Eating avocados as part of your daily diet can help improve gut health, according to a new study from the University of Illinois. Avocado is a healthy food, rich in dietary fiber and monounsaturated fats. However, it was not clear how the avocado impacted on microbes in the gastrointestinal or “gut” system.
“We know that eating avocado helps you feel full and lowers your blood cholesterol, but we didn’t know how it affects intestinal microbes and the metabolites that microbes produce,” says Sharon Thompson, a graduate student in the Division of Nutritional Sciences at U Eu and the lead author of the paper, 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 intestinal microbes that break down fiber and produce metabolites that support gut health. They also had greater microbial diversity compared to people who did not receive the avocado meals in the study.
“Microbial metabolites are compounds produced by microbes that influence health,” says Thompson. “Consumption of avocado has reduced bile acids and increased short-chain fatty acids. These changes correlate with health benefits.”
The study included 163 adults aged 25 to 45 with overweight or obesity – defined as a BMI of at least 25 kg / m2 – but otherwise healthy. They received one meal a day to eat as a substitute for breakfast, lunch or dinner. One group ate one avocado with each meal, while the control group ate a similar meal, but no avocado. Participants provided blood, urine, and feces samples during the 12-week study. They also reported how much of the meals provided they ate and, every four weeks, recorded everything they ate.
While other research on avocado consumption has focused on weight loss, participants in this study were not advised to restrict or change what they ate. Instead, they ate their normal diets, except for replacing one meal a day with the meal offered by the researchers.
The aim 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 U of I and lead author of the study.
“Our goal was to test the hypothesis that avocado fats and fiber 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 their stool.
“Higher fat excretion means that research participants absorb less energy from the food they eat. This was probably due to the reduction of bile acids, which are molecules that our digestive system secretes that allow us to absorb fats. We 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. Avocado fats are monounsaturated, which are heart-healthy fats.
The soluble fiber content is also very important, notes Holscher. An average avocado provides about 12 grams of fiber, which greatly meets the recommended amount of 28 to 34 grams of fiber per day.
“Less than 5% of Americans eat enough fiber. Most people consume about 12 to 16 grams of fiber a day. Incorporating avocado into your diet can help you get closer to following the fiber recommendation.” , she notes.
Fiber consumption is not only good for us; it is also important for the microbiome, says Holscher. “We can’t break down dietary fiber, but certain intestinal microbes can. When we consume dietary fiber, it’s a win-win for intestinal microbes and for us.”
The Holscher Research Laboratory specializes in the dietary modulation of the microbiome and its connections with health. “Just as we think about heart-healthy meals, we need to think about healthy gut meals and how to feed the microbiota,” she explains.
Avocado is an energy-dense food, but it is also nutrient-dense and contains important micronutrients that Americans do not eat enough, such as potassium and fiber.
“It’s just a very nicely packaged fruit that contains nutrients that are important for health. Our work shows that we can add gut health benefits to this list,” says Holscher.
The paper, “Avocado consumption alters gastrointestinal bacterial abundance and microbial metabolite concentrations in 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 Council and the USDA National Food and Agriculture Institute, Hatch Project 1009249. Sharon Thompson was supported by the USDA National Food and Agriculture Institute AFRI Predoctoral Fellowship, 2018-07785 Project and Illinois College ACES Fellowship Jonathan Baldwin Turner. Jennifer Kaczmarek was supported by a division of scholarships for excellence in nutritional sciences. Andrew Taylor was supported by a Department of Food Science and Human Nutrition. The Division of Nutritional Sciences provided initial funding by providing a margin of excellence.
The Division of Nutritional Sciences and the Department of Food and Human Nutrition are located in the College of Agricultural, Consumer and Environmental Sciences, University of Illinois.