Gut eukaryotic virome in colorectal carcinogenesis: Is that a trigger?

ATRX mutation modifies the DNA damage response in glioblastoma multiforme tumor cells and enhances patient prognosis

The presence of specific genetic mutations in patients with glioblastoma multiforme (GBM) is associated with improved survival outcomes. Disruption of the DNA damage response (DDR) pathway in tumor cells enhances the effectiveness of radiotherapy drugs, while increased mutational burden following tumor cell damage also facilitates the efficacy of immunotherapy. The ATRX gene, located on chromosome X, plays a crucial role in DDR. The aim of this research is to elucidate the correlation between ATRX mutations and GBM. Dataset obtained from TCGA-GBM were conducted an analysis on the genomic features, biological characteristics, immunopathological markers, and clinical prognosis of patients carrying ATRX mutations. Our findings revealed a significantly elevated level of microsatellite instability in individuals with ATRX mutants, along with significant alterations in the receptor-tyrosine kinase (RTK)-ras pathway among patients exhibiting combined ATRX mutations. TCGA-GBM patients with concurrent ATRX mutations exhibited sensitivity to 26 chemotherapeutic and anticancer drugs, which exerted their effects by modulating the DDR of tumor cells through highly correlated mechanisms involving the RTK-ras pathway. Additionally, we observed an enrichment of ATRX mutations in specific pathways associated with DDR among TCGA-GBM patients. Our model also demonstrated prolonged overall survival in patients carrying ATRX mutations, particularly showing strong predictive value for 3- and 5-year survival rates. Furthermore, additional protective factors such as younger age, female gender, combined IDH mutations, and TP53 mutations were identified. The results underscore the protective role and prognostic significance of ATRX mutations in GBM as a potential therapeutic target and biomarker for patient survival.

Exploring micronutrients and microbiome synergy: pioneering new paths in cancer therapy

The human microbiome is the complex ecosystem consisting of trillions of microorganisms that play a key role in developing the immune system and nutrient metabolism. Alterations in the gut microbiome have been linked to cancer initiation, progression, metastasis, and response to treatment. Accumulating evidence suggests that levels of vitamins and minerals influence the gut environment and may have implications for cancer risk and progression. Bifidobacterium has been reported to reduce the colorectal cancer risk by binding to free iron. Additionally, zinc ions have been shown to activate the immune cells and enhance the effectiveness of immunotherapy. Higher selenium levels have been associated with a reduced risk of several cancers, including colorectal cancer. In contrast, enhanced copper uptake has been implicated in promoting cancer progression, including colon cancer. The interaction between cancer and gut bacteria, as well as dysbiosis impact has been studied in animal models. The interplay between prebiotics, probiotics, synbiotics, postbiotics and gut bacteria in cancer offers the diverse physiological benefits. We also explored the particular probiotic formulations like VSL#3, Prohep, Lactobacillus rhamnosus GG (LGG), etc., for their ability to modulate immune responses and reduce tumor burden in preclinical models. Targeting the gut microbiome through antibiotics, bacteriophage, microbiome transplantation-based therapies will offer a new perspective in cancer research. Hence, to understand this interplay, we outline the importance of micronutrients with an emphasis on the immunomodulatory function of the microbiome and highlight the microbiome's potential as a target for precision medicine in cancer treatment.

Exploring the virome: An integral part of human health and disease

The human microbiome is a complex network of microorganisms that includes viruses, bacteria, and fungi. The gut virome is an essential component of the immune system, which is responsible for regulating the growth and responses of the host's immune system. The virome maintains a crucial role in the development of numerous diseases, including inflammatory bowel disease (IBD), Crohn's disease, and neurodegenerative disorders. The human virome has emerged as a promising biomarker and therapeutic target. This comprehensive review summarizes the present understanding of the virome and its implications in matters of health and disease, with a focus on the Human Microbiome Project.

Commensal microbiome and gastrointestinal mucosal immunity: Harmony and conflict with our closest neighbor

BACKGROUND

The gastrointestinal tract contains a wide range of microorganisms that have evolved alongside the immune system of the host. The intestinal mucosa maintains balance within the intestines by utilizing the mucosal immune system, which is controlled by the complex gut mucosal immune network.

OBJECTIVE

This review aims to comprehensively introduce current knowledge of the gut mucosal immune system, focusing on its interaction with commensal bacteria.

