These reviews analyze the influence of exercise on the gut microbiome and overall health. Moderate exercise promotes a healthy immune system, whereas prolonged high-intensity exercise can cause leaky gut and subsequent systemic inflammation, which can disrupt microbial balance. The combination of aerobic and resistance training significantly affects bacterial diversity, which is associated with a lower prevalence of chronic metabolic disorders. Furthermore, exercise improves gut microbiome diversity, increases SCFA production, improves nutrient utilization, and modulates neuronal and hormonal pathways, thereby improving gut barrier integrity. Probiotic supplementation is associated with decreased inflammation, improved athletic performance, and fewer gastrointestinal disorders, suggesting a mutually influential relationship between the gut microbiome and physical activity. The bidirectional relationship between physical activity and the gut microbiome is exemplified by how exercise can promote beneficial bacteria, while a healthy gut microbiome can potentially improve exercise capacity through various mechanisms.
Firmicutes and Bacteroidetes are the two most abundant phyla, representing up to 90% of the gut flora in adults. An increase in Firmicutes and a decrease in Bacteroidetes in terms of their relative abundance under exercise intervention. The Firmicutes phyla contain several genera of highly diverse bacteria that are beneficial for improving gut health in adults, while the increased abundance of Bacteroidetes is often associated with poorer microbial composition and certain unhealthy habits such as a sedentary lifestyle and a high-fat diet. The F/B ratio is often proposed as a potential biomarker in research on human gut flora due to its high sensitivity to exercise intervention or other environmental factors. Consider a high F/B ratio as a marker of dysbiosis in adults, especially in obesity. While our results showed a slight increase in the F/B ratio after the exercise intervention, physical exercise played a positive role in modulating microbial ecology and improving gut health. This is likely explained by the high protein intake of elite athletes and the high variability in relative abundance between different individuals and metabolic characteristics. Currently, the change in the F/B ratio is not sufficient to consider exercise interventions as the gold standard for regulating the gut flora beneficial to health.
At the genus level, Ruminococcus gauvreauii, Anaerostipes, and an uncultured genus of Lachnospiraceae, all belonging to the SCFA-producing phylum Firmicutes, were found to have significantly increased relative abundance in the adult gut after the exercise intervention, which was positively correlated with insulin sensitivity and cardiorespiratory fitness. A sharp increase in Bifidobacterium abundance was reported in many studies in this review, suggesting a positive association with acetate production. The acetate metabolic pathway in intestinal epithelial cells could increase the release of IL-18 and then activate the epithelial IL-18 receptor and promote intestinal barrier integrity . The genera Roseburia hominis and Akkermansia muciniphila were found to have significantly higher relative abundance in adults performing active exercise compared to sedentary individuals , and both genera were shown to have a beneficial impact on gastrointestinal tract health, lipid metabolism, and the host immune system by producing butyrate. Furthermore, acetate and butyrate producers, represented by Bifidobacterium and Akkermansia muciniphila, were found to be significantly increased following an 8-week exercise training intervention.
Fu rthermore, the gut microbiota plays a key role in gut-brain communication by generating neuroactive molecules. The predominant inhibitory neurotransmitter in the CNS, γ-aminobutyric acid (GABA), is crucial for both brain activity and gastrointestinal physiological processes. Moderate exercise increased hypothalamic GABA levels, leading to decreased resting blood pressure and sympathetic tone. Propionate and GABA levels increased significantly in responders after 12 weeks of exercise intervention. The gut microbiota can synthesize and regulate neurotransmitter activity and interact with the CNS to regulate brain functions. Several microbial species such as Bacteroides can convert glutamate to GABA, and strains of the Lactobacillus genus have been shown to be GABA-containing products. Furthermore, dopamine and norepinephrine can be synthesized in the gastrointestinal tract during stress. Physical exercise stimulates intestinal sensory nerves, which leads to a suppression of monoamine oxidase expression.
In short, it is known that the gut microbiota improves mood symptoms, including stress and anxiety, and may mediate positive benefits in the brain. This experiment showed a dramatic increase in BDNF and neurotransmitter concentrations, improvements in cognitive ability, and mood stabilization.
