Bacteria, viruses, fungi, and protists are present on all epithelia of the human body, including oral, gut, skin, lung, and vaginal and urinary tracts. The most extensively studied bacteriome is that of the intestine, in which the adult form contains more than 4 × 1013 cells and up to 1000 different species. At birth, the gut bacteriome is simple and of low number but then expands rapidly in both number and diversity by around three days. At this point, when the lower bowel is anaerobic, Bifidobacterium, Clostridium, and Bacteroides constitute most of the species. The switch to solid foods drives further expansion and complexity in the bacteriome until it generally stabilises into an adult-like form (a high proportion of Bacillota (formerly Firmicutes) and Bacteroidota (Bacteroidetes), moderate levels of Actinomycetota (Actinobacteria), and low numbers of Cyanobacteria, Fusobacteriota, Pseudomonadota (Proteobacteria), Synergistota, and Verrucomicrobiota) by about two years of age. The acquisition of the gut by various microbes in a time-critical and progressive manner is vital in driving the proper development and function of the gut epithelium and immune system. Failure of crucial bacteria to colonise at critical developmental stages can lead to impaired gut integrity and poor immune function. Furthermore, prolonged dysbiosis can lead to acute/chronic inflammation and high susceptibility to infection.The colonisation of the gut depends on multiple interdependent factors, including host and microbial genetics and bioactive factors, environment, antibiotics, and nutrition and nutritional factors. While a healthy regime, and lifestyle is a generally recommended approach to help in maintaining gut and immune function, a comprehensive understanding on how specific bioactive diets products can promote colonisation of the gut by potentially health-promoting bacteria and counteract the debilitation effects of dysbiosis on host gut inflammation and susceptibility is lacking.In this Research Topic, we welcome Original Research articles, Technology Reports, Reviews, Brief Research Reports, and Mini Reviews that cover, but are not limited to, the following areas:1 Current research on colonisation of the human intestine and modulation of healthy gut and immune function.2 Preclinical studies on use of well-defined dietary products to modulate gut microbiome and enhance resistance to disorders such as pathogen infections.3 Preclinical studies on use of probiotics [single or multiples], alone or in combination with prebiotics, postbiotics, and synbiotics, to modulate the gut microbiome and enhance resistance to disorders such as pathogen infections.4 Preclinical studies on use of host-derived live-biotherapeutic products to modulate the gut microbiome and enhance resistance to disorders such as pathogen infections.5 Studies done on pathogen/commensal bacterial interactions within the healthy or disturbed microbiota of mouth, lung, skin, vagina, urinary tract and other non-intestinal epithelia. 6 Studies aiming to increase awareness regarding the key role of microbiota in maintaining a good health balance and wellbeing.
Bacteria, viruses, fungi, and protists are present on all epithelia of the human body, including oral, gut, skin, lung, and vaginal and urinary tracts. The most extensively studied bacteriome is that of the intestine, in which the adult form contains more than 4 × 1013 cells and up to 1000 different species. At birth, the gut bacteriome is simple and of low number but then expands rapidly in both number and diversity by around three days. At this point, when the lower bowel is anaerobic, Bifidobacterium, Clostridium, and Bacteroides constitute most of the species. The switch to solid foods drives further expansion and complexity in the bacteriome until it generally stabilises into an adult-like form (a high proportion of Bacillota (formerly Firmicutes) and Bacteroidota (Bacteroidetes), moderate levels of Actinomycetota (Actinobacteria), and low numbers of Cyanobacteria, Fusobacteriota, Pseudomonadota (Proteobacteria), Synergistota, and Verrucomicrobiota) by about two years of age. The acquisition of the gut by various microbes in a time-critical and progressive manner is vital in driving the proper development and function of the gut epithelium and immune system. Failure of crucial bacteria to colonise at critical developmental stages can lead to impaired gut integrity and poor immune function. Furthermore, prolonged dysbiosis can lead to acute/chronic inflammation and high susceptibility to infection.The colonisation of the gut depends on multiple interdependent factors, including host and microbial genetics and bioactive factors, environment, antibiotics, and nutrition and nutritional factors. While a healthy regime, and lifestyle is a generally recommended approach to help in maintaining gut and immune function, a comprehensive understanding on how specific bioactive diets products can promote colonisation of the gut by potentially health-promoting bacteria and counteract the debilitation effects of dysbiosis on host gut inflammation and susceptibility is lacking.In this Research Topic, we welcome Original Research articles, Technology Reports, Reviews, Brief Research Reports, and Mini Reviews that cover, but are not limited to, the following areas:1 Current research on colonisation of the human intestine and modulation of healthy gut and immune function.2 Preclinical studies on use of well-defined dietary products to modulate gut microbiome and enhance resistance to disorders such as pathogen infections.3 Preclinical studies on use of probiotics [single or multiples], alone or in combination with prebiotics, postbiotics, and synbiotics, to modulate the gut microbiome and enhance resistance to disorders such as pathogen infections.4 Preclinical studies on use of host-derived live-biotherapeutic products to modulate the gut microbiome and enhance resistance to disorders such as pathogen infections.5 Studies done on pathogen/commensal bacterial interactions within the healthy or disturbed microbiota of mouth, lung, skin, vagina, urinary tract and other non-intestinal epithelia. 6 Studies aiming to increase awareness regarding the key role of microbiota in maintaining a good health balance and wellbeing.