Healthy axis: Towards an integrated view of the gut-brain health

Beneficial Effects of Micronutrient Supplementation in Restoring the Altered Microbiota and Gut-Retina Axis in Patients with Neovascular Age-Related Macular Degeneration-A Randomized Clinical Trial

Background/Objectives: Age-related macular degeneration (AMD) is a leading cause of visual impairment in the elderly and is characterized by a multifactorial etiology. Emerging evidence points to the potential involvement of the gut-retina axis in AMD pathogenesis, prompting exploration into novel therapeutic strategies. This study aims to investigate the effects of some micronutrients (such as lutein and zeaxanthin) and saffron (as a supplement)-known for their anti-inflammatory properties-on ophthalmological and microbial parameters in neovascular AMD (nAMD) patients. Methods: Thirty naive nAMD patients were randomized to receive daily micronutrient supplementation alongside anti-VEGF (vascular endothelial growth factor) therapy, or anti-VEGF treatment alone, over a 6-month period, with comparisons made to a healthy control (HC) group (N = 15). Ophthalmological assessments, biochemical measurements, and stool samples were obtained before and after treatment. Gut microbiota (GM) characterization was performed using 16S rRNA sequencing, while short-chain fatty acids (SCFAs), medium-chain fatty acids (MCFAs), and long-chain fatty acids (LCFAs) were analyzed with a gas chromatography-mass spectrometry protocol. Results: Compared to HC, nAMD patients exhibited reduced GM alpha diversity, altered taxonomic composition, and decreased total SCFA levels, in addition to elevated levels of proinflammatory octanoic and nonanoic acids. Micronutrient supplementation was associated with improved visual acuity relative to the group treated with anti-VEGF alone, along with a decrease in the total amount of MCFAs, which are metabolites known to have adverse ocular effects. Conclusions: In conclusion, despite certain limitations-such as the limited sample size and the low taxonomic resolution of 16S rRNA sequencing-this study highlights compositional and functional imbalances in the GM of nAMD patients and demonstrates that micronutrient supplementation may help restore the gut-retina axis. These findings suggest the therapeutic potential of micronutrients in enhancing ocular outcomes for nAMD patients, underscoring the complex interaction between GM and ocular health.

Symptom Clusters and Quality of Life in Patients With Breast Cancer Receiving Endocrine Therapy in China

OBJECTIVES

Breast cancer patients undergoing endocrine therapy experience various symptoms that have long-term effects on their quality of life. However, which symptom clusters are expressed and affect patients' quality of life remain significantly controversial. Therefore, we aimed to explore symptom clusters among breast cancer patients receiving endocrine therapy and identify the impact of these clusters on their quality of life.

DATA SOURCES

This secondary analysis of data from a cross-sectional study aimed to explore the symptom experiences and quality of life of breast cancer patients receiving endocrine therapy. The participants were invited to complete the Functional Assessment of Cancer Therapy-Breast (FACT-B) and Endocrine Subscale (ES). Principal component analysis, Spearman correlation analyses, and multiple linear regression were used to explore symptom clusters and identify their influence on quality of life.

CONCLUSION

Data from 613 participants were obtained, and 19 symptoms were included in the principal component analysis, which identified five symptom clusters: the systemic, pain and emotional, sexual, vaginal, and vasomotor symptom clusters. Adjustment for covariates revealed that the systemic and pain and emotional symptom clusters were negative predictors of quality of life. The fitted model explained approximately 38.1% of the variance.

IMPLICATIONS FOR NURSING PRACTICE

This study demonstrated that breast cancer patients receiving endocrine therapy experienced symptoms that tended to occur in five clusters (i.e., systemic, pain and emotional, sexual, vaginal, and vasomotor symptoms). Developing interventions for the systemic and pain and emotional symptom clusters may effectively improve patients' quality of life.