There is an association between changes in the microbiota and CNS diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and autism spectrum disorder (ASD). We also summarize studies on various types of microecological agents (such as probiotics, prebiotics, synbiotics, and postbiotics) and exercise in improving symptoms of CNS diseases. Among neurotrophic factors, BDNF is a widely studied neurotrophic factor. BDNF plays a crucial role in neuronal plasticity, synaptic transmission, neuronal resilience to stress, neuronal differentiation and maturation, and the activation of other supporting molecules such as NF-κB.
Studies have shown that in the early stages of AD, BDNF levels in the blood and brain of patients are relatively low, and BDNF levels positively correlate with cognitive function. Research by Mattson et al. has shown that exercise significantly increases BDNF expression in the brain. In fact, one study found that in APP/PS1 mice, 12 weeks of treadmill running increased BDNF levels in the hippocampus threefold while reducing Aβ deposition by 50% and significantly improving spatial memory.
While this article centers around rebooting our microbe balance; How much of what so many of us have formally been doing can not take full affect until we pave the way for the newly realized need for a foundation the lead microbes lay down for those microbes to follow impacting not only our moods, mental acuity, our immune system and probably much more.
Gui shares how exercise, physical activity has an important impact also.
On a personal note, I find myself having memory problems. Some it seems may be just there is so much collapse of learned Foundation Beliefs across our social landscapes, but also, in this alternative health sphere, once bringing welcomed, but now seen as partial relief. As this has once been a personal experience coming from not just similar extreme summer heat, but also the change in better foods releasing what I believe are toxins absorbed years ago. Perhaps as we move along this better path, because I have experienced good results so far with some of the new recommendations, I sense a possible need for ways to gather up the heavy metals or the chem toxins we just can't seem to keep out of our bodies, lives. Milk thistle, Broken Cell Chlorella have worked well in the past, but perhaps they too need a protocol so as not to interfere with a Gut Reboot. It just seems there is so much to absorb, relearn in so many subjects and the experienced before release of toxins are causing myself some memory problems.
And yes, I saw the article from the other newsletter on this but after reading the paid sub first. My concerns are from the even more intense and heavy hitter toxins and heavy metals not just from we all get hit with, but those from an intense work environment.
Just, it's normal for memory to weaken a little with age. As you point out, stress, bad memories, and the reality of a decadent humanity with wars and corruption negatively affect us. It's blueberry and cherry season in Spain, and my wife and I are taking advantage of these organic delicacies from the Picos de Europa (northern Spain), which are excellent for gut and brain health, as the second study reports.
The important thing is that we take care of our health with healthy habits to avoid falling into neurodegenerative diseases. Research shows that the gut microbiota of people with cognitive disorders differs from that of neurologically healthy older populations. Cognitive functions tend to deteriorate with age, particularly memory. Episodic, working, and recognition memory are the most susceptible to age-related decline. One of the most common age-related cognitive declines is dementia, and Alzheimer's disease (AD) is the most severe type of dementia. Studies investigating the gut microbiota in individuals with AD have consistently reported an increased abundance of pro-inflammatory phyla and a decrease in anti-inflammatory phyla compared to age-matched control groups. A notable decrease in the Firmicutes phylum, an increase in the pro-inflammatory Bacteroidetes phylum, and a decrease in the Actinobacteria phylum were observed. This shift in these latter phyla was primarily driven by a significant reduction in the Bifidobacterium genus, known for its anti-inflammatory properties, among participants with AD in the United States. Furthermore, a study of AD patients and participants with dementia elsewhere found that these individuals exhibited reduced diversity in their gut microbiota compared to normal aging control groups.
It has been reported that 10% of adults aged 70 years and older were diagnosed with dementia in 2019. This gap is notable, especially considering the incurable nature of Alzheimer's disease (AD). There is a notable lack of emphasis on the healthy aging population in the context of gut microbiota and cognitive functioning.
