Comparison study of plasma coenzyme Q10 levels in healthy subjects supplemented with ubiquinol versus ubiquinone

Effects of coenzyme Q10 supplementation on oxidative stress biomarkers following reperfusion in STEMI patients undergoing primary percutaneous coronary intervention

Introduction

It is well-established that oxidative stress is deeply involved in myocardial ischemia-reperfusion injury. Considering the potent antioxidant properties of coenzyme Q10 (CoQ10), we aimed to assess whether CoQ10 supplementation could exert beneficial effects on plasma levels of oxidative stress biomarkers in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPIC).

Methods

Seventy patients with the first attack of STEMI, eligible for PPCI were randomly assigned to receive either standard treatments plus CoQ10 (400 mg before PPCI and 200 mg twice daily for three days after PPCI) or standard treatments plus placebo. Plasma levels of oxidative stress biomarkers, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total antioxidant capacity (TAC), and malondialdehyde (MDA) were measured at 6, 24, and 72 hours after completion of PPCI.

Results

The changes in plasma levels of the studied biomarkers at 6 and 24 hours after PPCI were similar in the both groups (P values>0.05). This is while at 72 hours, the CoQ10- treated group exhibited significantly higher plasma levels of SOD (P value<0.001), CAT (P value=0.001), and TAC (P value<0.001), along with a lower plasma level of MDA (P value=0.002) compared to the placebo-treated group. The plasma activity of GPX showed no significant difference between the groups at all the study time points (P values>0.05).

Conclusion

This study showed that CoQ10 has the potential to modulate the balance between antioxidant and oxidant biomarkers after reperfusion therapy. Our results suggest that CoQ10, through its antioxidant capacity, may help reduce the reperfusion injury in ischemic myocardium.

Orally ingested ubiquinol-10 or ubiquinone-10 reaches the intestinal tract and is absorbed by the small intestine of mice mostly in its original form

Coenzyme Q10 (CoQ10) is an important lipid-soluble antioxidant and an essential component of the mitochondria. The oral bioavailability of the reduced form of CoQ10, ubiquinol-10, has been reported to be greater than that of the oxidized form of CoQ10, ubiquinone-10, in some studies. In contrast, it has also been highlighted that the oral bioavailability of ubiquinol-10 is not superior to that of ubiquinone-10 because ubiquinol-10 may be oxidized during digestion. In fact, it has not been shown which form of CoQ10 exists in the process from oral intake to absorption in the gastrointestinal tract. In this study, the amounts of ubiquinol-10 and ubiquinone-10 were measured in the gastrointestinal content and small intestine tissue after oral administration of ubiquinol-10 or ubiquinone-10 to C57BL/6J mice. The form of CoQ10 detected in the gastrointestinal content and small intestine tissue was almost the same as that when administered orally. The results of our study suggested that the orally administered ubiquinol-10 and ubiquinone-10 mostly reached the small intestine without oxidizing to ubiquinone-10 and reducing to ubiquinol-10, and both were absorbed by the small intestine tissue in almost their original forms.

The Rationale for Vitamin, Mineral, and Cofactor Treatment in the Precision Medical Care of Autism Spectrum Disorder

Children with autism spectrum disorder may exhibit nutritional deficiencies due to reduced intake, genetic variants, autoantibodies interfering with vitamin transport, and the accumulation of toxic compounds that consume vitamins. Importantly, vitamins and metal ions are essential for several metabolic pathways and for neurotransmitter functioning. The therapeutic benefits of supplementing vitamins, minerals (Zinc, Magnesium, Molybdenum, and Selenium), and other cofactors (coenzyme Q10, alpha-lipoic acid, and tetrahydrobiopterin) are mediated through their cofactor as well as non-cofactor functions. Interestingly, some vitamins can be safely administered at levels far above the dose typically used to correct the deficiency and exert effects beyond their functional role as enzyme cofactors. Moreover, the interrelationships between these nutrients can be leveraged to obtain synergistic effects using combinations. The present review discusses the current evidence for using vitamins, minerals, and cofactors in autism spectrum disorder, the rationale behind their use, and the prospects for future use.

Bioavailability of Reduced Coenzyme Q10 (Ubiquinol-10) in Burn Patients

Mitochondrial dysfunction has been implicated in the pathogenesis of inflammation and multi-organ dysfunction in major trauma, including burn injury. Coenzyme Q10 (CoQ10) is a metabolite of the mevalonate pathway and an essential cofactor for the electron transport in the mitochondria. In addition, its reduced form (ubiquinol) functions as an antioxidant. Little is known as to whether oral CoQ10 supplementation effectively increases intracellular CoQ10 levels in humans. To study the bioavailability of CoQ10 supplementation, we conducted a randomized, double-blind, placebo-controlled study of reduced CoQ10 (ubiquinol-10) (1800 mg/day, t.i.d.) in burn patients at a single, tertiary-care hospital. Baseline plasma CoQ10 levels were significantly lower in burn patients than in healthy volunteers, although plasma CoQ10/cholesterol ratio did not differ between the groups. CoQ10 supplementation increased plasma concentrations of total and reduced CoQ10 and total CoQ10 content in peripheral blood mononuclear cells (PBMCs) in burn patients compared with the placebo group. CoQ10 supplementation did not significantly change circulating levels of mitochondrial DNA, inflammatory markers (e.g., interleukins, TNF-α, IFN-γ), or Sequential Organ Failure Assessment (SOFA) scores compared with the placebo group. This study showed that a relatively high dose of reduced CoQ10 supplementation increased the intracellular CoQ10 content in PBMCs as well as plasma concentrations in burn patients.

The Role of NLRP3 Inflammasome Activation and Oxidative Stress in Varicocele-Mediated Male Hypofertility

Varicocele (VC) is the most common abnormality identified in men evaluated for hypofertility. Increased levels of reactive oxygen species (ROS) and reduced antioxidants concentrations are key contributors in varicocele-mediated hypofertility. Moreover, inflammation and alterations in testicular immunity negatively impact male fertility. In particular, NLRP3 inflammasome activation was hypothesized to lead to seminal inflammation, in which the levels of specific cytokines, such as IL-1β and IL-18, are overexpressed. In this review, we described the role played by oxidative stress (OS), inflammation, and NLRP3 inflammasome activation in VC disease. The consequences of ROS overproduction in testis, including inflammation, lipid peroxidation, mitochondrial dysfunction, chromatin damage, and sperm DNA fragmentation, leading to abnormal testicular function and failed spermatogenesis, were highlighted. Finally, we described some therapeutic antioxidant strategies, with recognized beneficial effects in counteracting OS and inflammation in testes, as possible therapeutic drugs against varicocele-mediated hypofertility.

