在头癌中口腔和肠道微生物群之间的跨学科沟通

The oral cavity, or the mouth, is a complex structure in humans that plays a vital role in our day-to-day lives. Its role is not only in chewing and swallowing food; it also plays a role in speech and facial expressions.
Teeth: The teeth are the hardest structures in our bodies. Humans have two sets of teeth throughout their lifetime: deciduous (baby) teeth and permanent teeth. Each tooth consists of several parts: the crown (visible part), the root (embedded in the jaw), enamel (hard outer...

The oral microbiome includes a complex ecosystem comprising over 700 microbial species, identified through genomic sequencing and culture-based analyses to date. This community includes a core microbiome, found universally among individuals, and a variable component influenced by environmental factors such as diet, lifestyle, and host genetics. Site-specific conditions, including oxygen gradients, pH levels, and nutrient availability, determine the spatial distribution of these microorganisms...

The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more...

The human gastrointestinal (GI) tract is characterized by distinct physicochemical conditions that shape its microbial communities. Among these, the stomach presents a particularly challenging environment for microbial colonization due to its highly acidic pH, ranging from 1 to 3. This extreme acidity effectively limits microbial density. However, certain acid-tolerant microorganisms are capable of surviving in this niche. Notably, Helicobacter pylori can colonize the gastric mucosa,...

The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such...