Bifidobacterium longum R0175 attenuates post-myocardial infarction depressive-like behaviour in rats

A medical and molecular approach to kefir as a therapeutic agent of human microbiota

The imbalanced microbial composition called dysbiosis constitutes a tendency related to different kind of human diseases. To overcome the disadvantages of dysbiosis, the consumption of probiotics is an emerging and promising topic of the last decade. Kefir is a probiotic fermented beverage produced from the fermentation of kefir grains with changing varieties of milk and displays a symbiotic association of bacteria and yeast. The discovery of the concept that fermented foods/beverages such as kefir could modify gut microbiota in humans has widened the borders of precision medicine and now microbiome therapeutics can be considered as a significant part of this field. Kefir seems to have potential to guide and manipulate future replacement/complementary therapies with a variety of beneficial biological/medical properties it has. The aim of this review was a comprehensive recapitulation of probiotic beverage kefir's significant properties mainly focusing of antioxidative, immunomodulatory, apoptotic, antitumor and neuroprotective properties. Apoptotic/antimetastatic effects are regulated at the molecular level by increases in TGF-β1, caspase-3, p53, Bax, Bax:Bcl-2 ratio, p21 and decreases in TGF-α, Bcl-2 and MMP polarization. Neuroprotective effects are revealed upon upregulation of SOD/catalase and anti-inflammatory Treg cells, decreases in repetitive behavior and modulation of apoptotic genes. Besides these significant features that may offer advantages in supplementary cancer therapies, the scope was also extended to recent emerging medical topics and also discussed and evaluated the concept of "psychobiotics". The therapeutic potential of psychobiotic effect is majorly attributed to the increased ratios of Clostridium butyricum, Lactobacillus and Bifidobacterium.

The therapeutic value of bifidobacteria in cardiovascular disease

There has been an increase in cardiovascular morbidity and mortality over the past few decades, making cardiovascular disease (CVD) the leading cause of death worldwide. However, the pathogenesis of CVD is multi-factorial, complex, and not fully understood. The gut microbiome has long been recognized to play a critical role in maintaining the physiological and metabolic health of the host. Recent scientific advances have provided evidence that alterations in the gut microbiome and its metabolites have a profound influence on the development and progression of CVD. Among the trillions of microorganisms in the gut, bifidobacteria, which, interestingly, were found through the literature to play a key role not only in regulating gut microbiota function and metabolism, but also in reducing classical risk factors for CVD (e.g., obesity, hyperlipidemia, diabetes) by suppressing oxidative stress, improving immunomodulation, and correcting lipid, glucose, and cholesterol metabolism. This review explores the direct and indirect effects of bifidobacteria on the development of CVD and highlights its potential therapeutic value in hypertension, atherosclerosis, myocardial infarction, and heart failure. By describing the key role of Bifidobacterium in the link between gut microbiology and CVD, we aim to provide a theoretical basis for improving the subsequent clinical applications of Bifidobacterium and for the development of Bifidobacterium nutritional products.

Oral probiotic therapy improves motor function in a rodent model of sensorimotor stroke

Ischemic stroke is a debilitating neurological disease with few effective therapeutics. Previous work has shown that oral probiotic treatment prior to stroke can attenuate cerebral infarction and neuroinflammation, highlighting the gut-microbiota-brain axis as a novel therapeutic target. Whether a more clinically relevant, post-stroke, administration of probiotics can improve stroke outcomes is unknown. In this study, we examined the effect of post-stroke oral probiotic therapy on motor behavior in the pre-clinical mouse endothelin-1 (ET-1) model of sensorimotor stroke. We found that post-stroke oral probiotic therapy with Cerebiome^® (Lallemand, Montreal, Canada), containing B. longum R0175 and L. helveticus R0052, improved functional recovery and changed the composition of the post-stroke gut microbiota. Interestingly, oral Cerebiome^® administration did not result in alterations of lesion volume or the number of CD8+/Iba1+ cells in the injured tissue. Overall, these findings suggest that probiotic treatment following injury can improve sensorimotor function.

Heat-killed Lactobacillus helveticus improves mood states: a randomised, double-blind, placebo-controlled study

