Porcine enteric coronaviruses (PECs) include porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), and porcine deltacoronavirus (PDCoV). Infections with PECs can cause severe diarrhea in pigs, particularly newborn piglets, resulting in high mortality rates and posing a serious threat and economic loss to the global swine industry. Such infections induce oxidative stress to activate various transcription factors and alter their transcriptional pathways, thereby affecting cellular metabolism and the viral life cycle. This leads to cellular dysfunction and further promotes viral replication, forming a vicious cycle. The oxidative stress associated with PECs is considered one of the potential common pathogenic mechanisms. This review summarizes the information about the oxidative stress induced by infections with PECs and emphasizes that antioxidant strategies represent one of the effective approaches to counteract such infections.

Colorectal cancer (CRC), one of the most common malignancies of the digestive system, is characterized by complex pathogenic mechanisms and an overall poor prognosis. The gut microbiota and its metabolites play a dual role in CRC by modulating various forms of programmed cell death (PCD), either promoting or inhibiting tumorigenesis and influencing the tumor responses to chemotherapy and immunotherapy. This review systematically summarizes recent advances in understanding how the gut microbiota regulates CRC initiation, progression, and responses to therapies through the modulation of apoptosis, autophagy, ferroptosis, and pyroptosis. Furthermore, it discusses the potential clinical-translational implications of these findings, aiming to provide a theoretical foundation for elucidating CRC pathogenesis and developing novel therapeutic strategies targeting the gut microbiota.

Respiratory viral infections pose a severe threat to global public health security, and exploring effective strategies to prevent them is of clinical significance. The gut microbiota plays a crucial role in regulating anti-infective immunity by remodeling the immune microenvironment, maintaining the immune homeostasis and boosting antiviral defenses of the host. Conversely, dysbiosis of the gut microbiota can disrupt immune homeostasis, resulting in impaired innate immune responses and abnormal activation of adaptive immunity, thereby raising the risk of respiratory viral infections in the host. This study elaborates on the essential role of the gut microbiota in the antiviral immune response of the host across multiple aspects. (1) It thoroughly explains how the gut microbiota contributes to forming an immune defense barrier by performing physiological functions such as secreting antimicrobial peptides, metabolizing nutrients, preserving mucosal barrier integrity, and modulating immune homeostasis of the host. (2) It analyzes the antiviral immune regulatory network that involves the regulation of type I interferon responses and immune cell differentiation, all within the context of gut microbiota balance and dysbiosis. (3) It explores how probiotics exert antiviral effects through mechanisms such as inhibiting viral proliferation, improving the host’s immune response, reducing secondary infections, and restoring gut microbiota balance. Although breakthroughs have been made in understanding the ternary interaction network of the microbiota, the immune system, and viral infection, the molecular mechanisms behind its dynamic balance and precise regulation still urgently need detailed investigation. Specifically, the mechanisms of interactions between gut microbiota metabolites and host epigenetic regulation, along with the long-term protective strategies of microbiota-induced immune homeostasis against viral infection, remain to be systematically revealed through multi-omics technologies.

As a crucial group of probiotics, lactic acid bacteria (LAB) play a vital role in the gut microbial ecosystem of insects. This article comprehensively reviewed the species composition, ecological functions, and practical values of LAB in the guts of major insect orders, including Hymenoptera, Diptera, Coleoptera, Hemiptera, Lepidoptera, Blattodea, and Orthoptera. To date, multiple LAB genera including Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Enterococcus, Bifidobacterium, and Weissella were successfully identified from insect guts. The community composition of these bacteria was shaped by factors such as host phylogeny, dietary traits, developmental stages, gut microenvironment, and external ecological conditions. The LAB in insect guts not only assist the hosts in degrading recalcitrant complexes by secreting extracellular enzymes but also inhibit pathogens through the synthesis of antimicrobial substances such as bacteriocins. Additionally, they modulate host immune responses, promote growth and development, regulate host behavior, and participate in the metabolic detoxification of xenobiotics, thereby enhancing host survival and adaptability. Furthermore, insect-derived LAB held great potential in the production of resource insects, pest management, agricultural waste utilization, and green manufacturing. In summary, insect guts represent an important reservoir for the discovery and isolation of novel LAB.