RESULTS

The gut mucosal immune network includes gut-associated lymphoid tissue, mucosal immune cells, cytokines, and chemokines. The connection between microbiota and the immune system occurs through the engagement of bacterial components with pattern recognition receptors found in the intestinal epithelium and antigen-presenting cells. This interaction leads to the activation of both innate and adaptive immune responses. The interaction between the microbial community and the host is vital for maintaining the balance and health of the host's mucosal system.

CONCLUSION

The gut mucosal immune network maintains a delicate equilibrium between active immunity, which defends against infections and damaging non-self antigens, and immunological tolerance, which allows for the presence of commensal microbiota and dietary antigens. This balance is crucial for the maintenance of intestinal health and homeostasis. Disturbance of gut homeostasis leads to enduring or severe gastrointestinal ailments, such as colorectal cancer and inflammatory bowel disease. Utilizing these factors can aid in the development of cutting-edge mucosal vaccines that have the ability to elicit strong protective immune responses at the primary sites of pathogen invasion.

The emerging role of the gut virome in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in neonates, particularly preterm infants. Many factors can lead to NEC, but microbial dysbiosis is one of the most important risk factors that can induce this disease. Given the major role of the gut virome in shaping bacterial homeostasis, virome research is a fledgling but rapidly evolving area in the field of microbiome that is increasingly connected to human diseases, including NEC. This review provides an overview of the development of the gut virome in newborns, discusses its emerging role in NEC, and explores promising therapeutic applications, including phage therapy and fecal virome transplantation.

The role of microbiomes in gastrointestinal cancers: new insights

Gastrointestinal (GI) cancers constitute more than 33% of new cancer cases worldwide and pose a considerable burden on public health. There exists a growing body of evidence that has systematically recorded an upward trajectory in GI malignancies within the last 5 to 10 years, thus presenting a formidable menace to the health of the human population. The perturbations in GI microbiota may have a noteworthy influence on the advancement of GI cancers; however, the precise mechanisms behind this association are still not comprehensively understood. Some bacteria have been observed to support cancer development, while others seem to provide a safeguard against it. Recent studies have indicated that alterations in the composition and abundance of microbiomes could be associated with the progression of various GI cancers, such as colorectal, gastric, hepatic, and esophageal cancers. Within this comprehensive analysis, we examine the significance of microbiomes, particularly those located in the intestines, in GI cancers. Furthermore, we explore the impact of microbiomes on various treatment modalities for GI cancer, including chemotherapy, immunotherapy, and radiotherapy. Additionally, we delve into the intricate mechanisms through which intestinal microbes influence the efficacy of GI cancer treatments.

Gut virome in inflammatory bowel disease and beyond

OBJECTIVE

The gut virome is a dense community of viruses inhabiting the gastrointestinal tract and an integral part of the microbiota. The virome coexists with the other components of the microbiota and with the host in a dynamic equilibrium, serving as a key contributor to the maintenance of intestinal homeostasis and functions. However, this equilibrium can be interrupted in certain pathological states, including inflammatory bowel disease, causing dysbiosis that may participate in disease pathogenesis. Nevertheless, whether virome dysbiosis is a causal or bystander event requires further clarification.

DESIGN

This review seeks to summarise the latest advancements in the study of the gut virome, highlighting its cross-talk with the mucosal microenvironment. It explores how cutting-edge technologies may build upon current knowledge to advance research in this field. An overview of virome transplantation in diseased gastrointestinal tracts is provided along with insights into the development of innovative virome-based therapeutics to improve clinical management.

RESULTS

Gut virome dysbiosis, primarily driven by the expansion of Caudovirales, has been shown to impact intestinal immunity and barrier functions, influencing overall intestinal homeostasis. Although emerging innovative technologies still need further implementation, they display the unprecedented potential to better characterise virome composition and delineate its role in intestinal diseases.

CONCLUSIONS

The field of gut virome is progressively expanding, thanks to the advancements of sequencing technologies and bioinformatic pipelines. These have contributed to a better understanding of how virome dysbiosis is linked to intestinal disease pathogenesis and how the modulation of virome composition may help the clinical intervention to ameliorate gut disease management.

The Archaeome's Role in Colorectal Cancer: Unveiling the DPANN Group and Investigating Archaeal Functional Signatures

BACKGROUND AND AIMS

Gut microbial imbalances are linked to colorectal cancer (CRC), but archaea's role remains underexplored. Here, using previously published metagenomic data from different populations including Austria, Germany, Italy, Japan, China, and India, we performed bioinformatic and statistical analysis to identify archaeal taxonomic and functional signatures related to CRC.

