticosterone, restored neurotransmitters like gamma-aminobutyric acid (GABA) and serotonin, and improved anxiety-related behaviors. Metagenomic (16S rRNA) and metabolomic analyses revealed enhanced amino acid metabolism, energy metabolism, and short-chain fatty acid (SCFA) production in FBR-treated mice. FBR-enriched beneficial gut bacteria, aligning the microbiota profile with that of non-stressed mice. FBR also modulated GABA receptor-related gene expression, promoting relaxation. Network pharmacology identified quercetin, GABA, glutamic acid, phenylalanine, and ferulic acid as bioactive compounds with neuroprotective potential. These findings highlight FBR's potential as a gut-brain axis-targeted therapeutic for anxiety and stress-related disorders.

The co-fermentation of whole-grain black barley and quinoa improves murine cognitive impairment induced by a high-fat diet via altering gut microbial ecology and suppressing neuroinflammation

A high-fat diet (HFD) is associated with various adverse health outcomes, including cognitive impairment and an elevated risk of neurodegenerative conditions. This relationship is partially attributed to the influence of an HFD on the gut microbiota. The objective of this research was to evaluate the neuroprotective benefits of co-fermented black barley and quinoa with Lactobacillus (FG) against cognitive impairments triggered by an HFD and to investigate the microbiota-gut-brain axis mechanisms involved. C57BL/6J mice were randomized into four groups: the normal control group (NC, n = 10), the high-fat diet group (HFD, n = 10), the high-fat diet group supplemented with FG (HFG, 10 mL per kg BW, n = 10), and the high-fat diet group supplemented with Lactobacillus (HFL, 10 mL per kg BW, n = 10). Our results showed that the FG intervention enhanced the behavioral and locomotor skills of the mice, elevated the levels of dopamine (DA) and norepinephrine (NPI) in brain tissues, and alleviated synaptic ultrastructural damage in the hippocampus. Furthermore, FG intervention was observed to exert a protective effect on both the blood-brain barrier and the colonic barrier, as evidenced by an increase in the mRNA levels of Zona occludens-1 (ZO-1), Claudin-4, and Occludin in the hippocampus and colon. These beneficial effects may be attributed to FG's regulation of gut microbiota dysbiosis, which involves the restoration of intestinal flora diversity, reduction of the Firmicutes/Bacteroidetes (F/B) ratio, and a decrease in the levels of pro-inflammatory bacteria such as s_Escherichia coli E and g_Escherichia; moreover, there was an increase in the abundances of anti-inflammatory bacteria, such as s_Bacteroides thetaiotaomicron and s_Parabacteroides goldsteinii. Metagenomic analysis revealed that the FG treatment downregulated the lipopolysaccharide (LPS) pathway and upregulated neurotransmitter biosynthetic pathways. These probiotic effects of FG resulted in reduced production and "leakage" of LPS and decreased mRNA expression of Toll-like receptor 4 (Tlr4), cluster of differentiation 14 (CD14), and myeloid differentiation factor 88 (Myd88) in hippocampal and colon tissues. Consequently, a reduction was observed in the levels of inflammatory cytokines in the serum, hippocampus, and colon, along with suppression of the immunoreactivity of microglia and astrocytes. Our results suggest that FG may serve as an intervention strategy for preventing cognitive impairments caused by an HFD.

Probiotaceuticals: Back to the future?