Shared biological mechanisms of depression and obesity: focus on adipokines and lipokines

Depression and obesity are both common disorders currently affecting public health, frequently occurring simultaneously within individuals, and the relationship between these disorders is bidirectional. The association between obesity and depression is highly co-morbid and tends to significantly exacerbate metabolic and related depressive symptoms. However, the neural mechanism under the mutual control of obesity and depression is largely inscrutable. This review focuses particularly on alterations in systems that may mechanistically explain the in vivo homeostatic regulation of the obesity and depression link, such as immune-inflammatory activation, gut microbiota, neuroplasticity, HPA axis dysregulation as well as neuroendocrine regulators of energy metabolism including adipocytokines and lipokines. In addition, the review summarizes potential and future treatments for obesity and depression and raises several questions that need to be answered in future research. This review will provide a comprehensive description and localization of the biological connection between obesity and depression to better understand the co-morbidity of obesity and depression.

A complete guide to human microbiomes: Body niches, transmission, development, dysbiosis, and restoration

Humans are supra-organisms co-evolved with microbial communities (Prokaryotic and Eukaryotic), named the microbiome. These microbiomes supply essential ecosystem services that play critical roles in human health. A loss of indigenous microbes through modern lifestyles leads to microbial extinctions, associated with many diseases and epidemics. This narrative review conforms a complete guide to the human holobiont-comprising the host and all its symbiont populations- summarizes the latest and most significant research findings in human microbiome. It pretends to be a comprehensive resource in the field, describing all human body niches and their dominant microbial taxa while discussing common perturbations on microbial homeostasis, impacts of urbanization and restoration and humanitarian efforts to preserve good microbes from extinction.

Do common antibiotic treatments influence emotional processing?

Antibiotics are among the most commonly prescribed medications worldwide, yet research in recent years has revealed the detrimental effect they can have on the human microbiome, with implications for health. The community of microorganisms inhabiting the gut has been shown to regulate physiological and neural processes. Since studies in both humans and animal models have revealed that the gut microbiome can affect the brain, influencing emotion and cognition, here we investigate whether antibiotic treatment is associated with changes in emotional processing and mood with a between-subject design in 105 young healthy adult volunteers, using both psychological tests and questionnaires. As both the immune system and vagal signalling can mediate the microbiome-gut-brain axis, we also assess whether there is any evidence of such changes in participant physiology. We find that individuals who have taken antibiotics in the past three months show a stronger emotional bias towards sadness and at a physiological level they have a higher heart rate (though this does not mediate the relationship with negative bias). While we cannot rule out a possible role of prior infection, our findings are in any case highly relevant in light of research revealing that antibiotics are linked to increased susceptibility to depression and anxiety. Our results also have implications for listing antibiotic use as an exclusion criterion in studies on emotional processing and psychophysiology.

Fungal Forces in Mental Health: Microbial Meddlers or Function Fixers?

In the mental health field, the gut-brain axis and associated pathways represent putative mechanisms by which gastrointestinal (GI) microbes and their gene products and metabolites can access and influence the central nervous system (CNS). These GI-centered investigations focus on bacteria, with significant information gaps existing for other microbial community members, such as fungi. Fungi are part of a complex and functionally diverse taxonomic kingdom whose interactions with hosts can be conversely deadly and beneficial. As serious sources of morbidity and mortality, fungal pathogens can quickly turn healthy microbiomes into toxic cycles of inflammation, gut permeability, and dysbiosis. Fungal commensals are also important human symbionts that provide a rich source of physiological functions to the host, such as protection against intestinal injuries, maintenance of epithelial structural integrities, and immune system development and regulation. Promising treatment compounds derived from fungi include antibiotics, probiotics, and antidepressants. Here I aim to illuminate the many attributes of fungi as they are applicable to overall improving our understanding of the mechanisms at work in psychiatric disorders. Healing the gut and its complex ecosystem is currently achievable through diet, probiotics, prebiotics, and other strategies, yet it is critical to recognize that the success of these interventions relies on a more precisely defined role of the fungal and other non-bacterial components of the microbiome.

Microbiota, Bacterial Carbonic Anhydrases, and Modulators of Their Activity: Links to Human Diseases?

