The gut microbiota contributes to changes in the host immune response induced by Trichinella spiralis

Microbiome-Metabolomics Analysis of the Impacts of Balantidium Coli Infection in Rhesus Monkeys (Macaca mulatta)

Balantidium coli (B. coli) is a prevalent intestinal parasite in monkeys, significantly impacting their health. Previous studies have demonstrated that B. coli infection in pigs leads to severe dysregulation of the gut microbiota. However, there has been no report on the alterations in fecal microbiota and metabolites in rhesus monkeys infected with B. coli. In order to investigate the differences in gut microbiota and metabolites between healthy rhesus monkeys and those infected with B. coli, we conducted gene sequencing and gas chromatography-mass spectrometry (GC-MS) analysis of fecal samples from 6 healthy rhesus monkeys and 5 rhesus monkeys infected with B. coli. The results revealed significant differences in the composition of gut microbiota between rhesus monkeys infected with B. coli and healthy ones (p < 0.01). The abundance of Campylobacterota was significantly increased (p < 0.01), while the abundance of Bacteroidota was significantly decreased (p < 0.05). Prevotella 9 was the dominant genus in both groups, showing a significant increase in the infected group (p < 0.05). At the species level, Brachyspira hampsonii was significantly increased in the infected group (p < 0.01), whereas Prevotella copri, which was the dominant species in both groups, showed a significant decrease in the infected group (p < 0.05). Metabolomics studies indicated a significant decrease in levels of metabolites such as dihydrolipoamide, 9(Z),11(E)-Conjugated Linoleic Acid, and 8,9-DiHETrE within fecal samples from rhesus monkeys infected with B. coli (p < 0.05). Correlation analysis of the microbiome and metabolome suggested a close relationship between differential microbiota and metabolites. In conclusion, this study suggests that the colonization of B. coli is associated with dysbiosis of the monkey gut microbiota. This study provides a new insight that using intestinal microbes instead of antibiotics to treat balantidiosis can also serve as a reference for further research on the relationship between gut microbiota and metabolomics in host infections by other protozoa.

Leveraging microphysiological systems to expedite understanding of host-parasite interactions

Microphysiological systems (MPS) replicate the dynamic interactions between cells, tissues, and fluids. They have emerged as transformative tools for biology and have been increasingly applied to host-parasite interactions. Offering a better representation of cellular behavior compared with traditional in vitro models, MPS can facilitate the study of parasite tropism, immune evasion, and life cycle transitions across diverse parasitic diseases. Applications span multiple host tissues and pathogens, leveraging advanced bioengineering and microfabrication techniques to address long-standing knowledge gaps. Here, we review recent advances in MPS applied to parasitic diseases and identify persisting challenges and opportunities for investment. By refining these systems and integrating host multicellular models and parasites, MPS hold vast potential to revolutionize parasitology, enhancing our ability to combat parasitic diseases through deeper mechanistic understanding and targeted interventions.

Protective Effect and Gut Microbiota Modulation of Grifola frondosa Antioxidant Peptides in Sodium Dextran Sulfate-Induced Ulcerative Colitis Mice

Grifola frondosa antioxidant peptides (GFAP) were prepared through trypsin enzymolysis and characterized. This study conducted a comprehensive assessment of clinical symptoms, colon pathological injuries, levels of inflammatory factors, expression of inflammation-related proteins, and alterations in gut microbiota composition in mice with ulcerative colitis (UC). The findings demonstrated that GFAP effectively mitigated UC, alleviated mucosal damage, and reduced inflammatory infiltration. Specifically, GFAP administration resulted in significant reductions in pro-inflammatory cytokines IL-6, IL-1β, and TNF-α, while enhancing the expression levels of tight junction proteins such as Occludin and ZO-1. Additionally, GFAP treatment led to decreased levels of Toll-like receptor 4 (TLR-4), inducible nitric oxide synthase (iNOS), and TNF-α. Noteworthy, GFAP also influenced the gut microbiota by decreasing the abundance of Proteobacteria and increasing Bacteroidetes and Firmicutes. Moreover, specific bacteria like Bacteroides uniformis and Alistipes exhibited elevated abundances following GFAP treatment. In summary, GFAP exhibited preventive and protective effects against UC in mice by effectively alleviating clinical symptoms and modulating gut microbiota composition.

The gut microbiota is essential for Trichinella spiralis-evoked suppression of colitis

BACKGROUND

Inflammatory bowel disease (IBD) increases the risk of colorectal cancer, and it has the potential to diminish the quality of life. Clinical and experimental evidence demonstrate protective aspects of parasitic helminth infection against IBD. However, studies on the inhibition of inflammation by helminth infection have overlooked a key determinant of health: the gut microbiota. Although infection with helminths induces alterations in the host microbiota composition, the potential influence and mechanism of helminth infections induced changes in the gut microbiota on the development of IBD has not yet been elucidated. In this study, we analyzed the intersection of helminth Trichinella spiralis and gut bacteria in the regulation of colitis and related mechanisms.