Probiotic research has undergone some exciting and unanticipated changes in direction since the 2010 commentary by GSH, which speculated on probiotics being ultimately utilized as "factories" capable of releasing pharmaceutical-grade metabolites with therapeutic potential for a wide range of primarily gastrointestinal disorders. Indeed, the unrelenting search for new alternatives to antibiotics has further stimulated the development of "next-generation" probiotics. Postbiotics, defined as inanimate microorganisms and/or their components that confer a health benefit on the host, remain at the forefront of current probiotic research, with increasing numbers of probiotic species, strains, and substrains now being identified and further exploited as pharmabiotics; probiotics with a proven pharmacologic role in health and disease that have been subjected to clinical trial prior to approval by regulatory bodies. However, perhaps the most unanticipated probiotic development over the past 15 y has been the emergence of psychobiotics with the potential to improve aspects of mental health, such as depression and anxiety, through the release of bioactive metabolites. Moreover, the recent identification of pharmacobiotics, probiotics capable of facilitating the effectiveness of conventional pharmaceutical drugs, is opening new avenues for probiotic applications to combat a range of diseases, including cancers of the digestive system. Although in its infancy, recent reports of oncobiotics with antineoplastic properties are further expanding the potential for certain next-generation probiotics to impact current cancer treatment regimens and possibly even contribute to cancer prevention. Looking to the next 15 y of probiotic development, one could perhaps predict the ultimate development of regulatory-approved xenopostbiotic formulations comprising metabolites with the capacity to improve digestive health, decrease the severity of intestinal disease, and increase the effectiveness of conventional pharmaceuticals, whilst simultaneously improving cognitive functioning and mental welfare. Although speculative, these xenopostbiotic formulations could prove especially effective for the adjunctive treatment of serious chronic diseases such as cancer.

Gaba-producing lactobacilli boost cognitive reactivity to negative mood without improving cognitive performance: A human Double-Blind Placebo-Controlled Cross-Over study

BACKGROUND

Psychobiotic bacteria are probiotics able to influence stress-related behavior, sleep, and cognitive outcomes. Several in vitro and human studies were performed to assess their physiological potential, to find strains having psychotropic activity in humans, and to elucidate the metabolic pathways involved. In our previous in vitro study, we identified two strains Levilactobacillus brevis P30021 and Lactiplantibacillus plantarum P30025, able to produce GABA and acetylcholine, being promising candidates to provide an effect on mood and cognitive performance.

AIM

To investigate the effects of probiotics in the alleviation on the cognitive performance of moderately stressed healthy adults. Secondary outcomes were related to mood improvement, production of GABA, glutamate, acetylcholine, and choline and modification of the microbiota composition.

METHODS

A 12-week randomized, double-blind, placebo-controlled, cross-over study investigated the effects of a probiotic formulation (Levilactobacillus brevis P30021 and Lactiplantibacillus plantarum P30025) on psychological, memory, and cognition parameters in 44 (Probiotic = 44, Placebo = 43) adults with a mean age of 29 ± 5.7 years old by CogState Battery test. Subjects-inclusion criteria was a mild-moderate (18.7 ± 4.06) stress upon diagnosis using the DASS-42 questionnaire.

RESULTS

Probiotic treatment had no effect on subjective stress measures. The probiotic formulation showed a significant beneficial effect on depressive symptoms by reducing cognitive reactivity to sad mood (p = 0.034). Rumination significantly improved after intake of the probiotic (p = 0.006), suggesting a potential benefit in reducing the negative cognitive effects associated with depression and improving overall mental health. When stratifying the treated subjects according to the response, we found an increase in the abundance of the probiotic genera in the gut microbiota of positive responders (p = 0.009 for Lactiplantibacillus and p = 0.004 for L.brevis). No relevant correlations were observed between the neurotransmitter concentration in the faecal sample, scores of LEIDS, DASS-42, and cognitive tests.

CONCLUSION

We highlight the potential of this probiotic preparation to act as psycobiotics for the relief of negative mood feelings. The assessment of the psychotropic effects of dietary interventions in human participants has many challenges. Further interventional studies investigating the effect of these psychobiotic bacteria in populations with stressed-related disorders are required including longer period of intervention and larger sample size in order to verify the effects of the treatment on further stress-related indicators.

Effects of regulating gut microbiota by electroacupuncture in the chronic unpredictable mild stress rat model

OBJECTIVE

This study aims to investigate the effect of electroacupuncture (EA) treatment on depression, and the potential molecular mechanism of EA in depression-like behaviors rats.

METHODS

A total of 40 male Sprague Dawley rats were divided into three groups: normal control, chronic unpredictable mild stress (CUMS), and EA (CUMS + EA). The rats in CUMS and EA groups underwent chronic stress for 10 weeks, and EA group rats received EA treatment for 4 weeks starting from week 7. Body weight and behavioral tests, including the sucrose preference test (SPT), the forced swimming test (FST), and the open field test (OFT) were monitored. Gut microbiota composition was assessed via 16S rDNA sequencing, and lipid metabolism was analyzed by using UPLC-Q-TOF/MS technology.

