Your Gut Microbiome May be Driving your Sweet Tooth
The average American adult, teenager, and child consumes about 17 teaspoons of added sugar daily. This equals to about 270 calories a day from added sugar alone, with the highest sources coming from sugar-sweetened beverages. Keep in mind that these sugars include both refined (granulated white table sugar, powdered sugar, high-fructose corn syrup) and unrefined sugars (honey, maple syrup, coconut sugar, agave nectar). Given our widespread accessibility to sugary beverages and foods in grocery stores and through the internet, sugar cravings have become much easier to satisfy than to suppress. Other than discipline, could improving our gut microbiome help us consume food for nutritional need rather than for pleasure?
While it might feel like sugar cravings are driven primarily by mood, exercise, or stress, your microbes may also be playing an important role. Research continues to reveal how the gut microbiome is involved in eating behaviors via the gut-brain axis, the bi-directional pathway between the gut and the brain. This pathway is established by the vagus nerve, a connection that allows the gastrointestinal (GI) tract to send information about the state of inner organs to the brain through sensory nerve fibers. The vagus nerve is not only responsible for regulating heart rate, respiratory rate, and digestion, but it has also been shown to influence eating behaviors.
“This pathway is established by the vagus nerve, a connection that allows the gastrointestinal (GI) tract to send information about the state of inner organs to the brain through sensory nerve fibers.”
Recent findings have discovered a potential reason for overeating sugary foods. A team of researchers examined eating behaviors in mice given a four-week course of antibiotics, completely disrupting their gut microbiota. Compared to mice with intact gut microbiota, the mice taking the antibiotics ate 50% more high-sugar pellets in a binge-like manner. Interestingly, when the antibiotic-treated mice were given fecal transplants from mice not treated with antibiotics, their intact microbiomes were restored, and their eating habits returned to normal. The researchers eventually identified two groups of bacteria that were responsible for suppressing their over-eating behaviors: Lactobacillus johnsonii and a group of bacteria known as S24-7. Although more research is needed in humans, these findings offer insight into the potential role for specific probiotics for reducing sugar cravings. Additionally, this study highlights the risk of disrupting gut microbiota by the intake of antibiotics and how reducing the presence of beneficial bacteria can be related to eating disorders.
“The researchers eventually identified two groups of bacteria that were responsible for suppressing their over-eating behaviors: Lactobacillus johnsonii and a group of bacteria known as S24-7.”
The imbalance of microbes in the intestines, as observed in the antibiotic-treated mice, is also known as gut dysbiosis. Dysbiosis is defined by an imbalance in bacterial composition, changes in bacterial metabolic activities, or changes in bacterial distribution within the gut. Dysbiosis is typically temporary and mild, but it is essential to understand that in addition to antibiotics, it can be caused by dietary changes, alcohol, stress, or exposure to harmful bacteria. If left untreated, dysbiosis can become a risk factor for certain diseases such inflammatory bowel diseases, obesity or even depression. There are certain intestinal bacteria that researchers are finding could be involved in obesity by controlling appetite and food reward signaling. Sugar cravings have also been observed in some individuals more than others. For example, research indicates that obese individuals seeking bariatric or weight loss surgeries are more likely to experience addiction to foods high in fat and sugar, a behavior that is rapidly reduced by the surgery. Therefore, correcting dysbiosis may help prevent and even treat eating disorders related to health problems such as obesity and other addictive behaviors.
Luckily, some forms of gut dysbiosis can be repaired by re-introducing probiotics in the gut. Consuming probiotic-rich foods such as yogurt, kefir, sauerkraut, or kimchi can help improve dysbiosis by increasing the diversity and richness of beneficial bacteria in the GI tract. Evidence from mostly animal, and some human studies has even suggested a potential benefit of prebiotic and various probiotic strains for treating obesity. In fact, several studies on mice reported less weight gain and fat accumulation when taking Lactobacillus and Bifidobacterium strains compared to placebo-treated animals. Furthermore, experimental studies have shown that consuming prebiotics (food for probiotics) can stimulate the growth of Lactobacillus and Bifidobacterium in the GI tract and therefore, restore the gut microbial ecosystem. Garlic and asparagus are some of the most well-known prebiotic foods to stimulate the growth of Bifidobacteria and Lactobacillus bacteria.
“Consuming probiotic-rich foods such as yogurt, kefir, sauerkraut, or kimchi can help improve dysbiosis by increasing the diversity and richness of beneficial bacteria in the GI tract.”
These findings suggest that certain gut microbes may influence eating behaviors and sugar cravings via the gut-brain axis. Disrupting the gut microbial ecosystem through antibiotic leads to dysbiosis, increasing the risk for both gut and eating disorders. To prevent such disruptions, it is important to limit the use of antibiotics, consume a diet without ultra-processed foods, but rich in naturally fermented foods, fiber, and prebiotic foods such as onions, garlic, asparagus, and leeks to promote diversity and richness of the gut microbial ecosystem.
Thus, reducing sugar cravings won’t be achieved by simply cutting sugar consumption or by replacing sugar with non-nutrient sweeteners, as demonstrated by several studies. While further research in human studies is needed into the pathophysiology of sugar cravings, it is evident that maintaining a rich and diverse gut microbiome from early in life, by pursuing healthier eating behaviors and by limiting the use of antibiotics to the treatment of demonstrate bacterial infections can not only reduce food addiction but prevent a number of other major health problems.
Monica Echeverri holds a Master of Science in Human Nutrition and Functional Medicine from the University of Western States and currently works as a food photographer, writer, and recipe developer for natural food brands and wellness publications. She has experience in community nutrition education and enjoys spending her time in the kitchen creating healthy recipes that she shares on her Instagram, @mealsbymonica.