What Health Professionals Should Know When Counseling Clients
A well-functioning gut plays a vital role in maintaining overall health. At the center of gut health is the gut microbiome—a diverse community of trillions of microorganisms, including bacteria, yeasts, and viruses, that reside in the digestive tract. These microbes help digest nutrients and produce bioactive compounds that influence systems throughout the body.
Emerging research indicates that the composition and activity of the gut microbiome may affect the risk of various health conditions, such as obesity, type 2 diabetes, inflammatory bowel disease, and colorectal cancer. The microbiome is also closely linked to immune function, potentially impacting how the body responds to illness and inflammation. Changes in gut microbiota composition are also associated with improved acne conditions, nonalcoholic fatty liver disease, and kidney disease. As a result, helping clients understand and support their gut health is an increasingly important part of preventive healthcare.
Nutrition’s Influence on the Gut Microbiome
Prebiotics and probiotics are both important to gut health but serve different purposes. Prebiotics are naturally occurring, non-digestible carbohydrates—such as inulin and fructooligosaccharides—that nourish beneficial gut bacteria. On the other hand, probiotics are live microorganisms that may provide health benefits when consumed in adequate amounts. Simply put, prebiotics feed the good bacteria, while probiotics are the good bacteria.
While supplements are available, many whole foods naturally supply prebiotics—for instance, fruit fibers like pectin support beneficial gut microbes. A single serving of avocado (one-third of a medium fruit) contains approximately 1.2 grams of pectin, making it a valuable food-based source of fiber.
Scientists are continuing to uncover how different types of fiber, especially soluble fiber, influence the gut microbiome. Foods such as fruits, vegetables, whole grains, legumes, nuts, and seeds all offer a mix of soluble and insoluble fiber. Including a variety of these plant-based foods in the diet supports microbial diversity and contributes to overall digestive health.
Research Shows Food and Nutrient Impacts on the Gut
Research links eating avocados and their nutrients to changes in the gut microbiome and other health benefits. Although the results of the research below cannot be generalized to all populations, and more research is needed, they suggest a role for avocados or their nutrients in health.
- A study of 128 melanoma patients found that those who ate a high-fiber diet, which promotes healthy gut microbes and avoided probiotics, had better responses to immunotherapy, with a 30% lower risk of cancer progression for every 5g increase in daily fiber. The participants reported their eating patterns and any use of probiotic supplements in the month before receiving immunotherapy.
- In a weight-loss study* of 51 overweight or obese adults, researchers found that the gut microbiota differed in response to an avocado-inclusive and control diet. Participants were advised to eat 500 calories less each day and one avocado daily, compared to a control group following the same dietary guidance without avocado.
- In a trial* of 163 overweight adults, researchers reported changes to gut bacteria and metabolite levels when participants ate one avocado a day for 12 weeks compared to a diet that excluded avocado.
- A meta-analysis of 12 studies including 2570 participants found that blood folate levels are significantly lower in inflammatory bowel disease or ulcerative colitis than in control patients. There was no relationship found for Crohn’s disease. The results do not infer causation and are limited by potential confounding factors. Avocados are a good source of folate.
- A study* evaluated the impact of daily avocado consumption for 6 months on gut microbiota in 230 adults with abdominal obesity. The avocado group showed higher gut microbiota diversity and significant increases in Faecalibacterium prausnitzii and Bacterium AF16_15 compared to controls. Improvements were more pronounced in participants with lower baseline diet quality, highlighting avocados’ potential prebiotic benefits.
*Supported by the Avocado Nutrition Center
Practical Tips for Professionals
Many Americans consume just 16 grams of fiber daily—far short of the recommended 28 grams. This gap offers a practical opportunity for dietitians and healthcare professionals to recommend foods like avocados, which are nutrient-dense, versatile, and widely accepted.
Encourage clients to consume at least 28 grams of fiber daily to meet the recommended intake. One serving of fresh avocado (about 50 grams or 1/3 of a medium fruit) provides 3 grams of fiber, with approximately 65% being insoluble. This combination of soluble and insoluble fiber can support digestive health by promoting regularity and microbial diversity. In individuals with IBS, fiber may help relieve constipation by softening stool and making it easier to pass.
Some tips to help clients boost their fiber and support their gut:
- Encourage variety: Eating various plant-based foods fosters gut microbial diversity.
- Recommend avocado as a functional food: Use as a topping for toast, sandwiches, or salads, or as a fat substitute in baked goods.
- Promote label reading: Educate clients to choose foods with at least 3 grams of fiber per serving.
- Highlight avocado’s dual fiber: With soluble and insoluble fiber, avocados offer complementary gut health benefits.
Conclusion
The relationship between diet and gut microbiome is one of the most promising fields in health science today. Avocados provide a unique package of nutrients, including fiber, pectin, and folate, all contributing to gut health. While more large-scale studies are needed to generalize findings across populations, the evidence suggests that avocados can be valuable to a gut-supportive diet. Health professionals can confidently recommend avocados as part of a dietary pattern that promotes microbial diversity, enhances SCFA production, and supports long-term digestive and metabolic health.