Nutraceutical and Dietary Strategies for Up-Regulating Macroautophagy

Macroautophagy is a "cell cleansing" process that rids cells of protein aggregates and damaged organelles that may contribute to disease pathogenesis and the dysfunctions associated with aging. Measures which boost longevity and health span in rodents typically up-regulate macroautophagy, and it has often been suggested that safe strategies which can promote this process in humans may contribute to healthful aging. The kinase ULK1 serves as a trigger for autophagy initiation, and the transcription factors TFEB, FOXO1, ATF4 and CHOP promote expression of a number of proteins which mediate macroautophagy. Nutraceutical or dietary measures which stimulate AMPK, SIRT1, eIF5A, and that diminish the activities of AKT and mTORC1, can be expected to boost the activities of these pro-autophagic factors. The activity of AMPK can be stimulated with the phytochemical berberine. SIRT1 activation may be achieved with a range of agents, including ferulic acid, melatonin, urolithin A, N1-methylnicotinamide, nicotinamide riboside, and glucosamine; correction of ubiquinone deficiency may also be useful in this regard, as may dietary strategies such as time-restricted feeding or intermittent fasting. In the context of an age-related decrease in cellular polyamine levels, provision of exogenous spermidine can boost the hypusination reaction required for the appropriate post-translational modification of eIF5A. Low-protein plant-based diets could be expected to increase ATF4 and CHOP expression, while diminishing IGF-I-mediated activation of AKT and mTORC1. Hence, practical strategies for protecting health by up-regulating macroautophagy may be feasible.

Coenzyme Q10 in the Treatment of Heart Failure with Preserved Ejection Fraction: A Prospective, Randomized, Double-Blind, Placebo-Controlled Trial

Background

Heart failure with preserved ejection fraction (HFpEF) is common in elderly people and is increasing in prevalence. No specific treatment for this condition exists. Coenzyme Q10 (CoQ10) is an essential cofactor for energy production, with reduced levels being noted in HF. Previous studies have suggested a possible role for CoQ10 in the treatment of HF. This study examined the effect of CoQ10 supplementation on diastolic function in HFpEF patients.

Methods

We conducted a prospective, randomized, double-blind, placebo-controlled trial including patients aged > 55 years presenting with New York Heart Association class II–IV heart failure symptoms and left ventricular ejection fraction > 50%, with impaired diastolic function. Echocardiography and levels of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) were performed at baseline and following 4 months of CoQ10 or placebo supplementation.

Results

A total of 39 patients were enrolled—19 in the CoQ10 group and 20 in the placebo group. Baseline clinical characteristics were similar between groups, while compliance was high and also similar between the CoQ10 and placebo groups. There was no significant effect of treatment on indices of diastolic function (difference in the lateral E/e' ratio: −0.86 ± 6.57 in the CoQ10 group, +0.18 ± 3.76 in the placebo group; p = 0.561) or on serum NT-proBNP levels (− 72 pg/mL vs. − 42 pg/mL; p = 0.195).

Conclusions

In this pilot trial in elderly patients with HFpEF, treatment with CoQ10 did not significantly affect echocardiographic indices of diastolic function and serum NT-proBNP levels.

Trial Registration

This trial was registered in the US National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov identifier: NCT02779634).

Coenzyme Q at the Hinge of Health and Metabolic Diseases

Coenzyme Q is a unique lipidic molecule highly conserved in evolution and essential to maintaining aerobic metabolism. It is endogenously synthesized in all cells by a very complex pathway involving a group of nuclear genes that share high homology among species. This pathway is tightly regulated at transcription and translation, but also by environment and energy requirements. Here, we review how coenzyme Q reacts within mitochondria to promote ATP synthesis and also integrates a plethora of metabolic pathways and regulates mitochondrial oxidative stress. Coenzyme Q is also located in all cellular membranes and plasma lipoproteins in which it exerts antioxidant function, and its reaction with different extramitochondrial oxidoreductases contributes to regulate the cellular redox homeostasis and cytosolic oxidative stress, providing a key factor in controlling various apoptosis mechanisms. Coenzyme Q levels can be decreased in humans by defects in the biosynthesis pathway or by mitochondrial or cytosolic dysfunctions, leading to a highly heterogeneous group of mitochondrial diseases included in the coenzyme Q deficiency syndrome. We also review the importance of coenzyme Q levels and its reactions involved in aging and age-associated metabolic disorders, and how the strategy of its supplementation has had benefits for combating these diseases and for physical performance in aging.

Role of Coenzyme Q10 in Health and Disease: An Update on the Last 10 Years (2010-2020)

The present review focuses on preclinical and clinical studies conducted in the last decade that contribute to increasing knowledge on Coenzyme Q₁₀'s role in health and disease. Classical antioxidant and bioenergetic functions of the coenzyme have been taken into consideration, as well as novel mechanisms of action involving the redox-regulated activation of molecular pathways associated with anti-inflammatory activities. Cardiovascular research and fertility remain major fields of application of Coenzyme Q₁₀, although novel applications, in particular in relation to topical application, are gaining considerable interest. In this respect, bioavailability represents a major challenge and the innovation in formulation aspects is gaining critical importance.

Coenzyme Q nanodisks counteract the effect of statins on C2C12 myotubes

Depletion of coenzyme Q (CoQ) is associated with disease, ranging from myopathy to heart failure. To induce a CoQ deficit, C2C12 myotubes were incubated with high dose simvastatin. This resulted in a concentration-dependent inhibition of cell viability. Simvastatin-induced effects were prevented by co-incubation with mevalonic acid. When myotubes were incubated with 60 μM simvastatin, mitochondrial CoQ content decreased while co-incubation with CoQ nanodisks (ND) increased mitochondrial CoQ levels and improved cell viability. Incubation of myotubes with simvastatin also led to a reduction in oxygen consumption rate (OCR). When myotubes were co-incubated with simvastatin and CoQ ND, the decline in OCR was ameliorated. The data indicate that CoQ ND represent a water soluble vehicle capable of delivering CoQ to cultured myotubes. Thus, these biocompatible nanoparticles have the potential to bypass poor CoQ oral bioavailability as a treatment option for individuals with severe CoQ deficiency syndromes and/or aging-related CoQ depletion.