RESULTS

In comparison to CUMS group, EA could improve the behavior including bodyweight, immovability time, sucrose preference index, crossing piece index and rearing times index. After 4 weeks of EA treatment, 5-HT in hippocampus, serum and colon of depressive rats were simultaneously increased, indicating a potential alleviation of depression-like behaviors. In future studies revealed that EA could regulate the distribution and functions of gut microbiota, and improve the intestinal barrier function of CUMS rats. The regulation of intestinal microbial homeostasis by EA may further affect lipid metabolism in CUMS rats, and thus play an antidepressant role.

CONCLUSION

This study suggested that EA has potential antidepressant effects by regulating gut microbiota composition and abundance, subsequently affecting lipid metabolism.

Associations between short-chain fatty acid levels and mood disorder symptoms: a systematic review

Background: Available evidence points to a possible role of Short Chain Fatty Acids (SCFAs) in mood disorders. This is the first systematic review to map the associations between SCFA levels and mood disorder symptoms.Methods: Following the PRISMA guidelines, the databases PubMed, Embase, and PsycINFO were searched for studies that assessed SCFA levels in human populations with mood disorder symptoms, or animal models of mood disorder. Risk of bias was assessed by the Strengthening of Reporting of Observational Studies in Epidemiology (STROBE) checklist.Results: 19 studies were included and could be divided into animal (n=8) and human studies (n=11), with the animal studies including 166 animals and 100 controls, and the human studies including 662 participants and 330 controls. The studies were characterized by heterogeneity and methodological challenges on multiple parameters, limiting the validity and transferability of findings. Notably, only two of the clinical studies assessed the presence of mood disorder with diagnostic criteria, and no studies of mania or bipolar disorder met the inclusion criteria.Discussion: Despite significant methodological limitations, associations between SCFA levels and depressive symptoms were reported in most of the studies. However, the direction of these associations and the specific SCFAs identified varied. The quantification of SCFA levels in mood disorders is an emerging yet sparsely studied research field. Although there is some evidence suggesting a link between SCFAs and depressive symptoms, the directionality of effects and mechanisms are unclear and the relation to manic symptoms is uninvestigated.

Feeding gut microbes to nourish the brain: unravelling the diet-microbiota-gut-brain axis

The prevalence of brain disorders, including stress-related neuropsychiatric disorders and conditions with cognitive dysfunction, is rising. Poor dietary habits contribute substantially to this accelerating trend. Conversely, healthy dietary intake supports mood and cognitive performance. Recently, the communication between the microorganisms within the gastrointestinal tract and the brain along the gut-brain axis has gained prominence as a potential tractable target to modulate brain health. The composition and function of the gut microbiota is robustly influenced by dietary factors to alter gut-brain signalling. To reflect this interconnection between diet, gut microbiota and brain functioning, we propose that a diet-microbiota-gut-brain axis exists that underpins health and well-being. In this Review, we provide a comprehensive overview of the interplay between diet and gut microbiota composition and function and the implications for cognition and emotional functioning. Important diet-induced effects on the gut microbiota for the development, prevention and maintenance of neuropsychiatric disorders are described. The diet-microbiota-gut-brain axis represents an uncharted frontier for brain health diagnostics and therapeutics across the lifespan.

Sourdough bread as nutritional intervention tool for improvement of cognitive dysfunction in diabetic rats

BACKGROUND

The current research targeted to study the impact of nutritional intervention by two sourdough breads in improvement of cognitive dysfunction in diabetic rats.

METHODS

Type-2 diabetes was induced in rats by Streptozotocin-Nicotinamide (STZ-NC). Diabetic rats were fed on balanced diet or balanced diet containing 20% of sourdough bread I or II for a month. Lipid profile, oxidative stress, inflammatory markers and cognitive functions were assessed in all rats. Gene expression of brain-derived neurotrophic factor (BDNF) and nuclear respiratory factor 2 (NRF-2) were assessed in hippocampal tissue, while expression of phosphoenol pyruvate carboxy kinase (PEPCK), and glucose transporter 2 (GLUT2) genes were evaluated in hepatic tissue. Chemical composition and fatty acids profile were evaluated in the prepared sourdough bread.

