Role of the normal gut microbiota

Gut virome: New key players in the pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory illness of the intestine. While the mechanism underlying the pathogenesis of IBD is not fully understood, it is believed that a complex combination of host immunological response, environmental exposure, particularly the gut microbiota, and genetic susceptibility represents the major determinants. The gut virome is a group of viruses found in great frequency in the gastrointestinal tract of humans. The gut virome varies greatly among individuals and is influenced by factors including lifestyle, diet, health and disease conditions, geography, and urbanization. The majority of research has focused on the significance of gut bacteria in the progression of IBD, although viral populations represent an important component of the microbiome. We conducted this review to highlight the viral communities in the gut and their expected roles in the etiopathogenesis of IBD regarding published research to date.

Fecal microbiota transplantation in allergic diseases

Microorganisms such as bacteria, fungi, viruses, parasites living in the human intestine constitute the human intestinal microbiota. Dysbiosis refers to compositional and quantitative changes that negatively affect healthy gut microbiota. In recent years, with the demonstration that many diseases are associated with dysbiosis, treatment strategies targeting the correction of dysbiosis in the treatment of these diseases have begun to be investigated. Faecal microbiota transplantation (FMT) is the process of transferring faeces from a healthy donor to another recipient in order to restore the gut microbiota and provide a therapeutic benefit. FMT studies have gained popularity after probiotic, prebiotic, symbiotic studies in the treatment of dysbiosis and related diseases. FMT has emerged as a potential new therapy in the treatment of allergic diseases as it is associated with the maintenance of intestinal microbiota and immunological balance (T helper 1/T helper 2 cells) and thus suppression of allergic responses. In this article, the definition, application, safety and use of FMT in allergic diseases will be discussed with current data.

Beyond digestion: Exploring how the gut microbiota modulates human social behaviors

For a long time, traditional medicine has acknowledged the gut's impact on general health. Contemporary science substantiates this association through investigations of the gut microbiota, the extensive community of microorganisms inhabiting our gastrointestinal system. These microscopic residents considerably improve digestive processes, nutritional absorption, immunological function, and pathogen defense. Nevertheless, a variety of gastrointestinal and extra-intestinal disorders can result from dysbiosis, an imbalance of the microbial composition of the gut microbiota. A groundbreaking discovery is the gut-brain axis, a complex communication network that links the enteric and central nervous system (CNS). This bidirectional communication allows the brain to influence gut activities and vice versa, impacting mental health and mood disorders like anxiety and depression. The gut microbiota can influence this communication by creating neurotransmitters and short-chain fatty acids, among other biochemical processes. These factors may affect our mental state, our ability to regulate our emotions, and the hypothalamic-pituitary-adrenal (HPA) axis. This study aimed to explore the complex interrelationships between the brain and the gut microbiota. We also conducted a thorough examination of the existing understanding in the area of how microbiota affects social behaviors, including emotions, stress responses, and cognitive functions. We also explored the potential of interventions that focus on the connection between the gut and the brain, such as using probiotics to treat diseases of the CNS. This research opens up new possibilities for addressing mental health and neurological conditions in an innovative manner.

Gut microbiota interact with breast cancer therapeutics to modulate efficacy

The gut microbiome, or the community of microorganisms residing in the gastrointestinal tract, has emerged as an important factor in breast cancer etiology and treatment. Specifically, the impact of gut bacterial populations on breast cancer therapeutic outcomes is an emerging area of research. The microbiota's role in modifying the pharmacokinetics of chemotherapy and endocrine-targeting therapies can alter drug efficacy and toxicity profiles. In addition, the gut microbiome's capacity to regulate systemic inflammation and immune responses may influence the effectiveness of both conventional and immunotherapeutic strategies for the treatment of breast cancer. Overall, while the bidirectional interactions between the gut microbiome and breast cancer therapies are still being studied, its impact is increasingly recognized. Future research may provide more definitive insights and help develop personalized therapeutic strategies to harness the microbiome to improve breast cancer treatment outcomes.

