Dietary choline, via gut microbe- generated trimethylamine-N- oxide, aggravates chronic kidney disease-induced cardiac dysfunction by inhibiting hypoxia-induced factor 1α

The Interplay Between Dietary Choline and Cardiometabolic Disorders: A Review of Current Evidence

PURPOSE OF REVIEW

Choline is an essential nutrient for human health and cellular homeostasis as it is necessary for the synthesis of lipid cell membranes, lipoproteins, and the synthesis of the neurotransmitter acetylcholine. The aim of this review is to analyze the beneficial effects of choline and its significance in cellular metabolism and various inflammatory pathways, such as the inflammasome. We will discuss the significance of dietary choline in cardiometabolic disorders, such as non-alcoholic fatty liver disease (NAFLD), cardiovascular disease (CVD), and chronic kidney disease (CKD) as well as in cognitive function and associated neuropsychiatric disorders.

RECENT FINDINGS

Choline deficiency has been related to the development of NAFLD and cognitive disability in the offspring as well as in adulthood. In sharp contrast, excess dietary intake of choline mediated via the increased production of trimethylamine by the gut microbiota and increased trimethylamine-N-oxide (TMAO) levels has been related to atherosclerosis in most studies. In this context, CVD and CKD through the accumulation of TMAO, p-Cresyl-sulfate (pCS), and indoxyl-sulfate (IS) in serum may be the result of the interplay between excess dietary choline, the increased production of TMAO by the gut microbiota, and the resulting activation of inflammatory responses and fibrosis. A balanced diet, with no excess nor any deficiency in dietary choline, is of outmost importance regarding the prevention of cardiometabolic disorders as well as cognitive function. Large-scale studies with the use of next-generation probiotics, especially Akkermansia muciniphila and Faecalibacterium prausnitzii, should further examine their therapeutic potential in this context.

Gut dysbiosis: Ecological causes and causative effects on human disease

The gut microbiota plays a role in many human diseases, but high-throughput sequence analysis does not provide a straightforward path for defining healthy microbial communities. Therefore, understanding mechanisms that drive compositional changes during disease (gut dysbiosis) continues to be a central goal in microbiome research. Insights from the microbial pathogenesis field show that an ecological cause for gut dysbiosis is an increased availability of host-derived respiratory electron acceptors, which are dominant drivers of microbial community composition. Similar changes in the host environment also drive gut dysbiosis in several chronic human illnesses, and a better understanding of the underlying mechanisms informs approaches to causatively link compositional changes in the gut microbiota to an exacerbation of symptoms. The emerging picture suggests that homeostasis is maintained by host functions that control the availability of resources governing microbial growth. Defining dysbiosis as a weakening of these host functions directs attention to the underlying cause and identifies potential targets for therapeutic intervention.