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Guillermou's avatar

This review highlights the evolving notion of the gut-brain axis (GBA) as an equally sensitive pathological marker of neurodegenerative diseases (NDDs), particularly Alzheimer's disease, Parkinson's disease, multiple sclerosis, and chronic stroke. Furthermore, GBA represents a potent therapeutic target for the treatment of NDDs. This intimate pathological link between the gut and NDDs suggests that the gut-brain axis (GBA) acts as an underexplored area for developing therapies for NDDs. Traditionally, the classification of NDDs depends on their clinical presentation, manifesting primarily as extrapyramidal and pyramidal movement disorders, with neuropathological evaluation at autopsy as the gold standard for diagnosis. NDDs are a global health problem; in the US alone, 12 million Americans will suffer from NDDs by 2030. While the etiology may vary, the gut microbiome serves as a key underlying element in the development and prognosis of NDDs. In particular, an associated microbiome Inflammation affects neurodegenerative disorders (NDDs). Conversely, sequestering this inflammatory microbiome by correcting the dysbiotic state of the gut can generate therapeutic effects on NDDs. To this end, treatment with bacteria that produce short-chain fatty acids, the main metabolites responsible for maintaining intestinal homeostasis, improves the inflammatory microbiome. This intimate pathological link between the gut and NDDs suggests that the gut-brain axis (GBA) acts as an underexplored area for developing therapies for NDDs.

Neurological disorders, especially those presenting with neurodegeneration, have been associated with harmful environmental factors identified in childhood; in particular, an unbalanced diet that alters early gene expression leads to epigenetic changes that manifest in adulthood. Early neurobehavioral deficits accompany epigenome remodeling by environmental factors such as smoking, alcohol, stress, and pesticide exposure.

The pathogenesis of Alzheimer's disease coincides with a microbiota Dysfunctional gut (Figure 2). Irritable bowel syndrome, characterized by an altered gut microbiota, is one of the main pathophysiological factors in Alzheimer's disease (AD). Bacteria that invade the gut microbiome have the capacity to excrete large amounts of amyloid and lipopolysaccharides, which can contribute to AD pathology. Furthermore, because AD is an age-related disorder, the gut-brain barrier (GBB) and the gastrointestinal tract epithelium become more permeable with age, allowing polysaccharides and amyloid to access the brain, readily causing inflammation. Such age-induced compromise of the BBB and gut suggests that the GBA may be involved in the early stages of proteinopathy and inflammation associated with AD.

https://www.mdpi.com/1422-0067/23/3/1184 (2022)------------------------------------------------------------

Physical and psychological stress alters the activity of the gut-brain axis, which can cause dysfunction. of the intestinal barrier, which, in turn, can induce cognitive and mood impairments through exacerbated inflammation and increased permeability of the blood-brain barrier (BBB)

https://www.sciencedirect.com/science/article/abs/pii/S0889159122000277 (2022)-----------------------------

Alzheimer's disease is the most prevalent type of dementia affecting the elderly, characterized by beta-amyloid (Aβ) plaques and tau neurofibrillary tangles that cause intellectual impairment, neuroinflammation, and memory decline. Neuroinflammatory variants such as IL-1β, TNF-α, and IL-6 have been identified in patients with Alzheimer's disease. Previous research has revealed that amyloid functions as an antimicrobial peptide in the brain. The gut microbiota is considered a dynamic factor in the etiology of the disease due to the presence of microbiota-derived metabolites in the cerebrospinal fluid of patients. Several studies have demonstrated the importance of gut microbes in host cognition and the dysbiosis associated with neurodegeneration in old age. Dysbiosis in the gut microbiota leads to the production of amyloid and lipopolysaccharides (LPS), which alter the permeability of the digestive tract and also disrupt the function of the blood-brain barrier.

A β-peptide has antibacterial properties and is part of the innate immune system that protects against pathogenic microorganisms. Furthermore, bacterial amyloid exhibits chemical similarity to human Aβ-peptide, leading to Aβ-peptide denaturation and accumulation, propagation of the gut-brain axis pathway, and activation of microglial cells. Bacterial-derived amyloids, such as prions, tau, α-syn, and other amyloids, have been reported to act as initiators and assemble with host amyloids in patients with Alzheimer's disease.