The Use of Coenzyme Q10 in Cardiovascular Diseases

CoQ10 is an endogenous antioxidant produced in all cells that plays an essential role in energy metabolism and antioxidant protection. CoQ10 distribution is not uniform among different organs, and the highest concentration is observed in the heart, though its levels decrease with age. Advanced age is the major risk factor for cardiovascular disease and endothelial dysfunction triggered by oxidative stress that impairs mitochondrial bioenergetic and reduces NO bioavailability, thus affecting vasodilatation. The rationale of the use of CoQ10 in cardiovascular diseases is that the loss of contractile function due to an energy depletion status in the mitochondria and reduced levels of NO for vasodilatation has been associated with low endogenous CoQ10 levels. Clinical evidence shows that CoQ10 supplementation for prolonged periods is safe, well-tolerated and significantly increases the concentration of CoQ10 in plasma up to 3–5 µg/mL. CoQ10 supplementation reduces oxidative stress and mortality from cardiovascular causes and improves clinical outcome in patients undergoing coronary artery bypass graft surgery, prevents the accumulation of oxLDL in arteries, decreases vascular stiffness and hypertension, improves endothelial dysfunction by reducing the source of ROS in the vascular system and increases the NO levels for vasodilation.

Secondary coenzyme Q deficiency in neurological disorders

Coenzyme Q (CoQ) is a ubiquitous lipid serving essential cellular functions. It is the only component of the mitochondrial respiratory chain that can be exogenously absorbed. Here, we provide an overview of current knowledge, controversies, and open questions about CoQ intracellular and tissue distribution, in particular in brain and skeletal muscle. We discuss human neurological diseases and mouse models associated with secondary CoQ deficiency in these tissues and highlight pharmacokinetic and anatomical challenges in exogenous CoQ biodistribution, recent improvements in CoQ formulations and imaging, as well as alternative therapeutical strategies to CoQ supplementation. The last section proposes possible mechanisms underlying secondary CoQ deficiency in human diseases with emphasis on neurological and neuromuscular disorders.

Stability of Reduced and Oxidized Coenzyme Q10 in Finished Products

The efficiency of coenzyme Q10 (CoQ10) supplements is closely associated with its content and stability in finished products. This study aimed to provide evidence-based information on the quality and stability of CoQ10 in dietary supplements and medicines. Therefore, ubiquinol, ubiquinone, and total CoQ10 contents were determined by a validated HPLC-UV method in 11 commercial products with defined or undefined CoQ10 form. Both forms were detected in almost all tested products, resulting in a total of CoQ10 content between 82% and 166% of the declared. Ubiquinol, ubiquinone, and total CoQ10 stability in these products were evaluated within three months of accelerated stability testing. Ubiquinol, which is recognized as the less stable form, was properly stabilized. Contrarily, ubiquinone degradation and/or reduction were observed during storage in almost all tested products. These reactions were also detected at ambient temperature within the products’ shelf-lives and confirmed in ubiquinone standard solutions. Ubiquinol, generated by ubiquinone reduction with vitamin C during soft-shell capsules’ storage, may lead to higher bioavailability and health outcomes. However, such conversion and inappropriate content in products, which specify ubiquinone, are unacceptable in terms of regulation. Therefore, proper CoQ10 stabilization through final formulations regardless of the used CoQ10 form is needed.

Coenzyme Q10 for Patients With Cardiovascular Disease: JACC Focus Seminar

Coenzyme Q₁₀ (CoQ₁₀) is a naturally occurring compound that is found in animals and all humans. It has a fundamental role in cellular energy production. Although it is produced in the body, tissue deficiency can occur due to medications such as statins, which inhibit the mevalonate pathway. The clinical syndromes of statin-associated muscle symptoms (SAMS) and some of the features observed in patients with heart failure (HF) may be related to blood and tissue deficiency of CoQ₁₀. Numerous clinical trials of CoQ₁₀ in SAMS have yielded conflicting results. Yet, the weight of evidence as reflected in meta-analyses supports the use of exogenous CoQ₁₀ in SAMS. In patients with HF, large-scale randomized clinical trials are lacking, although one relatively contemporary trial, Q-SYMBIO, suggests an adjunctive role for CoQ₁₀. The possibility that statin-related CoQ₁₀ deficiency may play a role in patients with diastolic HF is an intriguing hypothesis that warrants further exploration.

Ubiquinol Supplementation Improves Gender-Dependent Cerebral Vasoreactivity and Ameliorates Chronic Inflammation and Endothelial Dysfunction in Patients with Mild Cognitive Impairment

Ubiquinol can protect endothelial cells from multiple mechanisms that cause endothelial damage and vascular dysfunction, thus contributing to dementia. A total of 69 participants diagnosed with mild cognitive impairment (MCI) received either 200 mg/day ubiquinol (Ub) or placebo for 1 year. Cognitive assessment of patients was performed at baseline and after 1 year of follow-up. Patients' cerebral vasoreactivity was examined using transcranial Doppler sonography, and levels of Ub and lipopolysaccharide (LPS) in plasma samples were quantified. Cell viability and necrotic cell death were determined using the microvascular endothelial cell line bEnd3. Coenzyme Q10 (CoQ) levels increased in patients supplemented for 1 year with ubiquinol versus baseline and the placebo group, although higher levels were observed in male patients. The higher cCoQ concentration in male patients improved cerebral vasoreactivity CRV and reduced inflammation, although the effect of Ub supplementation on neurological improvement was negligible in this study. Furthermore, plasma from Ub-supplemented patients improved the viability of endothelial cells, although only in T2DM and hypertensive patients. This suggests that ubiquinol supplementation could be recommended to reach a concentration of 5 μg/mL in plasma in MCI patients as a complement to conventional treatment.

