Molecular Identification and Selection of Probiotic Strains Able to Reduce the Serum TMAO Level in Mice Challenged with Choline

Lactiplantibacillus plantarum HM-P2 influences gestational gut microbiome and microbial metabolism

Introduction

Human milk-derived probiotics are beneficial bacteria that provide gestational health benefits, for both pregnant women and their offspring. The study aims to investigate whether the administration of human milk-derived probiotic L. plantarum HM-P2 could effectively influence gestational health.

Methods

The gestational humanized microbiome model was built by fecal microbiome transplant from gestational women into germ-free (GF) mice.

Results

HM-P2 was successfully planted and increased the top crypt depth of the colon, and microbes such as L. reuteri, Anaerofilum sp. An201, and Gemmiger were up-regulated in the HM-P2 group throughout gestation. HM-P2 significantly promoted the contents of intestinal caproic acid, bile acids, and tryptophan catabolites such as serotonin. Gut microbes were associated with these bile acids and tryptophans.

Discussion

HM-P2 could modulate the microbial community and microbial metabolites in gestational humanized GF mice. This probiotic strain could be a potential gestational dietary supplement with health benefits.

Revisiting the Role of Carnitine in Heart Disease Through the Lens of the Gut Microbiota

L-Carnitine, sourced from red meat, dairy, and endogenous synthesis, plays a vital role in fatty acid metabolism and energy production. While beneficial for cardiovascular, muscular, and neural health, its interaction with the gut microbiota and conversion into trimethylamine (TMA) and trimethylamine N-oxide (TMAO) raise concerns about heart health. TMAO, produced through the gut-microbial metabolism of L-carnitine and subsequent liver oxidation, is associated with cardiovascular risks, including atherosclerosis, heart attacks, and stroke. It contributes to cholesterol deposition, vascular dysfunction, and platelet aggregation. Omnivorous diets, rich in L-carnitine, are associated with higher TMAO levels compared to plant-based diets, which are linked to lower cardiovascular disease risks. Dietary interventions, such as increasing fiber, polyphenols, and probiotics, can modulate the gut microbiota to reduce TMAO production. These strategies seek to balance L-carnitine's benefits with its potential risks related to TMAO production. Future research should focus on personalized approaches to optimize L-carnitine use while mitigating its cardiovascular impacts, exploring microbial modulation and dietary strategies to minimize the TMAO levels and associated risks.

Effect of Lactobacillus plantarum supplementation on trimethylamine-N-oxide levels in 30 patients with atherosclerotic cardiovascular disease: A double-blind randomized controlled trial

INTRODUCTION

Trimethylamine-N-oxide (TMAO) is a metabolite produced by intestinal microbiota. It is well recognized as an independent risk marker for cardiovascular and renal diseases and mortality.

Gut microbial metabolism in Alzheimer's disease and related dementias

Multiple studies over the last decade have established that Alzheimer's disease and related dementias (ADRD) are associated with changes in the gut microbiome. These alterations in organismal composition result in changes in the abundances of functions encoded by the microbial community, including metabolic capabilities, which likely impact host disease mechanisms. Gut microbes access dietary components and other molecules made by the host and produce metabolites that can enter circulation and cross the blood-brain barrier (BBB). In recent years, several microbial metabolites have been associated with or have been shown to influence host pathways relevant to ADRD pathology. These include short chain fatty acids, secondary bile acids, tryptophan derivatives (such as kynurenine, serotonin, tryptamine, and indoles), and trimethylamine/trimethylamine N-oxide. Notably, some of these metabolites cross the BBB and can have various effects on the brain, including modulating the release of neurotransmitters and neuronal function, inducing oxidative stress and inflammation, and impacting synaptic function. Microbial metabolites can also impact the central nervous system through immune, enteroendocrine, and enteric nervous system pathways, these perturbations in turn impact the gut barrier function and peripheral immune responses, as well as the BBB integrity, neuronal homeostasis and neurogenesis, and glial cell maturation and activation. This review examines the evidence supporting the notion that ADRD is influenced by gut microbiota and its metabolites. The potential therapeutic advantages of microbial metabolites for preventing and treating ADRD are also discussed, highlighting their potential role in developing new treatments.

