Promising Effects of Neurorestorative Diets on Motor, Cognitive, and Gastrointestinal Dysfunction after Symptom Development in a Mouse Model of Parkinson's Disease

Gut microbiota in Alzheimer's disease: Understanding molecular pathways and potential therapeutic perspectives

Accumulating evidence suggests that gut microbiota (GM) plays a crucial role in Alzheimer's disease (AD) pathogenesis and progression. This narrative review explores the complex interplay between GM, the immune system, and the central nervous system in AD. We discuss mechanisms through which GM dysbiosis can compromise intestinal barrier integrity, enabling pro-inflammatory molecules and metabolites to enter systemic circulation and the brain, potentially contributing to AD hallmarks. Additionally, we examine other pathophysiological mechanisms by which GM may influence AD risk, including the production of short-chain fatty acids, secondary bile acids, and tryptophan metabolites. The role of the vagus nerve in gut-brain communication is also addressed. We highlight potential therapeutic implications of targeting GM in AD, focusing on antibiotics, probiotics, prebiotics, postbiotics, phytochemicals, and fecal microbiota transplantation. While preclinical studies showed promise, clinical evidence remains limited and inconsistent. We critically assess clinical trials, emphasizing challenges in translating GM-based therapies to AD patients. The reviewed evidence underscores the need for further research to elucidate precise molecular mechanisms linking GM to AD and determine whether GM dysbiosis is a contributing factor or consequence of AD pathology. Future studies should focus on large-scale clinical trials to validate GM-based interventions' efficacy and safety in AD.

TAT-PPA1 protects against oxidative stress-induced loss of dopaminergic neurons

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN) of the midbrain, resulting in severe motor impairments. Inorganic pyrophosphatase 1 (PPA1) plays a key role in various biological processes, and this study introduces a cell-penetrating PPA1 fusion protein (TAT-PPA1) to explore its transduction into cells and brain tissues. TAT-PPA1 effectively penetrates SH-SY5Y cells and the SN region of PD animal models without toxicity, exhibiting protective effects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP-)-induced cell death. TAT-PPA1 revealed an inhibitory influence on the MAPK signaling pathway and MPTP-induced reactive oxygen species (ROS) production. TAT-PPA1 suppresses JNK, AKT, p53, ERK, and p38 phosphorylation, showcasing its multifaceted role in cell survival pathways. In the MPTP-induced PD animal model, TAT-PPA1 prevents dopaminergic cell death and enhances motor function. This study shows that TAT-PPA1 protects against oxidative stress and cell death in neurodegenerative diseases, suggesting potential as a PD treatment.

Microbiome-based therapeutics for Parkinson's disease

Recent experimental and clinical data demonstrate a significant dysregulation of the gut microbiome in individuals with Parkinson's disease (PD). With an immense influence on all aspects of physiology, this dysregulation has potential to directly or indirectly contribute to disease pathology. Experimental models have bridged these associations toward defined contributions, identifying various microbiome-dependent impacts to PD pathology. These studies have laid the foundation for human translation, examining whether certain members of the microbiome and/or whole restoration of the gut microbiome community can provide therapeutic benefit for people living with PD. Here, we review recent and ongoing clinically-focused studies that use microbiome-targeted therapies to limit the severity and progression of PD. Fecal microbiome transplants, prebiotic interventions, and probiotic supplementation are each emerging as viable methodologies to augment the gut microbiome and potentially limit PD symptoms. While still early, the data in the field to date support continued cross-talk between experimental systems and human studies to identify key microbial factors that contribute to PD pathologies.

The role of gut-derived short-chain fatty acids in Parkinson's disease

The emerging function of short-chain fatty acids (SCFAs) in Parkinson's disease (PD) has been investigated in this article. SCFAs, which are generated via the fermentation of dietary fiber by gut microbiota, have been associated with dysfunction of the gut-brain axis and, neuroinflammation. These processes are integral to the development of PD. This article examines the potential therapeutic implications of SCFAs in the management of PD, encompassing their capacity to modulate gastrointestinal permeability, neuroinflammation, and neuronal survival, by conducting an extensive literature review. As a whole, this article emphasizes the potential therapeutic utility of SCFAs as targets for the management and treatment of PD.

Cold-pressed perilla seed oil: Investigating its protective influence on the gut-brain axis in mice with rotenone-induced Parkinson's disease

Perilla seed oil, derived from a regional plant native to northern Thailand, undergoes cold-pressing to analyze its bioactive components, notably alpha-linolenic acid (ALA). ALA, constituting approximately 61% of the oil, serves as a precursor for therapeutic omega-3 fatty acids, EPA and DHA, with neurodegenerative disease benefits and anti-inflammatory responses. This study administered different concentrations of perilla seed oil to male C57BL/6 mice, categorized as low dose (LP 5% w/w), middle dose (MP 10% w/w), and high dose (HP 20% w/w), along with a fish oil (FP 10% w/w) diet. An experimental group received soybean oil (5% w/w). Over 42 days, these diets were administered while inducing Parkinson's disease (PD) with rotenone injections. Mice on a high perilla seed oil dose exhibited decreased Cox-2 expression in the colon, suppressed Iba-1 microglia activation, reduced alpha-synuclein accumulation in the colon and hippocampus, prevented dopaminergic cell death in the substantia nigra, and improved motor and non-motor symptoms. Mice on a middle dose showed maintenance of diverse gut microbiota, with an increased abundance of short-chain fatty acid (SCFA)-producing bacteria (Bifidobacteria, Lactobacillus, and Faecalibacteria). A reduction in bacteria correlated with PD (Turicibacter, Ruminococcus, and Akkermansia) was observed. Results suggest the potential therapeutic efficacy of high perilla seed oil doses in mitigating both intestinal and neurological aspects linked to the gut-brain axis in PD.

The Protective Effect of Uridine in a Rotenone-Induced Model of Parkinson's Disease: The Role of the Mitochondrial ATP-Dependent Potassium Channel

The effect of the modulators of the mitochondrial ATP-dependent potassium channel (mitoKATP) on the structural and biochemical alterations in the substantia nigra and brain tissues was studied in a rat model of Parkinson's disease induced by rotenone. It was found that, in experimental parkinsonism accompanied by characteristic motor deficits, both neurons and the myelin sheath of nerve fibers in the substantia nigra were affected. Changes in energy and ion exchange in brain mitochondria were also revealed. The nucleoside uridine, which is a source for the synthesis of the mitoKATP channel opener uridine diphosphate, was able to dose-dependently decrease behavioral disorders and prevent the death of animals, which occurred for about 50% of animals in the model. Uridine prevented disturbances in redox, energy, and ion exchanges in brain mitochondria, and eliminated alterations in their structure and the myelin sheath in the substantia nigra. Cytochemical examination showed that uridine restored the indicators of oxidative phosphorylation and glycolysis in peripheral blood lymphocytes. The specific blocker of the mitoKATP channel, 5-hydroxydecanoate, eliminated the positive effects of uridine, suggesting that this channel is involved in neuroprotection. Taken together, these findings indicate the promise of using the natural metabolite uridine as a new drug to prevent and, possibly, stop the progression of Parkinson's disease.

