Preference to sweets

Preference to sweets differs from one person to another. It may be related only with personal inherent preference but also with occurrence of type II diabetes mellitus and its control. When we try dieting, that could be the highest wall to overcome.

An article in recent Nature Microbiology reported that carbohydrate preference is regulated by the following mechanism. It is not confirmed by the other researchers yet and there could be other pathways of regulation. It is still an interesting finding.

Various long chain free fatty acids are contained in foods. Unsaturated free fatty acid may work as the starter of this pathway. At first, I thought long chain free fatty acid rich, that is, gourmet meal might upregulate the prefernce. But, in reality, it is the opposite. When we take the gourmet meal, it may down regulate appetite for sweets. 

The mechanism could be summarized as below;

A receptor for free fatty acid, FFAR4 reacts with long chain fatty acid on intestinal wall. >A bacterial flora in intestine, Phocaiecola vulgatus, proliferates. This is one of the intestinal microbiome. Breast milk feeding is believed to increase it. >Panthoteinic acid is produced by Phocaiecola vulgatus. >A gut hormone, GLP1, is secretd from intestinal secretary cell through panthoteinic acid. >A growth factor, FGF21, is produced in liver and circulates to brain by the function of GLP1. >At hypothalamus, carbohydrate preference is down regulated by FGF21.

Among the substances or hormone involved in this pathway, GLP1 or GLP1 agonist has drawn attention as a drug for type II diabetes mellitus and as a dieting drug. The researchers who have found this substance/function and its clinical use have recently been awarded for Laskar award in the US. It is an advantageous point as a drug for diabetes mellitus that GLP1 won't cause hypoglycemia on human in hunger. 

I was impressed at what elaborate pathway is present in living body. There could be other pathways as told before. With more amount of knowledge gained, we could control our health/disease. Intestinal microbiota has been believed to work as an internal milieu. It is believed to have immunological function on living body as well. With breast milk fed infants, intestinal normal flora may determine even preference of sweets. It's surprising a flora in intestine could work as a component of this cascade. 

When I was a med student, none of these findings were known. Nowadays, med students should understand and memorize them to be a doctor. Huge amount of new knowledge piled up. What a big task for them!