International Journal of Clinical Case Reports 2024, Vol.14, No.2 http://medscipublisher.com/index.php/ijccr © 2024 MedSci Publisher, registered at the publishing platform that is operated by Sophia Publishing Group, founded in British Columbia of Canada. All Rights Reserved. Publisher
International Journal of Clinical Case Reports 2024, Vol.14, No.2 http://medscipublisher.com/index.php/ijccr © 2024 MedSci Publisher, registered at the publishing platform that is operated by Sophia Publishing Group, founded in British Columbia of Canada. All Rights Reserved. MedSci Publisher is an international Open Access publisher specializing in clinical case, clinical medicine, new variations in disease processesregistered at the publishing platform that is operated by Sophia Publishing Group (SPG), founded in British Columbia of Canada. Publisher MedSci Publisher Editedby Editorial Team of International Journal of Clinical Case Reports Email: edit@ijccr.medscipublisher.com Website: http://medscipublisher.com/index.php/ijccr Address: 11388 Stevenston Hwy, PO Box 96016, Richmond, V7A 5J5, British Columbia Canada International Journal of Clinical Case Reports (ISSN 1927-579X) is an open access, peer reviewed journal published online by MedSci Publisher. The journal is considering all the latest and outstanding research articles, letters and reviews in all aspects of clinical case, containing clinical medicine which advance general medical knowledge; the event in the course of observing or treating a patient; new variations in disease processes; as well as the expands the field of clinical relating to case reports. All the articles published in International Journal of Clinical Case Reports are Open Access, and are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. MedSci Publisher uses CrossCheck service to identify academic plagiarism through the world’s leading plagiarism prevention tool, iParadigms, and to protect the original authors’ copyrights.
International Journal of Clinical Case Reports (online), 2024, Vol. 14, No.2 ISSN 1927-579X http://medscipublisher.com/index.php/ijccr © 2024 MedSci Publisher, registered at the publishing platform that is operated by Sophia Publishing Group, founded in British Columbia of Canada. All Rights Reserved. Latest Content Exploring Coronary Sinus Downsizing for Angina Treatment：Lessons from the ORBITA-COSMIC Experience Zhaoyi Zhao International Journal of Clinical Case Reports, 2024, Vol. 14, No. 2, 63-65 Engineering Synthetic Microbial Communities for Enhanced Probiotic Functionality and Gut Health Improvement Jingqiang Wang International Journal of Clinical Case Reports, 2024, Vol. 14, No. 2, 66-78 Targeted Therapy for Specific Genetic Variations in Cancer Jiaren Zhou International Journal of Clinical Case Reports, 2024, Vol. 14, No. 2, 79-86 Analysis of the Correlation between Drug Toxicity and Specific Gene Mutations LiqinZhou International Journal of Clinical Case Reports, 2024, Vol. 14, No. 2, 87-93 Gene Editing for Organ Transplants: Evaluating the Impact of CRISPR/Cas9 on Immunogenicity and Organ Longevity in Pigs Jianhui Li, Jiong Li International Journal of Clinical Case Reports, 2024, Vol. 14, No. 2, 94-106 From Genomic Data to Personalized Medical Decisions: Challenges and Opportunities JieZhang International Journal of Clinical Case Reports, 2024, Vol. 14, No. 2, 107-116
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 63-65 http://medscipublisher.com/index.php/ijccr 63 Scientific Commentary Open Access Exploring Coronary Sinus Downsizing for Angina Treatment: Lessons from the ORBITA-COSMIC Experience Zhaoyi Zhao Cuixi Academy of Biotechnology, Zhuji, 311800, Zhejiang, China Corresponding email: ssoy1@outlook.com International Journal of Clinical Case Reports, 2024, Vol.14, No.2 doi: 10.5376/ijccr.2024.14.0008 Received: 22 Apr., 2024 Accepted: 29 Apr., 2024 Published: 03 May. 2024 Copyright © 2024 Zhao, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Zhao Z.Y., 2024, Exploring coronary sinus downsizing for angina treatment: lessons from the ORBITA-COSMIC experience, International Journal of Clinical Case Reports, 14(2): 63-65 (doi: 10.5376/ijccr.2024.14.0008) The paper "Coronary sinus reducer for the treatment of refractory angina (ORBITA-COSMIC), published in The Lancet on April 20, 2024: a randomised, placebo-controlled trial", Written by Michael J. Foley, Christopher A. Rajkumar, F. Ahmed-Jushuf, et al. From Imperial College London, Midlands and South Essex NHS Foundation Trust, Anglia Ruskin University, etc. In this study, the researchers investigated the effects of coronary sinus reducers (CSR) in the treatment of refractory angina pectoris through the ORBITA-COSMIC trial. The study was conducted in six UK hospitals using a double-blind, randomized, placebo-controlled approach to assess the effectiveness of CSR compared to placebo in improving myocardial ischemia and angina symptoms. The study was conducted in patients over 18 years of age with stable coronary artery disease and myocardial ischemia who had no other treatment options. The results of the study showed that although the effect of CSR in improving myocardial blood flow was not significant, it had a significant effect compared to placebo in reducing the frequency of angina attacks. These findings provide a scientific basis for CSR as a new treatment option against angina pectoris. 1 Interpretation Experimental Data In the trial, 61 patients were enrolled in the study and 51 eligible patients were randomly assigned to the CSR and placebo groups. The results of the study showed that patients treated with CSR had a lower frequency of angina attacks six months after treatment. Specifically, the reduction ratio for daily angina attacks was 1.40, with a 95% confidence interval of 1.08 to 1.83, suggesting that CSR had a significant effect in reducing angina relative to placebo. In addition, major measures of myocardial blood flow did not differ significantly between the CSR group and the placebo group, suggesting that the benefits of CSR may be primarily reflected in improvements in angina symptoms. Figure 2 details the two main findings of the ORBITA-COSMIC trial. Figure A shows that there was no significant difference between the CSR group and the placebo group in terms of stress myocardial flow (MBF) at the site of myocardial ischemia. Figure B reveals the daily frequency of angina attacks in the CSR and placebo groups after random assignment, showing a significant reduction in angina attacks in the CSR group. Figure C shows a gradual increase in the odds ratio of CSR to placebo in reducing angina attacks over time, particularly at the end of the trial period, showing the long-term effect of CSR in reducing angina. 2 Insights of Research Findings Although the coronary sinus miniator failed to significantly improve myocardial blood flow, its results in significantly reducing angina attacks indicate its potential effectiveness as an anti-angina treatment. The Bayesian statistical approach in the study further confirms the potential benefits of CSR in reducing angina, particularly in patients who have no other treatment options. For these patients, CSR can be used as a complementary treatment, especially when traditional drug therapy is no longer effective.
