The Gut-Brain Axis: What Controls Appetite in the Brain?

The Gut-Brain Axis: What Controls Appetite in the Brain?

What controls appetite in the brain? The answer may surprise you. It’s the gut! Emerging research is confirming that there is a clear connection between the gut, the brain, and appetite.

The Prebiotic Brain

A 2023 study used brain imaging to determine if consuming a prebiotic supplement in the form of inulin would reduce the urge to eat high-calorie foods.1 As it turns out, there is a part of the brain that lights up when deciding what to eat. In this study, that part of the brain didn’t light up as much if the study participants took the prebiotic supplement compared to the participants who did not take the supplement, which meant the prebiotic people ate fewer high-calorie foods.

This research builds on a 2022 analysis of several studies showing that the gut and brain are in constant communication with each other.2 This means supporting gut health, supports brain health as well. And prebiotics are a great way to do that.

What Are Prebiotics?

Prebiotics are a type of fiber that feeds the good bacteria (e.g., probiotics) in the gut.3 Without prebiotics for nourishment, probiotics are not as strong or effective.4 Research demonstrates that prebiotics can help support both gut health and the immune system.5

Foods that are high in prebiotics include dandelion greens, garlic, onions, leeks, asparagus, bananas, apples, and oats. But it can be hard to get enough prebiotic foods in the diet so that’s why you can also get prebiotics as a dietary supplement.

High-quality Prebiotics

If your diet is not high in the prebiotic foods mentioned, you may want to consider taking a prebiotic supplement. But how do you choose which one to take? Good prebiotic supplements will contain prebiotic chicory root fiber (inulin), which is the prebiotic that was used in the 2023 study mentioned.

In addition, probiotics become even more effective when combining them with prebiotics. For example, the probiotic Bacillus coagulans and prebiotic chicory root is a great combination. 

Research is clear that prebiotics and probiotics can support the gut and the immune system but now it’s known that they can also support the brain and appetite.

Ready to take your gut health to the next level? Gut Guru is a prebiotic and probiotic blend packed with both inulin and up to 2 billion CFU of Bacillus coagulans. The plus side? It comes in a delicious blueberry gummy.

Follow @zhou_nutrition for more fitness and wellness tips!


  1. Medawar E, Beyer F, Thieleking R, et al. Prebiotic diet changes neural correlates of food decision-making in overweight adults: a randomized controlled within-subject cross-over trial. Gut. 2023;0:1-13.
  2. Althubeati S, Avery A, Tench CR, Lobo DN, Salter A, Eldeghaidy S. Mapping brain activity of gut-brain signaling to appetite and satiety in healthy adults: A systematic review and functional neuroimaging meta-analysis. Neurosci Biobehav Rev. 2022;136:104603.
  3. Davani-Davari D, Negahdaripour M, Karimzadeh I, et al. Prebiotics: Definition, Types, Sources, Mechanisms, and Clinical Applications. Foods. 2019;8(3):92.
  4. You S, Ma Y, Yan B, et al. The promotion mechanism of prebiotics for probiotics: A review. Front Nutr. 2022;9:1000517.
  5. Carlson JL, Erickson JM, Lloyd BB, Slavin JL. Health Effects and Sources of Prebiotic Dietary Fiber. Curr Dev Nutr. 2018;2(3).


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