Advanced Gut & Microbiome Research

Fungal infections have a key effect on the commercial poultry production and welfare. Infections caused by fungi and their food contaminants are zoonotic and influence food safety. Eggs and cooked meats remain major public health concerns. Therefore, this research is aimed at examining the pathology and understanding the epidemiology of fungal infection in layer chicken flocks. The study was carried out on twenty-layer flocks from Kafrelsheikh Governorate, Egypt, from January 2019 to December 2020. In total, 600 samples were collected from 100 healthy and diseased layer chickens from different organs (skin, liver, lung, kidney, spleen, and ovary). In this work, we present the clinical and pathological characteristics of some fungal pathogens (Aspergillus spp. and Fusarium spp.) in layer chicken flocks, as they are responsible for reducing the egg production. In total, 19 fungal strains were isolated from individual chickens, and these were analysed to determine the fungal species. The total proportion of fungal infections at the farm level was (3/20) 15%. The main clinical signs were emaciation and mortalities that reached . We report the first isolation of Aspergillus piperis and Fusarium species from the ovary of poultry, which is the main reason for egg retention and multiple numerous nodules of occasional caseating centers in layer ovaries. The histopathological findings of Aspergillus infection are indicated by the presence of branched hyphae that tend to be numerous and progressive. Furthermore, we found spherules with multiple endospores of Fusarium spp. in the ovaries. Morphological and molecular identification and analysis were performed to confirm the etiological agents.

Recent research reveals that the increasing prevalence of food allergies (FA) is due in part to changes in the commensal microbiome. Studies in humans have shown that compared with healthy controls, individuals have distinct gut microbiomes during the onset and progression of FA. Mechanistic studies have established that the gut microbiota can affect the growth of immune tolerance to food antigens by modifying regulatory T cell differentiation, regulating basophil populations, and enhancing intestinal barrier function. New therapeutic and preventive approaches to altering the gut microbiota using diet adjustments, probiotics, prebiotics, synbiotics, postbiotics, fecal microbiota transplantation, and Chinese medicine have been developed towards FA. Herein, we summarized the latest evidence on the gut microbiota profiles and functions associated with FA, oral tolerance mechanisms, and gut microbiota-targeted therapeutic strategies for FA.

The human gut is colonized by a variety of microorganisms especially bacteria. There are multiple evidences that gut microflora dysbiosis is a novel risk factor for development of various intestine-related diseases such as irritable bowel syndrome and inflammatory bowel disease as well as nonintestinal diseases including obesity, type II diabetes, and cardiovascular diseases. A mutual relationship among the host’s immune system and the metabolites produced by the gut microflora, including trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), and bile acids, is present. Alterations in the host-microbial interaction lead to impaired homeostasis and thus contribute towards the activation of several pathways that causes progression of cardiovascular diseases. This review summarizes the role of gut microflora dysbiosis in the development and progression of atherosclerosis, coronary artery disease, and hypertension. Dysbiosis has been implicated in the pathogenesis of atherosclerosis by TLR activation, intracellular Ca²⁺ release, FXR-induced signalling, and decreased removal of cholesterol from peripheral macrophages, while in hypertension the mechanism involved is prolonged haemodynamic effects of angiotensin-II and oxLDL-induced hypertension. In fact, CVDs are the leading cause of mortality across the globe; thus, targeting the gut microflora in the treatment of these diseases along with the conventional therapy can markedly reduce the cardiovascular disease burden. The gut microbiota-targeted treatment including prebiotics, probiotics, and postbiotics can be therapeutically beneficial. In future, the heart-gut axis can be presented as a novel and clinically relevant area for research.

More focus is being paid to the relationship between gastrointestinal microbiota and human health. The microbiota-gut-brain axis was created as a result of the intricate networks and connections between the gastrointestinal bacteria and the host, highlighting the significant impact that this environment may have on brain health and central nervous system problems. To communicate with the central nervous system, the gastrointestinal, autonomic, immune, neuroendocrine, and neuroendocrine systems engage in a bidirectional interaction with the microbiota. Through a number of neurological processes, including stimulation of the altered neurotransmitter function, hypothalamic-pituitary-adrenal axis, and immune system activity, changes in this network may have an impact on both health and sickness. Anxiety and sadness are two neuropsychiatric conditions that may be impacted by the microbiota-gut-brain axis, according to a recent study. Numerous host disorders, including obesity, diabetes, and inflammation, have already been related to alterations in the gut microbiota’s makeup. In this article, the effects of the gut microbiota on the functioning of the central nervous system are examined, with a focus on the symptoms of anxiety and depression. After examining how stress affects the autonomic, neuroendocrine, immunological, and neurotransmitter systems, modern gastrointestinal-based therapies stress the importance of the microbiome in the prevention and treatment of brain-based diseases including anxiety and depression.

Drug-related liver injury (DILI) is increasing in the incidence of liver injury due to nonviral liver disease and has become a health problem that should not be underestimated. As a hot research topic in recent years, gut microbiota have been studied in various tumors, cardiovascular metabolic diseases, and human immunity. However, there is still a lack of research related to gut microbiota and DILI. It is known that they can influence each other through the regulation of the “gut-liver axis,” and the relationship between them and the possible mechanisms of action are still at the research stage. Human leukocyte antigen (HLA) gene polymorphisms are closely related to the development of DILI, and the gene can also affect changes in the composition of gut microbes. In this paper, we review the possible relationships and mechanisms between DILI and gut microbiota in order to provide new research directions for the prevention and treatment of DILI in the future. In the future, untargeted therapies using antibiotics, probiotics, or FMT will be replaced by personalised and precision medicine approaches, such as bioengineered bacterial strains or drugs that modulate specific bacterial enzymes and metabolic pathways.

Gastrointestinal disease is characterized by gastrointestinal dysfunction with dysbiosis of the microbiome. Probiotics may act as biological agents in treating gastrointestinal diseases through modifying gut microbiota. However, several challenges, including safety, stress resistance, postcolonization quantification, and evaluation models, may hinder the application of probiotics in gastrointestinal diseases. This review introduces the emerging methods for delivering probiotics as well as available materials. Furthermore, we elucidated bacteriocins and their role in helping probiotics obtain a competitive advantage over other strains and challenges of large-scale application. Bacteriocins produced by probiotics also showed promising efficacy in gastrointestinal diseases including the capacity of immune stimulation, intestinal barrier protection, and cytotoxicity against intestinal tumorigenesis. For the quantification of probiotics in complex microbiomes and evaluation methods of probiotic encapsulated delivery systems, recent fluorescent labeling technology and various in vitro and in vivo models were also reviewed. Given the widespread use of probiotic agents in the microecological therapy of gastrointestinal diseases, further understanding of the multiple challenges of probiotic application and the updated methods to improve the colonization and evaluation system of probiotics is of great significance for probiotics as live biotherapeutics.