Lactobacillus from the Altered Schaedler Flora maintain IFNγ homeostasis to promote behavioral stress resilience

Is anxiety and depression transmissible? Depressed mother rats transmit anxiety- and depression-like phenotypes to cohabited rat pups through gut microbiota assimilation

OBJECTIVE

This study is to investigate the role of gut microbiota transmission in the development of anxiety/depression in offspring exposed to maternal depression.

METHOD

Offspring rats were cohabitated with their depressed mother or father rats (which exposed to chronic unpredictable mild stress (CUMS)) for 2, 4, and 6 months, the anxiety- and depression-like behaviors, and interaction/caring activities between mother/father and their pups were detected. The gut microbiota composition and its relationship with behaviors were analyzed. Fecal microbiota transplantation (FMT) was performed to establish the gut microbiota of depressed/normal mother rats in the offspring rats to further confirm the role of "depressive gut microbiota" transmission in mediating the anxiety/depression in the pups.

RESULTS

Anxiety and depression phenotypes can be transmitted from depressed mother rats to their cohabited offspring. Frequent interactions and gut microbiota assimilation were observed between rat mothers and their pups. Remodeling of the gut microbiota in pups by FMT could induce or attenuate anxiety- and depression-like phenotypes depending on the origin of the fecal microbiota. By comparison, the pups cohabiting with depressed father rats exhibited milder anxiety and depression.

CONCLUSIONS

These data together support that depressed mothers can transmit anxiety/depression to their pups through gut microbiota assimilation, which is related to frequent interactions. Our study reinforces the significance of mental health of mothers in preventing the occurrence of childhood anxiety and depression, and pointing out the possibility of remodeling intestinal microbiota as an effective therapeutic approach for treating anxiety/depression in children.

Lactobacillus reuteri or Lactobacillus rhamnosus GG intervention facilitates gut barrier function, decreases corticosterone and ameliorates social behavior in LPS-exposed offspring

Probiotic therapy with Lactobacillus reuteri and Lactobacillus rhamnosus (LGG) demonstrates potential as an adjunctive treatment for autism spectrum disorder (ASD). In a rat model of ASD induced by lipopolysaccharide (LPS) injection during pregnancy, we evaluated the effects of these probiotics on offspring. Administration of L. reuteri or LGG for three weeks post-birth improved social deficits and reduced anxiety in LPS-exposed rats. Additionally, probiotics significantly modified short-chain fatty acid profiles, increasing butyric acid levels and decreasing propionic acid levels. They also enhanced colonic barrier integrity by upregulating tight junction proteins, including ZO-1, Occludin, and Claudin4. RNA sequencing identified differential gene expression in pathways related to inflammation, the HPA axis, and reactive oxygen species metabolism, with NADPH oxidase 1 (NOX1) emerging as a crucial gene. Validation studies confirmed that Lactobacillus strains reduced inflammatory cytokines, inhibited corticosterone secretion, increased antioxidant levels, and suppressed the NF-κB/NOX1 pathway. In an H2O2-induced oxidative stress model using Caco-2 cells, pre-treatment with L. reuteri, LGG, or NF-κB inhibitors enhanced cellular antioxidants, inhibited NF-κB/NOX1 activation, and improved barrier function. Overall, L. reuteri and LGG administration improved social behavior, bolstered colonic barrier function, and mitigated HPA axis overactivation in LPS-exposed rats, while also alleviating oxidative stress in the colon and Caco-2 cells. These findings suggest that L. reuteri and LGG have substantial clinical potential for ASD treatment by targeting multiple pathophysiological mechanisms, including inflammation, HPA axis dysregulation, and oxidative stress, thereby presenting a promising adjunctive therapeutic strategy for enhancing social behavior and gut health in ASD.

