A growing body of research points to the gut microbiota’s potential significance in controlling the metabolic phenotype. In fact, a number of studies indicate that the gut microbiota plays a crucial part in controlling energy intake and satiety signaling.
Short-chain fatty acids (SCFAs), a kind of microbial metabolite produced by the gut microbiota, might affect satiety. Researchers in the current paper provide an overview of what is now known about the relationships between microbial metabolites and satiety signaling.
SCFAs are primarily created when dietary fiber ferments. The most prevalent SCFAs are acetate, propionate, and butyrate, which make up roughly 95% of all SCFAs produced in people. The satiation-related hormones peptide YY (PYY) and glucagon-like peptide 1 are secreted as a result of these SCFAs (GLP-1).
It has been demonstrated that SCFA infusion into the colon increases GLP-1 and PYY levels in the blood. Distal SCFA treatment, but not proximal, appears to raise PYY levels in people, according to in vivo investigations. Furthermore, GLP-2, cholecystokinin (CCK), and stomach inhibitory peptide secretion are all impacted by SCFAs (GIP).
In obese/overweight humans, acute increases in serum SCFAs have been associated with decreases in systemic ghrelin concentrations, indicating the possibility that SCFAs may affect hunger perceptions.Six trials that looked at short-term effects found that fiber interventions decreased ad libitum calorie intake. Eight of the nine studies that examined the intervention’s effects on subjective appetite ratings found that the breath hydrogen levels were higher, a sign of microbial fermentation. Importantly, studies that found no benefit of the intervention also noted elevated breath hydrogen levels.
Seven studies demonstrated greater release of satiety hormones in response to fiber/prebiotic intervention. In two long-term studies, obese/overweight individuals who received a 12-week fiber and an eight-week oligofructose intervention consumed less energy ad libitum.
Only two studies found that fiber intervention increased levels of satiety hormones.