Targeting Gut Microbiota with Probiotics and Phenolic Compounds in the Treatment of Atherosclerosis: A Comprehensive Review

Atherosclerosis (AS) is a chronic inflammatory vascular disease. Dysregulated lipid metabolism, oxidative stress, and inflammation are the major mechanisms implicated in the development of AS. In addition, evidence suggests that gut dysbiosis plays an important role in atherogenesis, and modulation of the gut microbiota with probiotics and phenolic compounds has emerged as a promising strategy for preventing and treating AS. It has been shown that probiotics and phenolic compounds can improve atherosclerosis-related parameters by improving lipid profile, oxidative stress, and inflammation. In addition, these compounds may modulate the diversity and composition of the gut microbiota and improve atherosclerosis. The studies evaluated in the present review showed that probiotics and phenolic compounds, when consumed individually, improved atherosclerosis by modulating the gut microbiota in various ways, such as decreasing gut permeability, decreasing TMAO and LPS levels, altering alpha and beta diversity, and increasing fecal bile acid loss. However, no study was found that evaluated the combined use of probiotics and phenolic compounds to improve atherosclerosis. The available literature highlights the synergistic potential between phenolic compounds and probiotics to improve their health-promoting properties and functionalities. This review aims to summarize the available evidence on the individual effects of probiotics and phenolic compounds on AS, while providing insights into the potential benefits of nutraceutical approaches using probiotic strains, quercetin, and resveratrol as potential adjuvant therapies for AS treatment through modulation of the gut microbiota.

Treatment with Gac Fruit Extract and Probiotics Reduces Serum Trimethylamine N-Oxide in Chronic Kidney Disease Rats

Chronic kidney disease (CKD) affects more than 850 million people worldwide, contributing to morbidity and mortality, particularly through cardiovascular disease (CVD). The altered composition in CKD patients leads to increased production and absorption of uremic toxins such as trimethylamine (TMA) and its oxidized form, trimethylamine N-oxide (TMAO), which are associated with cardiovascular risks. This study investigated the potential of supplementary interventions with high-carotenoid-content gac fruit extract and probiotics to mitigate serum TMAO by modulating the gut microbiota. We conducted an animal study involving 48 male Wistar rats, divided into six groups: the control, CKD control, and four treatment groups receiving gac fruit extract, carotenoid extract, or combinations with Ligilactobacillus salivarius and Lactobacillus crispatus and Lactobacillus casei as a standard probiotic. CKD was induced in rats using cisplatin and they were supplemented with choline to enhance TMA production. The measures included serum creatinine, TMAO levels, gut microbiota composition, and the expression of fecal TMA lyase and intestinal zonula occluden-1 (ZO-1). CKD rats showed increased TMA production and elevated serum levels of TMAO. Treatment with gac fruit extract and selective probiotics significantly altered the composition of the gut microbiota by decreasing Actinobacteriota abundance and increasing the abundance of Bacteroides. This combination effectively promoted ZO-1 expression, reduced fecal TMA lyase, and subsequently lowered serum TMAO levels, demonstrating the therapeutic potential of these interventions. Our results highlight the benefits of gac fruit extract combined with probiotics for the effective reduction in serum TMAO levels in rats with CKD, supporting the further exploration of dietary and microbial interventions to improve outcomes in patients with CKD.

Metabolomic and genomic insights into TMA degradation by a novel halotolerant strain - Paracoccus sp. PS1

Trimethylamine N-oxide (TMAO) is a gut metabolite that acts as a biomarker for chronic diseases, and is generated by the oxidation of trimethylamine (TMA) produced by gut microflora. Since, microbial degradation of TMA is predicted to be used to restrict the production of TMAO, we aimed to isolate bacterial strains that could effectively degrade TMA before being oxidized to TMAO. As marine fish is considered to have a rich content of TMAO, we have isolated TMA degrading isolates from fish skin. Out of the fourteen isolates, depending on their rapid TMA utilization capability in mineral salt medium supplemented with TMA as a sole carbon and nitrogen source, isolate PS1 was selected as our desired isolate. Its TMA degrading capacity was further confirmed through spectrophotometric, Electrospray Ionization Time-of-Flight Mass Spectrometry (ESI TOF-MS) and High performance liquid chromatography (HPLC) analysis and in silico analysis of whole genome (WG) gave further insights of protein into its TMA degradation pathways. PS1 was taxonomically identified as Paracoccus sp. based on its 16S rRNA and whole genome sequence analysis. As PS1 possesses the enzymes required for degradation of TMA, clinical use of this isolate has the potential to reduce TMAO generation in the human gut.

Lactobacillus rhamnosus GG aggravates vascular calcification in chronic kidney disease: A potential role for extracellular vesicles

AIMS

Lactobacillus rhamnosus GG (LGG) is a probiotic with great promise in future clinical application, which can significantly promote bone formation. However, the effect of LGG on CKD-related vascular calcification is unclear. In this study, we aimed to investigate the effect of LGG on CKD-related vascular calcification.