Specific species of gut bacteria are linked to better cognitive functioning. For example, the abundance of bacteria from the phylum Verrucomicrobia was found to be positively associated with verbal memory, visual scanning, working memory, and cognitive flexibility, and the phylum Firmicutes was associated with, among others, better immediate and delayed recall. Specific families within Firmicutes, such as Gemellaceae and Clostridiaceae, were associated with better concentration, recall speed, attention, and working memory quality. The Ruminococcus gauvreauii group and Carnobacteriaceae within this phylum also showed positive correlations with certain cognitive functions, while Lachnospiraceae had an inverse association with cognition, for example, spatial working memory. It appears that the Firmicutes/Bacteroidetes ratio (F/B or Bacillota-to-Bacteroidetes, according to the more recent nomenclature) is another important factor in predicting cognitive functioning. The F/B ratio is often studied in the context of human health, particularly in relation to obesity and other metabolic conditions, but it appears to be also connected to cognitive health. In general, any deviation from F/B is considered dysbiosis and is detrimental to the host. The F/B ratio is recognized as an important index of gut microbiota health and is also influenced by the amount of physical exercise , so it is not surprising that it can also influence the cognitive status of the host.
We should consider that diets rich in fiber, polyphenols, and compounds with anti-inflammatory or antioxidant properties promote microbiome diversity and health . The components analyzed in a review, including berries , fermented papaya, hop flavonoids, and antioxidant vitamins , exhibit a combination of similar yet diverse effects on cognitive functions. Many of these interventions share common pathways, such as reducing oxidative stress, improving redox status, improving cerebral blood flow, strengthening gut-brain communication, supporting neuroprotection, and regulating mood through the production of SCFAs. Foods rich in polyphenols, such as berries, are especially notable for their ability to improve memory, mood, and cognitive performance. These benefits are attributed to increased cerebral blood flow, improved endothelial function, and modulation of neuroprotective pathways. For example, the polyphenols present in blueberries and blackcurrants are linked to increased neurogenesis, while resveratrol and peanut-derived hydroxybenzoic acids reduce anxiety and improve memory thanks to their anti-inflammatory and antioxidant properties. Fermented papaya acts through various systemic pathways, improving oxidative balance and reducing damage to cellular components such as DNA and proteins. While its effects are more systemic than localized to the brain, reducing oxidative stress indirectly supports brain health by mitigating neuroinflammatory processes.
Antioxidant vitamins, such as vitamins C, B2, and D, improve cognitive function through various mechanisms. For example, vitamin C has been shown to reduce oxidative stress in brain tissue, promote neurotransmitter synthesis, and improve mental clarity. Vitamin D influences cognitive outcomes through its interaction with the vitamin D receptor (VDR), which regulates gene expression involved in brain function and neuroprotection. A combined treatment of vitamins C and B2 has shown synergistic effects, further improving mood and memory in clinical trials. Vitamin supplementation yielded more consistent results, with higher levels of beneficial bacteria such as Akkermansia and Faecalibacterium, and increased SCFA production. Mechanistically, antioxidants support the production of SCFAs, such as butyrate, propionate, and acetate, which are key metabolites produced by the gut microbiota. SCFAs exert protective effects on the gut barrier by stimulating mucin production and the expression of tight junction proteins, such as occludin and claudin, thereby improving barrier integrity and reducing endotoxin translocation, which decreases systemic inflammation. In the context of the gut-brain axis, SCFAs modulate microglial activity in the brain, potentially reducing neuroinflammation and supporting neurogenesis in the hippocampus [ 9 . Antioxidants may also influence redox balance in the gut, promoting microbiome diversity and encouraging the growth of SCFA-producing bacteria, such as Faecalibacterium prausnitzii and Akkermansia muciniphila. In summary, antioxidant supplementation, which includes vitamins C, B2, and D, as well as polyphenols such as xanthohumol, fermented papaya, peanut, and berry extracts, shows the potential to improve cognitive function and gut health by modulating gut microbiome diversity and reducing inflammation. These antioxidants may support the gut-brain axis, primarily by increasing short-chain fatty acid (SCFA) production and improving gut barrier integrity, helping to mitigate oxidative stress, a factor often associated with cognitive decline and neurodegenerative diseases.
Spanish Researchers Discover Beneficial Bacteria in Ancient Ethiopian Foods
A study co-led by the University of Valencia (UV) spin-off Darwin Bioprospecting and the Institute of Integrative Systems Biology (I2SysBio, UV-CSIC) has described the microbial diversity present in traditional fermented foods and beverages from Ethiopia. The objective is to use advanced technologies to identify beneficial bacteria for functional foods and human health. The work is published in the journal Frontiers in Microbiology.