Probiotics and Food Bioactives: Unraveling Their Impact on Gut Microbiome, Inflammation, and Metabolic Health

This review paper delves into the role of probiotics and food bioactives in influencing gut health and overall well-being, within the context of probiotics and food bioactives, emphasizing their roles in modulating inflammation, gut microbiota, and metabolic health. Probiotics are defined as live microorganisms that confer health benefits to the host, primarily through their impact on the gut microbiome; a complex community of microorganisms crucial for maintaining health. The review aims to elucidate how probiotics, incorporated into both traditional and modern food systems, can enhance gut health and address metabolic disorders. It examines the types of probiotics present in various foods and their mechanisms of action, including their effects on immune function and metabolic health. By exploring the links between probiotics and health outcomes such as digestive health, immune support, and mental health, the review identifies specific conditions where probiotics show significant promise. Hurldes such as inconsistencies in research findings, variability in probiotic strains, and dosages are addressed. The paper also suggests future research directions, including the potential for personalized probiotic interventions. The review concludes by summarizing key findings and emphasizing the critical role of probiotics in food systems for promoting overall health and mitigating metabolic diseases.

Gut microbiota and kidney function in autosomal dominant polycystic kidney disease participants in Cameroon: a cross-sectional study

BACKGROUND AND HYPOTHESIS

Gut dysbiosis characterized by an imbalance in pathobionts (Enterobacter, Escherichia and Salmonella) and symbionts (Bifidobacterium, Lactobacillus and Prevotella) can occur during chronic kidney disease (CKD) progression. We evaluated the associations between representative symbionts (Bifidobacterium and Lactobacillus) and pathobionts (Enterobacteriaceae) with kidney function in persons with autosomal dominant polycystic kidney disease (ADPKD).

METHODS

In this cross-sectional study, 29 ADPKD patients were matched to 15 controls at a 2:1 ratio. Clinical data and biological samples were collected. The estimated glomerular filtration rate (eGFR) was calculated from the serum creatinine concentration using the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Microbial DNA extracted from stool specimens and amplified by qPCR was used to quantify Enterobacteriaceae, Bifidobacterium and Lactobacillus abundance. Differences between ADPKD subgroups and controls were assessed using nonparametric tests.

RESULTS

The mean age (SD) of the 44 participants was 40.65 (± 11.9) years. Among the participants with ADPKD, 62.1% experienced flank pain, and 48.3% had hypertension. Their median eGFR [IQR] was 74.4 [51.2-94.6] ml/min/1.73m2. All stool samples had Enterobacteriaceae. Lactobacillus abundance was lower in ADPKD participants with more pronounced kidney function decline (CKD G3-5: 0.58 ng/μL) than in those with milder damage and controls (G1-2: 0.64 ng/μL, p = 0.047; controls: 0.71 ng/μL, p = 0.043), while Enterobacteriaceae abundance was greater in ADPKD patients with lower kidney function (CKD G3-5: 78.6 ng/μL) than in those in the other two groups (G1-2: 71.6 ng/μL, p = 0.048; controls: 70.5 ng/μL, p = 0.045).

CONCLUSION

Decreased kidney function was associated with decreased symbiont and increased pathobiont abundance in ADPKD patients, suggesting a potential role for the microbiota in disease progression and possible targets for further research.

Microbiota awareness levels of medical students: the case of Trakya university

BACKGROUND

Human microbiota is noteworthy for its ability to encode a much greater variety and quantity of proteins than human cells. Despite its dynamic and complex nature, it has been associated with healthy living for over a century. The knowledge and attitudes of healthcare professionals, especially physicians, influence the use of pro-prebiotic interventions to modulate the microbiota. This study aimed to examine the awareness of medical students about the microbiota and the factors influencing their awareness.

METHODS

The study was conducted between May 15 and August 15, 2023, with the participation of 235 medical students. The students were administered a 13-item questionnaire and the Microbiota Awareness Scale (MAS). The questionnaire and scale were administered face-to-face, and the results were statistically analyzed.

RESULTS

The students' MAS total mean score was 70.34 ± 8.15. The MAS scores of medical students in the 4th, 5th, and 6th grades who underwent clinical training, those who conducted research on microbiota independently, those who had previously used prebiotics/probiotics, and those who rated themselves highly on microbiota knowledge were statistically higher.

CONCLUSIONS

The study revealed that students' awareness of the microbiota increased with advancing years of medical education, reaching a high level by the time of graduation. To enable future physicians to effectively communicate this knowledge to the public and incorporate it into clinical practice, it is crucial to provide comprehensive education on microbiota, probiotics, and prebiotics during medical training. Additionally, promoting scientific research and organizing activities in these areas are essential for fostering deeper understanding and practical application.