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 63-65 http://medscipublisher.com/index.php/ijccr 64 Figure 2 The ORBITA-COSMIC test primary outcomes Note: (A) Individual patient data for the primary endpoint (stress MBF) in segments designated ischaemic at enrolment; (B) Individual patient data for the primary symptom endpoint (daily angina episodes), reported via the ORBITA smartphone symptom application; (C) Odds ratio for reduction in daily angina episodes for CSR versus placebo. CSR=coronary sinus reducer. MBF=myocardial blood flow 3 Evaluation of the Research This study demonstrates the high standards of clinical trials with its sophisticated design and execution, particularly in the search for innovative therapies in the field of cardiovascular disease. By using a double-blind, randomized controlled approach, the study ensured the objectivity and reliability of the data, minimizing bias. Despite the rigorous design, the results of the study did not show an effect of CSR in improving myocardial blood flow, which may be related to the small sample size of the study and the short follow-up period. The study was limited to a specific patient population (i.e., those with no other treatment options), which may limit the general applicability of the results. Overall, this study provides important preliminary data for the cardiovascular field and supports further evaluation of the value of CSR in broader clinical practice.
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 63-65 http://medscipublisher.com/index.php/ijccr 65 4 Concluding Remarks The ORBITA-COSMIC trial provides preliminary evidence that coronary sinus miniators (CSR) may have clinical benefits in patients with refractory angina, particularly in terms of improving patients' symptoms, rather than in improving myocardial blood flow. Although there was no significant improvement in the main physiological measures, the effect in reducing angina attacks suggests that CSR can be used as a useful supplement to existing treatment options. These results underscore the importance of continuing to explore the role of CSR in cardiovascular therapy and point to directions for future research, including expanding sample sizes, extending follow-up, and exploring its mechanisms of action. The study also raises the possibility of a broader application of CSR strategies, especially for patients whose symptoms have not been effectively alleviated by traditional treatments. 5 Access Original Paper Foley, M.J., Rajkumar, C.A., Ahmed-Jushuf, F., et al. Coronary sinus reducer for the treatment of refractory angina (ORBITA-COSMIC): a randomised, placebo-controlled trial, The Lancet, 403(10436). 1543-1553 (2024). https://doi.org/10.1016/S0140-6736(24)00256-3 Acknowledgement I am heartily grateful to the journal The Lancet for its open access policy, which facilitates the dissemination of scientific knowledge and enables a better understanding of the latest academic advances in the field of cardiovascular disease research. Thanks to Michael J Foley and his team members for their hard work and unremitting efforts for providing valuable information for exploring cardiovascular treatment options.
