Eating avocados as part of your daily diet can help improve gut health, a new study from the University of Illinois shows. Avocados are a healthy food high in dietary fiber and monounsaturated fat. However, it was not clear how avocados affected microbes in the gastrointestinal system or “gut”.
“We know that eating avocado helps you feel full and reduces the concentration of cholesterol in the blood, but we didn’t know how it affects gut microbes and metabolites produced by microbes,” says Sharon Thompson, PhD student in the Division of Nutritional Sciences at the U of Me and the lead author of the article, published in Journal of Nutrition.
The researchers found that people who ate avocados every day as part of a meal had a greater abundance of gut microbes that break down fiber and produce metabolites that support gut health. They also had greater microbial diversity than people who did not receive the avocado meals in the study.
“Microbial metabolites are compounds produced by health-affecting microbes,” says Thompson. “The consumption of avocados reduced bile acids and increased short-chain fatty acids. These changes are related to beneficial health outcomes.”
The study included 163 adults between 25 and 45 years of age with overweight or obesity – defined as a BMI of at least 25 kg / m2 – but otherwise healthy. They received one meal a day to be consumed as a substitute for breakfast, lunch or dinner. One group ate an avocado with each meal, while the control group ate a similar meal but without the avocado. Participants provided blood, urine, and stool samples during the 12-week study. They also reported the amount of meals provided they ate and every four weeks they recorded everything they ate.
While other research on avocado consumption has focused on weight loss, participants in this study were not advised to limit or change what they ate. Instead they ate their normal diets with the exception of replacing one meal a day with the meal provided by the researchers.
The purpose of this study was to explore the effects of avocado consumption on the gastrointestinal microbiota, says Hannah Holscher, assistant professor of nutrition in the Department of Food Science and Human Nutrition at the U of I and senior author of the study.
“Our goal was to test the hypothesis that the fats and fiber in avocados positively affect the gut microbiota. We also wanted to explore the relationships between gut microbes and health outcomes,” says Holscher.
Avocados are high in fat; However, the researchers found that while the avocado group consumed slightly more calories than the control group, some more fat was excreted in the stool.
“Greater fat excretion meant that the research participants were absorbing less energy from the foods they were eating. This was likely due to the reduction in bile acids, which are molecules secreted by our digestive system that allow us to absorb fat. found that the amount of bile acids in the stool was lower and the amount of fat in the stool was higher in the avocado group, “explains Holscher.
Different types of fats have differential effects on the microbiome. The fats in avocados are monounsaturated, which are heart-healthy fats.
Soluble fiber content is also very important, notes Holscher. An average avocado provides around 12 grams of fiber, which goes a long way in reaching the recommended amount of 28-34 grams of fiber per day.
“Less than 5% of Americans eat enough fiber. Most people consume 12 to 16 grams of fiber per day. Therefore, incorporating avocados into your diet can help you get closer to meeting the fiber recommendation,” he notes.
Eating fiber isn’t just good for us; it’s also important for the microbiome, says Holscher. “We can’t break down dietary fiber, but some gut microbes can. When we consume dietary fiber, it’s a win for gut microbes and for us.”
Holscher’s research laboratory specializes in the dietary modulation of the microbiome and its connections to health. “Just as we think about heart-healthy meals, we also need to think about gut-healthy meals and how to feed the microbiota,” he explains.
Avocado is an energy-dense food, but it’s also nutritious and contains important micronutrients that Americans don’t eat enough of, such as potassium and fiber.
“It’s just a really well packaged fruit that contains nutrients that are important to health. Our work shows we can add gut health benefits to that list,” says Holscher.
The article, “Avocado consumption alters gastrointestinal bacterial abundance and microbial metabolite concentrations among overweight or obese adults: a randomized controlled trial” is published in Journal of Nutrition.
The authors are Sharon Thompson, Melisa Bailey, Andrew Taylor, Jennifer Kaczmarek, Annemarie Mysonhimer, Caitlyn Edwards, Ginger Reeser, Nicholas Burd, Naiman Khan and Hannah Holscher.
Research funding was provided by the Hass Avocado Board and USDA National Institute of Food and Agriculture, Hatch project 1009249. Sharon Thompson was supported by USDA National Institute of Food and Agriculture AFRI Predoctoral Fellowship, project 2018-07785 , and the Illinois College of ACES Jonathan Baldwin Turner Fellowship. Jennifer Kaczmarek was supported by a Division of Nutrition Sciences Excellence Fellowship. Andrew Taylor was supported by a Department of Food Science and Human Nutrition Fellowship. The Division of Nutritional Sciences provided initial funding through the Margin of Excellence endowment.
The Division of Nutritional Sciences and the Department of Food Science and Human Nutrition are located at the College of Agricultural, Consumer and Environmental Sciences, University of Illinois.