The involvement of the human microbiome is crucial for different host functions such as protection, metabolism, reproduction, and especially immunity. However, both endogenous and exogenous factors can affect the balance of the microbiota, creating a state of dysbiosis, which can start various gastrointestinal or systemic diseases. The challenge of future medicine is to remodel the intestinal microbiota to bring it back to healthy equilibrium (eubiosis) and, thus, counteract its negative role in the diseases' onset. The shaping of the microbiota is currently practiced in different ways ranging from diet (or use of prebiotics, probiotics, and synbiotics) to phage therapy and antibiotics, including microbiota fecal transplantation. Furthermore, because microbiota modulation is a capillary process, and because many microbiota bacteria (both beneficial and pathogenic) have carbonic anhydrases (specifically the four classes α, β, γ, and ι), we believe that the use of CA inhibitors and activators can open up new therapeutic strategies for many diseases associated with microbial dysbiosis, such as the various gastrointestinal disorders and the same colorectal cancer.

Microbiota shaping — the effects of probiotics, prebiotics, and fecal microbiota transplant on cognitive functions: A systematic review

BACKGROUND

Dementia is a chronic progressive neurological disease affecting millions of people worldwide, and represents a relevant economic burden for healthcare systems. Although its pathogenesis is still unknown, recent findings have reported that a dysregulated gut-brain axis communication, a fundamental relationship mediated by several host and microbial molecules, is associated with cognitive disorders. In addition, gut microbiota manipulation reduces neuroinflammation, improving cognitive function by restoring the functional gut-brain axis.

AIM

To better define the effects of probiotics, prebiotics, synbiotics, and fecal microbiota transplant (FMT) on cognitive function.

METHODS

We performed a literature search of human randomized clinical trials to examine the effects of the administration of probiotics, prebiotics, synbiotics, or FMT on cognition outcomes in healthy or sick people of every age, sex, and nationality. We systematically searched Embase, Medline/PubMed, Cochrane Library, central and clinicaltrials.gov databases with a combination of comprehensive terms related to cognition and gut microbiota manipulation. Then we carefully reviewed and synthesized the data by type of study design and setting, characteristics of the studied population, kind of intervention (strain type or mixture type, dosage, and frequency of administration), control treatment, inclusion and exclusion criteria, follow-up duration, and cognitive or memory outcomes.

RESULTS

After examining the titles and abstracts, the initial literature screening identified 995 articles, but we added 23 papers in our systematic review. The analyses of these selected studies highlighted that both probiotic supplementation and FMT improved cognitive function regardless of the type and posology of administration and the adopted cognitive tests and questionnaires. We found that most of the studies conducted in healthy people showed a significant positive effect of the intervention on at least one of the performed cognitive tests. Regarding unhealthy subjects, while FMT and especially probiotic administration had multiple beneficial effects on different cognitive functions, supplementation with prebiotics did not provide any cognitive improvement.

CONCLUSION

Probiotic supplementation and FMT may represent a promising strategy to restore gut eubiosis and enhance the cognitive functions of healthy people and patients with neurological disorders.

Effect of Regular Physical Exercise on Gut Microbiota and Depressive Behaviors in Rats

Objective. The gut microbiota, as the critical mediator of the gut-brain axis, can produce and transport neuroactive substances, thus playing a significant role in the pathogenesis of depression. Although regular physical exercise is an important nondrug antidepressant, its specific effector mechanism is still unclear. Methods. Rats were randomly divided into four different groups (n = 10 for each group) as follows: normal group (G1), depression group (G2), fluoxetine treatment group (G3), and regular exercise treatment group (G4). All rats underwent forced swimming tests, tail suspension tests, open field tests, and elevated plus-maze tests to detect behavioristics. Then, corticosterone levels were detected by ELISA. Additionally, taxonomic analysis of the gut microbiota in all rats was performed after they were exercised regularly for 60 days. Results. Compared with the G1 group, the rats in the G2 group showed significant depression-like behaviors, with increased serum corticosterone levels. The proportions of Bacteroides, Actinomycetes, Proteobacteria, Saccharomyces, and Cyanobacteria in rats of the G2 group were lower than those in the G1 group, while the proportions of Firmicutes, Tenicotte, Deferrobacteria, and Fusobacteria were increased. Furthermore, after regular exercise treatment, the gut microbiota of rats was effectively improved, almost returning to the level of the G1 group, and depressive behavior and corticosterone levels were also restored, which was almost the same as the effect of fluoxetine treatment. Conclusion. Regular physical exercise could alleviate depressive-like behaviors by modulating the species and function of the gut microbiota.