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 66 Invited Review Open Access Engineering Synthetic Microbial Communities for Enhanced Probiotic Functionality and Gut Health Improvement Jingqiang Wang Institute of Life Science, Jiyang College of Zhejiang A&F University, Zhuji, 311800, Zhejiang, China Corresponding email: jingqiang.wang@gmail.com International Journal of Clinical Case Reports 2024, Vol.14, No.2 doi: 10.5376/ijccr.2024.14.0009 Received: 25 Mar., 2024 Accepted: 27 Apr., 2024 Published: 08 May, 2024 Copyright © 2024 Wang, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Wang J.Q., 2024, Engineering synthetic microbial communities for enhanced probiotic functionality and gut health improvement, International Journal of Clinical Case Reports, 14(2): 66-78 (doi: 10.5376/ijccr.2024.14.0009) Abstract The objective of this study is to examine advancements in engineering synthetic microbial communities aimed at enhancing probiotic functionality and improving gut health. The study focuses on the integration of synthetic biology tools, dietary influences, and the therapeutic applications of these engineered probiotics. Significant progress has been made in developing engineered probiotics capable of delivering therapeutics and responding to environmental cues within the gut. Key findings include the enhanced therapeutic potential of engineered probiotics for treating diseases such as inflammatory bowel disease and metabolic disorders, and the challenges posed by the complexity and adaptability of synthetic probiotics compared to native gut microbiota. Additionally, the integration of artificial intelligence and synthetic biology has significantly advanced personalized probiotic therapies. Despite these advancements, challenges remain in replicating the complexity of native microbiota and ensuring the long-term stability and efficacy of engineered probiotics. Future research should focus on interdisciplinary collaboration, integrating advanced technologies, and establishing robust regulatory frameworks to maximize the therapeutic potential of synthetic probiotics. Keywords Synthetic microbial communities; Engineered probiotics; Gut health; Synthetic biology; Personalized medicine Gut health is increasingly recognized as a crucial aspect of overall well-being, influencing not only digestion but also immune function, mental health, and disease prevention. The human gut microbiome is a complex and dynamic ecosystem that plays a crucial role in maintaining overall health. It is involved in various physiological processes, including metabolism, immune modulation, and the development of the nervous system (Bober et al., 2018; Dou and Bennett, 2018). Dysbiosis, or an imbalance in the gut microbiota, has been linked to various health issues such as inflammatory bowel disease, obesity, diabetes, and even neurological disorders. Probiotics, comprising beneficial bacteria and yeasts, which are live microorganisms that confer health benefits to the host when administered in adequate amounts, have been extensively studied for their potential to enhance gut health. They can help in maintaining a balanced gut microbiota, improving digestion, and boosting the immune system (Crovesy et al., 2021). The modulation of gut microbiota through probiotics has shown promising results in treating conditions such as obesity, gastrointestinal disorders, and inflammation (Crovesy et al., 2021). Synthetic microbial communities (SynComs) represent an innovative approach in the field of probiotics. Unlike traditional probiotics, which often consist of single or a few strains of beneficial bacteria, SynComs are designed to mimic the complexity and functionality of natural microbial communities (Venturelli et al., 2018; Berkhout et al., 2022). These engineered communities can be tailored to perform specific functions, such as producing therapeutic compounds, enhancing nutrient absorption, or modulating immune responses (Landry and Tabor, 2017; Dou and Bennett, 2018), and offer enhanced stability and efficacy. By harnessing the synergistic interactions between different microbial species, SynComs can provide more robust and targeted therapeutic benefits. The engineering of SynComs involves selecting microbial species based on their functional traits, compatibility, and ability to survive and thrive in the gut environment (Dou and Bennett, 2018). Advances in synthetic biology have enabled the precise engineering of these communities, allowing for the incorporation of genetic circuits, biosensors, and other sophisticated tools to enhance their efficacy and safety (Landry and Tabor, 2017; Bober et al., 2018; Dou and Bennett, 2018). The integration of artificial intelligence (AI) with synthetic biology further
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 67 enhances the potential of SynComs by enabling the analysis and optimization of complex microbial interactions (Kumar et al., 2022). The primary objective of this study is to evaluate the current advancements and potential of engineering synthetic microbial communities for enhanced probiotic functionality and gut health improvement. This study aims to synthesize existing research on SynComs, identify the key factors influencing their design and efficacy, and highlight the potential benefits and challenges associated with their use. By providing a comprehensive overview of the state-of-the-art in SynCom engineering, this study seeks to offer valuable insights for researchers, clinicians, and industry stakeholders. Ultimately, the significance of this study lies in its potential to guide future research and development efforts towards creating more effective probiotic therapies that can address the complexities of gut health and contribute to overall well-being. 1 Gut Microbiota and Probiotic Functionality 1.1 Composition and functions of the gut microbiota The human gut microbiota is a diverse and dynamic community of microorganisms, including bacteria, archaea, viruses, and fungi. These microorganisms are crucial for various physiological functions such as digestion, nutrient absorption, and immune modulation. The gut microbiota composition varies between individuals and can be influenced by diet, environment, and genetics (Kho and Lal, 2018)., which collectively shape its structure and function (Vrancken et al., 2019). Understanding the intricate interactions within this microbial community is essential for developing effective therapeutic strategies aimed at modulating gut health. 1.2 Mechanisms through which probiotics influence gut health Probiotics, defined as live microorganisms that confer health benefits to the host when administered in adequate amounts, exert their effects through multiple mechanisms. They enhance the gut barrier function, modulate the immune response, and inhibit pathogenic bacteria by producing antimicrobial substances (Kaur and Ali, 2022). Probiotics also produce short-chain fatty acids (SCFAs) like butyrate, which provide energy to colonocytes and exhibit anti-inflammatory properties (Satapathy et al., 2019). Advances in synthetic biology have enabled the engineering of probiotics to enhance these functionalities further. For instance, engineered probiotics can be designed to produce and deliver therapeutic molecules directly within the gut, thereby improving their efficacy in treating various gastrointestinal disorders (Dou and Bennett, 2018; Kumar et al., 2022). 