Influence of selected dosages of plastic microparticles on the porcine fecal microbiome

Studies conducted so far have shown that nano- and microplastic may disturb the intestinal microenvironment by interacting with the intestinal epithelium and the gut microbiota. Depending on the research model used, the effect on the microbiome is different-an increase or decrease in selected taxa resulting in the development of dysbiosis. Dysbiosis may be associated with intestinal inflammation, development of mental disorders or diabetes. The aim of the study was to analyze the intestinal microbiome in 15 gilts divided into 3 research groups (n = 5; control group, receiving micropartices at a dose 0.1 g/day (LD) and 1 g/day (HD)). Feaces were collected before and after 28 days of exposure to PET microplastics. The analysis of the intestinal microbiome was performed using next-generation sequencing. Alpha and beta diversity indices were compared, showing, that repetition affected only the abundance indices in the control and LD groups, but not in the HD group. The relationships between the number of reads at the phylum, genus and species level and the microplastic dose were calculated using statistical methods (r-Pearson correlation, generalized regression model, analysis of variance). The statistical analysis revealed, that populations of Family XIII AD3011 group, Coprococcus, V9D2013 group, UCG-010 and Sphaerochaeta increased with increasing MP-PET dose. The above-mentioned taxa are mainly responsible for the production of short-chain fatty acids (SCFA). It may be assumed, that SCFA are one of the mechanisms involved in the response to oral exposure to MP-PET.

Pharmacokinetics, mass balance, and metabolism of [14C]PLB1004, a selective and irreversible EGFR-TKI in humans

PURPOSE

PLB1004, developed by Beijing Avistone Biotechnology Co., Ltd., is a safe, highly selective, and efficient irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) employed in treating non-small-cell-lung-cancer (NSCLC). This study investigated its pharmacokinetics, mass balance, and metabolism in 6 healthy Chinese male subjects treated with 160 mg (70 µCi) [14C]PLB1004.

METHODS

Following drug administration, samples of blood, urine and feces were collected for quantitative determination of total radioactivity and metabolites were identified through radioactivity detection coupled with UHPLC-MS/MS.

RESULTS

Following drug administration, the median radioactive Tmax was 4.17 h in plasma, with the average t1/2 of PLB1004-related components in plasma of approximately 54.3 h. Over 264 h post-administration, the average cumulative excretion among the six subjects was 95.01% of the administered dose, with 84.71% and 10.30% excreted in feces and urine, respectively. Nine metabolites were characterized and identified and the parent drug PLB1004 was detected in plasma, urine, and feces. Among these metabolites, M689 was the most prevalent one in plasma, urine, and feces, constituting 25.37% of the total plasma radioactivity, and 55.88% and 1.73% of the administrated dose in feces and urine, respectively.

CONCLUSION

Fecal excretion emerged as PLB1004 excretion route, while urinary excretion via the kidneys served as the secondary route. The primarily metabolic pathways are oxidation, demethylation, dehydrogenation, and cysteine conjugation in humans.

Tissue source may affect the esophageal flora in patients with esophageal squamous cell carcinoma

The aim of the present study was to provide a theoretical basis for the selection of standard sampling methods in the study of the esophageal microbiota in patients with esophageal squamous cell carcinoma (ESCC) by comparing the differences in bacterial communities between surgical and endoscopic esophageal mucosal tissues. A total of 72 patients with ESCC who were diagnosed at Taihe Hospital (Shiyan, China) between July 2018 and July 2019 were selected to participate in the present study. The sequence V4 hypervariable region was amplified, and Illumina HiSeq sequencing was performed to analyze the differences between the two groups. The Shannon and Chao1 indices of the postoperative esophageal cancer tissue group samples (Group A) were higher than those of the esophageal mucosa tissue samples (Group B), and the difference was statistically significant (P<0.05). The Simpson index of Group A was higher than that of Group B, but the difference was not significant (P>0.05). The β diversity analysis demonstrated that the overall composition of the flora of the two groups was not significantly different. Linear discriminant analysis effect size analysis showed that the abundance of Megasphaera, Actinobacteria, Enterobacteriaceae and Enterobacteriales in Group A was significantly higher than that in Group B, but the abundance of Mogibacteriaceae in Group B was significantly higher than that in Group A. The top 60 species were selected using the random forest method to establish a model. The error rate of the prediction model constructed using the random forest method was 22.59%. The receiver operating characteristic (ROC) curve analysis confirmed that the present model was reliable and could effectively distinguish between the two groups of samples (area under the curve, 0.86). The source of the sample should be considered in studies investigating the esophageal flora. Considering the increased richness and improved uniformity of postoperative tissue microbiota compared with the mucosal group, it was predicted that postoperative tissue may be more conducive to the study of esophageal cancer microbiota.

