Gut bacteriome and metabolome of Ascaris lumbricoides in patients

Parasite-microbiota interactions: a pathway to innovative interventions for Chagas disease, leishmaniasis, and ascariasis

Parasitic infections are a major global health challenge, driven in part by complex interactions between parasites, host microbiota, and immune responses. Recent advances in microbiome research highlight the critical role of microbiota in influencing disease outcomes and treatment effectiveness. This review examines how changes in the microbiota impact parasite transmission, disease progression, and responses to treatment, focusing on key parasitic diseases such as Chagas disease, leishmaniasis, and ascariasis. The microbiota can either exacerbate or mitigate disease severity, depending on its composition, providing critical insights for novel therapeutic strategies. Emerging approaches discussed include the use of targeted probiotics, prebiotics, and microbiota-modulating drugs to influence parasite dynamics and enhance conventional therapies. The review also explores the potential of integrating microbiota knowledge into vaccine design and immunotherapy, aiming to develop vaccines that elicit stronger immune responses and identify new therapeutic targets. A multidisciplinary approach is essential for translating these findings into effective clinical solutions, with future research focusing on validating microbiota-based interventions in clinical settings. In conclusion, the interaction between microbiota and parasitic infections presents a promising avenue for innovative therapies, with the potential to significantly improve global health outcomes.

Ascaris lumbricoides a rare cause gastric perforation: a case report and brief literature review

Ascaris lumbricoides (AL), a prevalent nematode causing ascariasis, infects millions worldwide, with a higher risk in preschool and school-aged children. Though infections are usually mild, rare and life-threatening complications like gastrointestinal perforation exist. This article documents a case involving a 61-year-old deaf-mute man who presented with a month-long history of epigastric pain accompanied by nausea, anorexia, and constipation. The pain exacerbated, eventually extended to encompass the entire abdomen 4 h prior to being diagnosed with hollow viscus perforation. During the surgical procedure, three live ascarids were discovered within the abdominal cavity, and the jejunum was found to be filled with a large number of ascarids, accompanied by a perforation in the gastric antrum. Subsequently, the ascarids were extracted, and the perforated area was repaired. Postoperatively, the patient underwent anti-infection therapy, acid suppression, gastric mucosa protection, and nutritional support. On postoperative day (POD) 1, a single dose of 400 mg albendazole was administered. Fecal samples on POD 3, 5, and 6 tested positive for AL eggs. The patient recovered smoothly with no evidence of peptic ulcer disease on one-month follow-up endoscopy. Additionally, fecal tests conducted over three consecutive days did not detect any AL eggs. This case highlights the crucial importance of recognizing ascariasis-associated complications and underscores the paramount role of timely surgical intervention in such cases. Meanwhile, this article combines cases of gastrointestinal perforation caused by AL documented in the literature since 1903, elaborates on the epidemiological characteristics, pathogenesis, diagnosis, treatment, and prevention of ascariasis, and analyzes the reasons for the occurrence of such complications.

Multi-Omics Assessment of Puff Volume-Mediated Salivary Biomarkers of Metal Exposure and Oxidative Injury Associated with Electronic Nicotine Delivery Systems

BACKGROUND

Since their inception, electronic nicotine delivery systems (ENDS) have gained increasing popularity, sparking a vaping epidemic among adolescents in the US and globally. Several ENDS safety concerns have emerged as device features and formats that contribute to heavy metal exposure and toxicity continue to evolve and outpace regulatory efforts.

OBJECTIVES

Our objective was to integrate ENDS emission profiles with salivary proteome and metabolome data to characterize exposure factors that may influence adverse vaping-mediated health outcomes.

METHODS

A total of 56 participants (38 exclusive ENDS users and 18 non-ENDS users) were recruited. A subset of 15 exclusive ENDS users completed puffing topography assessments to obtain individual vaping behavior patterns using each participant's ENDS device. Inductively coupled plasma mass spectrometry was used to determine the metal content of emissions (12 ENDS devices) generated using a programmable ENDS aerosol generation system and saliva (15 exclusive ENDS users and 5 non-ENDS users). Saliva samples from 10 exclusive ENDS users and 5 non-ENDS users were analyzed for proteomic, metabolomic, inflammatory, and oxidative stress/damage biomarkers.