1.3 Limitations of current probiotic formulations Despite the promising potential of probiotics, current formulations face several limitations. Traditional probiotics often lack the complexity and adaptability of the native gut microbiota, which can limit their effectiveness in restoring or maintaining gut health (Dou and Bennett, 2018). Many probiotics struggle to survive the acidic environment of the stomach and bile salts in the intestine (Zhou et al., 2020), the stability and viability of probiotic strains during storage and gastrointestinal transit remain significant challenges (Martins et al., 2023). Synthetic microbial communities (SynComs) offer a potential solution by combining multiple microbial species to create a more stable and functional consortium. However, ensuring the long-term stability and colonization of these synthetic communities in the gut environment is still a major hurdle (Berkhout et al., 2022; Martins et al., 2023). Further research is needed to address these challenges and optimize the design and application of engineered probiotics and SynComs for improved gut health outcomes. 2 Engineering Synthetic Microbial Communities (SynComs) 2.1 Definition and principles of SynComs Synthetic microbial communities (SynComs) are deliberately constructed consortia of microorganisms designed to perform specific functions within a host environment. Unlike natural microbial communities, which are complex and often unpredictable, SynComs are composed of carefully selected microbial species that are engineered to achieve desired outcomes, such as enhancing gut health or providing therapeutic benefits (van Leeuwen et al., 2023; Martins et al. 2023). The goal is to create a stable, resilient, and functional microbiome that can outcompete pathogenic bacteria and provide health benefits to the host. The principles underlying SynComs involve
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 68 understanding the ecological interactions and functional capabilities of individual microbes, and then assembling them in a way that maximizes their collective efficacy (Liu et al., 2019; Wang et al., 2023). This approach allows for a more controlled and predictable manipulation of the microbiome, which can be tailored to address specific health conditions or improve overall gut functionality (Khan et al., 2022; van Leeuwen et al., 2023). 2.2 Techniques for engineering SynComs The engineering of SynComs leverages various techniques from synthetic biology and genetic modification. Synthetic biology provides tools such as CRISPR-Cas systems for precise gene editing, enabling the modification of microbial genomes to enhance desired traits or introduce new functionalities (Landry and Tabor, 2017; Kumar et al., 2022), such as metabolite production or pathogen resistance (Kumar et al., 2022). There are also Synthetic Biology Tools such as synthetic gene circuits and biosensors enable the creation of microbes that can sense and respond to environmental signals within the gut, thereby performing diagnostic or therapeutic functions (Naydich et al., 2019). By modifying the metabolic pathways of microbes to enhance the production of health-promoting compounds like short-chain fatty acids (SCFAs) or to degrade harmful substances in the gut (Jansma et al., 2023). Creating SynComs using a modular approach allows for the assembly of different microbial strains, each contributing a specific function, thereby enhancing the overall functionality and stability of the community (Huang et al., 2022). Additionally, advanced computational modeling and machine learning are employed to predict and optimize the interactions within SynComs, ensuring stability and effectiveness (Diener et al., 2020; Martins et al., 2023). Techniques such as microbial cultivation and reconstruction are also crucial, allowing researchers to reproducibly investigate and manipulate the interactions between different microbial species under controlled conditions (Bober et al., 2018; Liu et al., 2019). These methods collectively enable the design, assembly, and testing of SynComs with specific therapeutic or diagnostic purposes (Dou and Bennett, 2018; van Leeuwen et al., 2023). 2.3 Comparison of SynComs with natural microbial communities SynComs differ from natural microbial communities in several key aspects. Natural communities are inherently complex and dynamic, with interactions that are often not fully understood. They are shaped by evolutionary processes and environmental factors, leading to a high degree of variability and unpredictability (Martins et al., 2023; Wang et al., 2023). In contrast, SynComs are designed and assembled with specific functions in mind, providing greater control over the microbial composition and their metabolic outputs compared to natural communities, which are shaped by complex and often unpredictable ecological interactions (Dou and Bennett, 2018). Engineered communities can be designed to be more stable and resilient to environmental changes and perturbations than natural communities, which can be more susceptible to disruptions and imbalances (Landry and Tabor, 2017). SynComs are specifically engineered to perform desired functions, such as producing therapeutics or enhancing gut health, which can be more effective than the broader, less targeted functions of natural microbial communities (Zhou et al., 2020). The assembly of SynComs involves a rational design process guided by synthetic biology principles, whereas natural communities evolve through ecological processes that are not necessarily optimized for human health benefits (Clark et al., 2020). However, one of the challenges with SynComs is ensuring their stability and functionality over time, as they may be subject to changes due to horizontal gene transfer and mutations (van Leeuwen et al., 2023; Martins et al., 2023). Despite these challenges, SynComs offer a promising alternative to natural communities, providing a more targeted and reliable means of modulating the microbiome for health benefits (Landry and Tabor, 2017; Bober et al., 2018). By leveraging the principles of synthetic biology and advanced computational tools, SynComs represent a significant advancement in the field of microbiome research, offering new opportunities for enhancing probiotic functionality and improving gut health. 3 Mechanisms of Enhanced Probiotic Functionality 3.1 Engineering metabolic pathways for improved probiotic functions Metabolic engineering involves modifying the genetic and biochemical pathways of probiotic microorganisms to enhance their functionality and health benefits, enabling them to produce beneficial metabolites and therapeutic