Amyloids derived from bacteria, such as prions, tau, α-syn, and other amyloids, have been reported to act as initiators and assemble with host amyloids in patients with Alzheimer's disease. https://www.sciencedirect.com/science/article/pii/S0753332222013476 (2022)

https://www.mdpi.com/1422-0067/26/18/8905 (2025)

https://www.nature.com/articles/s44400-025-00048-6 (2025)

https://journals.sagepub.com/doi/abs/10.1177/13872877261441247 (2026)

https://link.springer.com/article/10.1007/s00702-026-03126-y (2026)

Sabina's avatar

Thank you Dr Mercola; I've recently read how Butyrate is essential for gut health and your article confirms it.

Sabina's avatar

I've also read that Butyrate makes one "more attractive" to others (!)...However how that mechanism works I don't understand

Guillermou's avatar

Interesting¡¡¡¡¡¡❤🌹. If we break down this idea from the perspectives of biochemistry and evolutionary biology, the indirect connection between butyrate and "attractiveness" (understood as vitality, social vigor, and perceived health) rests on three pillars:

--------1. The gut-brain axis and social behavior

Butyrate is a short-chain fatty acid (SCFA) that acts as a potent epigenetic signaling agent (HDAC inhibitor) and modulator of the central nervous system.

Reduction of social anxiety: By stimulating the production of brain-derived neurotrophic factor (BDNF) and modulating the GABAergic system, butyrate reduces states of anxiety and stress.

Social disposition: In animal models, a gut microbiota rich in butyrate producers promotes exploratory behaviors and less social avoidance. A person with less systemic inflammation and optimal neurotransmitter levels tends to project greater confidence, openness, and assertiveness—traits that are culturally perceived as "attractive."

-------2. The "Scent of Health" (Volatibuloma)

The human body emits volatile organic compounds (VOCs) through sweat, breath, and skin.

Body odor and the immune system: The gut microbiota regulates systemic inflammation. When dysbiosis is present, inflammatory metabolites increase, altering the VOC profile in the skin and subconsciously making it less attractive to others (an evolutionary mechanism for detecting mates with illnesses or incompatible immune systems).

Metabolic optimization: Butyrate improves the integrity of the intestinal barrier (upregulation of claudins and occlusins), decreasing metabolic endotoxemia (the passage of LPS into the bloodstream). Less internal inflammation results in healthier skin and sweat with chemical profiles associated with a healthy and vigorous organism.

-----------3. Modulation of dopamine and energy

Butyrate is involved in the expression of tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis. Stable levels of peripheral and central dopamine improve motivation, mood, and energy levels as perceived by others. Enthusiasm and vitality are, from a bio-behavioral perspective, primary factors of attraction.

In short: Butyrate is neither a love potion nor a pheromone. If it makes someone "more attractive," it's an indirect, secondary effect of homeostatic optimization: less inflammation, a better epithelial barrier, reduced social anxiety, and a metabolic signature (olfactory and behavioral) that the brains of others interpret, in a purely evolutionary way, as "a healthy organism."

https://www.nature.com/articles/nrmicro3089

https://pubmed.ncbi.nlm.nih.gov/32057924/

https://www.mdpi.com/2227-9059/9/2/120

https://www.researchgate.net/publication/333243792_A_Decision-Theoretic_Model_of_Behavior_Change

Te Time's avatar
2dEdited

We just got back from the Pat Summitt clinic yesterday. Awesome place. They know Alzheimer’s.

So, we found out my husband has a rare variate of Alzheimer’s disease. Posterior Cortical Atrophy.

Originally, by more than one doctor a couple of years ago that hubs had a stroke and that after the bran scan was told he had Alzheimer’s. His progression has been fast.

We are going for a brain scan next week. The doc at PT doesn’t believe he had a stroke. This rare variant, causes right inattention.

We wasted years with primary and neurologist.

Find a place that specializes in Alzheimer’s. Do not waste your time with primary and neurologist. I handed all my journey logs and they knew straight away what was going on. Now, everything makes sense. He’s probably in stage 6 now and remembers everything. He just can’t tell us what he wants. He remembers everyone. Crazy.

Doc believes he also had a couple of tumors. Not a stroke!

Guillermou's avatar

On the right track. Good luck and lots of hugs and music to your dear husband.❤❤🙏

The relationship between music and Alzheimer's is one of the most fascinating fields of neurobiology applied to health. Although the disease degrades many cognitive functions, the neural circuits linked to musical memory and rhythmic processing are usually among the last to be affected, making music an exceptionally powerful therapeutic tool.