From the Gut to the Brain: Is Microbiota a New Paradigm in Parkinson's Disease Treatment?

Parkinson's disease (PD) is recognized as the second most prevalent primary chronic neurodegenerative disorder of the central nervous system. Clinically, PD is characterized as a movement disorder, exhibiting an incidence and mortality rate that is increasing faster than any other neurological condition. In recent years, there has been a growing interest concerning the role of the gut microbiota in the etiology and pathophysiology of PD. The establishment of a brain-gut microbiota axis is now real, with evidence denoting a bidirectional communication between the brain and the gut microbiota through metabolic, immune, neuronal, and endocrine mechanisms and pathways. Among these, the vagus nerve represents the most direct form of communication between the brain and the gut. Given the potential interactions between bacteria and drugs, it has been observed that the therapies for PD can have an impact on the composition of the microbiota. Therefore, in the scope of the present review, we will discuss the current understanding of gut microbiota on PD and whether this may be a new paradigm for treating this devastating disease.

Buty and the beast: the complex role of butyrate in Parkinson's disease

Parkinson's disease (PD) is a complex neurodegenerative disease which is often associated with gastrointestinal (GI) dysfunction. The GI tract is home to a wide range of microorganisms, among which bacteria, that can influence the host through various mechanisms. Products produced by these bacteria can act in the gut but can also exert effects in the brain via what is now well established to be the microbiota-gut-brain axis. In those with PD the gut-bacteria composition is often found to be different to that of non-PD individuals. In addition to compositional changes, the metabolic activity of the gut-microbiota is also changed in PD. Specifically, it is often reported that key producers of short chain fatty acids (SCFAs) as well as the concentration of SCFAs themselves are altered in the stool and blood of those with PD. These SCFAs, among which butyrate, are essential nutrients for the host and are a major energy source for epithelial cells of the GI tract. Additionally, butyrate plays a key role in regulating various host responses particularly in relation to inflammation. Studies have demonstrated that a reduction in butyrate levels can have a critical role in the onset and progression of PD. Furthermore, it has been shown that restoring butyrate levels in those with PD through methods such as probiotics, prebiotics, sodium butyrate supplementation, and fecal transplantation can have a beneficial effect on both motor and non-motor outcomes of the disease. This review presents an overview of evidence for the altered gut-bacteria composition and corresponding metabolite production in those with PD, with a particular focus on the SCFA butyrate. In addition to presenting current studies regarding SCFA in clinical and preclinical reports, evidence for the possibility to target butyrate production using microbiome based approaches in a therapeutic context is discussed.

Gastrointestinal dysmotility in rodent models of Parkinson's disease

Multiple studies describe prodromal, nonmotor dysfunctions that affect the quality of life of patients who subsequently develop Parkinson's disease (PD). These prodromal dysfunctions comprise a wide array of autonomic issues, including severe gastrointestinal (GI) motility disorders such as dysphagia, delayed gastric emptying, and chronic constipation. Indeed, strong evidence from studies in humans and animal models suggests that the GI tract and its neural, mainly vagal, connection to the central nervous system (CNS) could have a major role in the etiology of PD. In fact, misfolded α-synuclein aggregates that form Lewy bodies and neurites, i.e., the histological hallmarks of PD, are detected in the enteric nervous system (ENS) before clinical diagnosis of PD. The aim of the present review is to provide novel insights into the pathogenesis of GI dysmotility in PD, focusing our attention on functional, neurochemical, and molecular alterations in animal models.

Rotenone impairs brain glial energetics and locomotor behavior in bumblebees

Bumblebees are essential pollinators of both wildflowers and crops and face multiple anthropogenic stressors, particularly the utilization of pesticides. Rotenone is an extensively applied neurotoxic pesticide that possesses insecticidal activities against a wide range of pests. However, whether environmentally realistic exposure levels of rotenone can damage neurons in bumblebee brains is still uncertain. Using single-cell RNA-seq, we revealed that rotenone induced cell-specific responses in bumblebee brains, emphasizing the disruption of energy metabolism and mitochondrial dysfunction in glial cells. Correspondingly, the gene regulatory network associated with neurotransmission was also suppressed. Notably, rotenone could specially reduce the number of dopaminergic neurons, impairing bumblebee's ability to fly and crawl. We also found impaired intestinal motility in rotenone-treated bumblebees. Finally, we demonstrated that many differentially expressed genes in our snRNA-seq data overlapped with rotenone-induced Parkinson's disease risk genes, especially in glial cells. Although rotenone is widely used owing to its hypotoxicity, we found that environmentally realistic exposure levels of rotenone induced disturbed glial energetics and locomotor dysfunction in bumblebees, which may lead to an indirect decline in this essential pollinator.

Advice to People with Parkinson's in My Clinic: Probiotics and Prebiotics

There is increasing evidence that microbial-based therapies can be useful in people with Parkinson's disease (PD). In this viewpoint, we provide a state-of-the-art review of the clinical and pre-clinical evidence for probiotics and prebiotics in PD. Currently, short-term clinical studies, including double-blind placebo-controlled randomized clinical trials, have demonstrated safety, and efficacy primarily in improving constipation-related symptoms. Pre-clinical studies consistently reported improvements in a range of biological markers and outcomes, including evidence for attenuation of gut dysfunction and neuroprotection. Bacteria from the genus Lactobacillus and Bifidobacterium have been the most frequently studied both in clinical and pre-clinical probiotics studies, while research into prebiotics is still limited and primarily involved resistant starch and fructooligosaccharides. We provide practical suggestions for clinicians on how to advise patients in the clinic regarding these popular treatments, and important caveats to be aware of. Finally, areas for further advancements are highlighted. It is envisaged that in the future, microbial-based therapies may benefit from personalization based on an enhanced understanding of a whole range of host factors and host-microbiome interactions.