Statin Treatment in Specific Patient Groups: Role for Improved Cardiovascular Risk Markers

Ample evidence supports the use of statin therapy for secondary prevention in patients with a history of atherosclerotic cardiovascular disease (ASCVD), but evidence is wanting in the case of primary prevention, low-risk individuals, and elderly adults 65+. Statins are effective in lowering low-density lipoprotein (LDL), which has long been a target for treatment decisions. We discuss the weakening dependence between cholesterol levels and mortality as a function of age and highlight recent findings on lipoprotein subfractions and other superior markers of ASCVD risk. The efficacy of statins is compared for distinct subsets of patients based on age, diabetes, ASCVD, and coronary artery calcium (CAC) status. Most cardiovascular risk calculators heavily weight age and overestimate one's absolute risk of ASCVD, particularly in very old adults. Improvements in risk assessment enable the identification of specific patient populations that benefit most from statin treatment. Derisking is particularly important for adults over 75, in whom treatment benefits are reduced and adverse musculoskeletal effects are amplified. The CAC score stratifies the benefit effect size obtainable with statins, and forms of coenzyme Q are discussed for improving patient outcomes. Robust risk estimator tools and personalized, evidence-based approaches are needed to optimally reduce cardiovascular events and mortality rates through administration of cholesterol-lowering medications.

Role of mitochondria, oxidative stress and the response to antioxidants in myalgic encephalomyelitis/chronic fatigue syndrome: A possible approach to SARS-CoV-2 'long-haulers'?

A significant number of SARS-CoV-2 (COVID-19) pandemic patients have developed chronic symptoms lasting weeks or months which are very similar to those described for myalgic encephalomyelitis/chronic fatigue syndrome. This study reviews the current literature and understanding of the role that mitochondria, oxidative stress and antioxidants may play in the understanding of the pathophysiology and treatment of chronic fatigue. It describes what is known about the dysfunctional pathways which can develop in mitochondria and their relationship to chronic fatigue. It also reviews what is known about oxidative stress and how this can be related to the pathophysiology of fatigue, as well as examining the potential for specific therapy directed at mitochondria for the treatment of chronic fatigue in the form of antioxidants. This study identifies areas which require urgent, further research in order to fully elucidate the clinical and therapeutic potential of these approaches.

Mitochondrial energetic impairment in a patient with late-onset glutaric acidemia Type 2

Glutaric acidemia type 2 (GA2), also called multiple acyl-CoA dehydrogenase deficiency, is an autosomal recessive disorder of fatty acid, amino acid, and choline metabolism resulting in excretion of multiple organic acids and glycine conjugates as well as elevation of various plasma acylcarnitine species (C4-C18). It is caused by mutations in the ETFA, ETFB, or ETFDH genes which are involved in the transfer of electrons from 11 flavin-containing dehydrogenases to Coenzyme Q₁₀ (CoQ₁₀ ) of the mitochondrial electron transport chain (ETC). We report a patient who was originally reported as the first case with primary myopathic CoQ₁₀ deficiency when he presented at 11.5 years with exercise intolerance and myopathy that improved after treatment with ubiquinone and carnitine. At age 23, his symptoms relapsed despite increasing doses of ubiquinone and he was shown to have biallelic mutations in the ETFDH gene. Treatment with riboflavin was started and ubiquinone was changed to ubiquinol. After 4 months, the patient recovered his muscle strength with normalization of laboratory exams and exercise tolerance. Functional studies on fibroblasts revealed decreased levels of ETFDH as well as of very long-chain acyl-CoA dehydrogenase and trifunctional protein α. In addition, the mitochondrial mass was decreased, with increased formation of reactive oxygen species and oxygen consumption rate, but with a decreased spared respiratory capacity, and decreased adenosine triphosphate level. These findings of widespread dysfunction of fatty acid oxidation and ETC enzymes support the impairment of a larger mitochondrial ETC supercomplex in our patient.

Ubiquinol Improves Endothelial Function in Patients with Heart Failure with Reduced Ejection Fraction: A Single-Center, Randomized Double-Blind Placebo-Controlled Crossover Pilot Study

BACKGROUND

Endothelial dysfunction is reportedly associated with worse outcomes in patients with chronic heart failure. Ubiquinol is a reduced form of coenzyme Q10 (CoQ10) that may improve endothelial function.

OBJECTIVE

We assessed the hypothesis that ubiquinol improves peripheral endothelial function in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS

In this randomized, double-blind, placebo-controlled, crossover pilot study, 14 patients with stable HFrEF were randomly and blindly allocated to ubiquinol 400 mg/day or placebo for 3 months. After a 1-month washout period, patients were crossed over to the alternative treatment. Before and after each treatment, we assessed peripheral endothelial function using the reactive hyperemia index (RHI) and analyzed it using the natural logarithm of RHI (LnRHI).

RESULTS

Peripheral endothelial function as assessed by LnRHI tended to improve with ubiquinol 400 mg/day for 3 months (p = 0.076). Original RHI values were also compared, and RHI significantly improved with ubiquinol treatment (pre-RHI 1.57 [interquartile range (IQR) 1.39-1.80], post-RHI 1.74 [IQR 1.63-2.02], p = 0.026), but not with placebo (pre-RHI 1.67 [IQR 1.53-1.85], post-RHI 1.51 [IQR 1.39-2.11], p = 0.198).

CONCLUSIONS

Ubiquinol 400 mg/day for 3 months led to significant improvement in peripheral endothelial function in patients with HFrEF. Ubiquinol may be a therapeutic option for individuals with HFrEF. Large-scale randomized controlled trials of CoQ10 supplementation in patients with HFrEF are needed.

CLINICAL TRIAL REGISTRATION

Japanese University Hospital Medical Information Network (UMIN-ICDR). Clinical Trial identifier number UMIN000012604.

Ubiquinol supplementation in elderly patients undergoing aortic valve replacement: biochemical and clinical aspects

Epidemiological data show a rise in the mean age of patients affected by heart disease undergoing cardiac surgery. Senescent myocardium reduces the tolerance to ischemic stress and there are indications about age-associated deficit in post-operative cardiac performance. Coenzyme Q10 (CoQ10), and more specifically its reduced form ubiquinol (QH), improve several conditions related to bioenergetic deficit or increased exposure to oxidative stress. This trial (Eudra-CT 2009-015826-13) evaluated the clinical and biochemical effects of ubiquinol in 50 elderly patients affected by severe aortic stenosis undergoing aortic valve replacement and randomized to either placebo or 400 mg/day ubiquinol from 7 days before to 5 days after surgery. Plasma and cardiac tissue CoQ10 levels and oxidative status, circulating troponin I, CK-MB (primary endpoints), IL-6 and S100B were assessed. Moreover, main cardiac adverse effects, NYHA class, contractility and myocardial hypertrophy (secondary endpoints) were evaluated during a 6-month follow-up visit. Ubiquinol treatment counteracted the post-operative plasma CoQ10 decline (p<0.0001) and oxidation (p=0.038) and curbed the post-operative increase in troponin I (QH, 1.90 [1.47-2.48] ng/dL; placebo, 4.03 [2.45-6.63] ng/dL; p=0.007) related to cardiac surgery. Moreover, ubiquinol prevented the adverse outcomes that might have been associated with defective left ventricular ejection fraction recovery in elderly patients.