Ethiopia, one of the most populous countries in Africa, boasts an enormous wealth of fermented and artisanal products. These foods are a fundamental part of its diet and cultural heritage. However, their microbial foundation remains largely unknown. In this article, the research team, with the participation of Wolaita Sodo University (Ethiopia) and the Ecuadorian company Quiitos S.A.S., seeks to rediscover the microbial biodiversity of ancient Ethiopian foods and lay the foundation for the development of safer, healthier, and more sustainable fermented products, details the UV.
The results show significant microbiological heterogeneity among products, reflecting both the variety of ingredients and processes and the ecosystemic richness of spontaneous fermentations.
Almost all the foods analyzed were dominated by bacteria from the Firmicutes phylum, especially lactobacilli and other lactic acid bacteria widely known for their ability to improve digestibility, preserve food, and generate compounds with probiotic effects. Distinct microbial profiles and strains with significant functional potential were found and described. "Tej (Ethiopian mead) particularly surprised us because of the almost complete dominance of Zymomonas mobilis, which demonstrates that some of these traditional products can be a natural source of strains with unique technological properties," highlights Carmen Sanz, researcher and director of the Health & Nutrition department at Darwin Bioprospecting and one of the authors of the article.
In addition to genomic analysis, the team has managed to isolate 79 live strains from laboratory cultures—many of them of interest to the food industry—which represent a valuable microbial collection for future developments such as controlled fermentations or customized probiotic formulations.
For the research, the team combined genetic sequencing techniques (metataxonomy), strain isolation and cultivation (culturomics), and physicochemical analysis. The microbial communities present in nine traditional foods are described in detail: two solid products (kotcho and injera), one condiment (datta), and six fermented beverages (tej, tella, cheka, kinito, borde, and shamita).
"It's about thoroughly understanding these traditional practices in order to improve them without losing their essence or cultural value," notes Manuel Porcar, a UV researcher at I2SysBio, one of the founders of the Darwin company, and co-author of the article.
This review explains the substantial and multifaceted impact of ultra-processed foods (UPFs) on the gut microbiome and its health implications. Artificial sweeteners, emulsifiers, preservatives, and food additives disrupt the delicate balance of the gut microbial ecosystem, reducing microbial diversity, promoting a pro-inflammatory environment, increasing intestinal permeability, and contributing to inflammation and dysbiosis.
These alterations are associated with adverse metabolic, gastrointestinal, and neuropsychiatric outcomes, as well as an elevated risk of chronic diseases, including metabolic syndrome, cardiovascular disease, and colorectal cancer.
The evidence presented underscores the crucial role of dietary quality in maintaining gut health. Transitioning to a diet with minimally processed, nutrient-dense foods can mitigate the harmful effects of UPFs and promote microbial resilience. Furthermore, incorporating probiotics, prebiotics, and lifestyle modifications offer potential strategies to restore gut homeostasis. A 2023 meta-analysis, which examined 26 observational studies investigating the link between ultra-processed food (UPF) intake and the risk of mental health disorders, indicated that UPF consumption was linked to an increased risk of depression, but not anxiety. Furthermore, a dose-response analysis highlighted a positive linear relationship between UPF intake and the risk of depression . Moreover, a comprehensive umbrella review conducted in 2024, which analyzed 39 meta-analyses to explore the connection between UPF and various health outcomes, found highly suggestive evidence of a correlation between UPF consumption and depression and common mental disorders . Studies demonstrate that WD accelerates beta-amyloid accumulation in animals and that the diet can induce and exacerbate AD pathology in humans and rodents . Prebiotics and probiotics appear to improve cognitive conditions in PD patients, emphasizing the role of diet and gut microbiota in disease pathogenesis . Furthermore, WD contributes to depression through nutrient-microglia and gut-immune interactions. Patients with major depressive disorder (MDD) have reduced gut microbiota richness and diversity compared to healthy individuals, with altered levels of Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria.
These reviews analyze the influence of exercise on the gut microbiome and overall health. Moderate exercise promotes a healthy immune system, whereas prolonged high-intensity exercise can cause leaky gut and subsequent systemic inflammation, which can disrupt microbial balance. The combination of aerobic and resistance training significantly affects bacterial diversity, which is associated with a lower prevalence of chronic metabolic disorders. Furthermore, exercise improves gut microbiome diversity, increases SCFA production, improves nutrient utilization, and modulates neuronal and hormonal pathways, thereby improving gut barrier integrity. Probiotic supplementation is associated with decreased inflammation, improved athletic performance, and fewer gastrointestinal disorders, suggesting a mutually influential relationship between the gut microbiome and physical activity. The bidirectional relationship between physical activity and the gut microbiome is exemplified by how exercise can promote beneficial bacteria, while a healthy gut microbiome can potentially improve exercise capacity through various mechanisms.