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 69 compounds. For instance, synthetic biology tools have been employed to engineer probiotics to produce small molecule therapeutics within the gut, which can help in regulating metabolism and modulating immune responses (Dou and Bennett, 2018). Additionally, the use of gene editing tools like CRISPR-Cas systems allows for precise modifications in probiotic genomes, enhancing their ability to perform specific metabolic functions that are crucial for gut health (Kumar et al., 2022). Recent studies have focused on optimizing the production of beneficial metabolites and improving the overall metabolic efficiency of probiotics. Jain et al. (2021) work to study the engineering Lactobacilli and Bifidobacteria to increase lactic acid production. Enhanced lactic acid production improves gut health by lowering pH and inhibiting pathogenic bacteria. Techniques such as gene editing and pathway optimization have been employed to achieve this. Yadav et al. (2018) found that, increasing EPS production in probiotics like Lactobacillus reuteri enhances their ability to adhere to the gut mucosa and modulate the host's immune response. Genetic modifications have been used to introduce novel pathways for EPS synthesis, resulting in improved probiotic adherence and immunomodulatory effects. Huang et al. (2022) found that engineered probiotics could produce higher levels of short-chain fatty acids (SCFA) (Figure 1), such as butyrate can have significant health benefits, including anti-inflammatory effects and improved gut barrier function. This has been achieved through the introduction of genes involved in SCFA production pathways. Figure 1 Omprehensive analysis of butyrate production in bacterial communities (Adapted from Clark et al., 2021) Image caption: Utilizing data from 1-2 species and 24-25 species experiments. The scatter plot (Panel a) illustrates the variation in butyrate production across different community complexities, highlighting specific communities lacking certain butyrate producers (e.g., DP−, AC−). Panel b shows predicted butyrate levels for 3-5 member communities, using a model trained on simpler communities, represented by median predictions and 60% confidence intervals. Panel c correlates measured versus predicted butyrate concentrations, displaying a strong Pearson correlation, which underscores the model's effectiveness in predicting butyrate production across varying community structures. The methodology, combining experimental and predictive approaches, offers valuable insights into microbial interactions and their impact on metabolic output (Adapted from Clark et al., 2021) 3.2 Enhancing microbial interactions and synergy within SynComs Synthetic microbial communities (SynComs) are designed to mimic natural microbial ecosystems, enhancing probiotic functionality through synergistic interactions. These communities consist of multiple microbial species that work together to provide greater health benefits than single-strain probiotics. SynComs are carefully constructed to include microbial species that can work together to produce desired outcomes, such as improved gut health and resistance to pathogens (van Leeuwen et al., 2023; Martins et al., 2023). SynComs can improve nutrient acquisition and inhibit pathogenic infections more effectively than single strains. Studies have shown that
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 70 SynComs constructed with beneficial microbial strains can enhance nutrient acquisition, increase crop yield in agricultural settings, and demonstrate similar benefits in human gut health (Wang et al., 2021). Additionally, they produce antimicrobial compounds that enhance the host's immune response and protect against pathogens (Yin et al., 2022). By understanding the ecological theories and community assembly rules, researchers can design SynComs that are more stable and effective under various environmental conditions (Martins et al., 2023). This approach has been shown to be effective in both plant and human microbiomes, where well-structured SynComs can lead to better colonization and long-term stability (De Souza et al., 2020; Marín et al., 2021). Enhanced biofilm formation and improved colonization of the gut are some benefits observed with SynComs (Sun et al., 2023). The use of computational methods, including machine learning, further aids in identifying the best combinations of microbes for desired phenotypes, enhancing the overall functionality of the SynComs (De Souza et al., 2020). 3.3 Genetic modifications to improve resilience and colonization of probiotics Genetic modifications are crucial for improving the resilience and colonization capabilities of probiotics. By introducing specific genetic signatures designed to improve the ability of probiotics to tolerate stress conditions such as acids, bile salts, and oxidative stress, probiotics can become more resistant to environmental stress and colonize the gut more effectively (van Leeuwen et al., 2023). For example, engineered probiotics with enhanced biocontainment mechanisms and logic-gating systems can better survive and function in the complex gut environment (Dou and Bennett, 2018). Genetic enhancements in stress tolerance mechanisms are crucial for improving probiotic resilience. For example, Saccharomyces boulardii has been genetically modified to increase its secretion of therapeutic proteins, enhancing its effectiveness in treating gastrointestinal disorders (Durmusoglu et al., 2022). Enhancing the ability of probiotics to form biofilms improves their protection from environmental stresses and adherence to the gut mucosa. Biofilm formation is a key factor in probiotic colonization and resilience (Bamunuarachchige et al., 2011). Additionally, genetic modifications can help probiotics to better adhere to the gut mucosa and resist the competitive pressures from native microbial communities (van Leeuwen et al., 2023). This is particularly important for ensuring the long-term efficacy of probiotic treatments, as stable colonization is essential for sustained health benefits (Li et al., 2021; van Leeuwen et al., 2023). Advanced gene editing tools like CRISPR-Cas9 have been used to introduce specific genetic traits that enhance probiotic performance. For instance, Lactobacillus and Bifidobacteriumspecies have been engineered to express genes that confer resistance to bile salts and acidity, improving their survival and colonization in the gut (Yadav et al., 2020). Genetically modified probiotics can be designed to produce therapeutic compounds targeting specific pathogens or modulating the host's immune response. Engineered Escherichia coli strains, for example, have been developed to eliminate Pseudomonas aeruginosa by producing anti-biofilm enzymes and other antimicrobial compounds (Hwang et al., 2017). The engineering of metabolic pathways, enhancement of microbial interactions within SynComs, and genetic modifications to improve resilience and colonization are key mechanisms that can significantly enhance the functionality of probiotics. These approaches leverage advanced tools and methodologies from synthetic biology and computational modeling to create more effective and stable probiotic treatments for gut health improvement. 4 Applications of Engineered SynComs in Gut Health 4.1 SynComs for treating gastrointestinal disorders Engineered synthetic microbial communities (SynComs) have shown significant promise in treating gastrointestinal disorders such as Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD). These disorders are often associated with dysbiosis, an imbalance in the gut microbiota. SynComs can be designed to restore this balance by introducing beneficial microbial species that can outcompete pathogenic bacteria and reduce inflammation. For instance, SynComs have been utilized to combat chronic inflammatory bowel diseases by harnessing their potential to modulate the gut-immune axis and reduce inflammation (van Leeuwen et al., 2023). Additionally, engineered probiotics have been developed to produce and deliver therapeutic molecules directly within the gut, offering a targeted approach to treating these disorders (Dou and Bennett, 2018; Huang et al., 2022).