METHODS

We analyzed published fecal metagenomic data from 390 subjects, comparing the archaeomes of CRC and healthy individuals. We conducted a biostatistical analysis to investigate the relationship between Candidatus Mancarchaeum acidiphilum (DPANN superphylum) and other archaeal species associated with CRC. Using the Prokka tool, we annotated the data focusing on archaeal genes, subsequently linking them to CRC and mapping them against UniprotKB and GO databases for specific archaeal gene functions.

RESULTS

Our analysis identified enrichment of methanogenic archaea in healthy subjects, with an exception for Methanobrevibacter smithii, which correlated with CRC. Notably, CRC showed a strong association with archaeal species, particularly Natrinema sp. J7-2, Ferroglobus placidus, and Candidatus Mancarchaeum acidiphilum. Furthermore, the DPANN archaeon exhibited a significant correlation with other CRC-associated archaea (p < 0.001). Functionally, we found a marked association between MvhB-type polyferredoxin and colorectal cancer. We also highlighted the association of archaeal proteins involved in the biosynthesis of leucine and the galactose metabolism process with the healthy phenotype.

CONCLUSIONS

The archaeomes of CRC patients show identifiable alterations, including a decline in methanogens and an increase in Halobacteria species. MvhB-type polyferredoxin, linked with CRC and species like Candidatus Mancarchaeum acidiphilum, Natrinema sp. J7-2, and Ferroglobus placidus emerge as potential archaeal biomarkers. Archaeal proteins may also offer gut protection, underscoring archaea's role in CRC dynamics.

Gut virome-colonising Orthohepadnavirus genus is associated with ulcerative colitis pathogenesis and induces intestinal inflammation in vivo

OBJECTIVES

Ulcerative colitis (UC) is a chronic inflammatory disorder of unknown aetiology. Gut virome dysbiosis is fundamental in UC progression, although its role in the early phases of the disease is far from fully understood. Therefore, we sought to investigate the role of a virome-associated protein encoded by the Orthohepadnavirus genus, the hepatitis B virus X protein (HBx), in UC aetiopathogenesis.

DESIGN

HBx positivity of UC patient-derived blood and gut mucosa was assessed by RT-PCR and Sanger sequencing and correlated with clinical characteristics by multivariate analysis. Transcriptomics was performed on HBx-overexpressing endoscopic biopsies from healthy donors.C57BL/6 mice underwent intramucosal injections of liposome-conjugated HBx-encoding plasmids or the control, with or without antibiotic treatment. Multidimensional flow cytometry analysis was performed on colonic samples from HBx-treated and control animals. Transepithelial electrical resistance measurement, proliferation assay, chromatin immunoprecipitation assay with sequencing and RNA-sequencing were performed on in vitro models of the gut barrier. HBx-silencing experiments were performed in vitro and in vivo.

RESULTS

HBx was detected in about 45% of patients with UC and found to induce colonic inflammation in mice, while its silencing reverted the colitis phenotype in vivo. HBx acted as a transcriptional regulator in epithelial cells, provoking barrier leakage and altering both innate and adaptive mucosal immunity ex vivo and in vivo.

CONCLUSION

This study described HBx as a contributor to the UC pathogenesis and provides a new perspective on the virome as a target for tailored treatments.

Gut microbiota interactions with antitumor immunity in colorectal cancer: From understanding to application

Colorectal cancer (CRC) is one of highly prevalent cancer. Immunotherapy with immune checkpoint inhibitors (ICIs) has dramatically changed the landscape of treatment for many advanced cancers, but CRC still exhibits suboptimal response to immunotherapy. The gut microbiota can affect both anti-tumor and pro-tumor immune responses, and further modulate the efficacy of cancer immunotherapy, particularly in the context of therapy with ICIs. Therefore, a deeper understanding of how the gut microbiota modulates immune responses is crucial to improve the outcomes of CRC patients receiving immunotherapy and to overcome resistance in nonresponders. The present review aims to describe the relationship between the gut microbiota, CRC, and antitumor immune responses, with a particular focus on key studies and recent findings on the effect of the gut microbiota on the antitumor immune activity. We also discuss the potential mechanisms by which the gut microbiota influences host antitumor immune responses as well as the prospective role of intestinal flora in CRC treatment. Furthermore, the therapeutic potential and limitations of different modulation strategies for the gut microbiota are also discussed. These insights may facilitate to better comprehend the interplay between the gut microbiota and the antitumor immune responses of CRC patients and provide new research pathways to enhance immunotherapy efficacy and expand the patient population that could be benefited by immunotherapy.