Multidirectional associations between the gut microbiota and Parkinson's disease, updated information from the perspectives of humoral pathway, cellular immune pathway and neuronal pathway

The human gastrointestinal tract is inhabited by a diverse range of microorganisms, collectively known as the gut microbiota, which form a vast and complex ecosystem. It has been reported that the microbiota-gut-brain axis plays a crucial role in regulating host neuroprotective function. Studies have shown that patients with Parkinson's disease (PD) have dysbiosis of the gut microbiota, and experiments involving germ-free mice and fecal microbiota transplantation from PD patients have revealed the pathogenic role of the gut microbiota in PD. Interventions targeting the gut microbiota in PD, including the use of prebiotics, probiotics, and fecal microbiota transplantation, have also shown efficacy in treating PD. However, the causal relationship between the gut microbiota and Parkinson's disease remains intricate. This study reviewed the association between the microbiota-gut-brain axis and PD from the perspectives of humoral pathway, cellular immune pathway and neuronal pathway. We found that the interactions among gut microbiota and PD are very complex, which should be "multidirectional", rather than conventionally regarded "bidirectional". To realize application of the gut microbiota-related mechanisms in the clinical setting, we propose several problems which should be addressed in the future study.

Microbiota and probiotics: chances and challenges - a symposium report

The 10th International Yakult Symposium was held in Milan, Italy, on 13-14 October 2022. Two keynote lectures covered the crewed journey to space and its implications for the human microbiome, and how current regulatory systems can be adapted and updated to ensure the safety of microorganisms used as probiotics or food processing ingredients. The remaining lectures were split into sections entitled "Chances" and "Challenges." The "Chances" section explored opportunities for the science of probiotics and fermented foods to contribute to diverse areas of health such as irritable bowel syndrome, major depression, Parkinson's disease, immune dysfunction, infant colic, intensive care, respiratory infections, and promoting healthy longevity. The "Challenges" section included selecting appropriate clinical trial participants and methodologies to minimise heterogeneity in responses, how to view probiotics in the context of One Health, adapting regulatory frameworks, and understanding how substances of bacterial origin can cross the blood-brain barrier. The symposium provided evidence from cutting-edge research that gut eubiosis is vital for human health and, like space, the microbiota deserves further exploration of its vast potential.

Emotional-Single Prolonged Stress: A promising model to illustrate the gut-brain interaction

Excessive stress can precipitate depression and anxiety diseases, and damage gastrointestinal functionality and microbiota changes, favoring the development of functional gastrointestinal disorders (FGIDs) - defined by dysregulation in the brain-gut interaction. Therefore, the present study investigated if Emotional-Single Prolonged Stress (E-SPS) induces depressive/anxiety-like phenotype and gut dysfunction in adult Swiss male mice. For this, mice of the E-SPS group were subjected to three stressors sequential exposure: immobilization, swimming, and odor of the predator for 7 days (incubation period). Next, animals performed behavior tests and 24 h later, samples of feces, blood, and colon tissue were collected. E-SPS increased the plasma corticosterone levels, immobility time in the tail suspension and forced swim test, decreased the grooming time in the splash test, OAT%, and OAE% in the elevated plus-maze test, as well as increased anxiety index. Mice of E-SPS had increased % of intestinal transit rate, % of fecal moisture content, and fecal pellets number, and decreased Claudin1 content in the colon. E-SPS decreased the relative abundance of Bacteroidetes phylum, Bacteroidia class, Bacteroidales order, Muribaculaceae and Porphyromonadaceae family, Muribaculum, and Duncaniella genus. However, E-SPS increased Firmicutes and Actinobacteria phylum, Coriobacteriales order, and the ratio of Firmicutes/Bacteroidetes, and demonstrated Mucispirillum genus presence. The present study showed that E-SPS induced depressive/anxiety-like phenotype, predominant diarrhea gut dysfunction, and modulated the gut bacterial microbiota profile in male adult Swiss mice. E-SPS might be a promising model for future studies on the brain-gut interaction and the development of FGIDs with psychological comorbidities.

The Mechanism of SNHG8/Microrna-421-3p/Sorting Nexin 8 Axis on Dopaminergic Neurons in Substantia Nigra in a Mouse Model of Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disease affecting the aging population. Particularly, long non-coding RNAs (lncRNAs) have been demonstrated to play vital roles in PD, while the role of lncRNA SNHG8 in PD remains to be further explored. C57BL/6 mice were induced by rotenone to establish a PD model in vivo, and then the dopaminergic (DA) neuronal damage and locomotor dysfunction in rotenone-treated mice were evaluated. Murine DA cell line MN9D was treated with rotenone to establish a cellular PD model in vitro. Then, the viability, apoptosis, mitochondrial dysfunction, endoplasmic reticulum stress, and autophagy in rotenone-treated MN9D cells were assessed. Expression levels of SNHG8, microRNA-421-3p (miR-421-3p), and sorting nexin 8 (SNX8) in the substantia nigra (SN) of PD mice and rotenone-treated MN9D cells were detected. The interaction between SNHG8 and miR-421-3p, and the targeting relationship between SNX8 and miR-421-3p were confirmed. SNHG8 and SNX8 expression levels were decreased while miR-421-3p expression level was increased in the SN of PD mice and rotenone-treated MN9D cells. Upregulated SNHG8 ameliorated dopaminergic neuron damage and locomotor dysfunction in PD mice. Meanwhile, upregulated SNHG8 enhanced viability, diminished apoptosis, and alleviated mitochondrial dysfunction, endoplasmic reticulum stress, and autophagy in rotenone-treated MN9D cells. Mechanistically, SNHG8 bound to miR-421-3p, and miR-421-3p targeted SNX8. Overexpressed SNHG8 downregulates miR-421-3p to alleviate rotenone-induced dopaminergic neuron injury in PD via upregulating SNX8.