RESULTS

Sourdough bread II showed higher content of phenolic compounds, fat, fiber and carbohydrates. Fatty acids profile revealed that sourdough bread I was higher in saturated fatty acids (16.08%), while sourdough bread sample II was higher in unsaturated fatty acids (79.33%). Sourdough bread I or II feeding rats' showed significant improvement in hyperglycemia, oxidative stress markers, inflammatory markers, lipid profile, liver and kidney functions in association with improvement in cognitive function. Gene expression of BDNF and NRF2 in hippocampal tissue were increased significantly, while hepatic GLUT2 and PEPCK gene expression were down-regulated in diabetic given sourdough bread I or II.

CONCLUSION

Sourdough bread II was superior in all the studied parameters. The anti-diabetic effect and protection from cognitive dysfunction of sourdough bread samples may be ascribed to the occurrence of dietary fibers, phenolic compounds, and polyunsaturated fatty acids.

Predispose, precipitate, perpetuate, and protect: how diet and the gut influence mental health in emerging adulthood

Medicine often employs the 4Ps of predisposing, precipitating, perpetuating, and protective factors to identify salient influences on illness states, and to help guide patient care. Mental illness is a significant cause of morbidity and mortality worldwide. Mental health is a complex combination of biological, psychological, environmental, and social factors. There is growing interest in the gut-brain-microbiome (GBM) axis and its impact on mental health. We use the medical model of the 4Ps to explore factors involving the connection between nutrition and the GBM axis and their associated risks with mental health problems in emerging adults (EAs), a life stage when mental illness onset is the most common. We review the impact of current dietary trends on the GBM and on mental health, and the role that gut microbiome-based interventions can have in modulating the GBM axis of EAs. We discuss the implications of gut health on the GBM and areas for clinical intervention.

Could psychobiotics and fermented foods improve mood in middle-aged and older women?

Menopause is a natural physiological phase during which women experience dramatic hormonal fluctuations. These lead to many symptoms, such as depression and anxiety, which, in turn, can negatively affect quality of life. Proper nutrition has an influential role in alleviating depression as well as anxiety. It is well known that gut microbiota dysbiosis contributes to the development of mood disorder. There is mounting evidence that modulating the gut-brain axis may aid in improving mood swings. In this context, this narrative review summarizes recent findings on how aging changes the composition of the gut microbiota and on the association between gut microbiota and mood disorders. In addition, it evaluates the effectiveness of psychobiotics and fermented foods in treating mood swings in middle-aged and older women. A search was done using PubMed, Scopus, and Google Scholar, and thirteen recent articles are included in this review. It is evident that psychobiotic supplementation and fermented foods can improve mood swings via several routes. However, these conclusions are based on only a few studies in middle-aged and older women. Therefore, long-term, well-designed randomized controlled trials are required to fully evaluate whether psychobiotics and fermented foods can be used to treat mood swings in this population.

Lactiplantibacillus plantarum as a promising adjuvant for neurological disorders therapy through the brain-gut axis and related action pathways

Dysbiosis in neurological disorders has highlighted the gut-microbiota-brain axis and psychobiotics and their ability to act on the brain-gut axis. Studying and discovering new approaches in therapies for neuropsychiatric disorders are strategies that have been discussed and put into practice. Lactiplantibacillus plantarum is a lactic acid bacteria species with an extensive history of safe use whose action as a psychobiotic has been successfully explored. This review describes and discusses the mechanisms of action of L. plantarum and its potential for the prevention and treatment of neurological disorders. Randomized and controlled trials in humans or animals and using supplements based on different strains of L. plantarum were selected. The psychobiotic effect of L. plantarum has been shown, mainly through its action on the Hypothalamic-Pituitary-Adrenal (HPA) axis and regulation of levels of pro-inflammatory cytokines. Furthermore, it could protect the integrity of the intestinal barrier and decrease inflammation, alleviating a series of symptoms of neurological diseases. The results showed improvements in cognitive function, memory, anxiety, hyperactivity, Attention Deficit Hyperactivity Disorder (ADHD), sleep quality, and growth stimulation of beneficial species of bacteria in the gut. Larger and deeper studies are needed to use psychobiotics to prevent and treat neurological disorders.