Exploring the Relationship between the Gut Mucosal Virome and Colorectal Cancer: Characteristics and Correlations

The fecal virome has been reported to be associated with CRC. However, little is known about the mucosal virome signature in CRC. This study aimed to determine the viral community within CRC tissues and their contributions to colorectal carcinogenesis. Colonic mucosal biopsies were harvested from patients with CRC (biopsies of both neoplasia and adjacent normal tissue (CRC-A)) and healthy controls (HC). The shot-gun metagenomic sequencing of virus-like particles (VLPs) was performed on the biopsies. Viral community, functional pathways, and their correlations to clinical data were analyzed. Fluorescence in situ hybridizations (FISH) for the localization of viruses in the intestine was performed, as well as quantitative PCR for the detection of Torque teno virus load in human mucosal VLP DNA. A greater number and proportion of core species were found in CRC tissues than in CRC-A and HC tissues. The diversity of the mucosal virome in CRC tissues was significantly increased compared to that in HC and CRC-A tissues. The mucosal virome signature of CRC tissues were significantly different from those of HC and CRC-A tissues at the species level. The abundances of eukaryotic viruses from the Anelloviridae family and its sub-species Torque teno virus (TTV) were significantly higher in CRC patients than in HC. Furthermore, increased levels of TTV in the intestinal lamina propria were found in the CRC group. Multiple viral functions of TTV associated with carcinogenesis were enriched in CRC tissues. We revealed for the first time that the mucosal virobiota signature of CRC is characterized by a higher diversity and more eukaryotic viruses. The enrichment of TTV species in CRC tissues suggests that they may play an oncogenic role in CRC. Targeting eukaryotic viruses in the gut may provide novel strategies for the prevention and treatment of CRC.

Bacterial, Viral and Parasitic Pathogens and Colorectal Cancer

Several viral, bacterial, and parasitic pathogens have been designated as human carcinogens by the World Health Organization [...].

Emerging applications of phage therapy and fecal virome transplantation for treatment of Clostridioides difficile infection: challenges and perspectives

Clostridioides difficile, which causes life-threatening diarrheal disease, is considered an urgent threat to healthcare setting worldwide. The current standards of care solely rely on conventional antibiotic treatment, however, there is a risk of promoting recurrent C. difficile infection (rCDI) because of the emergence of antibiotic-resistant strains. Globally, the alarming spread of antibiotic-resistant strains of C. difficile has resulted in a quest for alternative therapeutics. The use of fecal microbiota transplantation (FMT), which involves direct infusion of fecal suspension from a healthy donor into a diseased recipient, has been approved as a highly efficient therapeutic option for patients with rCDI. Bacteriophages or phages are a group of viruses that can infect and destroy bacterial hosts, and are recognized as the dominant viral component of the human gut microbiome. Accumulating data has demonstrated that phages play a vital role in microbial balance of the human gut microbiome. Recently, phage therapy and fecal virome transplantation (FVT) have been introduced as promising alternatives for the treatment of C. difficile -related infections, in particular drug-resistant CDI. Herein, we review the latest updates on C. difficile- specific phages, and phage-mediated treatments, and highlight the current and future prospects of phage therapy in the management of CDI.

Gut microbiota, an emergent target to shape the efficiency of cancer therapy

It is now well-acknowledged that microbiota has a profound influence on both human health and illness. The gut microbiota has recently come to light as a crucial element that influences cancer through a variety of mechanisms. The connections between the microbiome and cancer therapy are further highlighted by a number of preclinical and clinical evidence, suggesting that these complicated interactions may vary by cancer type, treatment, or even by tumor stage. The paradoxical relationship between gut microbiota and cancer therapies is that in some cancers, the gut microbiota may be necessary to maintain therapeutic efficacy, whereas, in other cancers, gut microbiota depletion significantly increases efficacy. Actually, mounting research has shown that the gut microbiota plays a crucial role in regulating the host immune response and boosting the efficacy of anticancer medications like chemotherapy and immunotherapy. Therefore, gut microbiota modulation, which aims to restore gut microbial balance, is a viable technique for cancer prevention and therapy given the expanding understanding of how the gut microbiome regulates treatment response and contributes to carcinogenesis. This review will provide an outline of the gut microbiota's role in health and disease, along with a summary of the most recent research on how it may influence the effectiveness of various anticancer medicines and affect the growth of cancer. This study will next cover the newly developed microbiota-targeting strategies including prebiotics, probiotics, and fecal microbiota transplantation (FMT) to enhance anticancer therapy effectiveness, given its significance.