Effects of a probiotic suspension Symprove™ on a rat early-stage Parkinson's disease model

An increasing number of studies in recent years have focused on the role that the gut may play in Parkinson's Disease (PD) pathogenesis, suggesting that the maintenance of a healthy gut may lead to potential treatments of the disease. The health of microbiota has been shown to be directly associated with parameters that play a potential role in PD including gut barrier integrity, immunity, function, metabolism and the correct functioning of the gut-brain axis. The gut microbiota (GM) may therefore be employed as valuable indicators for early diagnosis of PD and potential targets for preventing or treating PD symptoms. Preserving the gut homeostasis using probiotics may therefore lead to a promising treatment strategy due to their known benefits in improving constipation, motor impairments, inflammation, and neurodegeneration. However, the mechanisms underlying the effects of probiotics in PD are yet to be clarified. In this project, we have tested the efficacy of an oral probiotic suspension, Symprove™, on an established animal model of PD. Symprove™, unlike many commercially available probiotics, has been shown to be resistant to gastric acidity, improve symptoms in gastrointestinal diseases and improve gut integrity in an in vitro PD model. In this study, we used an early-stage PD rat model to determine the effect of Symprove™ on neurodegeneration and neuroinflammation in the brain and on plasma cytokine levels, GM composition and short chain fatty acid (SCFA) release. Symprove™ was shown to significantly influence both the gut and brain of the PD model. It preserved the gut integrity in the PD model, reduced plasma inflammatory markers and changed microbiota composition. The treatment also prevented the reduction in SCFAs and striatal inflammation and prevented tyrosine hydroxylase (TH)-positive cell loss by 17% compared to that observed in animals treated with placebo. We conclude that Symprove™ treatment may have a positive influence on the symptomology of early-stage PD with obvious implications for the improvement of gut integrity and possibly delaying/preventing the onset of neuroinflammation and neurodegeneration in human PD patients.

The Interplay between Gut Microbiota and Parkinson's Disease: Implications on Diagnosis and Treatment

The bidirectional interaction between the gut microbiota (GM) and the Central Nervous System, the so-called gut microbiota brain axis (GMBA), deeply affects brain function and has an important impact on the development of neurodegenerative diseases. In Parkinson’s disease (PD), gastrointestinal symptoms often precede the onset of motor and non-motor manifestations, and alterations in the GM composition accompany disease pathogenesis. Several studies have been conducted to unravel the role of dysbiosis and intestinal permeability in PD onset and progression, but the therapeutic and diagnostic applications of GM modifying approaches remain to be fully elucidated. After a brief introduction on the involvement of GMBA in the disease, we present evidence for GM alterations and leaky gut in PD patients. According to these data, we then review the potential of GM-based signatures to serve as disease biomarkers and we highlight the emerging role of probiotics, prebiotics, antibiotics, dietary interventions, and fecal microbiota transplantation as supportive therapeutic approaches in PD. Finally, we analyze the mutual influence between commonly prescribed PD medications and gut-microbiota, and we offer insights on the involvement also of nasal and oral microbiota in PD pathology, thus providing a comprehensive and up-to-date overview on the role of microbial features in disease diagnosis and treatment.

Are We What We Eat? Impact of Diet on the Gut-Brain Axis in Parkinson's Disease

Parkinson’s disease is characterized by motor and non-motor symptoms, such as defects in the gut function, which may occur before the motor symptoms. To date, there are therapies that can improve these symptoms, but there is no cure to avoid the development or exacerbation of this disorder. Dysbiosis of gut microbiota could have a crucial role in the gut–brain axis, which is a bidirectional communication between the central nervous system and the enteric nervous system. Diet can affect the microbiota composition, impacting gut–brain axis functionality. Gut microbiome restoration through probiotics, prebiotics, synbiotics or other dietary means could have the potential to slow PD progression. In this review, we will discuss the influence of diet on the bidirectional communication between gut and brain, thus supporting the hypothesis that this disorder could begin in the gut. We also focus on how food-based therapies might then have an influence on PD and could ameliorate non-motor as well as motor symptoms.

Fecal microbiota transplantation protects rotenone-induced Parkinson's disease mice via suppressing inflammation mediated by the lipopolysaccharide-TLR4 signaling pathway through the microbiota-gut-brain axis

BACKGROUND

Parkinson's disease (PD) is a prevalent neurodegenerative disorder, displaying not only well-known motor deficits but also gastrointestinal dysfunctions. Consistently, it has been increasingly evident that gut microbiota affects the communication between the gut and the brain in PD pathogenesis, known as the microbiota-gut-brain axis. As an approach to re-establishing a normal microbiota community, fecal microbiota transplantation (FMT) has exerted beneficial effects on PD in recent studies. Here, in this study, we established a chronic rotenone-induced PD mouse model to evaluate the protective effects of FMT treatment on PD and to explore the underlying mechanisms, which also proves the involvement of gut microbiota dysbiosis in PD pathogenesis via the microbiota-gut-brain axis.

RESULTS

We demonstrated that gut microbiota dysbiosis induced by rotenone administration caused gastrointestinal function impairment and poor behavioral performances in the PD mice. Moreover, 16S RNA sequencing identified the increase of bacterial genera Akkermansia and Desulfovibrio in fecal samples of rotenone-induced mice. By contrast, FMT treatment remarkably restored the gut microbial community, thus ameliorating the gastrointestinal dysfunctions and the motor deficits of the PD mice. Further experiments revealed that FMT administration alleviated intestinal inflammation and barrier destruction, thus reducing the levels of systemic inflammation. Subsequently, FMT treatment attenuated blood-brain barrier (BBB) impairment and suppressed neuroinflammation in the substantia nigra (SN), which further decreased the damage of dopaminergic neurons. Additional mechanistic investigation discovered that FMT treatment reduced lipopolysaccharide (LPS) levels in the colon, the serum, and the SN, thereafter suppressing the TLR4/MyD88/NF-κB signaling pathway and its downstream pro-inflammatory products both in the SN and the colon.

CONCLUSIONS

Our current study demonstrates that FMT treatment can correct the gut microbiota dysbiosis and ameliorate the rotenone-induced PD mouse model, in which suppression of the inflammation mediated by the LPS-TLR4 signaling pathway both in the gut and the brain possibly plays a significant role. Further, we prove that rotenone-induced microbiota dysbiosis is involved in the genesis of PD via the microbiota-gut-brain axis. Video abstract.

