Extracts of the hops plant have been shown to reduce weight and insulin resistance in rodents and humans, but until now, scientists have not been able to fully explain the mechanisms responsible for these benefits. Hop extracts are used as flavoring agents for their bitter properties.
In a study published in the journal Molecular Metabolism, a team from Scripps Research hypothesized that bitter taste receptors in the intestine could be mediating their beneficial effects in metabolic disease. Studies have shown that exposure of cultured enteroendocrine cells to bitter tastants can stimulate release of hormones. These findings have led to the suggestion that activation of bitter taste receptors may be of benefit in diabetes, but this tenet has not been tested.
For this study, the researchers assessed the ability of a pure derivative of a hops isohumulone to signal through bitter taste receptors. They also used isohumulone as a tool to assess the impact of bitter taste receptor activation in obesitydiabetes. The study tested the affect of isohumulone in mice to establish the full impact of activating gut bitter taste signalling. Acute treatment was found to stimulated secretion of hormones and enhanced glucose tolerance. Chronic treatment caused weight and fat mass loss, increased energy expenditure, enhanced glucose tolerance and insulin sensitivity, normalized plasma lipids, and induced broad suppression of inflammatory markers. Chronic isohumulone treatment altered enteroendocrine hormone levels and bile acid homeostasis and stimulated sustained hormone release. Combined treatment with a dipeptidyl peptidase IV inhibitor amplified the incretin-based benefits of this pure isohumulone.
Activation of bitter taste receptors in the gut result in a remodeling of enteroendocrine hormone release and bile acid metabolism that ameliorates multiple features of metabolic syndrome. Targeting extraoral bitter taste receptors may be useful in metabolic disease, the authors conclude
Source: Intestinal bitter taste receptor activation alters hormone secretion and imparts metabolic benefits. Bernard P. Kok et al. Molecular Metabolism (2018).