Targeting inflammation and gut microbiota with antibacterial therapy: Implications for central nervous system health

The complex symbiotic relationship between inflammation, the gut microbiota, and the central nervous system (CNS) has become a pivotal focus of contemporary biomedical research. Inflammation, as a physiological defense mechanism, plays a dual role as both a protective and pathological factor, and is intricately associated with gut microbiota homeostasis, often termed the "second brain." The gutbrain axis (GBA) exemplifies this multifaceted interaction, where gut health exerts significantly regulatory effects on CNS functions. Antibacterial therapies represent both promising and challenging strategies for modulating inflammation and gut microbiota composition to confer CNS benefits. However, while such therapies may exert positive modulatory effects on the gut microbiota, they also carry the potential to disrupt microbial equilibrium, potentially exacerbating neurological dysfunction. Recent advances have provided critical insights into the therapeutic implications of antibacterial interventions; nevertheless, the application of these therapies in the context of CNS health warrants a judicious and evidence-based approach. As research progresses, deeper investigation into the microbial-neural interface is essential to fully realize the potential of therapies targeting inflammation and the gut microbiota for CNS health. Future efforts should focus on refining antibacterial interventions to modulate the gut microbiota while minimizing disruption to microbial balance, thereby reducing risks and enhancing efficacy in CNS-related conditions. In conclusion, despite challenges, a more comprehensive understanding of the GBA, along with precise modulation through targeted antibacterial therapies, offers significant promise for advancing CNS disorder treatment. Continued research in this area will lead to innovative interventions and improved patient outcomes.

Lactobacillaceae-mediated eye-brain-gut axis regulates high myopia-related anxiety: from the perspective of predictive, preventive, and personalized medicine

Background

High myopia has become a major cause of blindness worldwide and can contribute to emotional deficits through its impact on the central nervous system. The potential crosstalk with gut microbiome positions high myopia as a valuable model for studying the eye-brain-gut axis, highlighting the intricate interplay between visual health, neurological function, and the gut microbiome. Understanding these connections is crucial from a predictive, preventive, and personalized medicine (PPPM) perspective, as it may reveal novel intervention targets for managing both visual and mental health.

Working hypothesis and methodology

In our study, we hypothesized that visual stimuli associated with high myopia may lead to gut microecological dysregulation, potentially triggering mood disorders such as anxiety and depression. To test this hypothesis, we assessed genetic associations between high myopia (N = 50,372) and depression (N = 674,452) as well as anxiety (N = 21,761) using inverse variance weighted as the primary analytical method. We also investigated the potential mediating role of the gut microbiome (N = 18,340). The findings were validated in an independent cohort and summarized through meta-analysis.

Results

A genetic causal relationship between high myopia and anxiety was found (odds ratio [OR] = 8.76; 95% confidence interval [CI], 2.69-28.54; p = 3.16 × 10-4), with 20.3% of the effect mediated by the gut microbiome family Lactobacillaceae (β = 0.517; 95% CI, 0.104-1.090; p = 0.037). The analysis also showed a suggestive causal relationship between high myopia and depression (OR = 1.25; 95% CI, 1.00-1.57; p = 0.048).

Conclusions

Our study shows that high myopia causes anxiety via the Lactobacillaceae family of the gut microbiome, supporting the eye-brain-gut axis concept. This underscores the need to shift from reactive to predictive, preventive, and personalized medicine (PPPM). Targeting Lactobacillaceae offers novel insights for early intervention and personalized treatment of high myopia-related anxiety and sheds light on interventions for other vision-related brain disorders.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-024-00387-z.

Environmental endocrine disrupting chemical-DEHP exposure-provoked biotoxicity about microbiota-gut-mammary axis in lactating mice via multi-omics technologies

Plastics, pervasive in humans and nature, often contain Di (2-ethylhexyl) phthalate (DEHP) that enhance plastic's elasticity. However, DEHP is an environmental endocrine disruptor, affecting organisms upon exposure. Understanding mammary gland development in lactating females is crucial for offspring nourishment and dairy production. Employing multi-omics technology, this study aimed to uncover DEHP's impact on the microbial-gut-mammary axis. Forty mice were exposed to varying DEHP doses for 18 d. We performed 16S sequencing, metabolomics, mammary tissue observation, and gene expression profiling. Results revealed DEHP's influence on microbial diversity, with increased Lactobacillus abundance and reduced Proteobacteria, alongside colonic inflammation. Elevated GMP and adenosine 5'-monophosphate levels in the bloodstream were noted, while ascorbic acid, glycitein, and others decreased. MEHP, a DEHP metabolite, damaged mammary tissues, inhibiting ERK1/2 phosphorylation, triggering apoptosis and ferroptosis. These findings unveil potential therapeutic targets for DEHP-induced chronic toxicity in humans and animals, aiding dairy livestock health and human well-being. This study underscores the importance of understanding the adverse effects of DEHP exposure on mammalian systems.