We investigated the effects of heat-killed Lactobacillus helveticus MCC1848 on daily mood states in healthy young adults. Participants (n=58) were randomised to receive heat-killed L. helveticus MCC1848 powder or placebo powder for 4 weeks. During the study period, adverse events were recorded in the participant diary. Mood states were assessed before and 2 and 4 weeks after initiation of the intervention. The primary outcomes were the shortened version of the Profile of Mood States 2 (POMS 2) scores. Secondary outcomes included other mood state (State-Trait Anxiety Inventory (STAI); visual analogue scale (VAS)), quality of life (acute form of the SF-36v2), sleep (Athens Insomnia Scale (AIS)) and fatigue (Chalder Fatigue Scale (CFS)) scores. Four weeks of heat-killed L. helveticus MCC1848 intake, compared to placebo, significantly improved the shortened version of the POMS 2 'friendliness' and the VAS 'relaxed' scores, which are two indicators of positive mood states. On the other hand, heat-killed L. helveticus MCC1848 intake had no significant effects on negative mood state items (e.g. anger, nervousness, confusion) assessed by the shortened version of the POMS 2, STAI and VAS. AIS and CFS scores also showed no significant differences. No adverse effects were observed with 4 weeks of heat-killed L. helveticus MCC1848 intake. These results suggest that daily consumption of heat-killed L. helveticus MCC1848 is safe and has the potential to improve positive mood states. UMIN Clinical Trial Registry: UMIN000043697.

Screening of the most efficacious lactic acid bacteria strain for myocardial infarction recovery and verification and exploration of its functions and mechanisms

Screening efficient strains by cell platform is cost-effective, but to date, no screening experiments have been performed for targeted lactic acid bacteria with hypoxic/reoxygenation (H/R)-treated cardiomyocytes, and their effects on the phosphoinositide 3-kinase (PI3K)/protein kinase b (Akt)/endothelial nitric oxide synthase (eNOS) pathway in myocardial infarction (MI) are unclear. Here we activated 102 strains of lactic acid bacteria and inoculated them into MRS medium for fermentation. The fermentation supernatants of the lactic acid bacteria were incubated with an H/R model of H9C2 cells. We found that Bifidobacterium longum ZL0210 had the greatest potential for inhibiting the apoptosis of H/R-induced H9C2 cells. Furthermore, it significantly increased the expression of heme oxygenase-1 (HO-1) and quinone oxidoreductase 1 (NQO1) in H9C2 cardiomyocytes, as well as the Bcl-2/Bax protein ratio, protecting damaged myocardial cells via an anti-apoptotic pathway. Intragastric administration of B. longum ZL0210 to mice for one week before and after establishment of an MI model drastically attenuated the myocardial cell hypertrophy and fibrosis of the MI mice. Meanwhile, B. longum ZL0210 significantly reduced the secretion of myocardial enzymes, increased the activity of antioxidant enzymes, and inhibited lipid-oxidative malondialdehyde (MDA) levels. Moreover, it upregulated the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) protein and the phosphorylation levels of PI3K, Akt, and eNOS, resulting in increased NO contents. In summary, we screened 102 strains of lactic acid bacteria with a cell platform and determined that B. longum ZL0210 was a favorable candidate for protecting the myocardium. We are the first to reveal the protective effects of B. longum ZL0210 for MI via activation of the PI3K/Akt/eNOS pathway through TRAIL.

Akkermansia muciniphila ameliorates depressive disorders in a murine alcohol-LPS (mALPS) model

Depression is the most common mental disorder in the world. Recently, an increasing number of studies have reported alcohol-related depression. However, there is no simple, efficient, and time-saving alcohol-related depression animal model yet. Based on the fact that people with alcohol addiction often have impaired gastrointestinal (GI) tract health like dysbiosis, which serves as a primary factor to augment lipopolysaccharides (LPS), we first developed a murine alcohol-LPS model (mALPS), with oral gavage of LPS in acute alcohol treated mice, and successfully observed depression-like symptoms. We found that acute alcohol treatment damaged the intestinal barrier and caused dysbiosis, which further increased the translocation of LPS and neuroinflammatory responses (TNF-α and IL-1β) and led to abnormal expression of the depression-related genes, i.e. BDND and IDO, reduced the levels of 5-HT and caused depressive behaviors in mice. Probiotic intervention could improve depressive symptoms without notable adverse effects. Akkermansia muciniphila (AKK), one of the next-generation probiotics, has been widely used for the restoration of the intestinal barrier and reduction of inflammation. Here, we found that AKK significantly ameliorated alcohol-related depressive behaviors in a mALPS model, through enhancing the intestinal barrier and maintaining the homeostasis of the gut microbiota. Furthermore, AKK reduced serum LPS, ameliorated neuroinflammation (TNF-α and IL-1β), normalized the expression of depression-related genes and increased the 5-HT levels in the hippocampus. Our study suggests that AKK supplements will be a promising therapeutic regime for alcohol-associated depression in the future.