Food4healthKG: Knowledge graphs for food recommendations based on gut microbiota and mental health

Food is increasingly acknowledged as a powerful means to promote and maintain mental health. The introduction of the gut-brain axis has been instrumental in understanding the impact of food on mental health. It is widely reported that food can significantly influence gut microbiota metabolism, thereby playing a pivotal role in maintaining mental health. However, the vast amount of heterogeneous data published in recent research lacks systematic integration and application development. To remedy this, we construct a comprehensive knowledge graph, named Food4healthKG, focusing on food, gut microbiota, and mental diseases. The constructed workflow includes the integration of numerous heterogeneous data, entity linking to a normalized format, and the well-designed representation of the acquired knowledge. To illustrate the availability of Food4healthKG, we design two case studies: the knowledge query and the food recommendation based on Food4healthKG. Furthermore, we propose two evaluation methods to validate the quality of the results obtained from Food4healthKG. The results demonstrate the system's effectiveness in practical applications, particularly in providing convincing food recommendations based on gut microbiota and mental health. Food4healthKG is accessible at https://github.com/ccszbd/Food4healthKG.

The Rising Role of Omics and Meta-Omics in Table Olive Research

Table olives are often the result of fermentation, a process where microorganisms transform raw materials into the final product. The microbial community can significantly impact the organoleptic characteristics and safety of table olives, and it is influenced by various factors, including the processing methods. Traditional culture-dependent techniques capture only a fraction of table olives' intricate microbiota, prompting a shift toward culture-independent methods to address this knowledge gap. This review explores recent advances in table olive research through omics and meta-omics approaches. Genomic analysis of microorganisms isolated from table olives has revealed multiple genes linked to technological and probiotic attributes. An increasing number of studies concern metagenomics and metabolomics analyses of table olives. The former offers comprehensive insights into microbial diversity and function, while the latter identifies aroma and flavor determinants. Although proteomics and transcriptomics studies remain limited in the field, they have the potential to reveal deeper layers of table olives' microbiome composition and functionality. Despite the challenges associated with implementing multi-omics approaches, such as the reliance on advanced bioinformatics tools and computational resources, they hold the promise of groundbreaking advances in table olive processing technology.

The inhibitory effects of plant additives on biogenic amine formation in fermented foods - a review

Fermented food has unique properties and high nutritional value, and thus, should constitute a basic element of a balanced and health-promoting diet. However, it can accumulate considerable amount of biogenic amines (BAs), which ingested in excess can lead to adverse health effects. The application of plant-derived additives represents a promising strategy to ensure safety or enhance the functional and organoleptic properties of fermented food. This review summarizes currently available data on the application of plant-origin additives with the aim to reduce BA content in fermented products. The importance of ensuring fermented food safety has been highlighted considering the growing evidence of beneficial effects resulting from the consumption of this type of food, as well as the increasing number of individuals sensitive to BAs. The examined plant-origin additives reduced the BA concentration to varying degrees, and their efficacy depended on the type of additive, matrix, autochthonous, and inoculated microorganisms, as well as the manufacturing conditions. The main mechanisms of action include antimicrobial effects and the inhibition of microbial decarboxylases. Further research on the optimization of bioactive substances extraction, standardization of their chemical composition, and development of detailed procedures for its use in fermented products manufacturing are needed.

Kombucha: Challenges for Health and Mental Health

BACKGROUND

Increasing research into probiotics is showing potential benefits for health in general and mental health in particular. Kombucha is a recent beverage and can be considered a probiotic drink, but little is known about its effects on physical and mental health. This product is experiencing growth in the market; however, there are no scientific results to support its potential for physical and mental health.

AIM

This review article aims to draw attention to this issue and to highlight the lack of studies in this area.

KEY FINDINGS AND CONCLUSIONS

The lack of legislation for the correct marketing of this product may also constrain clinical studies. However, clinical studies are of utmost importance for an in-depth understanding of the effects of this product on the human body. More research is needed, not only to better understand the impact of Kombucha on the human body, but also to ensure the application of regulatory guidelines for its production and marketing and enable its safe and effective consumption.

