You may have heard that your gut health plays a big role in how your body functions, but did you know it could affect your blood sugar, too? Research has shown that people with both type 1 and type 2 diabetes often have fewer of the “good” gut bacteria needed to support metabolism, immunity, and digestion. Thankfully, the good news is that what you eat can help bring your gut microbiome back into balance.
Let’s take a look at why gut health matters, how diabetes changes the microbiome, and how certain foods can help restore a healthier balance.
What Is the Gut Microbiome?
The gut microbiome is made up of trillions of small organisms, like bacteria, that live in your intestines. These microbes help your body digest food, absorb nutrients, and even protect against inflammation. Some gut bacteria also help regulate blood sugar and support your immune system.
When your gut bacteria are balanced, everything works more smoothly. But in people with diabetes, that balance is often disrupted.
How Gut Bacteria Change in Diabetes
Studies show that people with both type 1 and type 2 diabetes tend to have fewer beneficial bacteria that fight inflammation and support blood sugar control. At the same time, they may have more harmful bacteria and opportunistic pathogens that can increase gut inflammation and reduce insulin sensitivity. These changes are linked to:
- Poor blood sugar control
- Increased inflammation
- A weakened gut lining
- Greater risk of insulin resistance
For example, research has found that individuals with diabetes often have lower levels of beneficial bacteria such as Bifidobacteria and D. longicatena. In contrast, negative strains like Clostridiales and Oscillibacter tend to be more abundant. Some bacteria, like Coprococcus, appear to play a positive role in insulin sensitivity by forming networks of microbes that support metabolic health. Interestingly, even though Flavonifractor produces butyrate, which is a compound typically linked to gut health, it has been associated with increased insulin resistance.
The American Diabetes Association notes that having an unhealthy gut microbiome may increase the risk of the development and progression of diabetes. Therefore, supporting a healthy gut is one more tool for not only managing blood sugar, but also helping protect yourself from future diseases.
Gut-Healthy Foods to Include
The best way to nourish your gut is through food, especially options high in fiber or plant-based . One of the most prescribed diets for promoting gut health that also lowers the risk of diabetes and other chronic conditions is a Mediterranean-style diet. Here are some easy and tasty ways to feed your gut bacteria:
1.) Load Up on Fiber-Rich Foods
Fiber is a common prebiotic that acts as food for beneficial gut bacteria. Look for both soluble and insoluble fiber in foods like:
- Oats, beans, and lentils
- Apples, bananas, and berries
- Leafy greens, carrots, and broccoli
- \Whole grains like brown rice and quinoa
2.) Enjoy Fermented Foods
Fermented foods contain live bacteria, or probiotics, that support a balanced gut. Try adding:
- Yogurt with live cultures
- Kefir
- Sauerkraut and kimchi
- Some ages cheeses and sourdough bread
3.) Eat a Variety of Plant-Based Foods
Different plant foods feed different bacteria. Aim to eat a variety of fruits and vegetables daily to promote diversity in your gut microbiome.
- A good variety of fruits can include blueberries, strawberries, oranges, bananas, and apples
- A good variety of vegetables can include sweet potatoes, broccoli, bell peppers, spinach, and carrots
4.) Limit Ultra-Processed Foods
Highly processed foods with added sugars and preservatives can throw your gut off balance. Focus on consuming whole foods as often as possible. Some examples to avoid are:
- Processed meats like hot dogs
- Chips, cookies, crackers
- Frozen Pizzas
- Sweetened breakfast cereals
5.) Stay Hydrated
Water intake is always important. Hydration helps fiber move through the digestive tract and keeps your gut functioning properly.
Other Tips
It is also important to point out that gut-friendly eating doesn’t have to be rigid or complicated. Simple changes, like eating a couple more vegetables and reducing added sugars throughout the week, can go a long way in promoting gut health.
Probiotic supplementation is also a common method to balance your gut microbiota. However, you should note that not all probiotic supplements have the same effect. Some will support digestion, others immunity, and not all will have a noticeable effect on your blood sugar. Therefore, it is important to talk to your dietitian before choosing a supplement to see which options are best for meeting your goals.
Final Thoughts
Your gut plays a big role in your health and diabetes management. While further research is still ongoing, current evidence suggests that a healthier gut microbiome may help reduce inflammation, improve blood sugar control, and support digestive health. Start with simple food changes like adding more fiber, choosing fermented foods, and eating a variety of fruits and vegetables while limiting red meat, processed foods, and sweets. Your gut bacteria will thank you!
References
Bailey, M. A., & Holscher, H. D. (2018). Microbiome-mediated effects of the Mediterranean diet on inflammation. Advances in Nutrition, 9(3), 193-206. https://doi.org/10.1093/advances/nmy013
Byndloss, M., Devkota, S., Duca, F., Niess, J. H., Nieuwdorp, M., Orho-Melander, M., … & Zhao, L. (2024). The gut microbiota and diabetes: research, translation, and clinical applications—2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum. Diabetes, 73(9), 1391-1410. https://doi.org/10.2337/dci24-0052
Cedars‑Sinai Medical Center. (2023). Gut bacteria may play a role in diabetes. Cedars‑Sinai Newsroom. https://www.cedars‑sinai.org/newsroom/gut‑bacteria‑may‑play‑a‑role‑in‑diabetes/
Holscher, H. D. (2020). Diet affects the gastrointestinal microbiota and health. Journal of the Academy of Nutrition and Dietetics, 120(4), 495-499. DOI: 10.1016/j.jand.2019.12.016
Van Heck, J. I. P., Gacesa, R., Stienstra, R., Fu, J., Zhernakova, A., Harmsen, H. J. M., Weersma, R. K., Joosten, L. A. B., & Tack, C. J. (2022). The Gut Microbiome Composition Is Altered in Long-standing Type 1 Diabetes and Associates With Glycemic Control and Disease-Related Complications. Diabetes care, 45(9), 2084–2094. https://doi.org/10.2337/dc21-2225
Yoo, J. Y., Groer, M., Dutra, S. V. O., Sarkar, A., & McSkimming, D. I. (2020). Gut microbiota and immune system interactions. Microorganisms, 8(10), 1587. https://doi.org/10.3390/microorganisms8101587