Stress-induced mucin 13 reductions drive intestinal microbiome shifts and despair behaviors

Depression is a prevalent psychological condition with limited treatment options. While its etiology is multifactorial, both chronic stress and changes in microbiome composition are associated with disease pathology. Stress is known to induce microbiome dysbiosis, defined here as a change in microbial composition associated with a pathological condition. This state of dysbiosis is known to feedback on depressive symptoms. While studies have demonstrated that targeted restoration of the microbiome can alleviate depressive-like symptoms in mice, translating these findings to human patients has proven challenging due to the complexity of the human microbiome. As such, there is an urgent need to identify factors upstream of microbial dysbiosis. Here we investigate the role of mucin 13 as an upstream mediator of microbiome composition changes in the context of stress. Using a model of chronic stress, we show that the glycocalyx protein, mucin 13, is selectively reduced after psychological stress exposure. We further demonstrate that the reduction of Muc13 is mediated by the Hnf4 transcription factor family. Finally, we determine that deleting Muc13 is sufficient to drive microbiome shifts and despair behaviors. These findings shed light on the mechanisms behind stress-induced microbial changes and reveal a novel regulator of mucin 13 expression.

Nanovesicular Mediation of the Gut-Brain Axis by Probiotics: Insights into Irritable Bowel Syndrome

BACKGROUND

Dysbiosis, influenced by poor diet or stress, is associated with various systemic diseases. Probiotic supplements are recognized for stabilizing gut microbiota and alleviating gastrointestinal issues, like irritable bowel syndrome (IBS). This study focused on the tryptophan pathways, which are important for the regulation of serotonin levels, and on host physiology and behavior regulation.

METHODS

Nanovesicles were isolated from the plasma of subjects with chronic diarrhea, both before and after 60 days of consuming a probiotic mix (Acronelle®, Bromatech S.r.l., Milan, Italy). These nanovesicles were assessed for the presence of Tryptophan 2,3-dioxygenase 2 (TDO 2). Furthermore, the probiotics mix, in combination with H2O2, was used to treat HT29 cells to explore its cytoprotective and anti-stress effect.

RESULTS

In vivo, levels of TDO 2 in nanovesicles were enhanced in the blood after probiotic treatment, suggesting a role in the gut-brain axis. In the in vitro model, a typical H2O2-induced stress effect occurred, which the probiotics mix was able to recover, showing a cytoprotective effect. The probiotics mix treatment significantly reduced the heat shock protein 60 kDa levels and was able to preserve intestinal integrity and barrier function by restoring the expression and redistribution of tight junction proteins. Moreover, the probiotics mix increased the expression of TDO 2 and serotonin receptors.

CONCLUSIONS

This study provides evidence for the gut-brain axis mediation by nanovesicles, influencing central nervous system function.

Potential Therapeutic Effects of Bifidobacterium breve MCC1274 on Alzheimer's Disease Pathologies in AppNL-G-F Mice

We previously demonstrated that orally supplemented Bifidobacterium breve MCC1274 (B. breve MCC1274) mitigated Alzheimer's disease (AD) pathologies in both 7-month-old AppNL-G-F mice and wild-type mice; thus, B. breve MCC1274 supplementation might potentially prevent the progression of AD. However, the possibility of using this probiotic as a treatment for AD remains unclear. Thus, we investigated the potential therapeutic effects of this probiotic on AD using 17-month-old AppNL-G-F mice with memory deficits and amyloid beta saturation in the brain. B. breve MCC1274 supplementation ameliorated memory impairment via an amyloid-cascade-independent pathway. It reduced hippocampal and cortical levels of phosphorylated extracellular signal-regulated kinase and c-Jun N-terminal kinase as well as heat shock protein 90, which might have suppressed tau hyperphosphorylation and chronic stress. Moreover, B. breve MCC1274 supplementation increased hippocampal synaptic protein levels and upregulated neuronal activity. Thus, B. breve MCC1274 supplementation may alleviate cognitive dysfunction by reducing chronic stress and tau hyperphosphorylation, thereby enhancing both synaptic density and neuronal activity in 17-month-old AppNL-G-F mice. Overall, this study suggests that B. breve MCC1274 has anti-AD effects and can be used as a potential treatment for AD.