Production of GABA in milk fermented by Bifidobacterium adolescentis strains selected on the bases of their technological and gastrointestinal performance

There is an increasing interest in producing foods enriched in gamma-aminobutyric acid (GABA), due to their purported health promoting attributes. GABA is the main inhibitor neurotransmitter of the central nervous system, and several microbial species are capable to produce it through decarboxylation of glutamate. Among them, several lactic acid bacteria species have been previously investigated as an appealing alternative to produce GABA enriched foods via microbial fermentation. In this work we report for the first time an investigation into the possibility of utilizing high GABA-producing Bifidobacterium adolescentis strains as a mean to produce fermented probiotic milks naturally enriched in GABA. To this end, in silico and in vitro analyses were conducted in a collection of GABA-producing B. adolescentis strains, with the main goal to scrutinize their metabolic and safety traits, including antibiotic resistance patterns, as well as their technological robustness and performance to survive a simulated gastrointestinal passage. One of the strains, IPLA60004, exhibited better survival to lyophilization and cold storage (for up to 4 weeks at 4 °C), as well as survival to gastrointestinal passage, as compared to the other strains under investigation. Besides, the elaboration of milk drinks fermented with this strain, yielded products with the highest GABA concentration and viable bifidobacterial cell counts, achieving conversion rates of the precursor, monosodium glutamate (GMS), up to 70 %. To our knowledge, this is the first report on the elaboration of GABA enriched milks through fermentation with B. adolescentis.

Gut Microbiota and Behavioural Issues in Production, Performance, and Companion Animals: A Systematic Review

The literature has identified poor nutrition as the leading factor in the manifestation of many behavioural issues in animals, including aggression, hyperalertness, and stereotypies. Literature focused on all species of interest consistently reported that although there were no significant differences in the richness of specific bacterial taxa in the microbiota of individual subjects with abnormal behaviour (termed alpha diversity), there was variability in species diversity between these subjects compared to controls (termed beta diversity). As seen in humans with mental disorders, animals exhibiting abnormal behaviour often have an enrichment of pro-inflammatory and lactic acid-producing bacteria and a reduction in butyrate-producing bacteria. It is evident from the literature that an association exists between gut microbiota diversity (and by extension, the concurrent production of microbial metabolites) and abnormal behavioural phenotypes across various species, including pigs, dogs, and horses. Similar microbiota population changes are also evident in human mental health patients. However, there are insufficient data to identify this association as a cause or effect. This review provides testable hypotheses for future research to establish causal relationships between gut microbiota and behavioural issues in animals, offering promising potential for the development of novel therapeutic and/or preventative interventions aimed at restoring a healthy gut-brain-immune axis to mitigate behavioural issues and, in turn, improve health, performance, and production in animals.

The Survival of Psychobiotics in Fermented Food and the Gastrointestinal Tract: A Review

In recent years, scientists have been particularly interested in the gut-brain axis, as well as the impact of probiotics on the nervous system. This has led to the creation of the concept of psychobiotics. The present review describes the mechanisms of action of psychobiotics, their use in food products, and their viability and survival during gastrointestinal passage. Fermented foods have a high potential of delivering probiotic strains, including psychobiotic ones. However, it is important that the micro-organisms remain viable in concentrations ranging from about 10⁶ to 10⁹ CFU/mL during processing, storage, and digestion. Reports indicate that a wide variety of dairy and plant-based products can be effective carriers for psychobiotics. Nonetheless, bacterial viability is closely related to the type of food matrix and the micro-organism strain. Studies conducted in laboratory conditions have shown promising results in terms of the therapeutic properties and viability of probiotics. Because human research in this field is still limited, it is necessary to broaden our understanding of the survival of probiotic strains in the human digestive tract, their resistance to gastric and pancreatic enzymes, and their ability to colonize the microbiota.