Music is not processed in a single brain area; it activates a complex and distributed network that includes the limbic system (emotions), the temporal lobe (rhythm and pitch), and the prefrontal cortex (autobiographical memory).

• Neurobiological resilience: Even in advanced stages, many people retain the ability to recognize melodies, keep a beat, or remember lyrics, as these connections outlast the neurodegeneration of Alzheimer's.

• "Bridge" effect: It functions as an alternative pathway. When the areas responsible for language or verbal communication are blocked, music can serve as a "bridge" to reconnect the patient with their environment and caregivers.

• Emotional regulation: It helps to significantly reduce cortisol levels (the stress hormone) and agitation, improving mood and facilitating calm without the need for additional pharmacological intervention in many cases.

Observed therapeutic benefits:

1. Evocation of memories: Familiar songs act as mnemonic triggers, allowing the patient to access memories from their life that would otherwise seem inaccessible.

2. Reduction of behavioral symptoms: It is highly effective in mitigating the anxiety, aggression, and depression that often accompany cognitive decline.

3. Social connection: It facilitates non-verbal interaction (eye contact, smiles, swaying to the rhythm) between the patient and the caregiver, strengthening the emotional bond. 4. Physical stimulation: Encourages motor coordination through free movement, gentle dancing or the use of simple instruments.

https://www.alzinfo.org/articles/prevention/how-music-can-ease-the-agitation-of-alzheimers/

https://emera-group.es/noticias/musica-y-alzheimer-como-evitar-perdida-de-memoria/#:~:text=S%C3%AD.%20Incluso%20en%20fases%20avanzadas%20de%20la,a%20la%20memoria%20epis%C3%B3dica%20o%20sem%C3%A1ntica%20%5B1%5D.

https://www.bupasalud.com/salud/musicoterapia-alzheimer#:~:text=En%20cierto%20sentido%2C%20es%20una%20distracci%C3%B3n%20positiva,en%20la%20calidad%20del%20sue%C3%B1o%20del%20paciente.

https://www.sanitas.es/biblioteca-de-salud/tercera-edad/demencias-y-patologias/alzheimer/actividades-de-musicoterapia-para-personas-con-alzheimer#:~:text=As%C3%AD%2C%20la%20m%C3%BAsica%20act%C3%BAa%20como%20un%20sistema,autobiogr%C3%A1ficos%20que%20de%20otra%20manera%20permanecer%C3%ADan%20inaccesibles.

https://hic.fcv.org/co/blog/instituto-neurologico/musica-arte-y-terapia-ocupacional-en-el-alzheimer#:~:text=%C2%BFNecesitas%20ayuda?%20La%20m%C3%BAsica%20tambi%C3%A9n%20facilita%20la,v%C3%ADnculo%20entre%20el%20paciente%20y%20su%20cuidador.

Te Time's avatar

Thank you so much for this information. The fact that you took the time is amazing. Much appreciated

Guillermou's avatar

❤️❤️💕💕

Just steve's avatar

A solid Gut Health long recognized by those who pursue building good health, preventing Dis-Ease as opposed to manage symptoms after damage is done.

Solid Gut Brain connections slowly, begrudgingly being acknowledged outside of let's build Health Circles. There are threads going back countless centuries of cultures recognizing the Gut Brain connection.

Maybe Just Me but, right along with this is the Gut Body Connection...not just how certain offenders tear open the Gut affecting the Brain/Mind but also the body. Leaky Gut Dis-Ease's. How certain offenders bypass the Gut altogether and some make what amounts to a Direct Deposit into the Body, no Gut involved. You know...the pesky pokes that many, most maybe even all do more than address one issue and actually by bypassing the protection of the Gut, the Innate Immune Systems resources protection in respiratory, skin protections set us up for Dis-Ease's totally unnecessary.

Guillermou's avatar

Great report, Just. We need to compose a requiem for vaccines and all those who have promoted them. This should be a chronicle of a death foretold. Today, faced with the apathy of so many, it's time to write a requiem and dance so we don't cry for the crimes committed against humanity. Onward, RFK Jr., onward, MAHA! Fight with the weapons of truth, fight for the health of children and people, fight to overcome chronic diseases, fight against pharmaceutical corruption and its powerful lobbies. Fight against market monopolization and the technological advances that gave rise to an incredibly profitable medical industry, which generated the funding to promote a new faith in vaccines throughout the country, and where education and bribing doctors were the cornerstone of the industry.