METHODOLOGY/PRINCIPAL FINDINGS

T. spiralis infected mice were treated with antibiotics or cohoused with wild type mice, then challenged with dextran sodium sulfate (DSS)-colitis and disease severity, immune responses and goblet cells assessed. Gut bacteria composition was assessed by 16S rRNA sequencing and short-chain fatty acids (SCFAs) were measured. We found that protection against disease by infection with T. spiralis was abrogated by antibiotic treatment, and cohousing with T. spiralis- infected mice suppressed DSS-colitis in wild type mice. Bacterial community profiling revealed an increase in the abundance of the bacterial genus Muribaculum and unclassified_Muribaculaceae in mice with T. spiralis infection or mice cohoused with T. spiralis- infected mice. Metabolomic analysis demonstrated significantly increased propionic acid in feces from T. spiralis- infected mice. Data also showed that the gut microbiome modulated by T. spiralis exhibited enhanced goblet cell differentiation and elevated IL-10 levels in mice.

CONCLUSIONS

These findings identify the gut microbiome as a critical component of the anti- colitic effect of T. spiralis and gives beneficial insights into the processes by which helminth alleviates colitis.

Effect of Trichinella spiralis-Derived Antigens on Nonalcoholic Fatty Liver Disease Induced by High-Fat Diet in Mice

Nonalcoholic fatty liver disease (NAFLD) is a liver disease characterized by hepatic steatosis, inflammation, and fibrosis, as well as gut dysbiosis. No approved effective therapeutic medicine is available to date for NAFLD. Helminth therapy is believed to be a novel direction and therapeutic strategy for NAFLD. Our previous study showed that Trichinella spiralis-derived antigens (TsAg) had the potential for partially alleviating obesity via regulating gut microbiota. However, the effect of TsAg on NAFLD remains unclear. In this study, high-fat diet (HFD)-induced model mice were treated with TsAg and microbiota transplantation experiments, and alterations in the pathogenesis of nonalcoholic liver disease were assessed. The results showed that TsAg markedly reduced hepatic steatosis, improved insulin resistance, and regulated the abnormal expression of hepatic lipid-related genes. Of note, TsAg ameliorated hepatic inflammation by decreasing pro-inflammatory TNF-α and IL-1β, suppressing hepatic macrophage infiltration, as well as promoting M2 macrophage polarization. Moreover, TsAg reversed gut dysbiosis, as especially indicated by an increase in beneficial bacteria (e.g., Akkermansiaceae and Rikenellaceae). Furthermore, our study found that TsAg reduced LPS hepatic translocation and hepatic TLR4/NF-κB signaling, which further contributed to inhibiting hepatic inflammation. In addition, TsAg inhibited hepatic oxidative stress involving Nrf2/NQO-1 signaling. Microbiota transplantation showed that TsAg-altered microbiota is sufficient to confer protection against NAFLD in HFD-induced mice. Overall, these findings suggest that TsAg involving gut-liver axis and Nrf2/NQO-1 signaling is a novel promising candidate for NAFLD treatment. TsAg restores intestinal microbiota and intestinal barrier to inhibit bacteria and LPS translocation into the liver, contributing to reduce inflammation, oxidative stress, and hepatic steatosis in the liver of NAFLD mice. The effects were attributed to, at least in part, the inactivation of NF-κB pathway and the activation of Nrf-2/NQO-1 pathway. This study provides new insights for understanding immune modulation by T. spiralis-derived products as well as the potential application of TsAg as a modality for NAFLD.

Akkermansia muciniphila: a deworming partner independent of type 2 immunity

The gut microbiota has coevolved with the host for hundreds of millions of years, playing a beneficial role in host health. Human parasitic helminths are widespread and pose a pervasive global public health issue. Although Type 2 immunity provides partial resistance to helminth infections, the composition of the gut microbiota can change correspondingly. Therefore, it raises the question of what role the gut microbiota plays during helminth infection. Akkermansia muciniphila has emerged as a notable representative of beneficial microorganisms in the gut microbiota. Recent studies indicate that A. muciniphila is not merely associated with helminth infection but is also causally linked to infection. Here, we provide an overview of the crosstalk between A. muciniphila and enteric helminth infection. Our goal is to enhance our understanding of the interplay among A. muciniphila, helminths, and their hosts while also exploring the potential underlying mechanisms.