Social Theory and Health

Cutaneous microorganisms are growing in a microenvironment where skin hormones and neurohormones are present in abundance. These molecules are markers of the host physiology and microorganisms have developed strategies for detecting host factors that can represent a threat for their survival. Until now, our knowledge of these mechanisms are limited to bacteria, although the skin microbiota also includes an abundance of yeasts, fungi, viruses and even archaea. Several human hormones and neurotransmitters, including substance P, calcitonin gene related peptides, natriuretic peptides, catecholamines and even estradiol have been studied in this context. This was leading to the identification of original proteins, such as the thermo unstable ribosomal elongation factor EfTu, the chaperone DnaK or the enzyme AmiC, which have been developed by bacteria and have dual functions, in the cytoplasm where they were originally identified and in the bacterial membrane where they act as sensors for host factors. These sensors, designed as moonlighting proteins for their dual functions, are submitted to structural reorganizations and probably post-translational modifications. The occurrence of epigenetic mechanisms in the regulation of moonlighting proteins activity is a source of major complications since similar processes are activated during bacteria adaptation to the host physiology and even storage. Cutaneous bacterial endocrinology is a wide and complex emerging scientific field that requires a deep knowledge of both human and microbial physiology and careful experimental procedures.

Obesity is a significant global burden for individuals and healthcare systems with its array of associated chronic cardiometabolic diseases. While lifestyle modifications such as dietary interventions and increased physical activity are effective in weight management, recent investigations highlight the critical role of timing these interventions in accordance with our body's circadian clock. Over the past decade, multiple studies and meta analyses have investigated how the timing of exercise training influences white adipose tissue (WAT) biology, fat mass loss, and obesity, but physical activity guidelines have not yet adopted a recommendation for exercise timing due to conflicting conclusions. This review aims to summarize the latest findings in this field and touches upon contributing factors such as sex disparities and nutrition timing.

Bacteria–host communication plays a crucial role in symbiosis and pathogenesis. Investigations of pathogenic bacterial responses to host neurotransmitters, including catecholamines, have been the subject of several studies. Both Epinephrine (Epi) and Norepinephrine (NE) catecholamines can modulate bacterial physiology, affecting growth, motility, biofilm formation, virulence, and interactions with eukaryotic cells. This has been widely described in Gram-negative bacteria and mostly for pathogens (i.e. Escherichia coli, Campylobacter jejuni, Salmonella enterica, and Vibrio cholerae). In this review, we focused on whole and targeted bacterial gene expression that have been modulated upon exposure to Epi and NE catecholamines. A wide range of these genes were involved in various physiological aspects (i.e. general metabolism, stress responses, uptake/transport, motility, biofilm, and virulence).

Type 1 diabetes mellitus (T1DM) is an autoimmune disease which is characterized by the destruction of insulin producing pancreatic β-cells. Current evidence supports the contribution of T-cells, macrophages, B-cells, and dendritic cells to the pathogenesis of T1DM as well. T1DM-associated risk factors, including defects in host immune response, socioeconomic conditions and environmental factors create dysbiotic environment in the oral cavity, which support the growth of pathogenic microbial biofilms. Changes in microbial composition, together with the diminished immune response, lead to the development of two most common oral diseases, caries and periodontal diseases. In the present review, we summarized the current evidence on oral manifestations of T1DM, and described the shifts in oral microbial composition and oral immune response.