BREAKING: MEGA LAWSUIT FILED AGAINST BILL GATES AND OTHERS FOR 'CRIMES AGAINST HUMANITY' OVER COVID VACCINES

"The filing characterizes these actions as violations of international law, asserting that they rise to the level of crimes against humanity due to the scale and scope of the alleged harm..."

In the Netherlands, lawyer Peter Stassen is pressing ahead (despite his colleague being imprisoned by Dutch paramilitaries) with his lawsuit against Pfizer CEO Albert Bourla, Bill Gates, and other sociopaths behind the global rollout of mRNA vaccines, alleging that they have committed crimes against humanity.

https://diedsuddenlynews.substack.com/p/breaking-mega-lawsuit-filed-against?img=https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fd8964333-dd7e-4ade-aec4-57dd0c659dc1_680x397.jpeg&open=false (Dec 17, 2025)

Guillermou's avatar

Interesting points, Just. A team from the Severo Ochoa Molecular Biology Center and the Spanish National Research Council (CSIC) has demonstrated that reactive oxygen species (ROS), produced by mitochondrial metabolic activity, are essential for generating the first line of defense of the immune system, protecting the gut from inflammation. The interactions between mitochondria and the gut microbiome converge in intestinal homeostasis, exhibiting synergy in health and conflict in disease. Gut microbes can affect ROS levels, mitochondrial homeostasis, and host health.

Mitochondrial health is vital for epithelial barrier function, which includes paracellular junctions, the secreted extracellular barrier (mucus and antimicrobial peptides), and the commensal microbiota, all fundamental for inducing immune tolerance. The role of mitochondrial function in mechanisms such as mucosal repair, the microbiota, and the gut-brain axis is established.

A diet that avoids the promotion of endotoxins is linked to metabolic diseases, including cardiovascular, neurodegenerative, and cancerous diseases. Chronic endotoxemia is a major factor inducing systemic inflammation that leads to metabolic syndrome. Phytochemicals reduce endotoxins.

Specific components of the Western diet, such as PUFAs, monosaccharides, processed fats, gluten, alcohol, and additives, can affect the tight junctions between enterocytes, leading to increased intestinal permeability and the displacement of endotoxins into the bloodstream, including lipopolysaccharides derived from Gram-negative bacteria.

Increases in blood endotoxin levels were associated with increases in C-reactive protein concentrations and increases in intestinal permeability markers such as zonulite.

Probiotics help modify the gut microbiota, promote the growth of beneficial bacteria, and are an alternative source of short-chain fatty acids (SCFAs). They also reduce LPS expression and intestinal inflammation. Among them, Akkermansia muciniphila has the ability to reduce LPS expression, improving metabolic endotoxemia.

Inflammatory bowel disease (IBD) is considered a global health problem. It is well established that IBD patients exhibit an altered gut microbiota composition with an expansion of potentially pathogenic bacteria and reduced overall diversity.

Emerging studies implicate mitochondrial dysfunction in inflammatory bowel disease (IBD).

Mitochondrial dysfunction plays an important role in a wide range of chronic inflammatory diseases, from cancer to neurodegenerative disorders. Treating the underlying mitochondrial dysfunction provides a novel therapeutic strategy for inflammatory bowel disease (IBD). Emerging evidence suggests that the gut microbiota signals to the mitochondria of mucosal cells, including epithelial and immune cells. Signaling from the gut microbiota to mitochondria has been shown to alter mitochondrial metabolism, activate immune cells, induce inflammasome signaling, and disrupt epithelial barrier function.

Stress inhibits the vagal nerve and has detrimental effects on the gastrointestinal tract and microbiota, and is implicated in inflammatory bowel disease (IBD). Low vagal tone has been described in patients with IBD and IBS, which promotes peripheral inflammation.

https://www.mdpi.com/2076-2607/11/2/267 (2023).--

https://link.springer.com/article/10.1007/s11739-023-03374-w (2024).--

https://onlinelibrary.wiley.com/doi/full/10.1111/eci.14224 (2024).---

https://www.cell.com/trends/endocrinology-metabolism/abstract/S1043-2760(24)00087-0 (2024).—

https://ejhm.journals.ekb.eg/article_349082.html (2024).--

https://www.mdpi.com/1422-0067/24/23/17124 (2023).--

https://www.nature.com/articles/s41575-024-00931-2 (2024).--