High coenzyme Q10 plasma levels improve stress and damage markers in professional soccer players during competition

Ubiquinol, the reduced form of Coenzyme Q₁₀ (CoQ₁₀), is a key factor in bioenergetics and antioxidant protection. During competition, professional soccer players suffer from considerable physical stress causing high risk of muscle damage. For athletes, supplementation with several antioxidants, including CoQ₁₀, is widely recommended to avoid oxidative stress and muscle damage. We performed an observational study of plasma parameters associated with CoQ₁₀ levels in professional soccer players of the Spanish First League team Athletic Club de Bilbao over two consecutive seasons (n = 24-25) in order determine their relationship with damage, stress and performance during competition. We analyzed three different moments of the competition: preterm, initial phase and mid phase. Metabolites and factors related with stress (testosterone/cortisol) and muscle damage (creatine kinase) were determined. Physical activity during matches was analyzed over the 2015/16 season in those players participating in complete matches. In the mid phase of competition, CoQ₁₀ levels were higher in 2015/16 (906.8 ± 307.9 vs. 584.3 ± 196.3 pmol/mL, p = 0.0006) High levels of CoQ₁₀ in the hardest phase of competition were associated with a reduction in the levels of the muscle-damage marker creatine kinase (Pearsons' correlation coefficient (r) = - 0.460, p = 0.00168) and a trend for the stress marker cortisol (r = -0.252, p = 0.150). Plasma ubiquinol was also associated with better kidney function (r = -0.287, p = 0.0443 for uric acid). Furthermore, high CoQ₁₀ levels were associated with higher muscle performance during matches. Our results suggest that high levels of plasma CoQ₁₀ can prevent muscle damage, improve kidney function and are associated with higher performance in professional soccer players during competition.

Intrastriatal administration of coenzyme Q10 enhances neuroprotection in a Parkinson's disease rat model

Parkinson's disease is a neurodegenerative disorder, and no treatment has been yet established to prevent disease progression. Coenzyme Q10, an antioxidant, has been considered a promising neuroprotective agent; however, conventional oral administration provides limited efficacy due to its very low bioavailability. In this study, we hypothesised that continuous, intrastriatal administration of a low dose of Coenzyme Q10 could effectively prevent dopaminergic neuron degeneration. To this end, a Parkinson's disease rat model induced by 6-hydroxydopamine was established, and the treatment was applied a week before the full establishment of this disease model. Behavioural tests showed a dramatically decreased number of asymmetric rotations in the intrastriatal Coenzyme Q10 group compared with the no treatment group. Rats with intrastriatal Coenzyme Q10 exposure also exhibited a larger number of dopaminergic neurons, higher expression of neurogenetic and angiogenetic factors, and less inflammation, and the effects were more prominent than those of orally administered Coenzyme Q10, although the dose of intrastriatal Coenzyme Q10 was 17,000-times lower than that of orally-administered Coenzyme Q10. Therefore, continuous, intrastriatal delivery of Coenzyme Q10, especially when combined with implantable devices for convection-enhanced delivery or deep brain stimulation, can be an effective strategy to prevent neurodegeneration in Parkinson's disease.

Quantification of reduced and oxidized coenzyme Q10 in supplements and medicines by HPLC-UV

Coenzyme Q10 (CoQ10) supplements are widely used because of their antioxidant and anti-inflammatory effects, especially in the management of cardiovascular diseases. The latest pharmaceutical approach to increase CoQ10 bioavailability and efficiency is the formulation of its reduced form. Regardless of the growing number and usage of CoQ10 preparations, their analytics and quality control is inadequate, neglecting interconversion between the two CoQ10 forms. Therefore, this study proposes a HPLC-UV method for the simultaneous quantification of both reduced and oxidized coenzyme Q10, as well as total CoQ10, as a sum of its individual forms. The suitability of the developed method was confirmed by two additional approaches for total CoQ10 determination - its total reduction and oxidation, differing from the proposed procedure only in the final stage of sample preparation. The results for total CoQ10 content were consistent between the three procedures and also with the official USP method for total CoQ10 determination. The proposed method was applied to 13 dietary supplements and medicines in the form of soft- and hard-shell capsules, revealing the co-existence of both CoQ10 forms in 85% of the tested preparations. CoQ10 forms that were undeclared accounted for up to 75% of the CoQ10 content, which is overlooked by current official methods that evaluate only the total CoQ10 content. This validated HPLC-UV method for the unequivocal quantification of reduced and oxidized CoQ10 is therefore appropriate for the routine analysis of CoQ10 preparations in quality control laboratories, as well as for stability studies, and is suggested to be adopted as an official method.

The ying and yang of idebenone: Not too little, not too much - cell death in NQO1 deficient cells and the mouse retina

Idebenone has recently been investigated as a drug therapy for Leber's hereditary optic neuropathy (LHON), a rare genetic mitochondrial disease that causes rapid and progressive bilateral vision loss. Although several studies have shown that idebenone can promote vision recovery in patients with LHON, the evidence for the efficacy of idebenone is still limited. Idebenone failed to demonstrate superiority over placebo in the primary end-points of the only published randomised, double-blind, placebo-controlled trial. There appears to be a patient-specific response to idebenone with high variability in therapeutic outcomes. A recent study suggested that the cytosolic enzyme NAD(P)H: quinone acceptor oxidoreductase (NQO1) is the major enzyme involved in the activation of idebenone, and the beneficial effects of idebenone are dependent on the expression of NQO1. Here, we confirm the NQO1-dependent activity of idebenone, but we also show, for the first time, that the cytotoxicity of idebenone is linked to cellular expression of NQO1. Upon idebenone administration, cells deficient in NQO1 show a marked decrease in viability in comparison to NQO1 expressing cells, with idebenone causing ROS production and deleterious effects on ATP levels and cell viability. In addition, our data highlights that only cells expressing NQO1 can significantly activate idebenone, indicating that other proposed metabolic activation pathways, such as complex II and glycerol-3-phosphate dehydrogenase, do not play a significant role in idebenone activation. Furthermore, we provide evidence of idebenone-induced toxicity in the retina ex-vivo, which can be explained by the variation of NQO1 expression between different cell types in the mouse retina. Idebenone mediated cell rescue in the rotenone ex vivo model also indicated that this drug has a narrow therapeutic window. These findings will help to guide the development of future therapies and drug delivery strategies including intra-ocular administration. The specific dependence of idebenone activity on NQO1 may also explain the variation in patient outcomes in clinical trials.

