Desulfovibrio
Desulfovibrio is a genus of gram-negative, anaerobic, “sulfate-reducing” bacteria normally found in the gut. These bacteria use sulfate as a terminal electron acceptor, reducing it to hydrogen sulfide (H₂S), a gas known for its “rotten egg” – sulfurous – smell. While desulfovibrio are part of a healthy gut ecosystem in low numbers, an overgrowth can become problematic.
How does one get a desulfovibrio overgrowth?
Viral factors, antibiotics, chronic constipation, and diet can conspire to create an overgrowth. Here’s how this might typically play out:
First you get a viral infection, such as Epstein Barr, which leads to taking antibiotics. But before you even take those, the virus has already altered your microbiome, predisposing you toward constipation.
Antibiotics can reduce the numbers of commensal (good) microbes. This loss of balance (dysbiosis) can create an environment where desulfovibrio has less competition and proliferate.
Furthermore, the constipation allows more time for fermentation. This environment can favor the growth of sulfate-reducing bacteria.
This may actually be compounded by a perfectly healthy diet high in sulfate or sulfur-rich compounds from foods like cruciferous vegetables, eggs, and red meats. (Although an unhealthy diet rich in processed food will often be even higher in sulfur, particularly since it is used as a preservative in many conventional foods.) The sulfur-rich diet provides more substrate for sulfate-reducing bacteria.
The overall gut dysbiosis can lead to problems processing other seemingly healthy choices, such as becoming sensitive to lectins (which are present in most any seeds including grains and beans – the most famous lectin being gluten). The overall condition then compromises the intestinal barrier (sometimes referred to as “leaky gut”) which can further change the local environment in ways that support the overgrowth of specific bacterial groups, including desulfovibrio.
And there you have it: now you’ve got a desulfovibrio overgrowth, characterized by the sulfur-smelling gas you get whenever you eat foods with even trace amounts of sulfur in it.
Strains of Desulfovibrio
There are a few strains of desulfovibrio that have been identified in microbiome studies, and while research is still evolving, two of the better-known are:
Desulfovibrio piger
Commonly found in the human gut, this strain has been associated with inflammatory conditions in some studies.
Desulfovibrio desulfuricans
This strain may act as an opportunistic pathogen in immunocompromised individuals. It is sometimes considered more virulent than D. piger, though its precise role in human disease is still being studied.
Other Strains
Some strains may produce more H₂S (hydrogen sulfide) than others. Some strains utilize somewhat different substrates. Some are more virulent, or adhere differently, affecting how they interact with your gut lining and your immune response.
Consequences of Sulfur SIBO
There are so many frustrating consequences of sulfur-reducing bacteria predominance, it is hard to know where to start. One of the most terrifying consequences is that you will need to go on a low-sulfur diet, which means you will likely be producing less and less of your own glutathione – a critical antioxidant sometimes called “the mother of all antioxidants.” Sulfur is needed for its production.
Sulfur SIBO Symptoms
Bloating and gas (due to H₂S)
Abdominal pain (due to mucosal irritation from H₂S)
Diarrhea or constipation
Intestinal inflammation (due to H₂S damaging colonocytes – cells lining the colon)
Nerve issues (H₂S causing broader systemic effects)
Healing from Sulfur-SIBO
Collect Data
I highly recommend obtaining a thorough evaluation including stool analyses, breath tests (for SIBO), and inflammation markers. Then you can discuss symptoms, sensitivities, and any prior antibiotic or medication history that might have contributed to your dysbiosis. You may learn that you have something much more complex than a desulfovibrio overgrowth. Your case may also include elevated levels of helicobacter pylori, and testing for toxin residues in your urine may also reveal systemic mold colonization. Cases with chronic pain are often quite complex.
Elimination Diet
If you have an overgrowth of desulfovibrio, you’ll need to avoid sulfur-rich foods. You can learn which foods specifically are impacting you by doing an elimination diet (eating on a limited set of twelve low-sulfur foods) and then only reintroducing one food per week and watching for reactions.
I can’t underscore the importance of an elimination diet enough. This is a critical step in uncovering what is working for you, and what isn’t.
High-Sulfate Foods To Avoid
Cruciferous Vegetables: broccoli, cabbage, cauliflower. While not cruciferous, you may also react to asparagus. Some with sulfur SIBO will react to kale (which is cruciferous, but lower in sulfur), while others may not. Keep it out of your elimination diet, and introduce it later on in your journey to see how you do with it.
Eggs: very rich in sulfur-containing amino acids, especially the whites. (The yolks are not yellow from sulfur, but rather from antioxidants. Some people with sulfur SIBO can have yolks in moderation. But keep them out of your initial elimination diet.)
Red Meats: high in sulfur amino acids, which can be metabolized into sulfate.
Sulfite Additives: many processed foods and beverages contain sulfite preservatives.
Alliums: garlic, onions, and leeks. These may turn out to be fine for you, but keep them out of the first couple weeks of your low-sulfur diet, and reintroduce them in isolation to test each one out for reactions.
Prebiotics (Avoid These with SIBO)
While prebiotics are typically beneficial, in a gut with dysbiosis, they might inadvertently feed sulfate-reducing bacteria, leading to increased gas production and discomfort. For this reason, many people with sulfur-SIBO must go on a prebiotic-free diet until their gut dysbiosis is fully healed.
Eliminate All Trigger-Foods
The most common trigger-foods are corn, soy, and wheat. Do not touch these foods in any amounts. This is a critical part of healing from any chronic condition, especially when a microbiome imbalance is involved.
