Microbial contribution to the caloric restriction-triggered regulation of the intestinal levels of glutathione transferases, taurine, and bile acid

Abstract

Recently we showed that caloric restriction (CR) triggers an increase in the levels of free taurine, taurine-conjugated bile acids (BA), and other taurine conjugates in intestinal mucosa while decreasing glutathione (GSH) levels in wild-type male mice. In the current project, we decided to investigate whether the microbiota is involved in the response to CR by depleting gut bacteria. The antibiotics treatment diminished CR-specific increase in the levels of free taurine and its conjugates as well as upregulated expression and activity of GSH transferases (GST) in the intestinal mucosa. Further, it diminished a CR-related increase in BAs levels in the liver, plasma, and intestinal mucosa. Transplant of microbiota from CR mice to ad libitum fed mice triggered CR-like changes in MGST1 expression, levels of taurine and taurine conjugates in the mucosa of the ileum. We show for the first time, that microbiota contributes to the intestinal response to CR-triggered changes in BA, taurine, and GST levels.

Versatile Triad Alliance: Bile Acid, Taurine and Microbiota

“…Controversially, some reports show that taurine does not trigger significant change in the microbiota’s diversity or composition as well as the composition of SCFA produced when cultured with human feces [ 346 ]. Reciprocally, the presence of taurine in the intestine depends on microbiota [ 350 , 353 ]. One of the mechanisms involves microbiota-mediated BAs deconjugation and release of free taurine [ 132 ].…”

“…One of the mechanisms involves microbiota-mediated BAs deconjugation and release of free taurine [ 132 ]. Thus, microbiota transplant from calorie-restricted mice characterized by increased levels of BAs and taurine in the intestinal mucosa, raises levels of intestinal free taurine and various secondary taurine conjugates [ 353 ].…”

“…The conjugation of taurine with GSH increases intestinal taurine uptake during caloric restriction, playing an important role in taurine circulation and reuse. However, the potential roles of other taurine conjugates remain unknown [ 353 , 403 ].…”

The role of intestinal microbiota and its metabolites in intestinal and extraintestinal organ injury induced by intestinal ischemia reperfusion injury

“…Studies have confirmed that intestinal microbiota and its metabolites play a variety of important roles and functions in our normal life activities, including nutrient absorption, growth and development, biological barrier, immune regulation, fat metabolism, anti-tumor, etc [45][46][47]. The human intestinal microbiota is stimulated by large number of dietary nutrients to produce bioactive compounds such as bile acids, short-chain fatty acids (SCFA), ammonia, phenols, and endotoxins [18,[48][49][50]. These microbial-derived metabolites are the communication medium between the microbe and the host, which is essential to maintain the normal physiological state of the host.…”

“…Intestinal microbiota refers to the trillions of microorganisms that exist in the gastrointestinal tract, including bacteria, viruses, fungi, archaea and protozoa [9][10][11][12][13][14]. They can interact with the host in a variety of ways and play a critical role in nutrient metabolism, xenobiotics and drug metabolism, maintenance of the intestinal barrier, and the structure and function of the gastrointestinal tract [15][16][17][18][19]. In the past few decades, the research on intestinal microbiota and its metabolites and intestinal I/R injury and intestinal I/R-induced extraintestinal organ injury has increased rapidly.…”