Ca2+-Permeable Channels/Ca2+ Signaling in the Regulation of Ileal Na+/Gln Co-Transport in Mice

Intestinal mucosal microbiota mediate amino acid metabolism involved in the gastrointestinal adaptability to cold and humid environmental stress in mice

Growing evidence has demonstrated that cold and humid environmental stress triggers gastrointestinal (GI) disorders. In this study, we explored the effects of intestinal microbiota homeostasis on the intestinal mucus barrier and GI disorders by cold and humid environmental stress. Moreover, the inner link between the intestinal mucosal microbiota and metabolites in mice with cold and humid environmental stress was interpreted by integrative analysis of PacBio HiFi sequencing microbial genomics and targeted metabolomics. In the current study, we found (1) after the cold and wet cold and humid environmental stress intervened in the intestinal microbiota disorder and homeostasis mice respectively, the bacterial culturing and fluorescein diacetate (FDA) microbial activity detection of intestinal microbiota including feces, intestinal contents, and intestinal mucosa suggested that the cold and humid environmental stress decreased the colony of culturable bacteria and microbial activity, in which intestinal microbiota disorder aggravated the injury of the intestinal mucus barrier and the GI symptoms related to cold and humid environmental stress; (2) the serum amino acid transferases such as glutamate pyruvic transa (GPT), and glutamic oxaloacetic transaminase (GOT) in cold and humid environmental stressed mice increased significantly, indicating that the intestinal microbiota adapted to cold and humid environmental stress by regulating the host's amino acid metabolism; (3) the integrative analysis of multi-omics illustrated a prediction model based on the microbiota Lactobacillus reuteri abundance and host amino acid level that can predict intestinal mucoprotein Muc2 with an adjusted R2 of 75.0%. In conclusion, the cold and humid environmental stress regulates the neurotransmitter amino acids metabolic function both in intestinal mucosal microbiota and host serum by adjusting the composition of the dominant bacterial population Lactobacillus reuteri, which contributes to the intestinal mucus barrier injury and GI disorders caused by cold and humid environmental stress.

Ion channels and transporters regulate nutrient absorption in health and disease

Ion channels and transporters are ubiquitously expressed on cell membrane, which involve in a plethora of physiological process such as contraction, neurotransmission, secretion and so on. Ion channels and transporters is of great importance to maintaining membrane potential homeostasis, which is essential to absorption of nutrients in gastrointestinal tract. Most of nutrients are electrogenic and require ion channels and transporters to absorb. This review summarizes the latest research on the role of ion channels and transporters in regulating nutrient uptake such as K+ channels, Ca2+ channels and ion exchangers. Revealing the mechanism of ion channels and transporters associated with nutrient uptake will be helpful to provide new methods to diagnosis and find potential targets for diseases like diabetes, inflammatory bowel diseases, etc. Even though some of study still remain ambiguous and in early stage, we believe that ion channels and transporters will be novel therapeutic targets in the future.