RESULTS

A linear puff volume-dependent increase in particle emissions and heavy metals was observed in ENDS aerosols and saliva of exclusive ENDS users. Elevated puff volume-dependent levels of salivary cytokines, including tumor necrosis factor-alpha (TNFα ), interleukin-1 beta (IL-1β ), and IL-6, were observed alongside the oxidative damage indicators malondialdehyde (MDA), superoxide dismutase (SOD), and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Proteome-metabolome network analysis showed a higher risk of potentially developing neurological and respiratory diseases in ENDS users compared with non-ENDS users. Integrated salivary proteome-metabolome-metallome network analysis further demonstrated that heavy metals were associated with proteomic and metabolomic perturbations, with notable alterations in inflammatory response, immune function, and disease-related pathways.

DISCUSSION

A significant correlation between heavy metals, cytokines, and oxidative stress markers reveals a potential role of vaping behavior in exposure to metals and changes in markers associated with DNA damage and inflammation. Our study demonstrates the importance of characterizing vaping behavior and puffing topography when examining the human health implications of ENDS use. https://doi.org/10.1289/EHP14321.

Modulation of the rat intestinal microbiota in the course of Anisakis pegreffii infection

Background

Anisakis are globally distributed, marine parasitic nematodes that can cause human health problems, including symptoms such as vomiting, acute diarrhea, and allergic reactions. As parasitic nematodes that primarily affect the patient's digestive tract, intestinal helminths can interact directly with the host microbiota through physical contact, chemicals, or nutrient competition. It is widely accepted that the host microbiota plays a crucial role in the regulation of immunity.

Materials and methods

Nematodes collected from the abdominal cavity of marine fish were identified by molecular biology and live worms were artificially infected in rats. Infection was determined by indirect ELISA based on rat serum and worm extraction. Feces were collected for 16S rDNA-based analysis of microbiota diversity.

Results

Molecular biology identification based on ITS sequences identified the collected nematodes as A. pegreffii. The success of the artificial infection was determined by indirect ELISA based on serum and worm extraction from artificially infected rats. Microbiota diversity analysis showed that a total of 773 ASVs were generated, and PCoA showed that the infected group was differentiated from the control group. The control group contained five characterized genera (Prevotellaceae NK3B31 group, Turicibacter, Clostridium sensu stricto 1, Candidatus Stoquefichus, Lachnospira) and the infected group contained nine characterized genera (Rodentibacter, Christensenella, Dubosiella, Streptococcus, Anaeroplasma, Lactococcus, Papillibacter, Desulfovibrio, Roseburia). Based on the Wilcoxon test, four processes were found to be significant: bacterial secretion system, bacterial invasion of epithelial cells, bacterial chemotaxis, and ABC transporters.

Conclusion

This study is the first to analyze the diversity of the intestinal microbiota of rats infected with A. pegreffii and to determine the damage and regulation of metabolism and immunity caused by the infection in the rat gut. The findings provide a basis for further research on host-helminth-microbe correlationships.

Ascaris lumbricoides harbors a distinct gut microbiota profile from its human host: Preliminary insights

In indigenous populations where soil-transmitted helminths (STH) infections are endemic, STH parasites (i.e., Ascaris lumbricoides, Trichuris trichiura, hookworms) often co-exist and co-evolve with the gut microbiota of their human hosts. The association between STH infections and the gut microbiota of the colonized human hosts has been established, but few studies explored the gut microbiota of the parasites. This preliminary study aimed to characterize the microbiota of the STH parasite for further understanding the STH parasite-host relationship. The gut microbial genomic DNA from four adult A. lumbricoides worms recovered from a six-year-old indigenous Negrito boy living in an STH-endemic village in Perak, Peninsular Malaysia was extracted and sequenced for the V3-V4 region of the 16S rRNA. The microbiota profiles of these worms were characterized and compared with the gut microbiota of their human host, including the profiles from four STH-positive and three STH-negative individuals from the same tribe and village. The gut microbial structure of A. lumbricoides was found to be differed significantly from their human host. The worms contained lower gut bacterial abundance and diversity than human. This difference was evident in the beta diversity analysis which showed a clear separation between the two sample types. While both Firmicutes (52.3%) and Bacteroidetes (36.6%) are the predominant phyla followed by Proteobacteria (7.2%) in the human gut, the microbiota of Ascaris gut is highly dominated by Firmicutes, constituting 84.2% relative abundance (mainly from the genus Clostridium), followed by Proteobacteria (11.1%), Tenericutes (1.8%) and Bacteroidetes (1.5%). The parasites were also found to alter the microbial structure of the human gut following infection based on the relatively higher bacterial abundance in STH-positive versus STH-negative participants. Further studies with a greater number of Ascaris adults and human hosts are needed to confirm the gut microbiota profiles.