Firmicutes and Bacteroidetes are the two most abundant phyla, representing up to 90% of the gut flora in adults. An increase in Firmicutes and a decrease in Bacteroidetes in terms of their relative abundance under exercise intervention. The Firmicutes phyla contain several genera of highly diverse bacteria that are beneficial for improving gut health in adults, while the increased abundance of Bacteroidetes is often associated with poorer microbial composition and certain unhealthy habits such as a sedentary lifestyle and a high-fat diet. The F/B ratio is often proposed as a potential biomarker in research on human gut flora due to its high sensitivity to exercise intervention or other environmental factors. Consider a high F/B ratio as a marker of dysbiosis in adults, especially in obesity. While our results showed a slight increase in the F/B ratio after the exercise intervention, physical exercise played a positive role in modulating microbial ecology and improving gut health. This is likely explained by the high protein intake of elite athletes and the high variability in relative abundance between different individuals and metabolic characteristics. Currently, the change in the F/B ratio is not sufficient to consider exercise interventions as the gold standard for regulating the gut flora beneficial to health.
At the genus level, Ruminococcus gauvreauii, Anaerostipes, and an uncultured genus of Lachnospiraceae, all belonging to the SCFA-producing phylum Firmicutes, were found to have significantly increased relative abundance in the adult gut after the exercise intervention, which was positively correlated with insulin sensitivity and cardiorespiratory fitness. A sharp increase in Bifidobacterium abundance was reported in many studies in this review, suggesting a positive association with acetate production. The acetate metabolic pathway in intestinal epithelial cells could increase the release of IL-18 and then activate the epithelial IL-18 receptor and promote intestinal barrier integrity . The genera Roseburia hominis and Akkermansia muciniphila were found to have significantly higher relative abundance in adults performing active exercise compared to sedentary individuals , and both genera were shown to have a beneficial impact on gastrointestinal tract health, lipid metabolism, and the host immune system by producing butyrate. Furthermore, acetate and butyrate producers, represented by Bifidobacterium and Akkermansia muciniphila, were found to be significantly increased following an 8-week exercise training intervention.
Fu rthermore, the gut microbiota plays a key role in gut-brain communication by generating neuroactive molecules. The predominant inhibitory neurotransmitter in the CNS, γ-aminobutyric acid (GABA), is crucial for both brain activity and gastrointestinal physiological processes. Moderate exercise increased hypothalamic GABA levels, leading to decreased resting blood pressure and sympathetic tone. Propionate and GABA levels increased significantly in responders after 12 weeks of exercise intervention. The gut microbiota can synthesize and regulate neurotransmitter activity and interact with the CNS to regulate brain functions. Several microbial species such as Bacteroides can convert glutamate to GABA, and strains of the Lactobacillus genus have been shown to be GABA-containing products. Furthermore, dopamine and norepinephrine can be synthesized in the gastrointestinal tract during stress. Physical exercise stimulates intestinal sensory nerves, which leads to a suppression of monoamine oxidase expression.
In short, it is known that the gut microbiota improves mood symptoms, including stress and anxiety, and may mediate positive benefits in the brain. This experiment showed a dramatic increase in BDNF and neurotransmitter concentrations, improvements in cognitive ability, and mood stabilization.
There is an association between changes in the microbiota and CNS diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and autism spectrum disorder (ASD). We also summarize studies on various types of microecological agents (such as probiotics, prebiotics, synbiotics, and postbiotics) and exercise in improving symptoms of CNS diseases. Among neurotrophic factors, BDNF is a widely studied neurotrophic factor. BDNF plays a crucial role in neuronal plasticity, synaptic transmission, neuronal resilience to stress, neuronal differentiation and maturation, and the activation of other supporting molecules such as NF-κB.