Novel compound FLZ alleviates rotenone-induced PD mouse model by suppressing TLR4/MyD88/NF-κB pathway through microbiota-gut-brain axis

Parkinson's disease (PD) is the second most common neurodegenerative disease, but none of the current treatments for PD can halt the progress of the disease due to the limited understanding of the pathogenesis. In PD development, the communication between the brain and the gastrointestinal system influenced by gut microbiota is known as microbiota-gut-brain axis. However, the explicit mechanisms of microbiota dysbiosis in PD development have not been well elucidated yet. FLZ, a novel squamosamide derivative, has been proved to be effective in many PD models and is undergoing the phase I clinical trial to treat PD in China. Moreover, our previous pharmacokinetic study revealed that gut microbiota could regulate the absorption of FLZ in vivo. The aims of our study were to assess the protective effects of FLZ treatment on PD and to further explore the underlying microbiota-related mechanisms of PD by using FLZ as a tool. In the current study, chronic oral administration of rotenone was utilized to induce a mouse model to mimic the pathological process of PD. Here we revealed that FLZ treatment alleviated gastrointestinal dysfunctions, motor symptoms, and dopaminergic neuron death in rotenone-challenged mice. 16S rRNA sequencing found that PD-related microbiota alterations induced by rotenone were reversed by FLZ treatment. Remarkably, FLZ administration attenuated intestinal inflammation and gut barrier destruction, which subsequently inhibited systemic inflammation. Eventually, FLZ treatment restored blood-brain barrier structure and suppressed neuroinflammation by inhibiting the activation of astrocytes and microglia in the substantia nigra (SN). Further mechanistic research demonstrated that FLZ treatment suppressed the TLR4/MyD88/NF-κB pathway both in the SN and colon. Collectively, FLZ treatment ameliorates microbiota dysbiosis to protect the PD model via inhibiting TLR4 pathway, which contributes to one of the underlying mechanisms beneath its neuroprotective effects. Our research also supports the importance of microbiota-gut-brain axis in PD pathogenesis, suggesting its potential role as a novel therapeutic target for PD treatment.

The role of microbiota-gut-brain axis in neuropsychiatric and neurological disorders

Emerging evidence indicates that the gut microbiota play a crucial role in the bidirectional communication between the gut and the brain suggesting that the gut microbes may shape neural development, modulate neurotransmission and affect behavior, and thereby contribute to the pathogenesis and/or progression of many neurodevelopmental, neuropsychiatric, and neurological conditions. This review summarizes recent data on the role of microbiota-gut-brain axis in the pathophysiology of neuropsychiatric and neurological disorders including depression, anxiety, schizophrenia, autism spectrum disorders, Parkinson's disease, migraine, and epilepsy. Also, the involvement of microbiota in gut disorders co-existing with neuropsychiatric conditions is highlighted. We discuss data from both in vivo preclinical experiments and clinical reports including: (1) studies in germ-free animals, (2) studies exploring the gut microbiota composition in animal models of diseases or in humans, (3) studies evaluating the effects of probiotic, prebiotic or antibiotic treatment as well as (4) the effects of fecal microbiota transplantation.

Using Rotenone to Model Parkinson's Disease in Mice: A Review of the Role of Pharmacokinetics

Rotenone is a naturally occurring toxin that inhibits complex I of the mitochondrial electron transport chain. Several epidemiological studies have shown an increased risk of Parkinson's disease (PD) in individuals exposed chronically to rotenone, and it has received great attention for its ability to reproduce many critical features of PD in animal models. Laboratory studies of rotenone have repeatedly shown that it induces in vivo substantia nigra dopaminergic cell loss, a hallmark of PD neuropathology. Additionally, rotenone induces in vivo aggregation of α-synuclein, the major component of Lewy bodies and Lewy neurites found in the brain of PD patients and another hallmark of PD neuropathology. Some in vivo rotenone models also reproduce peripheral signs of PD, such as reduced intestinal motility and peripheral α-synuclein aggregation, both of which are thought to precede classical signs of PD in humans, such as cogwheel rigidity, bradykinesia, and resting tremor. Nevertheless, variability has been noted in cohorts of animals exposed to the same rotenone exposure regimen and also between cohorts exposed to similar doses of rotenone. Low doses, administered chronically, may reproduce PD symptoms and neuropathology more faithfully than excessively high doses, but overlap between toxicity and parkinsonian motor phenotypes makes it difficult to separate if behavior is examined in isolation. Rotenone degrades when exposed to light or water, and choice of vehicle may affect outcome. Rotenone is metabolized extensively in vivo, and choice of route of exposure influences greatly the dose used. However, male rodents may be capable of greater metabolism of rotenone, which could therefore reduce their total body exposure when compared with female rodents. The pharmacokinetics of rotenone has been studied extensively, over many decades. Here, we review these pharmacokinetics and models of PD using this important piscicide.

Review: The Role of Intestinal Dysbiosis in Parkinson's Disease

Several studies have highlighted the roles played by the gut microbiome in central nervous system diseases. Clinical symptoms and neuropathology have suggested that Parkinson’s disease may originate in the gut, which is home to approximately 100 trillion microbes. Alterations in the gastrointestinal microbiota populations may promote the development and progression of Parkinson’s disease. Here, we reviewed existing studies that have explored the role of intestinal dysbiosis in Parkinson’s disease, focusing on the roles of microbiota, their metabolites, and components in inflammation, barrier failure, microglial activation, and α-synuclein pathology. We conclude that there are intestinal dysbiosis in Parkinson’s disease. Intestinal dysbiosis is likely involved in the pathogenesis of Parkinson’s disease through mechanisms that include barrier destruction, inflammation and oxidative stress, decreased dopamine production, and molecular mimicry. Additional studies remain necessary to explore and verify the mechanisms through which dysbiosis may cause or promote Parkinson’s disease. Preclinical studies have shown that gastrointestinal microbial therapy may represent an effective and novel treatment for Parkinson’s disease; however, more studies, especially clinical studies, are necessary to explore the curative effects of microbial therapy in Parkinson’s disease.

The role of gut dysbiosis in Parkinson's disease: mechanistic insights andtherapeutic options

Parkinson's disease is a common neurodegenerative disease in which gastrointestinal symptoms may appear prior to motor symptoms. The gut microbiota of patients with Parkinson's disease shows unique changes, which may be used as early biomarkers of disease. Alteration in gut microbiota composition may be related to the cause or effect of motor or non-motor symptoms, but the specific pathogenic mechanisms are unclear. The gut microbiota and its metabolites have been suggested to be involved in the pathogenesis of Parkinson's disease by regulating neuroinflammation, barrier function and neurotransmitter activity. There is bidirectional communication between the enteric nervous system and the central nervous system, and the microbiota-gut-brain axis may provide a pathway for the transmission of α-synuclein. We highlight recent discoveries and alterations of the gut microbiota in Parkinson's disease, and highlight current mechanistic insights on the microbiota-gut-brain axis in disease pathophysiology. We discuss the interactions between production and transmission of α-synuclein and gut inflammation and neuroinflammation. In addition, we also draw attention to diet modification, use of probiotics and prebiotics and fecal microbiota transplantation as potential therapeutic approaches that may lead to a new treatment paradigm for Parkinson's disease.

