Tens of millions of individuals are actually taking medicines like semaglutide (Ozempic, Wegovy) or tirzepatide (Mounjaro) to handle blood sugar or drop a few pounds. These medicine work, and for many individuals they’ve made an actual distinction. They’re a really highly effective crutch.
However there is a intestine downside that is quietly displaying up in among the individuals taking these medicines, a intestine downside that the majority docs aren’t warning their sufferers about, as I’ve written about beforehand. It is known as SIBO, small intestinal bacterial overgrowth. And in case your thyroid gland is not working correctly, your threat might even be larger.
First, What Is SIBO?
Your digestive tract is residence to trillions of micro organism. The micro organism are concentrated within the colon, the big gut. SIBO occurs when these micro organism take up residence in your small gut, the place they do not belong in giant numbers.
Having micro organism in your small gut is an actual downside. They trigger a variety of bloating, fuel, continual constipation, or diarrhea that results in fatigue, mind fog, and poor nutrient absorption.
Your physique has bother absorbing key nutritional vitamins and minerals, corresponding to B12, iron, and magnesium, in addition to different vitamins it must perform properly. SIBO will be very disruptive to your life, making it exhausting to eat regular meals and making social interactions centered round meals extraordinarily tough. Carbohydrate-containing meals are notably tough to digest, resulting in a variety of bloating and ache.
Why GLP-1 Medicine Can Set off SIBO
GLP medicine will help you management your blood sugar. A technique they do that is by slowing down how shortly meals strikes via your intestine, and that is on objective. It prevents the blood sugar spikes after meals. However a sluggish intestine can be the proper atmosphere for micro organism to develop the place they do not belong.
A big 2025 examine by Dr. Yan Solar and colleagues at Case Western Reserve College examined greater than 216,000 sufferers with diabetes. These taking GLP-1 medicine had greater than twice the danger of growing SIBO in comparison with individuals on different diabetes medicines. The researchers concluded that docs ought to take a look at sufferers for SIBO earlier than giving them these medicine.
Now Add a Sluggish Thyroid
Your thyroid gland — a small butterfly-shaped gland in your neck — controls your metabolism. This consists of how properly your meals strikes via your intestine. When your thyroid is low, your total digestive system slows down.
The muscle tissue that push meals ahead via your intestines (peristalsis) do not work very effectively in case your thyroid perform is low. That is the identical slowdown that GLP-1 medicine trigger, and the analysis reveals that hypothyroidism (low thyroid perform) already considerably raises SIBO dangers by itself.
In a widely known examine, Dr. Elisa Lauritano and colleagues in Rome discovered that 54% of sufferers with low thyroid perform had SIBO, in comparison with simply 5% of individuals with regular thyroid perform. Cease for only a second and take into consideration that. Greater than half of individuals with low thyroid perform had SIBO, however individuals with regular thyroid perform hardly had it in any respect. So, low thyroid perform is a large threat issue for SIBO.
A 2025 examine by Dr. Ming Wei and colleagues at Cedars-Sinai discovered related outcomes, with SIBO in practically one in three hypothyroid sufferers versus one in six within the management group. So that is confirmed in multiple examine. Low thyroid perform could be very a lot linked to SIBO.
And this is the stunning half: You do not have to have a critical thyroid downside in your threat to go up. A examine by Dr. Biao Wang and colleagues discovered that girls with borderline low thyroid (a situation known as subclinical hypothyroidism that usually goes undiagnosed and untreated) had SIBO charges of 57% versus 32% in these with regular thyroid ranges. Borderline thyroid issues are way more frequent than individuals notice.
If a GLP-1 drug is already slowing your intestine, and your thyroid is including extra of the identical, these two issues are working collectively in a method that might make your life very depressing very quickly.
It Goes Each Methods
The interplay goes each methods. SIBO would not simply outcome from thyroid issues; it might additionally assist trigger them. Analysis by Dr. Sina Mehravar and colleagues at Cedars-Sinai discovered that individuals with SIBO have been 2.5 instances extra prone to develop Hashimoto’s thyroiditis (an autoimmune thyroid situation) over the next six years. A struggling intestine seems to set off immune system dysfunction, which then assaults the thyroid.
The intestine and thyroid are linked in ways in which run in each instructions. You may’t totally look after one whereas ignoring the opposite.
What You Can Do to Decrease Your Danger of SIBO
The excellent news is which you can assist your thyroid perform naturally with meals and way of life. You do not often want medicines.
Selenium
Selenium is an important nutrient right here. A 2024 evaluate of 35 scientific trials by Dr. Valentina Huwiler and colleagues at Bern College Hospital discovered that selenium decreased immune markers related to thyroid harm in Hashimoto’s sufferers. Brazil nuts are probably the greatest pure sources — one or two a day is sufficient. Sunflower seeds and complete grains additionally present selenium.