Gut-Brain Axis, Neurodegeneration and Mental Health: A Personalized Medicine Perspective

Neurological conditions such as neurodegenerative diseases and mental health disorders are a result of multifactorial underpinnings, leading to individual-based complex phenotypes. Demystification of these multifactorial connections will promote disease diagnosis and treatment. Personalized treatment rather than a one-size-fits-all approach would enable us to cater to the unmet healthcare needs based on protein-protein and gene-environment interactions. Gut-brain axis, as the name suggests, is a two-way biochemical communication pathway between the central nervous system (CNS) and enteric nervous system (ENS), enabling a mutual influence between brain and peripheral intestinal functions. The gut microbiota is a major component of this bidirectional communication, the composition of which is varied depending on the age, and disease conditions, among other factors. Gut microbiota profile is typically unique and personalized therapeutic intervention can aid in treating or delaying neurodegeneration and mental health conditions. Besides, research on the gut microbial influence on these conditions is gaining attention, and a better understanding of this concept can lead to identification of novel targeted therapies.

Graphical Abstract

What do experimental animal models of mood disorders tell clinicians about influence of probiotics on the gut-brain axis?

It is commonly pointed out that enteric microbiota have a significant impact on the behavioral and neurophysiological parameters relevant to brain-gut axis disorders. Accordingly, many data have demonstrated that probiotics can alter the central nervous system function via this gut-brain axis and commensal bacteria consumption can ameliorate stress-related neuropsychiatric disorders. Thus, modulating the enteric microbiota is increasingly considered a new therapeutic approach for these disorders, although so far there is a lack of reliable pre-clinical and clinical data confirming the usefulness of probiotics in the treatment of affective disorders. In this review, we discuss various mechanisms linking specific probiotic bacteria with behaviors related to anhedonia and the exact mechanisms of their action, including data provided by using animal models and tests. Finally, we point to potential clinical impact resulting from future studies investigating the gut-brain axis activity with respect to the efficacy of probiotic treatment of mental disorders.

Depressive hypertension: A proposed human endotype of brain/gut microbiome dysbiosis

BACKGROUND

Hypertension (HTN) is frequently linked with depression (DEP) in adults with cardiovascular disease (CVD), yet the underlying mechanism and successful management remain elusive. We approached this knowledge gap through the lens that humans are eukaryote-prokaryote "meta-organisms," such that cardiovascular disease dysregulation is a mosaic disorder involving dysbiosis of the gut. We hypothesized that patients diagnosed with hypertension plus depression harbor a unique gut microbial ecology with attending functional genomics engaged with their hosts' gut/brain axis physiology.

METHODS

Stool microbiome DNA was analyzed by whole metagenome shotgun sequencing in 54 subjects parsed into cohorts diagnosed with HTN only (N = 18), DEP only (N = 7), DEP plus HTN (DEP-HTN) (N = 8), or reference subjects with neither HTN nor DEP (N = 21). A novel battery of machine-learning multivariate analyses of de-noised data yielded effect sizes and permutational covariance-based dissimilarities that significantly differentiated the cohorts (false discovery rate (FDR)-adjusted P ≤ .05); data clustering within 95% confidence interval).

RESULTS

Metagenomic significant differences extricated the four cohorts. Data of the cohort exhibiting DEP-HTN were germane to the interplay of central control of blood pressure concomitant with the neuropathology of depressive disorders. DEP-HTN gut bacterial community ecology was defined by co-occurrence of Eubacterium siraeum, Alistipes obesi, Holdemania filiformis, and Lachnospiraceae bacterium 1.1.57FAA with Streptococcus salivariu. The corresponding microbial functional genomics of DEP-HTN engaged pathways degrading GABA and beneficial short chain fatty acids (SCFA), and are associated with enhanced sodium absorption and inflammasome induction.

CONCLUSIONS

These data suggest a new putative endotype of hypertension, which we denote "depressive-hypertension" (DEP-HTN), for which we posit a model that is distinctive from either HTN alone or DEP alone. An "endotype" is a subtype of a heterogeneous pathophysiological mechanism. The DEP-HTN model incorporates a unique signature of microbial taxa and functional genomics with crosstalk that putatively intertwines host pathophysiology involving the gastrointestinal tract with disruptions in central control of blood pressure and mood. The DEP-HTN endotype model engages cardiology with gastroenterology and psychiatry, providing a proof-of-concept foundation to explore future treatments, diagnosis, and prevention of HTN-coupled mood disorders.

Mechanism and therapeutic strategies of depression after myocardial infarction

Depression resulted as an important factor associated with the myocardial infarction (MI) prognosis. Patients with MI also have a higher risk for developing depression. Although the issue of depression after MI has become a matter of clinical concern, the molecular mechanism underlying depression after MI remains unclear, whereby several strategies suggested have not got ideal effects, such as selective serotonin reuptake inhibitors. In this review, we summarized and discussed the occurrence mechanism of depression after MI, such as 5-hydroxytryptamine (5-HT) dysfunction, altered hypothalamus-pituitary-adrenal (HPA) axis function, gut microbiota imbalance, exosomal signal transduction, and inflammation. In addition, we offered a succinct overview of treatment, as well as some promising molecules especially from natural products for the treatment of depression after MI.