New Avenues for Parkinson's Disease Therapeutics: Disease-Modifying Strategies Based on the Gut Microbiota

Parkinson's disease (PD) is a multifactorial neurodegenerative disorder that currently affects 1% of the population over the age of 60 years, and for which no disease-modifying treatments exist. Neurodegeneration and neuropathology in different brain areas are manifested as both motor and non-motor symptoms in patients. Recent interest in the gut-brain axis has led to increasing research into the gut microbiota changes in PD patients and their impact on disease pathophysiology. As evidence is piling up on the effects of gut microbiota in disease development and progression, another front of action has opened up in relation to the potential usage of microbiota-based therapeutic strategies in treating gastrointestinal alterations and possibly also motor symptoms in PD. This review provides status on the different strategies that are in the front line (i.e., antibiotics; probiotics; prebiotics; synbiotics; dietary interventions; fecal microbiota transplantation, live biotherapeutic products), and discusses the opportunities and challenges the field of microbiome research in PD is facing.

Pharmacological validation of TDO as a target for Parkinson's disease

Parkinson’s disease patients suffer from both motor and nonmotor impairments. There is currently no cure for Parkinson’s disease, and the most commonly used treatment, levodopa, only functions as a temporary relief of motor symptoms. Inhibition of the expression of the L‐tryptophan‐catabolizing enzyme tryptophan 2,3‐dioxygenase (TDO) has been shown to inhibit aging‐related α‐synuclein toxicity in Caenorhabditis elegans. To evaluate TDO inhibition as a potential therapeutic strategy for Parkinson’s disease, a brain‐penetrable, small molecule TDO inhibitor was developed, referred to as NTRC 3531‐0. This compound potently inhibits human and mouse TDO in biochemical and cell‐based assays and is selective over IDO1, an evolutionary unrelated enzyme that catalyzes the same reaction. In mice, NTRC 3531‐0 increased plasma and brain L‐tryptophan levels after oral administration, demonstrating inhibition of TDO activity in vivo. The effect on Parkinson’s disease symptoms was evaluated in a rotenone‐induced Parkinson’s disease mouse model. A structurally dissimilar TDO inhibitor, LM10, was evaluated in parallel. Both inhibitors had beneficial effects on rotenone‐induced motor and cognitive dysfunction as well as rotenone‐induced dopaminergic cell loss and neuroinflammation in the substantia nigra. Moreover, both inhibitors improved intestinal transit and enhanced colon length, which indicates a reduction of the rotenone‐induced intestinal dysfunction. Consistent with this, mice treated with TDO inhibitor showed decreased expression of rotenone‐induced glial fibrillary acidic protein, which is a marker of enteric glial cells, and decreased α‐synuclein accumulation in the enteric plexus. Our data support TDO inhibition as a potential therapeutic strategy to decrease motor, cognitive, and gastrointestinal symptoms in Parkinson’s disease.

The impact of the microbiota-gut-brain axis on Alzheimer's disease pathophysiology

The gut microbiota is a complex ecosystem that comprises of more than 100 trillion symbiotic microbial cells. The microbiota, the gut, and the brain form an association, 'the microbiota-gut-brain axis,' and synchronize the gut with the central nervous system and modify the behavior and brain immune homeostasis. The bidirectional communication between gut and brain occurs via the immune system, the vagus nerve, the enteric nervous system, and microbial metabolites, including short-chain fatty acids (SCFAs), proteins, and tryptophan metabolites. Recent studies have implicated the gut microbiota in many neurodegenerative diseases, including Alzheimer's disease (AD). In this review, we present an overview of gut microbiota, including Firmicutes, Bacteroidetes, SCFA, tryptophan, bacterial composition, besides age-related changes in gut microbiota composition, the microbiota-gut-brain axis pathways, the role of gut metabolites in amyloid-beta clearance, and gut microbiota modulation from experimental and clinical AD models. Understanding the role of the microbiota may provide new targets for treatment to delay the onset, progression, or reverse AD, and may help in reducing the prevalence of AD.

Brain foods - the role of diet in brain performance and health

The performance of the human brain is based on an interplay between the inherited genotype and external environmental factors, including diet. Food and nutrition, essential in maintenance of brain performance, also aid in prevention and treatment of mental disorders. Both the overall composition of the human diet and specific dietary components have been shown to have an impact on brain function in various experimental models and epidemiological studies. This narrative review provides an overview of the role of diet in 5 key areas of brain function related to mental health and performance, including: (1) brain development, (2) signaling networks and neurotransmitters in the brain, (3) cognition and memory, (4) the balance between protein formation and degradation, and (5) deteriorative effects due to chronic inflammatory processes. Finally, the role of diet in epigenetic regulation of brain physiology is discussed.

Dietary Intake of Parkinson's Disease Patients

Background and Aims: Dietary management, as an adjuvant therapy in Parkinson's disease (PD), provides clear benefits to patients. However, baseline information about the usual dietary intake of Parkinson's patients is lacking.

Methods: We conducted an observational cross-sectional study, investigating the dietary intake in Belgian PD patients, as well as their medication use and knowledge of possible food-drug interactions. A dietary record of 2 non-consecutive days, allowing the calculation of usual intake, was used. Medication use and knowledge of food-drug interactions were investigated using a self-administered questionnaire.

Results: The nutrient (both macro and micro) intake in this study was similar to the dietary pattern of the general Belgian population. However, results showed that the PD population had a high dietary fiber intake of 26.2 ± 7.7 g/day, which is in line with the recommended intake. The majority of the PD patients had an inadequate intake of vitamin D and iron (respectively, 55.9 and 76.5% of all participants). When looking into the knowledge about food-drug interactions, the majority of the PD patients claimed to be aware of the food-drug interaction between dietary proteins and levodopa. However, only 18.2% of the patients took all doses of levodopa out of meals.

Conclusion: Our results show that monitoring of dietary intake in PD patients is of importance to detect possible micronutrient insufficiencies. Patients should receive professional guidance in optimizing their diet to accommodate for different complaints inherent to PD, including constipation. Furthermore, the knowledge of patients regarding the importance of correct medication intake should be improved.