Our Hallelujah Weight loss program Glutathione Promoter not solely has N-acetylcysteine in it, but in addition 200 micrograms of selenium per capsule, which could be very protecting in your thyroid.
Iodine
Iodine issues too, since your thyroid wants it to make the hormones that regulate your metabolism. However watch out with iodine dietary supplements in case you have Hashimoto’s — an excessive amount of can truly worsen the autoimmune response in some individuals. Getting iodine from meals (like sea greens in average quantities) is protected for most individuals. Hallelujah Weight loss program Nascent Iodine will be diluted to protected ranges for most individuals as properly. Examine along with your supplier earlier than supplementing.
Anti-Inflammatory Weight loss program
Past particular vitamins, an anti-inflammatory, plant-based, whole-foods weight loss plan helps each the thyroid and the intestine. Eliminating processed meals, consuming vegetation, and extra fiber instantly reduces the irritation that drives autoimmune thyroid illness, and helps preserve intestine micro organism the place they belong.
Two Easy Steps to Take Now
First, for those who’re on a GLP-1 drug, ask your physician to verify your thyroid. A primary TSH and free T4 blood take a look at is all that’s wanted. Even borderline outcomes are price addressing, particularly if you’re already on a medicine that slows your intestine.
Second, in case you have SIBO, be certain your thyroid is a part of the dialog. The bacterial overgrowth is only a symptom of impaired intestine motility. Meals will not be transferring via quick sufficient, and that’s what must be addressed. The analysis has clearly proven that your thyroid perform is a significant participant in your intestine perform.
GLP-1 medicine are a crutch, and they’re a robust one which many individuals try out. They provide individuals hope that life will be completely different.
You continue to must make way of life and dietary adjustments to maintain the load off. Try our full information on wholesome weight reduction for extra concepts. You actually cannot keep on the GLP-1 medicine perpetually. However whilst you’re utilizing them, you wish to ensure you assist your thyroid perform in order that you do not find yourself with SIBO. That may put you in a worse place than you began in.
At Hallelujah Weight loss program, our mission is to equip you in order that your well being empowers you to perform the mission that God has for you. Unsure the best way to get began? Study extra proper right here.
References
Huwiler, V. V., Maissen-Abgottspon, S., Stanga, Z., Mühlebach, S., Trepp, R., Bally, L., & Bano, A. (2024). Selenium supplementation in sufferers with Hashimoto thyroiditis: A scientific evaluate and meta-analysis of randomized scientific trials. Thyroid, 34(3), 295–313. https://doi.org/10.1089/thy.2023.0556
Lauritano, E. C., Bilotta, A. L., Gabrielli, M., Scarpellini, E., Lupascu, A., Laginestra, A., Novi, M., Sottili, S., Serricchio, M., Cammarota, G., Gasbarrini, G., Pontecorvi, A., & Gasbarrini, A. (2007). Affiliation between hypothyroidism and small intestinal bacterial overgrowth. The Journal of Medical Endocrinology & Metabolism, 92(11), 4180–4184. https://doi.org/10.1210/jc.2007-0606
Mehravar, S., Wei, M., Leite, G., Barlow, G., Rezaie, A., Naji, P., Pimentel, M., & Mathur, R. (2025). SUN-396 Small intestinal bacterial overgrowth related to larger threat of Hashimoto’s thyroiditis. Journal of the Endocrine Society, 9. https://doi.org/10.1210/jendso/bvaf149.2405
Solar, Y., Veccia, D., Liu, B. D. X., Tse, W., Fass, R., & Track, G. (2025). Diagnostic analysis of an elevated threat of growing small intestinal bacterial overgrowth related to glucagon-like peptide-1 (GLP-1) receptor agonists and twin GLP-1/GIP receptor agonists: A worldwide retrospective multicenter cohort evaluation. Diagnostics, 15(17), Article 2264. https://doi.org/10.3390/diagnostics15172264
Wang, B., Xu, Y., Hou, X., Li, J., Cai, Y., Hao, Y., Ouyang, Q., Wu, B., Solar, Z., Zhang, M., & Ban, Y. (2021). Small intestinal bacterial overgrowth in subclinical hypothyroidism of pregnant ladies. Frontiers in Endocrinology, 12, Article 604070. https://doi.org/10.3389/fendo.2021.604070
Wei, M., Mehravar, S., Leite, G., Naji, P., Barlow, G., Hosseini, A., Rashid, M., Sanchez, M., Fajardo, C., Pimentel, M., & Mathur, R. (2025). Relationship between hypothyroidism, threat of small intestinal bacterial overgrowth, and duodenal microbiome alterations. The Journal of Medical Endocrinology & Metabolism. Advance on-line publication.https://doi.org/10.1210/clinem/dgaf495