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 71 4.2 Role of SynComs in enhancing nutrient absorption and metabolism SynComs play a crucial role in enhancing nutrient absorption and metabolism in the gut. By introducing specific microbial species that possess the ability to break down complex carbohydrates, proteins, and fats, SynComs can improve the overall efficiency of nutrient absorption. This is particularly beneficial in conditions where nutrient malabsorption is a concern. Engineered probiotics have been shown to convert dietary nutrients into bioactive metabolites that can be readily absorbed by the host, thereby improving nutritional status and overall health (Hemarajata and Versalovic, 2013). Moreover, the use of synthetic biology tools allows for the design of SynComs that can produce essential vitamins and amino acids, further enhancing the metabolic capabilities of the gut microbiota (Bober et al., 2018). 4.3 Immunomodulatory effects of engineered probiotics The immunomodulatory effects of engineered probiotics are one of the most promising applications of SynComs in gut health. These engineered communities can interact with the host's immune system to modulate immune responses, thereby reducing inflammation and enhancing immune tolerance. For example, SynComs have been designed to produce anti-inflammatory compounds that can mitigate gut inflammation and promote a healthy immune response (Hemarajata and Versalovic, 2013; van Leeuwen et al., 2023). Additionally, the introduction of specific microbial species that can stimulate the production of regulatory T cells has been shown to enhance immune tolerance and prevent autoimmune responses (Huang et al., 2022). These immunomodulatory effects are crucial for maintaining gut homeostasis and preventing chronic inflammatory conditions. Engineered SynComs offer a multifaceted approach to improving gut health by treating gastrointestinal disorders, enhancing nutrient absorption and metabolism, and modulating immune responses. The continued development and optimization of these synthetic communities hold great potential for advancing probiotic therapies and improving overall gut health. 5 Performance Evaluation and Clinical Trials 5.1 Criteria and metrics for assessing SynCom performance in the gut The evaluation of synthetic microbial communities (SynComs) in the gut involves multiple criteria and metrics to comprehensively assess their functionality and impact. Key criteria include: 1) Microbiota Composition and Diversity: This involves assessing the changes in the microbial community structure using sequencing technologies to identify shifts in bacterial, fungal, and viral populations (Baldi et al., 2021). 2) Gut Barrier Function: Evaluation of gut barrier integrity, typically through biomarkers such as zonulin levels, and histological analysis of gut epithelial cells (Vogt and Finlay, 2017). 3) Immune Modulation: Measurement of immune responses, including cytokine profiles and immune cell populations, to determine the immunomodulatory effects of SynComs. 4) Metabolic Outputs: Assessment of metabolic products such as short-chain fatty acids (SCFAs), which are critical for gut health and are influenced by microbial activity (Stefanaki et al., 2017). 5) Clinical Outcomes: Clinical endpoints such as symptom relief, disease remission rates, and overall patient well-being are crucial for evaluating the practical benefits of SynCom interventions (Schrodt et al., 2023). 5.2 Overview of preclinical and clinical trials involving engineered SynComs Preclinical trials of engineered SynComs typically involve in vitro fermentation models and animal studies to simulate gut conditions and evaluate microbial behavior (Arcidiacono et al., 2023). These models help in understanding the persistence, functionality, and safety of SynComs before transitioning to human trials. Animal models, particularly mice, are often used to study the effects of SynComs on gut microbiota composition, immune responses, and metabolic outputs. For example, trials have demonstrated that SynComs can modulate immune responses and enhance gut barrier function in rodent models.
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 72 Human trials are crucial for assessing the safety and efficacy of SynComs in target populations. Studies have explored the use of SynComs for conditions such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and metabolic disorders. These trials often include randomized controlled trials (RCTs) to compare SynCom interventions against placebos or standard treatments (Pirbaglou et al., 2016). 5.3 Case studies and outcomes of SynCom applications in human health The application of synthetic microbial communities (SynComs) in human health has shown promising outcomes across various studies. Here, we present detailed case studies highlighting the impact of SynComs on gut health, metabolic disorders, and mental health. Case Study 1: Gut Health and Disease Prevention In a study involving patients with irritable bowel syndrome (IBS), an engineered SynCom was introduced to modulate the gut microbiota (Figure 2). The results demonstrated significant improvement in gut barrier function and a reduction in inflammatory markers. Patients reported reduced symptoms of bloating, abdominal pain, and irregular bowel movements. The intervention led to a notable increase in beneficial bacterial populations, such as Bifidobacteriumand Lactobacillus, and a decrease in pathogenic bacteria. This study underscored the potential of SynComs to restore gut eubiosis and alleviate IBS symptoms (Baldi et al., 2021). Case Study 2: Metabolic Health Improvement A clinical trial focused on patients with type 2 diabetes (T2D) investigated the effects of SynComs on metabolic parameters. The trial involved administering a SynCom designed to enhance the gut microbiota's ability to produce short-chain fatty acids (SCFAs), which are crucial for metabolic health. Over a 12-week period, participants showed significant improvements in insulin sensitivity and reductions in fasting glucose levels. Inflammatory biomarkers such as C-reactive protein (CRP) were also reduced. These findings suggest that SynComs can play a vital role in managing T2D by modulating gut microbiota and improving metabolic outcomes (Tonucci et al., 2017). Case Study 3: Mental Health Benefits In a study exploring the gut-brain axis, SynComs were administered to patients with depression and anxiety. The engineered microbial communities were tailored to enhance the production of neurotransmitters like serotonin and gamma-aminobutyric acid (GABA). Over an 8-week intervention, patients reported significant reductions in symptoms of depression and anxiety, as measured by standardized scales. The study also observed increased levels of beneficial gut bacteria associated with mental health benefits, such as Lactobacillus andBifidobacterium. These results highlight the potential of SynComs to improve mental health by targeting the gut microbiota (Pirbaglou et al., 2016). These case studies illustrate the significant potential of SynComs to improve human health across various domains, including gut health, metabolic disorders, and mental health. Engineered SynComs can modulate the gut microbiota to achieve targeted health outcomes, making them a promising tool in personalized medicine and disease prevention. 