The Human Gut Virome and Its Relationship with Nontransmissible Chronic Diseases

The human gastrointestinal tract contains large communities of microorganisms that are in constant interaction with the host, playing an essential role in the regulation of several metabolic processes. Among the gut microbial communities, the gut bacteriome has been most widely studied in recent decades. However, in recent years, there has been increasing interest in studying the influences that other microbial groups can exert on the host. Among them, the gut virome is attracting great interest because viruses can interact with the host immune system and metabolic functions; this is also the case for phages, which interact with the bacterial microbiota. The antecedents of virome-rectification-based therapies among various diseases were also investigated. In the near future, stool metagenomic investigation should include the identification of bacteria and phages, as well as their correlation networks, to better understand gut microbiota activity in metabolic disease progression.

The gut virome: A new microbiome component in health and disease

The human gastrointestinal tract harbours an abundance of viruses, collectively known as the gut virome. The gut virome is highly heterogeneous across populations and is linked to geography, ethnicity, diet, lifestyle, and urbanisation. The currently known function of the gut virome varies greatly across human populations, and much remains unknown. We review current literature on the human gut virome, and the intricate trans-kingdom interplay among gut viruses, bacteria, and the mammalian host underlying health and diseases. We summarise evidence on the use of the gut virome as diagnostic markers and a therapeutic target. We shed light on novel avenues of microbiome-inspired diagnosis and therapies. We also review pre-clinical and clinical studies on gut virome-rectification-based therapies, including faecal microbiota transplantation, faecal virome transplantation, and refined phage therapy. Our review suggests that future research effort should focus on unravelling the mechanisms exerted by gut viruses/phages in human pathophysiology, and on developing phage-prompted precision therapies.

Cross-talk between the microbiome and chronic inflammation in esophageal cancer: potential driver of oncogenesis

Esophageal cancer (EC) is frequently considered a lethal malignancy and is often identified at a later stage. It is one of the major causes of cancer-related deaths globally. The conventional treatment methods like chemotherapy, radiotherapy, and surgery offer limited efficacy and poor clinical outcome with a less than 25% 5-year survival rate. The poor prognosis of EC persists despite the growth in the development of diagnostic and therapeutic modalities to treat EC. This underlines the need to elucidate the complex molecular mechanisms that drive esophageal oncogenesis. Apart from the role of the tumor microenvironment and its structural and cellular components in tumorigenesis, mounting evidence points towards the involvement of the esophageal microbiome, inflammation, and their cross-talk in promoting esophageal cancer. The current review summarizes recent research that delineates the underlying molecular mechanisms by which the microbiota and inflammation promote the pathophysiology of esophageal cancer, thus unraveling targets for potential therapeutic intervention.

Non-bacteria microbiome (virus, fungi, and archaea) in gastrointestinal cancer

The gastrointestinal tract houses millions of microbes collectively referred to as the gut microbiome. The gut microbes comprise of bacteria, viruses, fungi, archaea, and microscopic eukaryotes, which co-evolved or colonize the gut forming complex symbiotic and mutualistic relationships. A state of homeostasis is required between host and gut microbiome relationship to maintain several host beneficial processes. Alterations in the taxonomic and functional composition of the gut microbes are associated with several human diseases including gastrointestinal cancers. Owed to their overwhelming abundance and ease of characterization, several studies focus on the role of bacteria in gastrointestinal cancers. There is however growing evidence that non-bacteria gut microbes are associated with the pathogenesis of gastrointestinal cancers. This review details the association of non-bacteria gut microbes including fungi, viruses, and archaea and their potential manipulation in the prevention and treatment of human gastrointestinal cancers.

Bacterial-Viral Interactions in Human Orodigestive and Female Genital Tract Cancers: A Summary of Epidemiologic and Laboratory Evidence

Infectious agents, including viruses, bacteria, fungi, and parasites, have been linked to pathogenesis of human cancers, whereas viruses and bacteria account for more than 99% of infection associated cancers. The human microbiome consists of not only bacteria, but also viruses and fungi. The microbiome co-residing in specific anatomic niches may modulate oncologic potentials of infectious agents in carcinogenesis. In this review, we focused on interactions between viruses and bacteria for cancers arising from the orodigestive tract and the female genital tract. We examined the interactions of these two different biological entities in the context of human carcinogenesis in the following three fashions: (1) direct interactions, (2) indirect interactions, and (3) no interaction between the two groups, but both acting on the same host carcinogenic pathways, yielding synergistic or additive effects in human cancers, e.g., head and neck cancer, liver cancer, colon cancer, gastric cancer, and cervical cancer. We discuss the progress in the current literature and summarize the mechanisms of host-viral-bacterial interactions in various human cancers. Our goal was to evaluate existing evidence and identify gaps in the knowledge for future directions in infection and cancer.

