Protect Your Microbiome

The key to good health is in your gut! A recent study on mice sheds light on how sugar in our diet may impact our gut microbiome, along with the risk of diabetes and unwanted weight gain. This new research was published in Cell.Most of us recognize that a high-fat, high-sugar, “Western-style” diet can lead to obesity. This current study suggests that it’s not just the extra calories that are doing damage. According to Ivalyo Ivanov, PhD, associate professor of microbiology & immunology at Columbia University Vagelos College of Physicians and Surgeons, “The gut microbiome is indispensable for an animal's nutrition.” He and his colleagues examined the initial impact of a high-fat, high-sugar diet on the gut microbiome in mice.Your Gut on Sugar: Mouse EditionThe animals showed signs of metabolic syndrome including weight gain, insulin resistance and glucose intolerance after a month of the unhealthy diet. In addition, their microbiomes drastically changed. The number of healthy bacteria fell and unhealthy bacteria increased.A type of immune cell known as Th17 protects against diseases such as diabetes and weight gain. Bacteria called filamentous is vital to the animals’ health as it impacts Th17. This bacteria was reduced with the consumption of a Western-style diet.These immune cells protect our bodies from absorbing types of fats that lead to disease. Th17 cells create molecules that reduce the absorption of unhealthy lipids and reduce inflammation in the intestine. It’s important to protect these cells.Fat or Sugar?When examining the Western-style diet in mice, Ivanov and his team discovered that sugar -- and not fat -- caused issues with filamentous bacteria. Filamentous bacteria and the protective Th17 cells are taken down as a result of sugar intake. According to Ivanov, "When we fed mice a sugar-free, high-fat diet, they retain the intestinal Th17 cells and were completely protected from developing obesity and pre-diabetes, even though they ate the same number of calories."Removing sugar from the mice’s diet didn’t impact all of the animals. In mice that don’t have filamentous bacteria to start with, a beneficial effect wasn’t seen when sugar was taken out of their diets. The animals became heavy and developed diabetes. Ivanov notes that popular diets that advise sugar reduction may only work in individuals that have certain bacteria in their microbiota. Certain probiotics could be beneficial in those cases. Supplements of filamentous bacteria in Ivonov’s mice resulted in the regeneration of Th17 cells to protect against metabolic syndrome even with a high-fat diet.Bacteria in people may be different from filamentous bacteria in mice, but Ivanov believes other bacteria may have similar protective effects. Giving the mice Th17 cells offered protection and could be therapeutic in humans. His study stressed that a complicated relationship between diet, the microbiome, and the immune system is at play and can impact the development of obesity, type 2 diabetes, metabolic syndrome, and other chronic conditions. Ivanov states. "For optimal health, it is important not only to modify your diet but also improve your microbiome or intestinal immune system, for example, by increasing Th17 cell-inducing bacteria."How Can People Protect Their Microbiomes? 

1. Reduce added sugars in the diet -- especially from ultra-processed food.
2. Include fiber-rich foods to diversify gut bacteria. Beans, lentils, whole grains, fruits, and vegetables are key.
3. Avoid extreme diets that eliminate healthy carbs, such as a keto diet.
4. Choose healthy fats when able, including avocado, canola oil, corn oil, olive oil, and nuts and seeds.
5. Discuss the pros and cons of probiotics with your healthcare provider.

By Lisa Andrews, MEd, RD, LDReference:

1. Yoshinaga Kawano, Madeline Edwards, Yiming Huang, Angelina M. Bilate, Leandro P. Araujo, Takeshi Tanoue, Koji Atarashi, Mark S. Ladinsky, Steven L. Reiner, Harris H. Wang, Daniel Mucida, Kenya Honda, Ivaylo I. Ivanov. Microbiota imbalance induced by dietary sugar disrupts immune-mediated protection from metabolic syndrome. Cell, 2022; DOI: 10.1016/j.cell.2022.08.005