Feed yourself and your gut bacteria, at the same time!

by Rachel Stuck, RDN

You’re probably familiar with the word metabolism, the body’s process of breaking down food, and you’ve probably wished yours worked a little faster. But what about metabolites? Have you ever heard of them? Metabolites may be one of the most important but least appreciated aspects of wellness. Although metabolism is responsible for your energy cycle, your metabolites are responsible for your overall health. Instead of worrying about the speed of your metabolism, you might want to start focusing on your metabolites.

You might notice that the word metabolite sounds like metabolism. Metabolism is the round-the-clock process that breaks down and rebuilds the food we eat to turn it into energy and other needed substances. Metabolites are the substances formed during metabolism or necessary for metabolism. (1) The metabolites in our bodies are derived from diet and gut bacteria and are processed in the body. In other words, metabolites are either involved in metabolism or they are a product of metabolism.

Does that sound complicated? It’s easier to understand if you think of your body as a car. Your body’s check engine light may be lack of energy, upset stomach, weight gain, or anything else that makes you feel less than your best. Testing your gut metabolites is like taking your car to the shop. Now imagine that your mechanic discovers why your check engine light has been on for two years. Lots of things can go wrong with your car depending on how you drive it, how you maintain it, if it was assembled with a malfunctioning part, and many other factors. All of these factors may affect different components of your car, but together they affect the overall function. A good mechanic will not only figure out what needs to be done to make your car safe (and get that check engine light to finally go dark); as an expert with the right tools, he’ll tell you the best way to take care of your car.

Ixcela measures your blood sample for metabolites that reflect how well your gut microbiome is functioning. The gut has a close relationship with multiple elements of overall health, including cognitive function, digestive function, and emotional health, as well as immunity and nutrient utilization.

There are thousands of important metabolites in the body; however, Ixcela focuses on those related to the gut microbiome. The amount and diversity of gut-related metabolites reflect how well your gut is functioning. The exciting part is that these metabolites are considered actionable because they can be altered with dietary and lifestyle changes. When you get your Ixcela test results, you will learn what steps you can take to improve your gut function and start feeling and looking better.

Although food naturally contains metabolites, fixing a certain metabolite level is not always as simple as eating more foods that contain that metabolite. A healthy gut microbiome is needed to ensure metabolites can be digested and synthesized. Adopting an overall gut-healthy lifestyle is necessary to ensure healthy metabolite levels and optimal wellness.

When we look at the levels of gut metabolites in your blood, we see how well your diet is fueling your metabolic processes. If a metabolite is low, it might mean your diet is lacking the foods that contain that metabolite. It could also mean that the bacteria responsible for metabolizing this metabolite are not functioning properly or that the gut is suffering from dysbiosis, an imbalance of good and bad bacteria.

Below is a list of the eleven metabolites Ixcela measures and how diet either contributes to the metabolite level or affects it. This list does not include all processes that the metabolite is involved in, only a brief description of how it is related to gut bacteria and the health of the gut.

Tryptophan (TRP) Tryptophan (TRP) is found in cruciferous vegetables, bananas, eggs, meat (2)
Indole-3-Propionic Acid (IPA) Indole-3-Propionic Acid (IPA)is found in sprouted mung beans and sprouted chickpeas(3)

A fiber-rich diet increases the production of IPA
Indole-3-Lactic Acid (ILA) Indole-3-Lactic Acid (ILA)is found in fermented foods like yogurt, sauerkraut, kimchi, pickles, and kefir (4)
Tyrosine (TYR) Tyrosine (TYR)is found in meat, cheese, soy, nuts, and seeds (5)
Kynurenine (KYN) Kynurenine (KYN)is found in meat, cheese, cruciferous vegetables, bananas, plums, fermented foods, and kiwi (6)
3-Methylxanthine (3MXAN) 3-Methylxanthine (3MXAN) levels are related to caffeine intake(7)
Uric Acid (UA) To raise levels of Uric Acid (UA), include high-purine foods (beer, peas, dried beans, liver, anchovies, and mackerel) (8)
Xanthine (XAN) Xanthine (XAN)is found in coffee and green tea (9)
Indole-3-Acetic Acid (IAA) Indole-3-Acetic Acid (IAA)is found in sprouted seeds(10)
Serotonin (SER) Serotonin (SER) is a tryptophan metabolite, meaning it can be synthesized from tryptophan (11)
Indoxyl Sulfate (IDS) Indoxyl Sulfate (IDS) is a tryptophan metabolite, meaning it can be synthesized from tryptophan(12)