Follow a low-FODMAP diet, and eliminate sugar alcohols (e.g., sorbitol, xylitol) and artificial sweeteners, which can exacerbate fermentation.
If you have uncovered any foods which seem to be associated with foul-smelling gas for you (such as coconut oil, walnuts, avocados, etc), then remove these in the first phase of your elimination diet. Once again, only reintroduce foods at the rate of one per week. I know this sounds tedious and impossible, but gut problems tend to only get worse when problem foods continue to exacerbate constipation and/or excess gas.
What to Eat
This is going to be somewhat individual, so do not eat anything on this list during your elimination diet if you already know it is a potential problem for you.
✔ Wild-caught fish, purchased frozen (usually only an issue with seafood allergies or in the midst of an extreme histamine overload)
✔ Mild lettuces such as iceberg and romaine (only an issue for rare sensitivities to natural latex or extreme intolerance of any fiber, and for these cases a temporary carnivore diet may be required)
✔ Meat broth specifically made by including skins, tendons, ligaments, and organics (which is not the same as bone broth – I actually advise removing bones as soon as possible as bone broth can trigger histamine issues which are a common companion to sulfur SIBO)
✔ Well-cooked carrots (unless you react to the sugar-alcohols naturally present in foods, which can lead to being sensitive to carrots, beets, and sweet potatoes)
✔ Well-cooked zucchini (allergies to zucchini are rare)
✔ Avocado oil (generally safe for everyone and doesn’t feed any sulfur-reducing bacteria as some animal fats – particularly dairy fats – can)
✔ Potatoes, peeled, and thoroughly cooked (preferably pressure-cooked). Don’t include these if you have problems with all starches or significant nightshade sensitivities.
✔ Sweet potatoes, peeled, and thoroughly cooked (preferably pressure-cooked). Don’t include these if you are sensitive to mannitol, a sugar alcohol naturally present in sweet potatoes.
✔ Cucumber with peels and seeds thoroughly removed (to eliminate lectin content). Don’t include these if you’re struggling with fiber or raw foods.
✔ Peeled and cooked apples. Cooking changes the fiber content, and the high amount of malic acid can be beneficial for some conditions. Don’t include these if you have problems with fructose.
✔ Any berries besides strawberries. Strawberries are high histamine and a common trigger for individuals with chronic SIBO problems. Blueberries, cherries, blackberries, and raspberries are usually safe.
✔ Rice, almond, or oat milk. If you’re currently having dental problems, do not include oatmilk. If rice gives you cravings or indigestion, exclude rice milk. A nut allergy would be an obvious reason to exclude almonds. Coconut milk may be an alternative if these other three options are off the table.
✔ Chamomile, ginger, peppermint teas.
✔ Freeze-dried or baked fruits (which you can pair with your milk substitute), but not dried fruits (which are often too high in histamine).
Lifestyle Adjustments
✔ Stay hydrated. Dry conditions in your digestive system contribute to microbiome imbalance.
✔ Incorporate light physical activity (e.g., walking) to promote healthy gut motility. I like to do crunches for this.
✔ Engage in stress-relief practices (meditation, deep breathing, or gentle yoga).
✔ Ensure you’re getting plenty of sleep. If sleep is a tough one for you, consider radical shifts to your sleep protocol, which may include no technology use after a certain time, starting intermittent fasting and being sure not to eat four hours before bedtime. Some people benefit from shutting off all wi-fi and cell signals during sleep.
Microbial Modulation
You’re probably going to need herbal antimicrobials (like oregano oil) to help reduce desulfovibrio overgrowth, however, you may want to undergo testing before you start taking large amounts of various antimicrobials to make sure you’re actually starting the right microbes. If you start killing off some of the commensal microbes working in your favor and not getting enough of the problematic ones, you could accidentally make your situation worse.
You’ll likely want to follow a course of herbal antimicrobials with high-quality, targeted probiotic. Some strains of lactobacillus and bifidobacterium may help balance the gut and compete with sulfate-reducers, but again, testing is important as introducing the wrong species may make matters worse.
You may also want to include supplements such as L-glutamine, zinc carnosine, and digestive enzymes to help your gut repair itself. If histamine sensitivity is in the picture, you’ll likely want to find a high-quality source of grass-fed kidney supplementation, the highest source of the enzyme (DAO) which breaks down excess histamine in your body. For me, this was a game changer!
Reintroduction Protocol
Start with two to four weeks on your initial elimination diet. Your symptoms should be gone for five whole days before reintroducing foods.
Use a detailed food and symptom diary to identify thresholds and sensitivities. Share this information with a practitioner so that together you can develop a long-term dietary plan that minimizes triggers while ensuring nutritional adequacy.
Final Thoughts
The information on this page is no substitute for testing or guidance from a professional. However, the protocol sketched out on this page is intended to address both microbial imbalance (specifically targeting desulfovibrio overgrowth) and multiple food sensitivities (which often are a dysbiosis side-effect). Ideally, every step – from initial assessment to long-term management – should be personalized and monitored by a healthcare provider you trust.
The goals are to reduce fermentable substrates, restore gut barrier integrity, and re-establish a balanced microbiome – ultimately reducing your symptoms and improving overall digestive health. But of course, as always, each individual’s response will vary. The safest bet is a series of gradual changes – or very carefully calculated big-changes. Oversights can be serious – especially when embarking on a completely new and restrictive diet. So please run your ideas for a new diet by a professional if at all possible, and if that isn’t affordable (because insurance is sometimes insufficient), at least run your ideas by an online nutrition calculator.
I wish you the best.
— Raederle