Impact of electro-activated whey on growth, acid and bile resistance of Lacticaseibacillus rhamnosus GG and Lactobacillus acidophilus ATCC 4356

The aim of this work was to study the impact of electro-activated whey containing lactulose on the growth and survival Lacticaseibacillus rhamnosus GG and Lactobacillus acidophilus ATCC 4356 in acidic and bile salts containing media. Electro-activated whey was compared to whey and MRS alone and supplemented with lactulose. The results showed that OD₆₀₀ was the highest for all these bacteria when grown in the electro-activated medium. At the same time, the obtained results showed that the initial growth phase was the most delayed in this medium. The OD₆₀₀ results were verified by the bacteria plating method on nutrient agar. The obtained data showed that for each given bacteria, no significant difference was observed according to the CFU/mL results. Thus, it has been suggested that electro-activated whey could have a significant effect of bacterial fitness by enhancing their activity even at an equivalent population in each medium. A study of the stability of the probiotic bacteria for 14 days refrigerated storage at pH 4.6 and in the presence of bile salts revealed that the growth substrate did not significantly affect bacterial survival during this storage period and that all the tested probiotic bacteria remained close to 10⁹ CFU/mL. The 16S rRNA gene sequencing of Lacticaseibacillus rhamnosus GG after 24 h growth in different media showed highly significant difference in upregulated and downregulated genes between the electro-activated whey and the regular sweet whey even when it was supplemented with lactulose. The obtained results support the hypothesis that electro-activated whey has evident prebiotic effect compared to lactulose.

Alterations in intestinal microbiota and metabolites in individuals with Down syndrome and their correlation with inflammation and behavior disorders in mice

The intestinal microbiota and fecal metabolome have been shown to play a vital role in human health, and can be affected by genetic and environmental factors. We found that individuals with Down syndrome (DS) had abnormal serum cytokine levels indicative of a pro-inflammatory environment. We investigated whether these individuals also had alterations in the intestinal microbiome. High-throughput sequencing of bacterial 16S rRNA gene in fecal samples from 17 individuals with DS and 23 non-DS volunteers revealed a significantly higher abundance of Prevotella, Escherichia/Shigella, Catenibacterium, and Allisonella in individuals with DS, which was positively associated with the levels of pro-inflammatory cytokines. GC-TOF-MS-based fecal metabolomics identified 35 biomarkers (21 up-regulated metabolites and 14 down-regulated metabolites) that were altered in the microbiome of individuals with DS. Metabolic pathway enrichment analyses of these biomarkers showed a characteristic pattern in DS that included changes in valine, leucine, and isoleucine biosynthesis and degradation; synthesis and degradation of ketone bodies; glyoxylate and dicarboxylate metabolism; tyrosine metabolism; lysine degradation; and the citrate cycle. Treatment of mice with fecal bacteria from individuals with DS or Prevotella copri significantly altered behaviors often seen in individuals with DS, such as depression-associated behavior and impairment of motor function. These studies suggest that changes in intestinal microbiota and the fecal metabolome are correlated with chronic inflammation and behavior disorders associated with DS.

The Application of Metagenomics to Study Microbial Communities and Develop Desirable Traits in Fermented Foods

The microbial communities present within fermented foods are diverse and dynamic, producing a variety of metabolites responsible for the fermentation processes, imparting characteristic organoleptic qualities and health-promoting traits, and maintaining microbiological safety of fermented foods. In this context, it is crucial to study these microbial communities to characterise fermented foods and the production processes involved. High Throughput Sequencing (HTS)-based methods such as metagenomics enable microbial community studies through amplicon and shotgun sequencing approaches. As the field constantly develops, sequencing technologies are becoming more accessible, affordable and accurate with a further shift from short read to long read sequencing being observed. Metagenomics is enjoying wide-spread application in fermented food studies and in recent years is also being employed in concert with synthetic biology techniques to help tackle problems with the large amounts of waste generated in the food sector. This review presents an introduction to current sequencing technologies and the benefits of their application in fermented foods.

