Characterization of the serum and liver proteomes in gut-microbiota-lacking mice

Abstract

Current nutrition research is focusing on health promotion, disease prevention, and performance improvement for individuals and communities around the world. The humans with required nutritional ingredients depend on both how well the individual is provided with balanced foods and what state of gut microbiota the host has. Studying the mutually beneficial relationships between gut microbiome and host is an increasing attention in biomedical science. The purpose of this study is to understand the role of gut microbiota and to study interactions between gut microbiota and host. In this study, we used a shotgun proteomic approach to reveal the serum and liver proteomes in gut-microbiota-lacking mice. For serum, 15 and 8 proteins were uniquely detected in specific-pathogen-free (SPF) and germ-free (GF) mice, respectively, as well as the 3 and 20 proteins were significantly increased and decreased, respectively, in GF mice compared to SPF mice. Among the proteins of the serum, major urinary protein 1 (MUP-1) of GF mice was significantly decreased compared to SPF mice. In addition, MUP-1 expression is primarily regulated by testosterone. Lacking in gut flora has been implicated in many adverse effects, and now we have found its pathogenic root maybe gut bacteria can regulate the sex-hormone testosterone levels. In the liver, 8 and 22 proteins were uniquely detected in GF mice and SPF mice, respectively, as well as the 14 and 30 proteins were significantly increased and decreased, respectively, in GF mice compared to SPF mice. Furthermore, ingenuity pathway analysis (IPA) indicated that gut microbiota influence the host in cancer, organismal injury and abnormalities, respiratory disease; cell cycle, cellular movement and tissue development; cardiovascular disease, reproductive system disease; and lipid metabolism, molecular transport and small molecule biochemistry. Our findings provide more detailed information of the role of gut microbiota and will be useful to help study gut bacteria and disease prevention.

Fermentable fiber-induced hepatocellular carcinoma in mice recapitulates gene signatures found in human liver cancer

“…It is noteworthy that previous reports have associated a decrease in MUP to be indicative of early liver tumor development [41,42]. It is further interesting to acknowledge that MUP-1 in germ-free mice has been found to be significantly decreased compared to conventional, specific pathogen free mice [43], which suggests that the expression of MUP-1 and other MUP family members may be regulated by the gut https://doi.org/10.1371/journal.pone.0234726.g003 Table 1. Statistics from the Kaplan Meir survival analysis of HCC specific genes leading to poor patient survival.…”

Commensal Microbiota Enhance Both Osteoclast and Osteoblast Activities

“…In osteoblasts, it is critical for the suppression of androgen activity in osteoclastogenesis [ 38 ], but the Ar does not seem to suppress bone resorption through direct actions in osteoclasts [ 39 ]. Another study showed that the production of testosterone was reduced in GF mice [ 40 ]. In our study, the commensal microbiota may contribute to upregulation of androgen signaling by increasing Ar numbers in osteoblasts.…”

Mutual Interactions among Exercise, Sport Supplements and Microbiota

“…Thus, these studies suggest that the modulation of SCFA production by gut microbiota affects energy metabolism during exercise and hence contributes to exercise-induced adaptation. These products of microbiota fermentation can also be used as sources of energy in the liver and muscle cells to improve endurance performance by maintaining glycaemia over time [72,73].…”