Gut microbiome-gut brain axis-depression: interconnection

OBJECTIVES

The relationship between the gut microbiome and mental health, particularly depression, has gained significant attention. This review explores the connection between microbial metabolites, dysbiosis, and depression. The gut microbiome, comprising diverse microorganisms, maintains physiological balance and influences health through the gut-brain axis, a communication pathway between the gut and the central nervous system.

METHODS

Dysbiosis, an imbalance in the gut microbiome, disrupts this axis and worsens depressive symptoms. Factors like diet, antibiotics, and lifestyle can cause this imbalance, leading to changes in microbial composition, metabolism, and immune responses. This imbalance can induce inflammation, disrupt neurotransmitter regulation, and affect hormonal and epigenetic processes, all linked to depression.

RESULTS

Microbial metabolites, such as short-chain fatty acids and neurotransmitters, are key to gut-brain communication, influencing immune regulation and mood. The altered production of these metabolites is associated with depression. While progress has been made in understanding the gut-brain axis, more research is needed to clarify causative relationships and develop new treatments. The emerging field of psychobiotics and microbiome-targeted therapies shows promise for innovative depression treatments by harnessing the gut microbiome's potential.

CONCLUSIONS

Epigenetic mechanisms, including DNA methylation and histone modifications, are crucial in how the gut microbiota impacts mental health. Understanding these mechanisms offers new prospects for preventing and treating depression through the gut-brain axis.

IUPHAR themed review: The gut microbiome in schizophrenia

Gut microbial dysbiosis or altered gut microbial consortium, in schizophrenia suggests a pathogenic role through the gut-brain axis, influencing neuroinflammatory and neurotransmitter pathways critical to psychotic, affective, and cognitive symptoms. Paradoxically, conventional psychotropic interventions may exacerbate this dysbiosis, with antipsychotics, particularly olanzapine, demonstrating profound effects on microbial architecture through disruption of bacterial phyla ratios, diminished taxonomic diversity, and attenuated short-chain fatty acid synthesis. To address these challenges, novel therapeutic strategies targeting the gut microbiome, encompassing probiotic supplementation, prebiotic compounds, faecal microbiota transplantation, and rationalised co-pharmacotherapy, show promise in attenuating antipsychotic-induced metabolic disruptions while enhancing therapeutic efficacy. Harnessing such insights, precision medicine approaches promise to transform antipsychotic prescribing practices by identifying patients at risk of metabolic side effects based on their microbial profiles. This IUPHAR review collates the current literature landscape of the gut-brain axis and its intricate relationship with schizophrenia while advocating for integrating microbiome assessments and therapeutic management. Such a fundamental shift in proposing microbiome-informed psychotropic prescriptions to optimise therapeutic efficacy and reduce adverse metabolic impacts would align antipsychotic treatments with microbiome safety, prioritising 'gut-neutral' or gut-favourable drugs to safeguard long-term patient outcomes in schizophrenia therapy.

The effect of exercise on depression and gut microbiota: Possible mechanisms

Exercise can effectively prevent and treat depression and anxiety, with gut microbiota playing a crucial role in this process. Studies have shown that exercise can influence the diversity and composition of gut microbiota, which in turn affects depression through immune, endocrine, and neural pathways in the gut-brain axis. The effectiveness of exercise varies based on its type, intensity, and duration, largely due to the different changes in gut microbiota. This article summarizes the possible mechanisms by which exercise affects gut microbiota and how gut microbiota influences depression. Additionally, we reviewed literature on the effects of exercise on depression at different intensities, types, and durations to provide a reference for future exercise-based therapies for depression.

Research Progress in Ulcerative Colitis: The Role of Traditional Chinese Medicine on Gut Microbiota and Signaling Pathways

Ulcerative colitis (UC), one among other refractory diseases worldwide, has shown an increasing trend of progression to colorectal cancer in recent years. In the treatment of UC, traditional Chinese medicine has demonstrated good efficacy, with a high cure rate, fewer adverse effects, great improvement in the quality of patient survival, and reduction in the tendency of cancerous transformation. It shows promise as a complementary and alternative therapy. This review aims to evaluate and discuss the current research on UC, signaling pathways, and gut microbiota. We also summarized the mechanisms of action of various Chinese medicines (active ingredients or extracts) and herbal formulas, through signaling pathways and gut microbiota, with the expectation that they can provide references and evidence for treating UC and preventing inflammation-associated colorectal cancer by traditional Chinese medicine. We illustrate that multiple signaling pathways, such as TLR4, STAT3, PI3K/Akt, NF-[Formula: see text]B, and Keap1/Nrf2, can be inhibited by Chinese herbal treatments through the combined regulation of signaling pathways and gut microbiota, which can act individually or synergistically to inhibit intestinal inflammatory cell infiltration, attenuate gut oxidative responses, and repair the intestinal barrier.