MATERIALS AND METHODS

After 2 weeks of 5/6 nephrectomy, CKD rats received a special diet (4 % calcium and 1.8 % phosphate) combined with 1,25-dihydroxyvitamin D3 to induce vascular calcification. Meanwhile, CKD rats in the LGG group were gavaged orally with LGG (1 × 109 CFU bacteria/day). 16S RNA amplicon sequencing was performed to analyze the effect of LGG treatment on gut microbiota composition. Furthermore, differential ultracentrifugation was utilized to extract EVs. The effects of EVs on vascular calcification were evaluated in rat VSMCs, rat aortic rings, and CKD rat calcification models. In this study, vascular calcification was assessed by microcomputed tomography analysis, alizarin red staining, calcium content determination, and the expression of osteogenic transcription factors RUNX2 and BMP2.

KEY FINDINGS

LGG remarkably aggravated vascular calcification. LGG supplementation significantly altered gut microbiota composition in CKD rats, particularly increasing Lactobacillus. Interestingly, EVs presented a significant promoting effect on the development of calcification. Finally, mechanistic analysis proved that EVs aggravated vascular calcification through PI3K/AKT signaling.

SIGNIFICANCE

These results do not support the supplementation of LGG in CKD-associated vascular calcification patients. Our study presented a fresh perspective on LGG with potential risks and adverse effects. CKD patients should use specific probiotic strains cautiously.

The Interplay between Cardiovascular Disease, Exercise, and the Gut Microbiome

Cardiovascular disease (CVD) is the leading cause of death worldwide, with physical inactivity being a known contributor to the global rates of CVD incidence. The gut microbiota has been associated with many diseases including CVD and other comorbidities such at type 2 diabetes and obesity. Researchers have begun to examine the gut microbiome as a predictor of early disease states by detecting disruptions, or dysbiosis, in the microbiota. Evidence is lacking to investigate the potential link between the gut microbiota, exercise, and CVD risk and development. Research supports that diets with whole food have reduced instances of CVD and associated diseases, increased abundances of beneficial gut bacteria, and altered gut-derived metabolite production. Further, exercise and lifestyle changes to increase physical activity demonstrate improved health outcomes related to CVD risk and comorbidities and gut microbial diversity. It is difficult to study an outcome such as CVD when including multiple factors; however, it is evident that exercise, lifestyle, and the gut microbiota contribute to improved health in their own ways. This review will highlight current research findings and what potential treatments of CVD may be generated by manipulation of the gut microbiota and/or exercise.

Bifidobacterium breve and Bifidobacterium longum Attenuate Choline-Induced Plasma Trimethylamine N-Oxide Production by Modulating Gut Microbiota in Mice

Atherosclerosis is the main cause of myocardial infarction and stroke, and the morbidity and mortality rates of cardiovascular disease are among the highest of any disease worldwide. Excessive plasma trimethylamine-N-oxide (TMAO), an intestinal metabolite, promotes the development of atherosclerosis. Therefore, effective measures for reducing plasma TMAO production can contribute to preventing atherosclerosis. Probiotics are living microorganisms that are beneficial to the human body, and some of them can attenuate plasma TMAO production. To explore the effects of probiotic supplementation on plasma TMAO in choline-fed mice, we intragastrically administered eight strains of Bifidobacterium breve and eight strains of Bifidobacterium longum to mice for 6 weeks. B. breve Bb4 and B. longum BL1 and BL7 significantly reduced plasma TMAO and plasma and cecal trimethylamine concentrations. However, hepatic flavin monooxygenase (FMO) activity, flavin-containing monooxygenase 3 (FMO3), farnesoid X receptor (FXR) protein expression and TMAO fractional excretion were not significantly affected by Bifidobacterium supplementation. The treatment of Bifidobacterium strains modulated the abundances of several genera such as Ruminococcaceae UCG-009, Ruminococcaceae UCG-010, which belong to the Firmicutes that has been reported with cut gene clusters, which may be related to the reduction in intestinal TMA and plasma TMAO. Additionally, a reduction in Ruminococcaceae indicates a reduction in circulating glucose and lipids, which may be another pathway by which Bifidobacterium strains reduce the risk of atherosclerosis. The effect of Bifidobacterium strains on Bacteroides also suggests a relationship between the abundance of this genus and TMA concentrations in the gut. Therefore, the mechanism underlying these changes might be gut microbiota regulation. These Bifidobacterium strains may have therapeutic potential for alleviating TMAO-related diseases.