The contemporary approach to nutrition increasingly considers the role of non-nutritive bioactive compounds in modulating the immune system and maintaining health. This article provides up-to-date insight into the immunomodulatory effects of selected bioactive compounds, including micro- and macronutrients, vitamins, as well as other health-promoting substances, such as omega-3 fatty acids, probiotics, prebiotics, postbiotics (including butyric acid and sodium butyrate), coenzyme Q10, lipoic acid, and plant-derived components such as phenolic acids, flavonoids, coumarins, alkaloids, polyacetylenes, saponins, carotenoids, and terpenoids. Micro- and macronutrients, such as zinc, selenium, magnesium, and iron, play a pivotal role in regulating the immune response and protecting against oxidative stress. Vitamins, especially vitamins C, D, E, and B, are vital for the optimal functioning of the immune system as they facilitate the production of cytokines, the differentiation of immunological cells, and the neutralization of free radicals, among other functions. Omega-3 fatty acids exhibit strong anti-inflammatory effects and enhance immune cell function. Probiotics, prebiotics, and postbiotics modulate the intestinal microbiota, thereby promoting the integrity of the intestinal barrier and communication between the microbiota and the immune system. Coenzyme Q10, renowned for its antioxidant attributes, participates in the protection of cells from oxidative stress and promotes energy processes essential for immune function. Sodium butyrate and lipoic acid exhibit anti-inflammatory effects and facilitate the regeneration of the intestinal epithelium, which is crucial for the maintenance of immune homeostasis. This article emphasizes the necessity of an integrative approach to optimal nutrition that considers not only nutritional but also non-nutritional bioactive compounds to provide adequate support for immune function. Without them, the immune system will never function properly, because it has been adapted to this in the course of evolution. The data presented in this article may serve as a foundation for further research into the potential applications of bioactive components in the prevention and treatment of diseases associated with immune dysfunction.

An organism’s ability to function properly depends not solely on its diet but also on the intake of nutrients and non-nutritive bioactive compounds that exert immunomodulatory effects. This principle applies both to healthy individuals and, in particular, to those with concomitant chronic conditions, such as type 2 diabetes. However, the current food industry and the widespread use of highly processed foods often lead to nutritional deficiencies. Numerous studies have confirmed the occurrence of immune system dysfunction in patients with type 2 diabetes. This article elucidates the impact of specific nutrients on the immune system function, which maintains homeostasis of the organism, with a particular emphasis on type 2 diabetes. The role of macronutrients, micronutrients, vitamins, and selected substances, such as omega-3 fatty acids, coenzyme Q10, and alpha-lipoic acid, was taken into consideration, which outlined the minimum range of tests that ought to be performed on patients in order to either directly or indirectly determine the severity of malnutrition in this group of patients.

Growing evidence indicates that the gut microbiota is a central regulator of systemic immunity, acting through epithelial barrier integrity, microbial metabolites, and bidirectional signaling with innate and adaptive immune cells. Within this framework, probiotics have attracted substantial interest as tools for immune modulation; however, their effects are not uniform and should not be generalized across species or formulations. This review synthesizes current evidence on the gut microbiota–immune axis and examines how defined probiotic strains influence immune homeostasis, inflammation, and clinical outcomes. Particular emphasis is placed on strain-specific effects among lactic acid bacteria, bifidobacteria, yeast probiotics, and emerging nontraditional candidates, with attention to mechanisms involving cytokine signaling, regulatory T-cell induction, nuclear factor kappa B (NF-κB) modulation, toll-like receptor (TLR) pathways, short-chain fatty acids (SCFAs), tryptophan metabolites, and bile-acid-dependent signaling. The available literature indicates that the most meaningful immunological effects arise from precisely characterized strains acting in specific host contexts, whereas inconsistent trial design, small sample sizes, variable dosing, and poor strain resolution continue to limit translation. Overall, current data support a shift from generic probiotic use toward mechanism-based, strain-specific, and increasingly personalized strategies for immune modulation.