The Bifidogenic Effect of 2'Fucosyllactose Is Driven by Age-Specific Bifidobacterium Species, Demonstrating Age as an Important Factor for Gut Microbiome Targeted Precision Medicine

BACKGROUND

The human gut microbiota develops in concordance with its host over a lifetime, resulting in age-related shifts in community structure and metabolic function. Little is known about whether these changes impact the community's response to microbiome-targeted therapeutics. Providing critical information on this subject, faecal microbiomes of subjects from six age groups, spanning from infancy to 70-year-old adults (n = six per age group) were harvested. The responses of these divergent communities to treatment with the human milk oligosaccharide 2'-fucosyllactose (2'FL), fructo-oligosaccharides (FOS), and lactose was investigated using the Ex vivo SIFR® technology that employs bioreactor fermentation and is validated to be predictive of clinical findings. Additionally, it was evaluated whether combining faecal microbiomes of a given age group into a single pooled microbiome produced similar results as the individual microbiomes.

RESULTS

First, marked age-dependent changes in community structure were identified. Bifidobacterium levels strongly declined as age increased, and Bifidobacterium species composition was age-dependent: B. longum, B. catenulatum/pseudocatenulatum, and B. adolescentis were most prevalent for breastfed infants, toddlers/children, and adults, respectively. Metabolomic analyses (LA-REIMS) demonstrated that these age-dependent differences particularly impacted treatment effects of 2'FL (more than FOS/lactose). Further analysis revealed that while 2'FL enhanced production of short-chain fatty acids (SCFAs) and exerted potent bifidogenic effects, regardless of age, the specific Bifidobacterium species enhanced by 2'FL, as well as subsequent cross-feeding interactions, were highly age-dependent. Furthermore, single-pooled microbiomes produced results that were indicative of the average treatment response for each age group. Nevertheless, pooled microbiomes had an artificially high diversity, thus overestimating treatment responses (especially for infants), did not recapitulate interindividual variation, and disallowed for the correlative analysis required to unravel mechanistic actions.

CONCLUSIONS

Age is an important factor in shaping the gut microbiome, with the dominant taxa and their metabolites changing over a lifetime. This divergence affects the response of the microbiota to therapeutics, demonstrated in this study using 2'FL. These results evidence the importance of screening across multiple age groups separately to provide granularity of how therapeutics impact the microbiome and, consequently, human health.

Influence of TNF-α Inhibitors on Gut Microbiota and Immune Modulation in Treating Ankylosing Spondylitis: Insights into Therapeutic Mechanisms and Clinical Implications

Objective

This study aims to evaluate the impact of tumor necrosis factor (TNF) inhibitors on the gut microbiota in patients with ankylosing spondylitis (AS) and investigate the potential therapeutic benefits of microbial modulation. Given the role of gut microbiota in immune regulation and its association with autoimmune conditions like AS, this research seeks to identify microbial targets that could enhance treatment outcomes.

Methods

Patients with AS undergoing TNF inhibitor therapy and healthy controls were recruited for this study. Gut microbiota samples were collected and analyzed using 16S rRNA gene sequencing. Assessed key parameters included α-diversity and the relative abundance of dominant phyla, such as Firmicutes, Proteobacteria, Bacteroidota, Actinobacteriota, and Fusobacteriota.

Results

Tumor necrosis factor (TNF) inhibitor therapy was found to enhance the α-diversity of the gut microbiota in patients with AS. The dominant phyla identified included Firmicutes, Proteobacteria, Bacteroidota, Actinobacteriota, and Fusobacteriota. Comparative analysis showed that patients with AS had elevated levels of Proteobacteria and Pasteurellaceae, which were normalized following TNF inhibitor treatment. Functional predictive analysis suggested that pathways associated with Terpenoid backbone biosynthesis and photosynthesis were reduced in patients with AS, bringing them closer to the profiles observed in healthy controls.

Conclusion

TNF inhibitors may contribute to the treatment of AS by promoting beneficial microbes, reducing the prevalence of disease-associated microbes, and modulating microbial functions. These findings bring valuable insights into the mechanisms of how TNF inhibitors act and highlight potential microbial targets for therapeutic interventions in AS.

