Abstract

The gut micro biota, the largest symbiotic ecosystem with the host, has been shown to play important roles in maintaining intestinal homeostasis. Symbiosis of the gut micro biome is caused by the imbalance between the commensal and pathogenic micro biomes. The commensal micro biome regulates the maturation of the mucosal immune system, while the pathogenic micro biome causes immunity dysfunction, resulting in disease development. The gut mucosal system, which consists of lymph nodes, lamina propria and epithelial cells, constitutes a protective barrier for the integrity of the intestinal tract. The composition of the gut micro biota is under the surveillance of the normal mucosal immune system. Inflammation, which is caused by abnormal immune responses, influences the balance of the gut micro biome, resulting in intestinal diseases. In this review, we briefly outlined the interaction between the gut micro biota and the immune system and provided a reference for future studies [1].

The mammalian gut contains a microbial community, defined as the micro biome, which includes bacteria, viruses, fungi, etc. Microbial genome sequences contain 3 × 106 genes, which is approximately 150-fold the length of the human genome. In recent decades, next generation sequencing technology has contributed to understanding the intricate relationship between the micro biome and related diseases. 16S rRNA sequencing results showed that Formicates and Bacteroidetes make up approximately 92% of the human micro biome. Gut micro biota include 1,000 to 1,500 bacterial species; however, an individual contains only approximately 160 bacterial species, indicating that the composition of the micro biome is substantially different between individuals and is said to environmental changes and genetic inheritance. Environmental factors play a very important role in the gut micro biome. Even mice with an equivalent genotype housed in separate cages within an equivalent facility show different micro biota compositions. The composition of the mouse gut micro biome is especially influenced by variations in diet, age and inflammation. A review of studies also showed that the composition of the gut micro biome in an eczema population is influenced by environmental factors, including pregnancy duration, delivery method, feeding type, rearing style, number of siblings, lifestyle, etc. The intestinal micro biome, a microbial organ that is shaped in combination with the host’s genotype, responds to the growth process and environmental exposure. The coordinated interactions between intestinal microbial populations contribute to maintaining intestinal homeostasis and play a crucial role within the immune process.