Bioavailability of Coenzyme Q10: An Overview of the Absorption Process and Subsequent Metabolism

A lack of understanding of the processes determining the absorption and subsequent metabolism of coenzyme Q₁₀ (CoQ₁₀) has resulted in some manufacturers’ making incorrect claims regarding the bioavailability of their CoQ₁₀ supplements, with potential consequences for the use of such products in clinical trials. The purpose of the present review article is, therefore, to describe the various stages of exogenous CoQ₁₀ metabolism, from its first ingestion, stomach transit, absorption from the small intestine into the lymphatic system, transport in blood, and access into cells. In particular, the importance of CoQ₁₀ crystal dispersion in the initial formulation is emphasised, the absence of which reduces bioavailability by 75%. In addition, evidence comparing the relative bioavailability and efficacy of ubiquinone and ubiquinol forms of CoQ₁₀ has been reviewed.

Ubiquinol Ameliorates Endothelial Dysfunction in Subjects with Mild-to-Moderate Dyslipidemia: A Randomized Clinical Trial

In this randomized, double-blind, single-center trial (ANZCTR number ACTRN12619000436178) we aimed to investigate changes in endothelium-dependent vasodilation induced by ubiquinol, the reduced form of coenzyme Q10 (CoQ10), in healthy subjects with moderate dyslipidemia. Fifty-one subjects with low-density lipoprotein (LDL) cholesterol levels of 130–200 mg/dL, not taking statins or other lipid lowering treatments, moderate (2.5%–6.0%) endothelial dysfunction as measured by flow-mediated dilation (FMD) of the brachial artery, and no clinical signs of cardiovascular disease were randomized to receive either ubiquinol (200 or 100 mg/day) or placebo for 8 weeks. The primary outcome measure was the effect of ubiquinol supplementation on FMD at the end of the study. Secondary outcomes included changes in FMD on week 4, changes in total and oxidized plasma CoQ10 on week 4 and week 8, and changes in serum nitrate and nitrite levels (NOx), and plasma LDL susceptibility to oxidation in vitro on week 8. Analysis of the data of the 48 participants who completed the study demonstrated a significantly increased FMD in both treated groups compared with the placebo group (200 mg/day, +1.28% ± 0.90%; 100 mg/day, +1.34% ± 1.44%; p < 0.001) and a marked increase in plasma CoQ10, either total (p < 0.001) and reduced (p < 0.001). Serum NOx increased significantly and dose-dependently in all treated subjects (p = 0.016), while LDL oxidation lag time improved significantly in those receiving 200 mg/day (p = 0.017). Ubiquinol significantly ameliorated dyslipidemia-related endothelial dysfunction. This effect was strongly related to increased nitric oxide bioavailability and was partly mediated by enhanced LDL antioxidant protection.

Statins and muscle pain

Introduction: Statins remain among the most frequently prescribed drugs and constitute a cornerstone in the prevention of cardiovascular disease. However, muscle symptoms are often reported from patients on statins. Muscle symptoms are frequently reported as adverse events associated with statin therapy.Areas covered: In the present narrative review, statin-associated muscle pain is discussed. It elucidates potential mechanisms and possible targets for management.Expert opinion: In general, the evidence in support of muscle pain caused by statins is in some cases equivocal and not particularly strong. Reported symptoms are difficult to quantify. Rarely is it possible to establish a causal link between statins and muscle pain. In randomized controlled trials, statins are well tolerated, and muscle-pain related side-effects is similar to placebo. There are also nocebo effects of statins. Exchange of statin may be beneficial although all statins have been associated with muscle pain. In some patients reduction of dose is worth trying, especially in primary prevention Although the benefits of statins outweigh potential risks in the vast majority of cases, careful clinical judgment may be necessary in certain cases to manage potential side effects on an individual basis.

Short-term ubiquinol-10 supplementation alleviates tissue damage in muscle and fatigue caused by strenuous exercise in male distance runners

Background: Coenzyme Q10 (CoQ10) is the electron transporter in oxidative phosphorylation and an endogenous antioxidant. Recent researches have indicated that doses of 200-300 mg/day are needed to recognize effects to prevent oxidative damage in athletes, and the reduced form of CoQ10, ubiquinol-10, is more bioavailable than its oxidized form. Therefore, we hypothesized that higher doses of ubiquinol-10 could elevate plasma CoQ10 levels rapidly and exert physiological benefits in athletes. Therefore, a placebo controlled, double blinded test was carried out to determine the effects of ubiquinol-10 on the extravasate enzymes and fatigue levels of distance runners. Methods: Sixteen male collegiate distance runners were allocated to two groups receiving 300 mg/day of ubiquinol-10 (19.8 ± 1.7 years) or a placebo (20.1 ± 1.6 years) for 12 days during summer training that comprised 25- and 40-km runs on days 7 and 9, respectively. Results: Ubiquinol-10 elevated plasma CoQ10 concentration to 5.62 μg/mL and significantly decreased activities of the serum extravasate enzymes, CK, ALT, LDH (P < 0.01), and AST (P < 0.05) on day 6. Subjective fatigue status was significantly elevated on day 10 (the day after the 45-km run) in the placebo group (P < 0.001), but did not significantly change in the group given ubiquinol-10. Therefore, ubiquinol-10 could mitigate tissue damage and alleviate fatigue status in distance runners during summer training. Conclusions: Ubiquinol-10 (300 mg/day) supplementation elevated plasma CoQ10 concentrations almost to plateau levels, decreased extravasate enzymes within six days, and suppressed the subjective fatigue in male distance runners.