Docosahexaenoic acid protects motor function and increases dopamine synthesis in a rat model of Parkinson's disease via mechanisms associated with increased protein kinase activity in the striatum

Parkinson's disease (PD) is a devastating neurodegenerative disease that leads to motor deficits and selective destruction of nigrostriatal dopaminergic neurons. PD is typically treated by dopamine replacement agents; however, dopamine replacement loses effectiveness in the later stages of the disease. Here, we describe the neuroprotective effects of the omega-3 fatty acid docosahexaenoic acid (DHA) in the medial forebrain bundle 6-hydroxydopamine (6-OHDA) model of advanced-stage PD in rats. We show that daily administration of DHA protects against core symptoms of PD, including deficits in postural stability, gait integrity, and dopamine neurochemistry in motor areas of the striatum. Our results also demonstrate that DHA increases striatal dopamine synthesis via phosphorylation of the rate-limiting catecholamine synthesizing enzyme tyrosine hydroxylase, in a manner dependent on the second messenger-linked protein kinases PKA and PKC. We also show that DHA specifically reverses dopamine loss in the nigrostriatal pathway, with no effect in the mesolimbic or mesocortical pathways. This suggests that DHA is unlikely to produce pharmacotherapeutic or adverse effects that depend on dopamine pathways other than the nigrostriatal pathway. To our knowledge, previous reports have not examined the effects of DHA in such an advanced-stage model, documented that the dopamine synthesizing effects of DHA in vivo are mediated through the activation of protein kinases and regulation of TH activity, or demonstrated specificity to the nigrostriatal pathway. These novel findings corroborate the beneficial effects of omega-3 fatty acids seen in PD patients and suggest that DHA provides a novel means of protecting patients for dopamine neurodegeneration.

Improvement of Blood Plasmalogens and Clinical Symptoms in Parkinson's Disease by Oral Administration of Ether Phospholipids: A Preliminary Report

Introduction. Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease (AD). With the ageing of population, the frequency of PD is expected to increase dramatically in the coming decades. L-DOPA (1,3,4-dihydroxyalanine) is the most effective drug in the symptomatic treatment of PD. Nonmotor symptoms in PD include sleep problems, depression, and dementia, which are not adequately controlled with dopaminergic therapy. Here, we report the efficacy of oral administration of scallop-derived ether phospholipids to some nonmotor symptoms of PD.

Diet in Parkinson's Disease: Critical Role for the Microbiome

Background: Parkinson's disease (PD) is the most common movement disorder affecting up to 1% of the population above the age of 60 and 4–5% of those above the age of 85. Little progress has been made on efforts to prevent disease development or halt disease progression. Diet has emerged as a potential factor that may prevent the development or slow the progression of PD. In this review, we discuss evidence for a role for the intestinal microbiome in PD and how diet-associated changes in the microbiome may be a viable approach to prevent or modify disease progression.

Methods: We reviewed studies demonstrating that dietary components/foods were related to risk for PD. We reviewed evidence for the dysregulated intestinal microbiome in PD patients including abnormal shifts in the intestinal microbiota composition (i.e., dysbiosis) characterized by a loss of short chain fatty acid (SCFA) bacteria and increased lipopolysaccharide (LPS) bacteria. We also examined several candidate mechanisms by which the microbiota can influence PD including the NLRP3 inflammasome, insulin resistance, mitochondrial function, vagal nerve signaling.

Results: The PD-associated microbiome is associated with decreased production of SCFA and increased LPS and it is believed that these changes may contribute to the development or exacerbation of PD. Diet robustly impacts the intestinal microbiome and the Western diet is associated with increased risk for PD whereas the Mediterranean diet (including high intake of dietary fiber) decreases PD risk. Mechanistically this may be the consequence of changes in the relative abundance of SCFA-producing or LPS-containing bacteria in the intestinal microbiome with effects on intestinal barrier function, endotoxemia (i.e., systemic LPS), NLRP3 inflammasome activation, insulin resistance, and mitochondrial dysfunction, and the production of factors such as glucagon like peptide 1 (GLP-1) and brain derived neurotrophic factor (BDNF) as well as intestinal gluconeogenesis.

Conclusions: This review summarizes a model of microbiota-gut-brain-axis regulation of neuroinflammation in PD including several new mechanisms. We conclude with the need for clinical trials in PD patients to test this model for beneficial effects of Mediterranean based high fiber diets.

The Role of the Gut Microbiota in the Pathogenesis of Parkinson's Disease

It is well-recognized that the gut microbiota (GM) is crucial for gut function, metabolism, and energy cycles. The GM also has effects on neurological outcomes via many mechanisms, such as metabolite production and the gut-brain axis. Emerging evidence has gradually indicated that GM dysbiosis plays a role in several neurological diseases, such as Parkinson's disease (PD), Alzheimer's disease, depression, and multiple sclerosis. Several studies have observed that PD patients generally suffer from gastrointestinal disorders and GM dysbiosis prior to displaying motor symptoms, but the specific link between the GM and PD is not clearly understood. In this review, we aim to summarize what is known regarding the correlation between the GM and PD pathologies, including direct, and indirect evidence.

Dopaminergic neuron injury in Parkinson's disease is mitigated by interfering lncRNA SNHG14 expression to regulate the miR-133b/ α-synuclein pathway

This study explored the influence of long non-coding RNA (lncRNA) SNHG14 on α-synuclein (α-syn) expression and Parkinson’s disease (PD) pathogenesis. Firstly, we found that the expression level of SNHG14 was elevated in brain tissues of PD mice. In MN9D cells, the rotenone treatment (1μmol/L) enhanced the binding between transcriptional factor SP-1 and SNHG14 promoter, thus promoting SNHG14 expression. Interference of SNHG14 ameliorated the DA neuron injury induced by rotenone. Next, we found an interaction between SNHG14 and miR-133b. Further study showed that miR-133b down-regulated α-syn expression by targeting its 3’-UTR of mRNA and SNHG14 could reverse the negative effect of miR-133b on α-syn expression. Interference of SNHG14 reduced rotenone-induced DA neuron damage through miR-133b in MN9D cells and α-syn was responsible for the protective effect of miR-133b. Similarly, interference of SNHG14 mitigated neuron injury in PD mouse model. All in all, silence of SNHG14 mitigates dopaminergic neuron injury by down-regulating α-syn via targeting miR-133b, which contributes to improving PD.

Early and Accurate Identification of Parkinson Disease Among US Veterans

Early and accurate identification and management of veterans at risk for Parkinson disease is an important priority area for the US Department of Veterans Affairs because of the substantial impact on quality of life and disability-adjusted life years.

