The composition of human breast milk is an ideal combination of substances necessary for the healthy development of an infant’s body while protecting from pathogens and the balanced development of the microbiota. Its composition is dynamic and changes with the age of the child, meeting their current needs. The study provides a thorough overview of human milk components, such as immunological components, growth factors, hormones, carbohydrates, lipids, minerals, and vitamins. Authors focus on capturing the most important aspects of the effects of these substances on a newborn’s body, while also looking for specific connections and describing the effects on given systems. Supplementation and the use of ingredients are also discussed. The purpose of this paper is to present the current state of knowledge about the bioactive components of human milk and their impact on the growth, development, and health of the young child.

Atopic dermatitis (AD) is a chronic inflammatory skin condition with a high prevalence worldwide. AD pathogenesis is complex and consists of immune system dysregulation and impaired skin barrier, influenced by genetic and environmental factors. The purpose of the review is to show the complex interplay between atopic dermatitis and the microbiota. Human microbiota plays an important role in AD pathogenesis and the course of the disease. Dysbiosis is an important factor contributing to the development of atopic diseases, including atopic dermatitis. The gut microbiota can influence the composition of the skin microbiota, strengthening the skin barrier and regulating the immune response via the involvement of bacterial metabolites, particularly short-chain fatty acids, in signaling pathways of the gut–skin axis. AD can be modulated by antibiotic intake, dietary adjustments, hygiene, and living conditions. One of the promising strategies for modulating the course of AD is probiotics. This review offers a summary of how the microbiota influences the development and treatment of AD, highlighting aspects that warrant additional investigation.

A disturbance of the structure of the aortic wall results in the formation of aortic aneurysm, which is characterized by a significant bulge on the vessel surface that may have consequences, such as distention and finally rupture. Abdominal aortic aneurysm (AAA) is a major pathological condition because it affects approximately 8% of elderly men and 1.5% of elderly women. The pathogenesis of AAA involves multiple interlocking mechanisms, including inflammation, immune cell activation, protein degradation and cellular malalignments. The expression of inflammatory factors, such as cytokines and chemokines, induce the infiltration of inflammatory cells into the wall of the aorta, including macrophages, natural killer cells (NK cells) and T and B lymphocytes. Protein degradation occurs with a high expression not only of matrix metalloproteinases (MMPs) but also of neutrophil gelatinase-associated lipocalin (NGAL), interferon gamma (IFN-γ) and chymases. The loss of extracellular matrix (ECM) due to cell apoptosis and phenotype switching reduces tissue density and may contribute to AAA. It is important to consider the key mechanisms of initiating and promoting AAA to achieve better preventative and therapeutic outcomes.

The gut microbiota, dominated by bacteria from the Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria phyla, plays an essential role in fermenting indigestible carbohydrates, regulating metabolism, synthesizing vitamins, and maintaining immune functions and intestinal barrier integrity. Dysbiosis is associated with obesity development. Shifts in the ratio of Firmicutes to Bacteroidetes, particularly an increase in Firmicutes, may promote enhanced energy storage, appetite dysregulation, and increased inflammatory processes linked to insulin resistance and other metabolic disorders. The purpose of this literature review is to summarize the current state of knowledge on the relationship between the development and treatment of obesity and overweight and the gut microbiota. Current evidence suggests that probiotics, prebiotics, synbiotics, and fecal microbiota transplantation (FMT) can influence gut microbiota composition and metabolic parameters, including body weight and BMI. The most promising effects are observed with probiotic supplementation, particularly when combined with prebiotics, although efficacy depends on strain type, dose, and duration. Despite encouraging preclinical findings, FMT has shown limited and inconsistent results in human studies. Diet and physical activity are key modulators of the gut microbiota. Fiber, plant proteins, and omega-3 fatty acids support beneficial bacteria, while diets low in fiber and high in saturated fats promote dysbiosis. Aerobic exercise increases microbial diversity and supports growth of favorable bacterial strains. While microbiota changes do not always lead to immediate weight loss, modulating gut microbiota represents an important aspect of obesity prevention and treatment strategies. Further research is necessary to better understand the mechanisms and therapeutic potential of these interventions.

Recent studies increasingly highlight the complex interaction between gut microbiota and mental health, drawing attention to the role of the microbiota–gut–brain axis (MGBA) in the pathophysiology of mental and neurodevelopmental disorders. Changes in the composition of the gut microbiota—dysbiosis—are associated with conditions such as depression, schizophrenia, bipolar disorder (BD), autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), and neurodegenerative diseases such as Parkinson’s and Alzheimer’s. These microbial imbalances can affect brain function through a variety of mechanisms, including activation of the immune system, alteration of intestinal permeability, modulation of the digestive and central nervous systems, and changes in the production of neuroactive metabolites such as short-chain fatty acids, serotonin, and tryptophan derivatives. The aim of this paper is to review the current state of knowledge on therapeutic strategies targeting the gut microbiome—including probiotics, prebiotics, synbiotics, personalized dietary interventions, and fecal microbiota transplantation (FMT)—which are becoming promising adjuncts or alternatives to conventional psychopharmacology, offering a forward-looking and individualized approach to mental health treatment. Understanding the bidirectional and multifactorial nature of MGBA may pave the way for new, integrative treatment paradigms in psychiatry and neurology, requiring further research and exploration of their scope of application.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with a complex etiology whose exact mechanisms are not fully understood. In recent years, there has been growing interest in the role of the gastrointestinal microbiota in the pathogenesis of AD, particularly in the context of the gut–brain axis. The purpose of this review is to discuss the current state of knowledge regarding potential relationships between the composition of the gut microbiota and the development and progression of AD. Preclinical and clinical studies indicating that microbiota imbalances (dysbiosis) may contribute to increased inflammation, increased permeability of the intestinal and blood–brain barriers, and accumulation of pathological proteins such as beta-amyloid and tau are analyzed. The effects of diet, probiotics and microbiota interventions on cognitive function were also discussed. An attempt was also made to evaluate microbiota disruption as a potential early marker of AD development. Although the mechanisms require further study, the role of the gut microbiota appears to be an important and promising direction in understanding the pathophysiology of AD and developing potential therapeutic and diagnostic strategies.