Coenzyme Q10

Coenzyme Q₁₀ (CoQ₁₀) is among the most widely used dietary and nutritional supplements on the market. CoQ₁₀ has several fundamental properties that may be beneficial in several clinical situations. This article reviews the pertinent chemical, metabolic, and physiologic properties of CoQ₁₀ and the scientific data and clinical trials that address its use in two common clinical settings: statin-associated myopathy syndrome (SAMS) and congestive heart failure (CHF). Although clinical trials of CoQ₁₀ in SAMS have conflicting conclusions, the weight of the evidence, as seen in meta-analyses, supports the use of CoQ₁₀ in SAMS overall. In CHF, there is a lack of large-scale randomized clinical trial data regarding the use of statins in patients receiving contemporary treatment. However, one relatively recent randomized clinical trial, Q-SYMBIO, suggests an adjunctive role for CoQ₁₀ in CHF. Recommendations regarding the use of CoQ₁₀ in these clinical situations are presented.

Effect of liquid ubiquinol supplementation on glucose, lipids and antioxidant capacity in type 2 diabetes patients: a double-blind, randomised, placebo-controlled trial

Ubiquinone is a lipid antioxidant, and a novel liquid ubiquinol (a hydro-soluble, reduced form of coenzyme Q10) supplement was recently developed. The purpose of this study was to examine the levels of glucose, lipids and antioxidant capacity of type 2 diabetes patients after liquid ubiquinol supplementation. This study was designed as a randomised, double-blind, placebo-controlled trial. In all, fifty participants were randomly assigned to a placebo (n 25) or liquid ubiquinol (100 mg/d, n 25) group, and the intervention lasted for 12 weeks. Plasma coenzyme Q10, glucose homoeostasis parameters, lipid profiles, oxidative stress and antioxidative enzyme activities were measured during the study. After 12 weeks of supplementation, glyco Hb (HbA1c) value was significantly decreased in the liquid ubiquinol group (P=0·03), and subjects in the liquid ubiquinol group had significantly lower anti-glycaemic medication effect scores (MES) compared with those in the placebo group (P=0·03). The catalase (P<0·01) and glutathione peroxidase (P=0·03) activities were increased significantly after supplementation. Plasma coenzyme Q10 was correlated with the insulin level (P=0·05), homoeostatic model assessment-insulin resistance (P=0·07), quantitative insulin sensitivity check index (P=0·03) and the anti-hyperglycaemic agents' MES (P=0·03) after supplementation. Lipid profiles did not change after supplementation; however, the subjects in the placebo group had a significantly lower level of HDL-cholesterol after 12 weeks of intervention. In conclusion, oral intake of 100 mg/d liquid ubiquinol might benefit type 2 diabetes patients by increasing antioxidant enzyme activity levels, reducing HbA1c levels and maintaining HDL-cholesterol levels.

Statin-Associated Cardiomyopathy Responds to Statin Withdrawal and Administration of Coenzyme Q10

CONTEXT

Heart failure (HF) is rapidly increasing in incidence and is often present in patients receiving long-term statin therapy.

OBJECTIVE

To test whether or not patients with HF on long-term statin therapy respond to discontinuation of statin therapy and initiation of coenzyme Q10 (CoQ10) supplementation.

DESIGN

We prospectively identified patients receiving long-term statin therapy in whom HF developed in the absence of any identifiable cause. Treatment consisted of simultaneous statin therapy discontinuation and CoQ10 supplementation (average dosage = 300 mg/d).

MAIN OUTCOME MEASURES

Baseline and follow-up physical examination findings, symptom scores, echocardiograms, and plasma CoQ10 and cholesterol levels.

RESULTS

Of 142 identified patients with HF, 94% presented with preserved ejection fraction (EF) and 6% presented with reduced EF (< 50%). After a mean follow-up of 2.8 years, New York Heart Association class 1 increased from 8% to 79% (p < 0.0001). In patients with preserved EF, 34% had normalization of diastolic function and 25% showed improvement (p < 0.0001). In patients with reduced EF at baseline, the EF improved from a mean of 35% to 47% (p = 0.02). Statin-attributable symptoms including fatigue, muscle weakness, myalgias, memory loss, and peripheral neuropathy improved (p < 0.01). The 1-year mortality was 0%, and the 3-year mortality was 3%.

CONCLUSION

In patients receiving long-term statin therapy, statin-associated cardiomyopathy may develop that responds safely to statin treatment discontinuation and CoQ10 supplementation. Statin-associated cardiomyopathy may be a contributing factor to the current increasing prevalence of HF with preserved EF.

Coenzyme Q10 protects against burn-induced mitochondrial dysfunction and impaired insulin signaling in mouse skeletal muscle

Mitochondrial dysfunction is associated with metabolic alterations in various disease states, including major trauma (e.g., burn injury). Metabolic derangements, including muscle insulin resistance and hyperlactatemia, are a clinically significant complication of major trauma. Coenzyme Q10 (CoQ10) is an essential cofactor for mitochondrial electron transport, and its reduced form acts as a lipophilic antioxidant. Here, we report that burn injury induces impaired muscle insulin signaling, hyperlactatemia, mitochondrial dysfunction (as indicated by suppressed mitochondrial oxygen consumption rates), morphological alterations of the mitochondria (e. g., enlargement, and loss of cristae structure), mitochondrial oxidative stress, and disruption of mitochondrial integrity (as reflected by increased mitochondrial DNA levels in the cytosol and circulation). All of these alterations were significantly alleviated by CoQ10 treatment compared with vehicle alone. These findings indicate that CoQ10 treatment is efficacious in protecting against mitochondrial dysfunction and insulin resistance in skeletal muscle of burned mice. Our data highlight CoQ10 as a potential new strategy to prevent mitochondrial damage and metabolic dysfunction in burn patients.