Studies have shown that in the early stages of AD, BDNF levels in the blood and brain of patients are relatively low, and BDNF levels positively correlate with cognitive function. Research by Mattson et al. has shown that exercise significantly increases BDNF expression in the brain. In fact, one study found that in APP/PS1 mice, 12 weeks of treadmill running increased BDNF levels in the hippocampus threefold while reducing Aβ deposition by 50% and significantly improving spatial memory.
https://www.mdpi.com/2072-6643/16/21/3663 (2024).--
https://www.mdpi.com/2072-6643/16/7/1070 (2024).--
https://www.mdpi.com/1422-0067/25/19/10742 (2024).---
https://www.mdpi.com/2072-6643/17/10/1686 (2025).--
https://www.mdpi.com/2072-6643/17/11/1769 (2025).--
https://www.mdpi.com/2072-6643/17/11/1769# (2025).--
While this article centers around rebooting our microbe balance; How much of what so many of us have formally been doing can not take full affect until we pave the way for the newly realized need for a foundation the lead microbes lay down for those microbes to follow impacting not only our moods, mental acuity, our immune system and probably much more.
Gui shares how exercise, physical activity has an important impact also.
On a personal note, I find myself having memory problems. Some it seems may be just there is so much collapse of learned Foundation Beliefs across our social landscapes, but also, in this alternative health sphere, once bringing welcomed, but now seen as partial relief. As this has once been a personal experience coming from not just similar extreme summer heat, but also the change in better foods releasing what I believe are toxins absorbed years ago. Perhaps as we move along this better path, because I have experienced good results so far with some of the new recommendations, I sense a possible need for ways to gather up the heavy metals or the chem toxins we just can't seem to keep out of our bodies, lives. Milk thistle, Broken Cell Chlorella have worked well in the past, but perhaps they too need a protocol so as not to interfere with a Gut Reboot. It just seems there is so much to absorb, relearn in so many subjects and the experienced before release of toxins are causing myself some memory problems.
And yes, I saw the article from the other newsletter on this but after reading the paid sub first. My concerns are from the even more intense and heavy hitter toxins and heavy metals not just from we all get hit with, but those from an intense work environment.
Just, it's normal for memory to weaken a little with age. As you point out, stress, bad memories, and the reality of a decadent humanity with wars and corruption negatively affect us. It's blueberry and cherry season in Spain, and my wife and I are taking advantage of these organic delicacies from the Picos de Europa (northern Spain), which are excellent for gut and brain health, as the second study reports.
The important thing is that we take care of our health with healthy habits to avoid falling into neurodegenerative diseases. Research shows that the gut microbiota of people with cognitive disorders differs from that of neurologically healthy older populations. Cognitive functions tend to deteriorate with age, particularly memory. Episodic, working, and recognition memory are the most susceptible to age-related decline. One of the most common age-related cognitive declines is dementia, and Alzheimer's disease (AD) is the most severe type of dementia. Studies investigating the gut microbiota in individuals with AD have consistently reported an increased abundance of pro-inflammatory phyla and a decrease in anti-inflammatory phyla compared to age-matched control groups. A notable decrease in the Firmicutes phylum, an increase in the pro-inflammatory Bacteroidetes phylum, and a decrease in the Actinobacteria phylum were observed. This shift in these latter phyla was primarily driven by a significant reduction in the Bifidobacterium genus, known for its anti-inflammatory properties, among participants with AD in the United States. Furthermore, a study of AD patients and participants with dementia elsewhere found that these individuals exhibited reduced diversity in their gut microbiota compared to normal aging control groups.
It has been reported that 10% of adults aged 70 years and older were diagnosed with dementia in 2019. This gap is notable, especially considering the incurable nature of Alzheimer's disease (AD). There is a notable lack of emphasis on the healthy aging population in the context of gut microbiota and cognitive functioning.