As you can see, metabolites are found in a variety of plant- and animal-based foods. This is why Ixcela recommends a well-rounded diet that is rich in plant fibers, like vegetables, and adequate protein. A variety of dietary preferences can support a healthy gut, but it is important to understand how to follow a diet in a way that is beneficial to overall health.

When your mechanic advises you about your car, it’s up to you to do something about its upkeep. How will you change your driving habits or maintenance schedule to keep it running right? Similarly, you will need to make some changes to improve your gut health. If you have received your Ixcela recommendations and are looking for guidance about where to start, we suggest first reviewing your scores. Find the lowest score and then refer to your nutrition recommendations for that score. Then, check out Ixcela’s recipe library for inspiration and ideas about how to eat to improve that specific area of health. With the right diet for your unique gut microbiome, you will experience a positive shift in how you look and feel—no matter how many miles are on your odometer.

About the Author

Photo: Rachel Stuck, RDN

Registered Dietitian Nutritionist Rachel Stuck has a background in culinary arts and nutrition counseling. Rachel takes a positive approach to nutrition: she avoids recommending restrictive diets and instead focuses on helping people choose foods that promote health and well-being. She is passionate about empowering and assisting Ixcela members as they develop their unique, gut-healthy lifestyles.

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Interested in learning more about Ixcela? Check out Ixcela’s microbiome test, personalized nutrition and fitness plans, and other tools to help you optimize your health.


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  2. Jami Cooley. “Tryptophan Foods and Tryptophan Supplements: How They Help Your Health.” University Health News, 21 Nov. 2018, universityhealthnews.com/daily/nutrition/tryptophan-foods-tryptophan-supplements/.
  3. Mravec, Jozef, et al. “Click Chemistry-Based Tracking Reveals Putative Cell Wall-Located Auxin Binding Sites in Expanding Cells.” Nature News, Nature Publishing Group, 22 Nov. 2017, www.nature.com/articles/s41598-017-16281-w.
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  7. Chou, T. “Wake up and Smell the Coffee. Caffeine, Coffee, and the Medical Consequences.” The Western Journal of Medicine, U.S. National Library of Medicine, 15 Nov. 1992, www.ncbi.nlm.nih.gov/pubmed/1441496.
  8. Watts, R W. “Molecular Variation in Relation to Purine Metabolism.” Journal of Clinical Pathology. Supplement (Royal College of Pathologists), U.S. National Library of Medicine, 1974, www.ncbi.nlm.nih.gov/pmc/articles/PMC1347204/.
  9. Sumbaev, V V, and A Ia Rozanov. “Effect of Caffeine on Xanthine Oxidase Activity.” Ukrainskii Biokhimicheskii Zhurnal (1978), U.S. National Library of Medicine, Sept. 1997, www.ncbi.nlm.nih.gov/pubmed/9606845.
  10. Chung, KT, et al. “Formation of Indoleacetic Acid by Intestinal Anaerobes.” Journal of Bacteriology, U.S. National Library of Medicine, Oct. 1975,/.
  11. Waclawiková, Barbora, and Sahar El Aidy. “Role of Microbiota and Tryptophan Metabolites in the Remote Effect of Intestinal Inflammation on Brain and Depression.” Pharmaceuticals (Basel, Switzerland), MDPI, 25 June 2018, www.ncbi.nlm.nih.gov/pmc/articles/PMC6160932/.
  12. Leong, Sheldon C, and Tammy L Sirich. “Indoxyl Sulfate-Review of Toxicity and Therapeutic Strategies.” Toxins, MDPI, 30 Nov. 2016, www.ncbi.nlm.nih.gov/pmc/articles/PMC5198552/