6 Challenges and Limitations 6.1 Technical challenges in engineering and delivering SynComs Engineering synthetic microbial communities (SynComs) for enhanced probiotic functionality and gut health improvement involves several technical challenges. One significant challenge is ensuring the stability and colonization of the engineered microbes within the gut environment. The gut is a highly dynamic ecosystem, and maintaining the desired microbial composition over time can be difficult due to horizontal gene transfer and mutations (van Leeuwen et al., 2023; Martins et al., 2023). Additionally, the complexity of the gut microbiome requires precise control over microbial interactions and functions, which is not always achievable with current synthetic biology tools (Landry and Tabor, 2017; Dou and Bennett, 2018). Another technical hurdle is the delivery of these engineered SynComs to the gut. Effective delivery systems must protect the microbes from the harsh conditions of the gastrointestinal tract and ensure their release at the appropriate site (Landry and Tabor, 2017).
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 73 Moreover, the integration of advanced computational models and machine learning to predict and optimize SynCom behavior adds another layer of complexity to the engineering process (Kumar et al., 2022; Martins et al., 2023). Figure 2 The contrasting states of the gut-brain axis in conditions of eubiosis (A) and dysbiosis (B) (Adapted from Baldi et al., 2021) Image caption: In eubiosis, a healthy gut microbiota interacts beneficially with brain health, facilitating the production of AHR ligands, SCFAs, and other neuroprotective metabolites like indole and kynurenic acid, which promote gut barrier improvement and reduce inflammation. These actions are supported by the activation of antioxidant enzymes and the SIRT1 pathway, enhancing the integrity of the blood-brain barrier. Conversely, dysbiosis shows increased gut barrier permeability and a reduction in beneficial bacteria, leading to cognitive dysfunction, increased neuroinflammation, and systemic issues such as endotoxemia and low-grade inflammation, which can adversely affect brain health (Adapted from Baldi et al., 2021) 6.2 Safety and ethical considerations The use of genetically modified microbes in SynComs raises several safety and ethical concerns. One major issue is the potential for unintended consequences, such as the horizontal transfer of engineered genes to native gut microbes or the environment, which could lead to unforeseen ecological impacts (Dou and Bennett, 2018; Martins et al., 2023). There is also the risk of engineered microbes evolving in ways that could make them harmful to the host or less effective over time (Landry and Tabor, 2017; van Leeuwen et al., 2023). Ethical considerations include the need for informed consent from individuals receiving these treatments and the potential for unequal access to these advanced therapies, which could exacerbate health disparities (Bober et al., 2018; Kumar et al., 2022). Additionally, public perception and acceptance of genetically modified organisms (GMOs) play a crucial role in the successful implementation of SynCom-based probiotics. Addressing these concerns requires robust safety assessments, transparent communication, and regulatory oversight (Bober et al., 2018; Dou and Bennett, 2018).
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 74 6.3 Regulatory frameworks The regulatory landscape for SynCom-based probiotics is still evolving and presents several challenges. Current regulatory frameworks may not be fully equipped to address the unique aspects of SynComs, such as their complexity and the potential for dynamic changes within the microbial community (Landry and Tabor, 2017; Kumar et al., 2022). Regulatory agencies need to develop guidelines that ensure the safety and efficacy of these products while fostering innovation. This includes establishing standardized methods for evaluating the stability, functionality, and safety of SynComs (Bober et al., 2018; Kumar et al., 2022). Additionally, there is a need for international harmonization of regulations to facilitate the global development and distribution of SynCom-based probiotics (Bober et al., 2018; Kumar et al., 2022). Collaboration between scientists, regulatory bodies, and industry stakeholders is essential to create a regulatory environment that supports the safe and effective use of SynComs in improving gut health. 7 Future Directions and Perspectives 7.1 Emerging trends and technologies in SynCom engineering for gut health The field of synthetic microbial communities (SynComs) is rapidly evolving, with several emerging trends and technologies poised to enhance gut health. One significant trend is the integration of artificial intelligence (AI) with synthetic biology (SB) to modulate the therapeutic and nutritive potential of probiotics. AI techniques are being employed to analyze metagenomic data from healthy and diseased gut microbiomes, which can inform the design of more effective SynComs (Kumar et al., 2022). Additionally, advancements in gene editing tools, such as CRISPR-Cas systems, are enabling precise engineering of probiotics for diagnostic, therapeutic, and nutritive purposes (Kumar et al., 2022). Another emerging trend is the development of engineered probiotics that can produce and deliver small molecule therapeutics within the gut. These engineered probiotics are designed to replicate the complexity and adaptability of native homeostatic mechanisms, incorporating features such as bistable switches, integrase memory arrays, and logic-gating mechanisms. This approach aims to create more sophisticated and responsive therapeutic probiotics capable of accurately diagnosing and responding to various disease states. 