Gut-brain axis and neuroplasticity in health and disease: a systematic review

The gut microbiota emerged as a potential modulator of brain connectivity in health and disease. This systematic review details current evidence on the gut-brain axis and its influence on brain connectivity. The initial set of studies included 532 papers, updated to January 2024. Studies were selected based on employed techniques. We excluded reviews, studies without connectivity focus, studies on non-human subjects. Forty-nine papers were selected. Employed techniques in healthy subjects included 15 functional magnetic resonance imaging studies (fMRI), 5 diffusion tensor imaging, (DTI) 1 electroencephalography (EEG), 6 structural magnetic resonance imaging, 2 magnetoencephalography, 1 spectroscopy, 2 arterial spin labeling (ASL); in patients 17 fMRI, 6 DTI, 2 EEG, 9 structural MRI, 1 transcranial magnetic stimulation, 1 spectroscopy, 2 R2*MRI. In healthy subjects, the gut microbiota was associated with connectivity of areas implied in cognition, memory, attention and emotions. Among the tested areas, amygdala and temporal cortex showed functional and structural differences based on bacteria abundance, as well as frontal and somatosensory cortices, especially in patients with inflammatory bowel syndrome. Several studies confirmed the connection between microbiota and brain functions in healthy subjects and patients affected by gastrointestinal to renal and psychiatric diseases.

Diet-Gut Microbiota Relations: Critical Appraisal of Evidence From Studies Using Metagenomics

Diet may influence the gut microbiota and subsequently affect the host's health. Recent developments in methods analyzing the composition and function of the gut microbiota allow a deeper understanding of diet-gut microbiota relationships. A state-of-the-art methodology, shotgun metagenomics sequencing, offers a higher taxonomic resolution of the gut microbiota at the bacterial species and strain levels, and more accurate information regarding the functional potential of gut microbiota. Here, the available evidence on the relationship between diet and gut microbiota was critically reviewed, focusing on results emerging from recent metagenomics sequencing studies applied in randomized controlled trials and observational studies. The PubMed and Embase databases were used to search publications between January 2011 and September 2023. Thus far, the number of studies is limited, and the study designs and methods utilized have been variable. Nevertheless, the cumulative evidence from interventions relates to dietary fiber as a modifier of bacterial species, such as Anaerostipes hadrus and Faecalibacterium prausnitzii. Furthermore, observational studies have detected associations between different dietary patterns and food groups with certain microbial species. Utilization of metagenomics sequencing is becoming more common and will undoubtedly provide further insights into diet-gut microbiota relationships at the species level as well as their functional pathways in the near future. For reproducible results and to draw reliable conclusions across various studies on diet-gut microbiota relationships, there is a need for harmonization of the study designs and standardized ways of reporting.

Ecytonucleospora hepatopenaei (EHP) disease prevalence and mortality in Litopenaeus vannamei: a comparative study from Eastern India shrimp farms

Ecytonucleospora hepatopenaei (EHP), a microsporidian parasite first named and characterized from the Penaeus monodon (black or giant tiger shrimp), causes growth retardation and poses a significant threat to shrimp farming. We observed shrimp farms associated with disease conditions during our fish disease surveillance and health management program in West Bengal, India. Shrimp exhibited growth retardation and increased size variability, particularly in advanced stages, exhibiting soft shells, lethargy, reduced feeding and empty midguts. Floating white feces were observed on the surface of the pond water. Suspecting a microbial infection, the shrimp samples were collected and aseptically brought to the ICAR-CIFRI laboratory for molecular confirmation. A nested PCR was used to screen shrimp tissue, feces, feed and environmental samples for the possible presence of hepatopancreatic microsporidiosis caused by Ecytonucleospora hepatopenaei. The results confirmed that the shrimp samples were positive for EHP. Histopathological investigation revealed mature spores in the HP tubule lumen and epithelial cells along with necrotic tubule in the symptomatic group. Further, the transcription analysis revealed that ProPO, Hsp70 and α2-macroglobulin genes were significantly upregulated, while decreased expression of LGBP, PXN and Integrin ß was observed in shrimp infected with Hepatopancreatic microsporidiosis. Furthermore, compared with the healthy group, significant intestinal bacteria changes were observed in the EHP-infected group. The in vivo survival assay, using crustacean animal model Artemia franciscana, suggests that symptomatic shrimp gut samples harbour pathogenic Vibrio parahaemolyticus, V. harveyi and V. campbellii. These results significantly advance our understanding of the molecular and ecological aspects of EHP pathobiology.