Specific species of gut bacteria are linked to better cognitive functioning. For example, the abundance of bacteria from the phylum Verrucomicrobia was found to be positively associated with verbal memory, visual scanning, working memory, and cognitive flexibility, and the phylum Firmicutes was associated with, among others, better immediate and delayed recall. Specific families within Firmicutes, such as Gemellaceae and Clostridiaceae, were associated with better concentration, recall speed, attention, and working memory quality. The Ruminococcus gauvreauii group and Carnobacteriaceae within this phylum also showed positive correlations with certain cognitive functions, while Lachnospiraceae had an inverse association with cognition, for example, spatial working memory. It appears that the Firmicutes/Bacteroidetes ratio (F/B or Bacillota-to-Bacteroidetes, according to the more recent nomenclature) is another important factor in predicting cognitive functioning. The F/B ratio is often studied in the context of human health, particularly in relation to obesity and other metabolic conditions, but it appears to be also connected to cognitive health. In general, any deviation from F/B is considered dysbiosis and is detrimental to the host. The F/B ratio is recognized as an important index of gut microbiota health and is also influenced by the amount of physical exercise , so it is not surprising that it can also influence the cognitive status of the host.
We should consider that diets rich in fiber, polyphenols, and compounds with anti-inflammatory or antioxidant properties promote microbiome diversity and health . The components analyzed in a review, including berries , fermented papaya, hop flavonoids, and antioxidant vitamins , exhibit a combination of similar yet diverse effects on cognitive functions. Many of these interventions share common pathways, such as reducing oxidative stress, improving redox status, improving cerebral blood flow, strengthening gut-brain communication, supporting neuroprotection, and regulating mood through the production of SCFAs. Foods rich in polyphenols, such as berries, are especially notable for their ability to improve memory, mood, and cognitive performance. These benefits are attributed to increased cerebral blood flow, improved endothelial function, and modulation of neuroprotective pathways. For example, the polyphenols present in blueberries and blackcurrants are linked to increased neurogenesis, while resveratrol and peanut-derived hydroxybenzoic acids reduce anxiety and improve memory thanks to their anti-inflammatory and antioxidant properties. Fermented papaya acts through various systemic pathways, improving oxidative balance and reducing damage to cellular components such as DNA and proteins. While its effects are more systemic than localized to the brain, reducing oxidative stress indirectly supports brain health by mitigating neuroinflammatory processes.
Antioxidant vitamins, such as vitamins C, B2, and D, improve cognitive function through various mechanisms. For example, vitamin C has been shown to reduce oxidative stress in brain tissue, promote neurotransmitter synthesis, and improve mental clarity. Vitamin D influences cognitive outcomes through its interaction with the vitamin D receptor (VDR), which regulates gene expression involved in brain function and neuroprotection. A combined treatment of vitamins C and B2 has shown synergistic effects, further improving mood and memory in clinical trials. Vitamin supplementation yielded more consistent results, with higher levels of beneficial bacteria such as Akkermansia and Faecalibacterium, and increased SCFA production. Mechanistically, antioxidants support the production of SCFAs, such as butyrate, propionate, and acetate, which are key metabolites produced by the gut microbiota. SCFAs exert protective effects on the gut barrier by stimulating mucin production and the expression of tight junction proteins, such as occludin and claudin, thereby improving barrier integrity and reducing endotoxin translocation, which decreases systemic inflammation. In the context of the gut-brain axis, SCFAs modulate microglial activity in the brain, potentially reducing neuroinflammation and supporting neurogenesis in the hippocampus [ 9 . Antioxidants may also influence redox balance in the gut, promoting microbiome diversity and encouraging the growth of SCFA-producing bacteria, such as Faecalibacterium prausnitzii and Akkermansia muciniphila. In summary, antioxidant supplementation, which includes vitamins C, B2, and D, as well as polyphenols such as xanthohumol, fermented papaya, peanut, and berry extracts, shows the potential to improve cognitive function and gut health by modulating gut microbiome diversity and reducing inflammation. These antioxidants may support the gut-brain axis, primarily by increasing short-chain fatty acid (SCFA) production and improving gut barrier integrity, helping to mitigate oxidative stress, a factor often associated with cognitive decline and neurodegenerative diseases.
The links contain very interesting tables.
https://www.mdpi.com/2072-6643/16/6/852 (2024).--
https://pmc.ncbi.nlm.nih.gov/articles/PMC11764720/ (2025).--
Spanish Researchers Discover Beneficial Bacteria in Ancient Ethiopian Foods
A study co-led by the University of Valencia (UV) spin-off Darwin Bioprospecting and the Institute of Integrative Systems Biology (I2SysBio, UV-CSIC) has described the microbial diversity present in traditional fermented foods and beverages from Ethiopia. The objective is to use advanced technologies to identify beneficial bacteria for functional foods and human health. The work is published in the journal Frontiers in Microbiology.