Microbiota and IPF: hidden and detected relationships

Lung microbiota (LM) is an interesting new way to consider and redesign pathogenesis and possible therapeutic approach to many lung diseases, such as idiopathic pulmonary fibrosis (IPF), which is an interstitial pneumonia with bad prognosis. Chronic inflammation is the basis but probably not the only cause of lung fibrosis and although the risk factors are not completely clear, endogenous factors (e.g. gastroesophageal reflux) and environmental factors like cigarette smoking, industrial dusts, and precisely microbial agents could contribute to the IPF development. It is well demonstrated that many bacteria can cause epithelial cell injuries in the airways through induction of a host immune response or by activating flogosis mediators following a chronic, low-level antigenic stimulus. This persistent host response could influence fibroblast responsiveness suggesting that LM may play a role in repetitive alveolar injury in IPF. We reviewed literature regarding not only bacteria but also the role of virome and mycobiome in IPF. In fact, some viruses such as hepatitis C virus or certain fungi could be etiological agents or co-factors in the IPF progress. We aim to illustrate how the cross-talk between different local microbiotas throughout specific axis and immune modulation governed by microorganisms could be at the basis of lung dysfunctions and IPF development. Finally, since the future direction of medicine will be personalized, we suggest that the analysis of LM could be a goal to research new therapies also in IPF.

Psychological and Gastrointestinal Symptoms of Patients with Irritable Bowel Syndrome Undergoing a Low-FODMAP Diet: The Role of the Intestinal Barrier

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (LFD) improves both gastrointestinal (GI) symptoms and the psychological profile of patients with irritable bowel syndrome with diarrhea (IBS-D). The effects of 12 weeks of LFD on GI symptom and psychological profiles in relation to inflammation and the involvement of the intestinal barrier were studied in twenty IBS-D patients. The IBS Severity Scoring System, the Symptom Checklist-90-Revised, the Italian version of the 36-Item Short-Form Health Survey, the IBS-Quality of Life (QoL) questionnaire, and the Psychophysiological questionnaire were administered. The GI barrier function was assessed by sugar absorption test, the serum and fecal zonulin levels, and the serum levels of intestinal fatty-acid binding protein and diamine oxidase. Interleukins (ILs) and lipopolysaccharide (LPS) serum levels were evaluated along with dysbiosis. At the end of LFD, GI symptoms, psychological state (mainly anxiety, somatization, psychoticism, and interpersonal sensitivity), and QoL significantly improved in these patients. Simultaneously, an improvement in small intestinal permeability and intestinal mucosal integrity occurred, while IL-6, Il-10, LPS, and fermentative dysbiosis significantly decreased. The LFD can modify the immune-inflammatory features and enhance intestinal permeability and mucosal integrity, thus determining a concurrent improvement in the clinical and psychological conditions.

Future Directions in Reducing Gastrointestinal Disorders in Children With ASD Using Fecal Microbiota Transplantation

Research on the use of fecal microbiota transplantation (FMT) in the treatment of disorders related to digestive system ailments in children with autism spectrum disorders (ASDs) is a new attempt in a therapeutic approach. There are very little scientific evidences available on this emerging alternative method. However, it appears to be interesting not only because of its primary outcome, relieving the gastrointestinal (GI) symptoms, but also secondary therapeutic effect of alleviating autistic behavioral symptoms. FMT seems to be also promising method in the treatment of another group of pediatric patients, children with inflammatory bowel disease (IBD). The aim of this study is to discuss the potential use of FMT and modified protocols (MTT, microbiota transfer therapy) in the treatment of GI disorders in ASD children supported by reports on another disease, IBD concerning pediatric patients. Due to the few reports of the use of FMT in the treatment of children, these two patients groups were selected, although suffering from distant health conditions: neurodevelopmental disorder and gastrointestinal tract diseases, because of the the fact that they seem related in aspects of the presence of GI symptoms, disturbed intestinal microbiota, unexplained etiology of the condition and age range of patients. Although the outcomes for all are promising, this type of therapy is still an under-researched topic, studies in the group of pediatric patients are sparse, also there is a high risk of transmission of infectious and noninfectious elements during the procedure and no long-term effects on global health are known. For those reasons all obtained results should be taken with a great caution. However, in the context of future therapeutic directions for GI observed in neurodevelopmental disorders and neurodegenerative diseases, the topic seems worthy of attention.