The Plasma Bioavailability of Coenzyme Q10 Absorbed from the Gut and the Oral Mucosa

Coenzyme Q₁₀ (CoQ₁₀) has a central role in the generation of cellular bioenergy and its regulation. The hydrophobicity exhibited by the CoQ₁₀ molecule leads to reports of poor absorption profiles, therefore, the optimization of formulations and modes of delivery is an ever-evolving therapeutic goal. The aim of this study was to investigate different CoQ₁₀ formulations. The article summarizes the findings from an Australian comparative study involving adults administered CoQ₁₀ through different oral delivery platforms. A total of 11 participants (six males and five females) voluntarily participated in a comparative clinical study of three different CoQ₁₀ formulations across a six-week period, completing 198 person-hours of cumulative contribution equivalent to n = 33 participation. All of the eligible participants (n = 11) administered the three formulations blinded from who the commercial supplier of the formulation was and from what the chemical form of the CoQ₁₀ was that was being administered. The dosing between the CoQ₁₀ preparations were dispensed sequentially and were administered following three-week washouts. Three commercial preparations were tested, which included the following: formulations with capsules each containing ubiquinol and ubiquinone (150 mg/capsule), and a liposome ubiquinone formulation (40 mg/mL at 2 actuations of the pump). A significant inter-subject variation in the plasma level of CoQ₁₀ at baseline that was observed to increase with an increase in age. This trend persisted in the post administration of the different formulations. Furthermore, it was observed that the intestinal absorption and bioavailability of CoQ₁₀ varied significantly in the plasma between subjects, irrespective of whether the ubiquinol or ubiquinone forms were administered. The administration of CoQ₁₀ as a liposome for preparation showed the poorest response in bioavailability. Although the ubiquinol capsule form of CoQ₁₀ was observed to have increased in the plasma versus the ubiquinone capsules and the ubiquinol liposome at the two-hour interval, the inter-subject variation was such that the difference was not significant (p > 0.05). All of the CoQ₁₀ formulations showed no further increases in their plasma levels over the remaining study period (i.e., four hours). This study further concluded that the intestinal absorption of CoQ₁₀ is highly variable and is independent of the molecular form administered. Furthermore, it also concludes that liposomes are not an effective vehicle for the oral administration of CoQ₁₀, and as such, did not improve the oral mucosal/sublingual absorption and bioavailability of the molecule. Of interest was the observation that with the increasing subject age, there was an observed increase in the baseline plasma CoQ₁₀ levels in the participants prior to dosing. It was posited that the increase in the baseline plasma levels of CoQ₁₀ with an increase in age could be due to the loss of skeletal muscle mass, a result that still needs to be verified.

Bioavailability of coenzyme Q10 supplements depends on carrier lipids and solubilization

OBJECTIVES

Bioavailability of supplements with coenzyme Q10 (CoQ₁₀) in humans seems to depend on the excipients of formulations and on physiological characteristics of the individuals. The aim of this study was to determine which factors presented in CoQ₁₀ supplements affect the different response to CoQ₁₀ in humans.

METHODS

We tested seven different supplement formulations containing 100 mg of CoQ₁₀ in 14 young, healthy individuals. Bioavailability was measured as area under the curve of plasma CoQ₁₀ levels over 48 h after ingestion of a single dose. Measurements were repeated in the same group of 14 volunteers in a double-blind crossover design with a minimum of 4 wk washout between intakes.

RESULTS

Bioavailability of the formulations showed large differences that were statistically significant. The two best absorbable formulations were soft-gel capsules containing ubiquinone (oxidized CoQ₁₀) or ubiquinol (reduced CoQ₁₀). The matrix used to dissolve CoQ₁₀ and the proportion and addition of preservatives such as vitamin C affected the bioavailability of CoQ₁₀. Although control measurements documented that all formulations contained 100 mg of either CoQ₁₀ or ubiquinol, some of the participants showed high and others lower capacity to reach high increase of CoQ₁₀ in blood, indicating the participation of individual unknown physiological factors.

CONCLUSION

This study highlights the importance of individually adapted selection of best formulations to reach the highest bioavailability of CoQ₁₀ in humans.

Ubiquinol is superior to ubiquinone to enhance Coenzyme Q10 status in older men

Ubiquinol is a better form than ubiquinone to maintain the CoQ10 status in older adults.

Plasma coenzyme Q10 concentration, antioxidant status, and serum N-terminal pro-brain natriuretic peptide concentration in dogs with various cardiovascular diseases and the effect of cardiac treatment on measured variables

OBJECTIVE To determine the plasma total antioxidant capacity, erythrocyte superoxide dismutase activity, whole blood glutathione peroxidase activity, and plasma coenzyme Q₁₀ (CoQ₁₀) concentration in dogs with various stages of cardiovascular diseases and in healthy dogs; assess the influence of cardiac treatment on the levels of antioxidant variables, plasma CoQ₁₀ concentration, and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, and determine any correlation between the disease severity (NT-proBNP concentration) and antioxidant variables or CoQ₁₀ concentration. ANIMALS 43 dogs with various types and stages of cardiovascular diseases (congenital and acquired) and 29 healthy dogs. PROCEDURES Blood samples were collected from all dogs for spectrophotometric assessment of antioxidant variables. Plasma CoQ₁₀ concentration was determined with a high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry method. Serum NT-proBNP concentration was measured with an ELISA. RESULTS Values for antioxidant variables did not differ among groups of dogs with cardiovascular diseases, regardless of disease stage or treatment. Plasma CoQ₁₀ concentration was significantly increased in treated dogs with congestive heart failure (CHF), compared with untreated patients. However, plasma CoQ₁₀ concentration did not differ among heart failure classes. A significant, negative correlation between serum NT-proBNP and plasma CoQ₁₀ concentrations was identified in treated CHF-affected dogs, suggesting that low plasma CoQ₁₀ concentration may be associated with increased severity of CHF. CONCLUSIONS AND CLINICAL RELEVANCE The antioxidant variables evaluated were not altered in dogs with CHF, regardless of cardiac disease stage or treatment. Further investigation into the possible effects of CoQ₁₀ supplementation in dogs with advanced stages of CHF is warranted.

Extensive strain-level copy-number variation across human gut microbiome species

Within each bacterial species, different strains may vary in the set of genes they encode or in the copy number of these genes. Yet, taxonomic characterization of the human microbiota is often limited to the species level or to previously sequenced strains, and accordingly, the prevalence of intra-species variation, its functional role, and its relation to host health remain unclear. Here, we present a comprehensive large-scale analysis of intra-species copy-number variation in the gut microbiome, introducing a rigorous computational pipeline for detecting such variation directly from shotgun metagenomic data. We uncover a large set of variable genes in numerous species and demonstrate that this variation has significant functional and clinically relevant implications. We additionally infer intra-species compositional profiles, identifying population structure shifts and the presence of yet uncharacterized variants. Our results highlight the complex relationship between microbiome composition and functional capacity, linking metagenome-level compositional shifts to strain-level variation.