Ethiopia, one of the most populous countries in Africa, boasts an enormous wealth of fermented and artisanal products. These foods are a fundamental part of its diet and cultural heritage. However, their microbial foundation remains largely unknown. In this article, the research team, with the participation of Wolaita Sodo University (Ethiopia) and the Ecuadorian company Quiitos S.A.S., seeks to rediscover the microbial biodiversity of ancient Ethiopian foods and lay the foundation for the development of safer, healthier, and more sustainable fermented products, details the UV.
The results show significant microbiological heterogeneity among products, reflecting both the variety of ingredients and processes and the ecosystemic richness of spontaneous fermentations.
Almost all the foods analyzed were dominated by bacteria from the Firmicutes phylum, especially lactobacilli and other lactic acid bacteria widely known for their ability to improve digestibility, preserve food, and generate compounds with probiotic effects. Distinct microbial profiles and strains with significant functional potential were found and described. "Tej (Ethiopian mead) particularly surprised us because of the almost complete dominance of Zymomonas mobilis, which demonstrates that some of these traditional products can be a natural source of strains with unique technological properties," highlights Carmen Sanz, researcher and director of the Health & Nutrition department at Darwin Bioprospecting and one of the authors of the article.
In addition to genomic analysis, the team has managed to isolate 79 live strains from laboratory cultures—many of them of interest to the food industry—which represent a valuable microbial collection for future developments such as controlled fermentations or customized probiotic formulations.
For the research, the team combined genetic sequencing techniques (metataxonomy), strain isolation and cultivation (culturomics), and physicochemical analysis. The microbial communities present in nine traditional foods are described in detail: two solid products (kotcho and injera), one condiment (datta), and six fermented beverages (tej, tella, cheka, kinito, borde, and shamita).
"It's about thoroughly understanding these traditional practices in order to improve them without losing their essence or cultural value," notes Manuel Porcar, a UV researcher at I2SysBio, one of the founders of the Darwin company, and co-author of the article.
https://www.eleconomista.es/salud-bienestar/enfermedades/noticias/13443636/07/25/investigadores-espanoles-descubren-bacterias-beneficiosas-en-alimentos-ancestrales-de-etiopia.html
This review explains the substantial and multifaceted impact of ultra-processed foods (UPFs) on the gut microbiome and its health implications. Artificial sweeteners, emulsifiers, preservatives, and food additives disrupt the delicate balance of the gut microbial ecosystem, reducing microbial diversity, promoting a pro-inflammatory environment, increasing intestinal permeability, and contributing to inflammation and dysbiosis.
These alterations are associated with adverse metabolic, gastrointestinal, and neuropsychiatric outcomes, as well as an elevated risk of chronic diseases, including metabolic syndrome, cardiovascular disease, and colorectal cancer.
The evidence presented underscores the crucial role of dietary quality in maintaining gut health. Transitioning to a diet with minimally processed, nutrient-dense foods can mitigate the harmful effects of UPFs and promote microbial resilience. Furthermore, incorporating probiotics, prebiotics, and lifestyle modifications offer potential strategies to restore gut homeostasis. A 2023 meta-analysis, which examined 26 observational studies investigating the link between ultra-processed food (UPF) intake and the risk of mental health disorders, indicated that UPF consumption was linked to an increased risk of depression, but not anxiety. Furthermore, a dose-response analysis highlighted a positive linear relationship between UPF intake and the risk of depression . Moreover, a comprehensive umbrella review conducted in 2024, which analyzed 39 meta-analyses to explore the connection between UPF and various health outcomes, found highly suggestive evidence of a correlation between UPF consumption and depression and common mental disorders . Studies demonstrate that WD accelerates beta-amyloid accumulation in animals and that the diet can induce and exacerbate AD pathology in humans and rodents . Prebiotics and probiotics appear to improve cognitive conditions in PD patients, emphasizing the role of diet and gut microbiota in disease pathogenesis . Furthermore, WD contributes to depression through nutrient-microglia and gut-immune interactions. Patients with major depressive disorder (MDD) have reduced gut microbiota richness and diversity compared to healthy individuals, with altered levels of Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria.
https://www.mdpi.com/2072-6643/17/5/859 (2025).--