Theragra chalcogramma Hydrolysates, Rich of Fragment Gly-Leu-Pro-Ser-Tyr-Thr, Ameliorate Alcohol-Induced Cognitive Impairment via Attenuating Neuroinflammation and Enhancing Neuronal Plasticity in Sprague-Dawley Rats

Chronic alcohol abuse induces the cognitive deficits and is associated with low-grade inflammation and neurodegeneration. Currently, by virtue of the immunomodulatory and neuroprotective properties, nutrients represent a promising strategy to attenuate cognitive impairments. We previously prepared the hydrolysates from Theragra chalcogramma skin (TCH), and this study aims to evaluate the neuroprotection of TCH on alcohol-induced cognitive impairment (AICI) and to elucidate the associated mechanism. Behavioral results showed that TCH effectively ameliorated AICI and this amelioration was highly associated with the decrease of IL-1β and the increase of BDNF, CREB, and PSD95 in AICI rats (P < 0.05). Furthermore, TCH restored the histopathological impairment in hippocampus by reactivating extracellular signal-regulated kinase and suppressing Caspase-3 apoptosis signal pathways and modulating the abnormality of neurotransmitters acetylcholine and γ-aminobutyric acid(P < 0.05 or 0.01). Therefore, TCH exhibits potent attenuation of neuroinflammation and represents a potential ingredient for prevention of AICI.

Biological Role of Nutrients, Food and Dietary Patterns in the Prevention and Clinical Management of Major Depressive Disorder

Major Depressive Disorder (MDD) is a growing disabling condition affecting around 280 million people worldwide. This complex entity is the result of the interplay between biological, psychological, and sociocultural factors, and compelling evidence suggests that MDD can be considered a disease that occurs as a consequence of an evolutionary mismatch and unhealthy lifestyle habits. In this context, diet is one of the core pillars of health, influencing multiple biological processes in the brain and the entire body. It seems that there is a bidirectional relationship between MDD and malnutrition, and depressed individuals often lack certain critical nutrients along with an aberrant dietary pattern. Thus, dietary interventions are one of the most promising tools to explore in the field of MDD, as there are a specific group of nutrients (i.e., omega 3, vitamins, polyphenols, and caffeine), foods (fish, nuts, seeds fruits, vegetables, coffee/tea, and fermented products) or dietary supplements (such as S-adenosylmethionine, acetyl carnitine, creatine, amino acids, etc.), which are being currently studied. Likewise, the entire nutritional context and the dietary pattern seem to be another potential area of study, and some strategies such as the Mediterranean diet have demonstrated some relevant benefits in patients with MDD; although, further efforts are still needed. In the present work, we will explore the state-of-the-art diet in the prevention and clinical support of MDD, focusing on the biological properties of its main nutrients, foods, and dietary patterns and their possible implications for these patients.

Cherries and Blueberries-Based Beverages: Functional Foods with Antidiabetic and Immune Booster Properties

Nowadays, it is largely accepted that the daily intake of fruits, vegetables, herbal products and derivatives is an added value in promoting human health, given their capacity to counteract oxidative stress markers and suppress uncontrolled pro-inflammatory responses. Given that, natural-based products seem to be a promising strategy to attenuate, or even mitigate, the development of chronic diseases, such as diabetes, and to boost the immune system. Among fruits, cherries and blueberries are nutrient-dense fruits that have been a target of many studies and interest given their richness in phenolic compounds and notable biological potential. In fact, research has already demonstrated that these fruits can be considered functional foods, and hence, their use in functional beverages, whose popularity is increasing worldwide, is not surprising and seem to be a promising and useful strategy. Therefore, the present review reinforces the idea that cherries and blueberries can be incorporated into new pharmaceutical products, smart foods, functional beverages, and nutraceuticals and be effective in preventing and/or treating diseases mediated by inflammatory mediators, reactive species, and free radicals.

Effect of fermented foods on some neurological diseases, microbiota, behaviors: mini review

Fermented foods are among the traditional foods consumed for centuries. In recent years, awareness of fermented foods has been increasing due to their positive health benefits. Fermented foods contain beneficial microorganisms. Fermented foods, such as kefir, kimchi, sauerkraut, and yoghurt, contain Lactic acid bacteria (LAB), such as Lactobacilli, Bifidobacteria, and their primary metabolites (lactic acid). Although studies on the effect of consumption of fermented foods on diabetes, cardiovascular, obesity, gastrointestinal diseases on chronic diseases have been conducted, more studies are needed regarding the relationship between neurological diseases and microbiota. There are still unexplored mechanisms in the relationship between the brain and intestine. In this review, we answer how the consumption of fermented foods affects the brain and behavior of Alzheimer's disease, Parkinson's disease, multiple sclerosis disease, stroke, and gut microbiota.