New Research Shows Prebiotic Diet Influences Food Decision-Making for Weight Loss

Appetite control is the main mechanism of action for most prescription anti-obesity drugs today. However, there are significant adverse events with these drugs. Finding safer, natural ways to influence appetite is needed. Emerging research has identified a novel route to reduce appetite for weight loss.

The Gut-Brain Axis

A small, recently published randomized controlled trial used brain imaging via functional MRI to determine if prebiotic consumption in the form of inulin dulled the urge to eat poorly. Specifically, the researchers looked at reward-related brain activation of high-calorie foods. The researchers concluded that “a prebiotic intervention attenuated reward-related brain activation during food decision-making, paralleled by shifts in the gut microbiota.”

“This was a proof of concept study that should pave the way for larger studies in more diverse populations,” said Tina Kaczor, ND, FABNO, a naturopathic oncologist and Editor-in-Chief of the Natural Medicine Journal. “If larger studies confirm these findings, then we will have gained insight into how a prebiotic can actually change eating behavior.”

This latest study builds on previous research, including a 2022 systematic review and functional neuroimaging meta-analysis that mapped brain activation for the gut-brain axis. 

Behavioral patterning and biological reactions dictate hunger, satiety, and cravings. Prebiotic fibers from plants have always been associated with feeling fuller after a meal. 

"The simplest explanation is that fiber increases the volume of food per calorie, and the expansion of the stomach leads to feeling fuller," explained Kaczor, who is also the founder of Round Table Cancer Care and co-host of The Cancer Pod. “Of course, it’s much more complex than this.”

Probiotics, Prebiotics, and Gut Diversity

There is much debate about which is more beneficial, probiotics or prebiotics. The short answer is both are important; however, many argue that because prebiotics serve as food for probiotics, prebiotics are critical.

Kaczor uses the analogy of seed and soil, with probiotics being the seeds and prebiotics the soil. “While you need both for a healthy microbiome, the soil needs to be fertile for the probiotics to take hold,” said Kaczor. “For this reason, I think prebiotics are more important than probiotics.”

Gut microbiome diversity is key. Research indicates that decreased gut diversity is an indicator of an unhealthy microbiome that is linked to a variety of chronic conditions and poor quality of life compared to those with a diverse, balanced gut microbiome.  

To create a more diverse microbiome in her patients, Kaczor begins with diet by instructing patients to:

• Eat in season as much as possible.
• Choose unprocessed plant foods.
• Eat the rainbow of colors, including red, purple, yellow, and green.
• Eat different parts of the plants, including roots/tubers, nuts/seeds/legumes, leaves/stems, and fruits/berries.

"Like any new concept, it takes focus to first think about plant foods this way, but eventually, it becomes second nature," said Kaczor. 

What about supplements? “Probiotic supplements are sometimes needed, but they are not useful in the absence of prebiotics and other nutrients to maintain a diverse array of various organisms,” she explained.

Some high prebiotic foods include dandelion greens, garlic, onions, leeks, asparagus, bananas, oats, apples, and flaxseeds. Research indicates that by eating more prebiotic foods or taking a prebiotic supplement, there is an increased production of beneficial bacteria and metabolites, improved immunity, and a stronger gut barrier with a decrease in protein fermentation, pathogenic bacterial populations, and allergy risk.

Healthy Weight as a Way of Life

Based on emerging research, are prebiotics the answer to the obesity epidemic? Not so fast, said Kaczor.

“Prebiotics for weight loss may be helpful, but it is a small piece of a larger plan,” Kaczor explained. “The complexity of the inter-relationship of the huge variety of microbes in the gut is something that we cannot replicate in a capsule.” 

With her patients, Kaczor places the focus on being healthy, not necessarily on being thin. She emphasizes body composition with attention to building more muscle. She teaches her patients about healthy day-to-day habits such as exercise, sound sleep, and eating a diet that is naturally high in prebiotic plant-based foods. “No pill will ever render the health benefits of these routine habits,” Kaczor concluded.