Do Probiotics Improve Hunger?

One of the most promising scientific frontiers in nutrition has been our increasing understanding of the gut. It turns out it does a lot more than churn through our food. Instead, it looks more and more like the gut is a delicate and complex intra-cellular highway where our body and residing bacteria mediate different signaling pathways that have profound effects on our bodies.

This is particularly true with regards to hunger. A lot of the hunger we feel is independent of the amount of food we have in our stomach.  Hunger is a function of the mind as much as the tummy. And our brain receives a lot of its satiety signals from the gut before and after a meal.

Ghrelin: Hunger’s Silencing Hormone

Before a meal your stomach tends to release a hormone called ghrelin which is hunger inducing, and after a meal a whole slew of peptides can be released which tell your appetite: stop!!

There’s a lot of causal factors for how these signals get turned on and off, but at least one of them is becoming increasingly clear: bacteria.

Prebiotics: Telling Your Body “Don’t Eat!”

It seems that “nice” bacteria (prebiotics) have a tendency to cause our guts to produce more of the appetite-suppressing stuff. For example, in 2009 a double blind placebo study was done that measured the effect of prebiotics on people’s feelings of satiety (fullness) and hormone regulation. Here’s what they found:

Prebiotic supplementation was associated with an increase in plasma gut peptide concentrations (glucagon-like peptide 1 and peptide YY), which may contribute in part to changes in appetite sensation and glucose excursion responses after a meal in healthy subjects

There’s some jargon in there, but the take home point is this: a decent amount of prebiotics seems to cause our bodies to put our hunger-suppressing activities into a higher gear.

This sort of news is encouraging because the body’s sensitivity to these signals seems robust. That is, it responds to these signals no matter what. In a world where every other intervention aimed at preventing obesity ends in ugly failure, these sorts of findings illuminate a potential way to solve the problem.