Transcriptomic and metabolomic analyses to study the key role by which Ralstonia insidiosa induces Listeria monocytogenes to form suspended aggregates

Ralstonia insidiosa can survive in a wide range of aqueous environments, including food processing areas, and is harmful to humans. It can induce Listeria monocytogenes to form suspended aggregates, resulting from the co-aggregation of two bacteria, which allows for more persistent survival and increases the risk of L. monocytogenes contamination. In our study, different groups of aggregates were analyzed and compared using Illumina RNA sequencing technology. These included R. insidiosa under normal and barren nutrient conditions and in the presence or absence of L. monocytogenes as a way to screen for differentially expressed genes (DEGs) in the process of aggregate formation. In addition, sterile supernatants of R. insidiosa were analyzed under different nutrient conditions using metabolomics to investigate the effect of nutrient-poor conditions on metabolite production by R. insidiosa. We also undertook a combined analysis of transcriptome and metabolome data to further investigate the induction effect of R. insidiosa on L. monocytogenes in a barren environment. The results of the functional annotation analysis on the surface of DEGs and qPCR showed that under nutrient-poor conditions, the acdx, puuE, and acs genes of R. insidiosa were significantly upregulated in biosynthetic processes such as carbon metabolism, metabolic pathways, and biosynthesis of secondary metabolites, with Log2FC reaching 4.39, 3.96, and 3.95 respectively. In contrast, the Log2FC of cydA, cyoB, and rpsJ in oxidative phosphorylation and ribosomal pathways reached 3.74, 3.87, and 4.25, respectively. Thirty-one key components were identified while screening for differential metabolites, which mainly included amino acids and their metabolites, enriched to the pathways of biosynthesis of amino acids, phenylalanine metabolism, and methionine metabolism. Of these, aminomalonic acid and Proximicin B were the special components of R. insidiosa that were metabolized under nutrient-poor conditions.

Helminth-host-environment interactions: Looking down from the tip of the iceberg

In 1978, the theory behind helminth parasites having the potential to regulate the abundance of their host populations was formalized based on the understanding that those helminth macroparasites that reduce survival or fecundity of the infected host population would be among the forces limiting unregulated host population growth. Now, 45 years later, a phenomenal breadth of factors that directly or indirectly affect the host-helminth interaction has emerged. Based largely on publications from the past 5 years, this review explores the host-helminth interaction from three lenses: the perspective of the helminth, the host, and the environment. What biotic and abiotic as well as social and intrinsic host factors affect helminths? What are the negative, and positive, implications for host populations and communities? What are the larger-scale implications of the host-helminth dynamic on the environment, and what evidence do we have that human-induced environmental change will modify this dynamic? The overwhelming message is that context is everything. Our understanding of second-, third-, and fourth-level interactions is extremely limited, and we are far from drawing generalizations about the myriad of microbe-helminth-host interactions.Yet the intricate, co-evolved balance and complexity of these interactions may provide a level of resilience in the face of global environmental change. Hopefully, this albeit limited compilation of recent research will spark new interdisciplinary studies, and application of the One Health approach to all helminth systems will generate new and testable conceptual frameworks that encompass our understanding of the host-helminth-environment triad.

Mass Spectrometry-Based Metabolomics Revealed Effects of Metronidazole on Giardia duodenalis

Giardia duodenalis is a significant protozoan that affects humans and animals. An estimated 280 million G. duodenalis diarrheal cases are recorded annually. Pharmacological therapy is crucial for controlling giardiasis. Metronidazole is the first-line therapy for treating giardiasis. Several metronidazole targets have been proposed. However, the downstream signaling pathways of these targets with respect to their antigiardial action are unclear. In addition, several giardiasis cases have demonstrated treatment failures and drug resistance. Therefore, the development of novel drugs is an urgent need. In this study, we performed a mass spectrometry-based metabolomics study to understand the systemic effects of metronidazole in G. duodenalis. A thorough analysis of metronidazole processes helps identify potential molecular pathways essential for parasite survival. The results demonstrated 350 altered metabolites after exposure to metronidazole. Squamosinin A and N-(2-hydroxyethyl)hexacosanamide were the most up-regulated and down-regulated metabolites, respectively. Proteasome and glycerophospholipid metabolisms demonstrated significant differential pathways. Comparing glycerophospholipid metabolisms of G. duodenalis and humans, the parasite glycerophosphodiester phosphodiesterase was distinct from humans. This protein is considered a potential drug target for treating giardiasis. This study improved our understanding of the effects of metronidazole and identified new potential therapeutic targets for future drug development.