Early signs of colonic inflammation, intestinal dysfunction, and olfactory impairments in the rotenone-induced mouse model of Parkinson's disease

The factors that trigger the pathophysiology of Parkinson's disease (PD) are unknown. However, it is suggested that environmental factors, such as exposure to pesticides, play an important role, in addition to genetic predisposition and aging. Early signs of PD can appear in the gastrointestinal (GI) tract and in the olfactory system, preceding the onset of motor impairments by many years. The present study assessed the effects of oral rotenone administration (30 mg/kg) in inducing GI and olfactory dysfunctions associated with PD in mice. Here we show that rotenone transiently increased myeloperoxidase activity within 24 h of administration. Leucocyte infiltration in the colon, associated with histological damage and disrupted GI motility, were observed following treatment with rotenone for 7 days. Moreover, 7 days of treatment with rotenone disrupted olfactory discrimination in mice without affecting social recognition ability. The presence of specific deficits in olfactory function occurred with a concomitant decrease in tyrosine hydroxylase-positive neurons and an increase in serotonin (5-hydroxytryptamine) turnover in the olfactory bulb. These findings suggest that in Swiss mice, exposure to rotenone induces GI and olfactory dysfunction involving immunological and neurotransmitter alterations, similar to early signs of PD. This provides further evidence for the involvement of the gut-brain axis in PD.

Dietary Macronutrient Management to Treat Mitochondrial Dysfunction in Parkinson's Disease

Mitochondrial dysfunction has been demonstrated to play an important role in the pathogenesis of Parkinson’s disease (PD). The products of several PD-associated genes, including alpha-synuclein, parkin, pink1, protein deglycase DJ-1, and leucine rich repeat kinase 2, have important roles in mitochondrial biology. Thus, modifying mitochondrial function could be a potential therapeutic strategy for PD. Dietary management can alter mitochondrial function as shifts in dietary macronutrients and their ratios in food can alter mitochondrial energy metabolism, morphology and dynamics. Our studies have established that a low protein to carbohydrate (P:C) ratio can increase lifespan, motor ability and mitochondrial function in a parkin mutant Drosophila model of PD. In this review, we describe mitochondrial dysfunction in PD patients and models, and dietary macronutrient management strategies to reverse it. We focus on the effects of protein, carbohydrate, fatty acids, and their dietary ratios. In addition, we propose potential mechanisms that can improve mitochondrial function and thus reverse or delay the onset of PD.

Psychological co-morbidities in COPD: Targeting systemic inflammation, a benefit for both?

COPD is a chronic lung disease characterized by persistent respiratory symptoms and airflow limitation due to airway and/or alveolar abnormalities. Furthermore, COPD is often characterized by extrapulmonary manifestations and comorbidities worsening COPD progression and quality of life. A neglected comorbidity in COPD management is mental health impairment defined by anxiety, depression and cognitive problems. This paper summarizes the evidence for impaired mental health in COPD and focuses on current pharmacological intervention strategies. In addition, possible mechanisms in impaired mental health in COPD are discussed with a central role for inflammation. Many comorbidities are associated with multi-organ-associated systemic inflammation in COPD. Considering the accumulative evidence for a major role of systemic inflammation in the development of neurological disorders, it can be hypothesized that COPD-associated systemic inflammation also affects the function of the brain and is an interesting therapeutic target for nutra- and pharmaceuticals.

Dietary Galacto-Oligosaccharides and Resistant Starch Protect Against Altered CB1 and 5-HT1A and 2A Receptor Densities in Rat Brain: Implications for Preventing Cognitive and Appetite Dysfunction During a High-Fat Diet

SCOPE

A high-fat, but low-fiber, diet is associated with obesity and cognitive dysfunction, while dietary fiber supplementation can improve cognition.

METHODS AND RESULTS

This study examines whether dietary fibers, galacto-oligosaccharides (GOS) and resistant starch (RS), could prevent high-fat (HF)-diet-induced alterations in neurotransmitter receptor densities in brain regions associated with cognition and appetite. Rats are fed a HF diet, HF diet with GOS, HF diet with RS, or a low-fat (LF, control) diet for 4 weeks. Cannabinoid CB1 (CB1R) and 5HT_1A (5HT_1A R) and 5-HT_2A (5HT_2A R) receptor binding densities are examined. In the hippocampus and hypothalamus, a HF diet significantly increases CB1R binding, while HF + GOS and HF + RS diets prevented this increase. HF diet also increases hippocampal and hypothalamic 5-HT_1A R binding, while HF + GOS and HF + RS prevented the alterations. Increased 5-HT_2A binding is prevented by HF + GOS and HF + RS in the medial mammillary nucleus.

CONCLUSIONS

These results demonstrate that increased CB1R, 5-HT_1A R and 5-HT_2A R induced by a HF diet can be prevented by GOS and RS supplementation in brain regions involved in cognition and appetite. Therefore, increased fiber intake may have beneficial effects on improving learning and memory, as well as reducing excessive appetite, during the chronic consumption of a HF (standard Western) diet.

Additive Effects of Levodopa and a Neurorestorative Diet in a Mouse Model of Parkinson's Disease

Though Parkinson’s disease (PD) clinical picture is generally dominated by motor impairment, non-motor symptoms, such as cognitive decline and gastrointestinal dysfunctions, may develop before motor symptoms and have major effects on quality of life. L-3,4-di-hydroxy-phenylalanine (Levodopa) is the most commonly used treatment of motor symptoms but has serious side-effects with prolonged use and does not stop the degenerative process. Moreover, gastrointestinal dysfunctions interfere with the absorption of levodopa and modify its effectiveness. Since most patients are on levodopa treatment, there is a need for combinational therapies that allow for an effective reduction of both motor and non-motor symptoms. We have recently shown that a diet containing precursors and cofactors required for membrane phospholipid synthesis, as well as prebiotic fibers, had therapeutic effects in a PD mouse model. We now investigate the effects of combined administration of the same diet together with levodopa in the rotenone model of PD. Mice were injected with rotenone or vehicle in the striatum. The dietary intervention started after full induction of motor symptoms. The effects of dietary intervention and oral treatment with different doses of levodopa were assessed weekly. Motor and cognitive functions were tested, intestinal transit was analyzed and histological examination of the brain and the colon was assessed. Our results confirm our previous findings that rotenone-induced motor and non-motor problems were alleviated by the Active diet (AD). Levodopa showed an additive beneficial effect on rotarod performance in rotenone-treated animals fed with the AD. No negative interaction effects were found between the AD and levodopa. Our findings suggest that the dietary intervention might confer additional clinical benefits on patients receiving levodopa treatment.