Research Subject: Primary and secondary immunodeficiencies represent a growing clinical and public health challenge due to increased susceptibility to infections, impaired immune regulation, chronic inflammation, and disturbances in redox homeostasis. The pathophysiology of these disorders involves dysfunction of innate and adaptive immunity, altered cytokine production, oxidative stress, and reduced activity of antioxidant defense mechanisms. In recent years, attention has increasingly focused on the role of oxidative imbalance and chronic inflammation in weakening immune function. Ozone therapy, when used at controlled low doses, induces a hormetic response that triggers adaptive antioxidant pathways, modulates cytokine profiles, and enhances the activity of immune cells. Due to these properties, ozone has emerged as a potential adjunctive therapy aimed at restoring immune homeostasis and improving clinical outcomes in patients with immune disorders. Aim of Study: The aim of this review is to discuss the role of oxidative stress and immune dysregulation in the pathogenesis of immunodeficiencies and to provide an updated overview of current evidence regarding the therapeutic potential of ozone therapy. This article summarizes molecular mechanisms, biochemical effects, and clinical findings related to ozone-based interventions, with particular emphasis on cytokine modulation, redox balance, macrophage function, regulatory T cells (Treg), and NK cell activity. Materials and Methods: This review is based on scientific data retrieved from PubMed, Scopus, and Google Scholar. Included sources comprise randomized clinical trials, observational studies, meta-analyses, mechanistic studies, and review articles published between 1996 and 2025. Keywords used during the literature search included: “ozone therapy”, “immunomodulation”, “oxidative stress”, “inborn errors of immunity”, “secondary immunodeficiency”, “Treg cells”, “redox homeostasis”. Results: Analysis of current studies shows that controlled low-dose ozone (typically 10–40 µg/mL) activates the Nrf2/ARE antioxidant pathway, increases enzymatic defense (SOD, catalase, GPx), and reduces levels of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6. Clinical trials report improved lymphocyte profiles, enhanced macrophage phagocytic function, increased Treg activity, and reinforced NK cell responses. Patients receiving ozone therapy demonstrate reductions in inflammatory markers (CRP, IL-6, D-dimer), improved redox balance, decreased infection frequency, and better overall immune performance. The therapy is generally well tolerated when administered within established safety guidelines. Conclusions: Available evidence indicates that ozone therapy may serve as a valuable adjunct in the management of immunodeficiencies by modulating immune responses, reducing oxidative stress, and restoring homeostatic balance. Although current clinical outcomes are promising, further multicenter randomized trials are needed to standardize dosing protocols, assess long-term effectiveness, and confirm safety.

Oral findings such as inflammation, ulcerations, or lesions can indicate serious systemic diseases and should prompt suspicion of acquired chronic conditions or inborn errors of immunity (IEIs). Currently, there are approximately 500 disease entities classified as IEIs, with the list expanding annually. The awareness of the existence of such conditions is of paramount importance, as patients with these disorders frequently necessitate the utilization of enhanced diagnostic techniques. This is exemplified by patients with impaired antibody production, in whom conventional serological methods may prove to be undiagnostic. Patients with IEI may require distinct therapeutic approaches or antimicrobial prophylaxis throughout their lives. An accurate diagnosis and, more importantly, early identification of patients with immune deficiencies is crucial to ensure the quality and longevity of their lives. It is important to note that the failure to establish a proper diagnosis or to provide adequate treatment could also have legal implications for medical professionals. The article presents IEIs, which may manifest in the oral cavity, and their diagnosis alongside therapeutic procedures.

Non-celiac villous atrophy (NCVA) is a multifaceted and under-recognized clinical entity with an etiology beyond celiac disease. This review critically examines the diverse pathophysiological mechanisms underlying NCVA, including autoimmune enteropathies, immune deficiency-related disorders, infectious processes, drug-induced trauma, and metabolic or environmental influences. A comprehensive synthesis of peer-reviewed literature, clinical studies, and case reports was conducted, adopting a multidisciplinary perspective that integrates immunologic, infectious, metabolic, and pharmacologic insights. The literature search was performed in three phases: identification of relevant studies, critical assessment of selected publications, and synthesis of key findings. Searches were carried out in PubMed, Scopus, Web of Science, and Google Scholar databases. The final search, completed in June 2025, included international, English-language articles, electronic books, and online reports. Studies were included if they addressed NCVA in the context of pathophysiology, clinical manifestations, or management strategies, with priority given to publications from the last ten years (2015–2025). The search strategy used the primary term “non-celiac villous atrophy” combined with supplementary keywords such as autoimmune enteropathy, common variable immunodeficiency, tropical sprue, drug-related enteropathy, pathophysiology, immunological mechanisms, chronic inflammation, genetic factors, environmental influences, and clinical management. Histopathological evaluations reveal that NCVA often manifests with varying degrees of villous blunting, crypt hypertrophy, and intraepithelial lymphocytosis, albeit without the gliadin-specific immune response seen in celiac disease. Various immune pathways are involved, such as autoimmune deregulation and chronic inflammatory responses, while drug-induced and environmental factors further complicate its clinical picture. These findings highlight significant diagnostic challenges and underscore the need to adapt diagnostic algorithms that combine clinical history, serologic evaluations, and histopathologic analysis. In conclusion, an in-depth understanding of the heterogeneous etiology of NCVA is critical to improving diagnostic accuracy and optimizing therapeutic strategies. Future research should prioritize the identification of specific biomarkers and the development of targeted interventions to address the unique mechanisms underlying NCVA, thereby improving patient management and outcomes.