Dietary Patterns and Associated Microbiome Changes that Promote Oncogenesis

The recent increases in cancer incidences have been linked to lifestyle changes that result in obesity and metabolic syndrome. It is now evident that these trends are associated with the profound changes that occur in the intestinal microbiome, producing altered microbial population signatures that interact, directly or indirectly, with potentially pro-carcinogenic molecular pathways of transcription, proliferation, and inflammation. The effects of the entire gut microbial population on overall health are complex, but individual bacteria are known to play important and definable roles. Recent detailed examinations of a large number of subjects show a tight correlation between habitual diets, fecal microbiome signatures, and markers of metabolic health. Diets that score higher in healthfulness or diversity such as plant-based diets, have altered ratios of specific bacteria, including an increase in short-chain fatty acid producers, which in turn have been linked to improved metabolic markers and lowered cancer risk. Contrarily, numerous studies have implicated less healthy, lower-scoring diets such as the Western diet with reduced intestinal epithelial defenses and promotion of specific bacteria that affect carcinogenic pathways. In this review, we will describe how different dietary patterns affect microbial populations in the gut and illustrate the subsequent impact of bacterial products and metabolites on molecular pathways of cancer development, both locally in the gut and systemically in distant organs.

The Gut-Liver Axis in Cholestatic Liver Diseases

The gut-liver axis describes the physiological interplay between the gut and the liver and has important implications for the maintenance of health. Disruptions of this equilibrium are an important factor in the evolution and progression of many liver diseases. The composition of the gut microbiome, the gut barrier, bacterial translocation, and bile acid metabolism are the key features of this cycle. Chronic cholestatic liver diseases include primary sclerosing cholangitis, the generic term secondary sclerosing cholangitis implying the disease secondary sclerosing cholangitis in critically ill patients and primary biliary cirrhosis. Pathophysiology of these diseases is not fully understood but seems to be multifactorial. Knowledge about the alterations of the gut-liver axis influencing the pathogenesis and the outcome of these diseases has considerably increased. Therefore, this review aims to describe the function of the healthy gut-liver axis and to sum up the pathological changes in these cholestatic liver diseases. The review compromises the actual level of knowledge about the gut microbiome (including the mycobiome and the virome), the gut barrier and the consequences of increased gut permeability, the effects of bacterial translocation, and the influence of bile acid composition and pool size in chronic cholestatic liver diseases. Furthermore, therapeutic implications and future scientific objectives are outlined.

Virulence factor-related gut microbiota genes and immunoglobulin A levels as novel markers for machine learning-based classification of autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental condition for which early identification and intervention is crucial for optimum prognosis. Our previous work showed gut Immunoglobulin A (IgA) to be significantly elevated in the gut lumen of children with ASD compared to typically developing (TD) children. Gut microbiota variations have been reported in ASD, yet not much is known about virulence factor-related gut microbiota (VFGM) genes. Upon determining the VFGM genes distinguishing ASD from TD, this study is the first to utilize VFGM genes and IgA levels for a machine learning-based classification of ASD. Sequence comparisons were performed of metagenome datasets from children with ASD (n = 43) and TD children (n = 31) against genes in the virulence factor database. VFGM gene composition was associated with ASD phenotype. VFGM gene diversity was higher in children with ASD and positively correlated with IgA content. As Group B streptococcus (GBS) genes account for the highest proportion of 24 different VFGMs between ASD and TD and positively correlate with gut IgA, GBS genes were used in combination with IgA and VFGMs diversity to distinguish ASD from TD. Given that VFGM diversity, increases in IgA, and ASD-enriched VFGM genes were independent of sex and gastrointestinal symptoms, a classification method utilizing them will not pertain only to a specific subgroup of ASD. By introducing the classification value of VFGM genes and considering that VFs can be isolated in pregnant women and newborns, these findings provide a novel machine learning-based early risk identification method for ASD.