Infection and Immunity Program, Biomedicine Discovery Institute, Department of Biochemistry, Monash University, Clayton, Australia.
Published: May 2017
AI Article Synopsis
Article Abstract
Gut dysbiosis might underlie the pathogenesis of type 1 diabetes. In mice of the non-obese diabetic (NOD) strain, we found that key features of disease correlated inversely with blood and fecal concentrations of the microbial metabolites acetate and butyrate. We therefore fed NOD mice specialized diets designed to release large amounts of acetate or butyrate after bacterial fermentation in the colon. Each diet provided a high degree of protection from diabetes, even when administered after breakdown of immunotolerance. Feeding mice a combined acetate- and butyrate-yielding diet provided complete protection, which suggested that acetate and butyrate might operate through distinct mechanisms. Acetate markedly decreased the frequency of autoreactive T cells in lymphoid tissues, through effects on B cells and their ability to expand populations of autoreactive T cells. A diet containing butyrate boosted the number and function of regulatory T cells, whereas acetate- and butyrate-yielding diets enhanced gut integrity and decreased serum concentration of diabetogenic cytokines such as IL-21. Medicinal foods or metabolites might represent an effective and natural approach for countering the numerous immunological defects that contribute to T cell-dependent autoimmune diseases.
Introduction: The gut microbiome, allegedly involved in both healthy homeostasis and development of disease, is found to be associated with several types of cancer. Short chain fatty acids (SCFAs), important metabolites derived from the gut microbiota, are described to carry both protective and promoting features in cancer development. Limited research exists on neuroendocrine tumors (NET) and their association with microbiota derived SCFAs.
Plant-produced sulfoquinovose (SQ, 6-deoxy-6-sulfoglucose) is one of the most abundant sulfur-containing compounds in nature and its bacterial degradation plays an important role in the biogeochemical sulfur and carbon cycles and in all habitats where SQ is produced and degraded, particularly in gut microbiomes. Here, we report the enrichment and characterization of a strictly anaerobic SQ-degrading bacterial consortium that produces the C-sulfonate isethionate (ISE) as the major product but also the C-sulfonate 2,3-dihydroxypropanesulfonate (DHPS), with concomitant production of acetate and hydrogen (H). In the second step, the ISE was degraded completely to hydrogen sulfide (HS) when an additional electron donor (external H) was supplied to the consortium.
The gut microbiota is a complex and dynamic ecosystem that plays a crucial role in human health and disease, including obesity, diabetes, cardiovascular diseases, neurodegenerative diseases, inflammatory bowel disease, and cancer. Chronic inflammation is a common feature of these diseases and is closely related to angiogenesis (the process of forming new blood vessels), which is often dysregulated in pathological conditions. Inflammation potentially acts as a central mediator.
Exhaled breath offers an interesting matrix of low invasive sampling of potentially relevant information about the organism's metabolism in the form of volatile organic compounds (VOC). The VOC can be exhaled by the ructus (Islam et al., 2023) or passed the blood-lung barrier for expiration through the lungs.
Acidogenic co-fermentation of waste activated sludge (WAS) and food waste (FW) under thermophilic conditions enhances process consistency, while overcoming the problem of acetic acid consumption due to growing methanogens. Two long-term continuous co-fermentation experiments were carried out with a WAS:FW mixture (70:30 % in VS) at organic loading rate of 8 gVS/(L·d). Experiment 1 assessed the impact of temperature (35 °C and 55 °C) and WAS origin (WAS_A and WAS_B) in two collection periods.