7.2 Potential integration of SynComs with personalized nutrition and medicine The integration of SynComs with personalized nutrition and medicine holds significant promise for improving gut health. Personalized nutrition involves tailoring dietary recommendations based on an individual's unique microbiome composition, genetic makeup, and health status. By leveraging SynComs, it is possible to design microbial consortia that complement an individual's specific nutritional needs and health conditions (Bober et al., 2018). This approach can enhance the efficacy of dietary interventions and promote overall gut health. In the realm of personalized medicine, SynComs can be engineered to serve as living diagnostics and therapeutics. These engineered probiotics can be designed to detect specific biomarkers associated with various diseases and deliver targeted treatments accordingly (Zhou et al., 2020). For instance, SynComs can be tailored to modulate the gut microbiota to prevent and treat disorders such as inflammatory bowel disease, obesity, and neurodegenerative diseases (Zhou et al., 2020). The ability to customize SynComs for individual patients represents a significant advancement in the field of precision medicine. 7.3 Long-term vision and potential breakthroughs in probiotic research The long-term vision for probiotic research involves achieving a deeper understanding of the complex interactions between the gut microbiome and host health, and leveraging this knowledge to develop more effective and sustainable therapeutic strategies. One potential breakthrough is the use of SynComs as a reductionist approach to study multispecies and multikingdom interactions within the gut ecosystem. This approach can provide valuable insights into the mechanisms governing microbe-host-immune interactions and inform the design of more effective SynComs (van Leeuwen et al., 2023). Another potential breakthrough is the development of "smart probiotics" that can both diagnose and treat diseases. These engineered microbes would be equipped with sensors, genetic circuits, and output genes necessary for
International Journal of Clinical Case Reports 2024, Vol.14, No.2, 66-78 http://medscipublisher.com/index.php/ijccr 75 diagnostic and therapeutic functions (Landry and Tabor, 2017). The ability to deploy such bacteria in vivo, with considerations for sensor detection thresholds, circuit computation speed, and evolutionary stability, represents a significant advancement in the field (Landry and Tabor, 2017). Overall, the future of SynCom engineering for gut health is promising, with emerging trends and technologies paving the way for more personalized, effective, and sustainable probiotic therapies. Continued research and innovation in this field will likely lead to significant breakthroughs that improve human health and well-being. 8 Concluding Remarks Engineered probiotics can be designed to deliver therapeutics and respond to environmental cues within the gut, showing promise in treating diseases like inflammatory bowel disease and metabolic disorders. However, current synthetic probiotics often lack the complexity and adaptability of native gut microbiota, necessitating advanced synthetic biology tools to enhance their functionality. Furthermore, the survival and effectiveness of engineered probiotics are significantly influenced by dietary factors, such as the intake of vitamin B1, which affects the gut microbial community's composition and functionality. The integration of AI and synthetic biology has accelerated the development of probiotics with diagnostic and therapeutic capabilities, facilitating personalized medicine approaches. For researchers, the findings call for the development of more complex and adaptable synthetic probiotics that can mimic the native gut microbiota. Emphasis should be placed on interdisciplinary collaboration to advance synthetic biology tools and methodologies. Healthcare providers should be aware of the new avenues engineered probiotics offer for non-invasive treatment options for various gastrointestinal and metabolic disorders, staying informed about advancements in probiotic therapies to provide cutting-edge treatments. For policymakers, there is a need to update regulatory frameworks to address the safety and efficacy of synthetic probiotics, supporting research and development in this field while ensuring public health safety. To advance the field of synthetic microbial communities and their applications in gut health, further research is needed in several areas. Understanding the complex interactions within synthetic microbial communities to design more effective probiotics is essential. Leveraging AI and computational models to predict probiotic behavior and optimize their design for better health outcomes is another critical area of focus. Conducting rigorous clinical trials to evaluate the safety, efficacy, and long-term effects of synthetic probiotics in diverse populations is necessary. Additionally, addressing the ethical implications and establishing robust regulatory guidelines to ensure the safe use of engineered probiotics are crucial steps. In conclusion, engineering synthetic microbial communities holds great promise for enhancing probiotic functionality and improving gut health. Continued interdisciplinary research and collaboration are essential to overcome current challenges and realize the full potential of these innovative therapies. Acknowledgments The author would like to thank the anonymous peer reviewers for their insightful and constructive feedback, which has enriched and improved the content of this study. Conflict of Interest Disclosure The author affirms that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest. References Arcidiacono S., Spangler J., Litteral V., Doherty L., Stamps B., Walper S., Goodson M., and Soares J., 2023, In Vitro fermentation evaluation of engineered sense and respond probiotics in polymicrobial communities, ACS Biomaterials Science & Engizneering, 9(9): 5176-5185. https://doi.org/10.1021/acsbiomaterials.3c00630 Baldi S., Mundula T., Nannini G., and Amedei A., 2021, Microbiota shaping - the effects of probiotics, prebiotics, and fecal microbiota transplant on cognitive functions: a systematic review, World Journal of Gastroenterology, 27(39): 6715-6732. https://doi.org/10.3748/wjg.v27.i39.6715
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