Gut Health
Functional medicine care for SIBO, SIFO, IBS, inflammatory bowel disease (Crohn's disease and ulcerative colitis), candida and fungal overgrowth, and leaky gut.
I'm Dr. Stephanie Daniel, DO. I founded Functional Medicine SF in 2012. Gut health is part of almost every plan I write, because the gut affects immunity, inflammation, mood, hormones and how well you tolerate treatment.
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You may have been told you have IBS and given little beyond a diet to try. Or you've treated SIBO or candida before and the symptoms came back. Or you have Crohn's disease or ulcerative colitis and want to look beyond medication alone. Common symptoms of gut imbalance include:
- Bloating, gas or abdominal discomfort
- Constipation, diarrhea, or alternating between the two
- Reflux or feeling full quickly
- New food sensitivities
- Sugar and carbohydrate cravings
- Recurrent yeast infections, thrush, or skin problems such as eczema or rashes
- Brain fog, fatigue or low mood that seem tied to digestion
Why gut problems are often missed or hard to resolve
Standard GI workups look for structural disease, such as ulcers, inflammatory bowel disease or celiac disease. When those are ruled out, you may be told you have IBS, a label that describes symptoms but doesn't explain them. And if you do have inflammatory bowel disease (IBD), standard care focuses on controlling inflammation with medication, often without looking at diet, the microbiome, or what else may be driving flares.
Gut problems are also rarely just one thing. An overgrowth of bacteria in the small intestine (SIBO) or of yeast (SIFO and candida) may sit alongside low stomach acid, slow motility, a damaged gut lining and reduced beneficial bacteria. Treating only the overgrowth often leads to relapse.
The gut also responds to the rest of the body. Antibiotics, stress, high-sugar diets and impaired immunity can all disrupt it. Mold exposure and mast cell activation are common contributors in the patients I see. And because the gut works best in a "rest and digest" state, a nervous system stuck in fight-or-flight can slow healing.
How I evaluate gut health
I start with a detailed history of your symptoms, diet, past treatments, antibiotic use, and what has helped or made things worse. From there, I choose testing based on your situation. Tools I use include:
- Comprehensive stool testing. I prefer methods that combine culture, microscopy, PCR and stool chemistry. This combination can detect bacteria, yeast and parasites, and markers of digestion and inflammation. DNA-only microbiome tests miss fungi and parasites, and their results vary by lab.
- Organic acids testing, a urine test that can show markers of yeast and bacterial overgrowth, and of oxalates, which can be linked to fungal colonization.
- Lactulose breath testing when symptoms suggest SIBO. I interpret it alongside organic acids testing and your symptoms.
- A simple at-home stomach acid screen, because low stomach acid is common and affects digestion and overgrowth.
- Related testing when the picture calls for it, such as mycotoxin testing or an evaluation for histamine and mast cell activation.
How I sequence treatment
My approach follows The Longevity Hierarchy™, a framework I developed for organizing care around what your body can tolerate right now. It has two aims: reduce the load your body is carrying, and expand its capacity to handle treatment. Microbiome imbalances, in the gut and in the sinuses, are one of the loads I look at most often.
For the gut itself, I use five steps:
- Remove what's irritating the gut. This means trigger foods, and treating overgrowth of yeast, bacteria or parasites with prescription and botanical options. For candida, I use a phased diet, with strict elimination at first and then planned reintroduction.
- Replace what's missing, such as stomach acid or digestive enzymes, when testing shows a need.
- Reinoculate with beneficial bacteria and the fiber that feeds them, added slowly.
- Repair the gut lining with targeted nutrients and food-based support such as bone broth and collagen.
- Rebalance sleep, stress and nervous system tone, which the gut depends on.
Keeping your bowels moving every day comes first, because the bowel is one of the body's main exit routes for toxins. In more complex cases, especially with mold or mast cell activation, I often stabilize first and treat the gut later. When I treat fungal overgrowth, I build up slowly and make sure clearing never outpaces the body's ability to eliminate what's released. If you have IBD, I work alongside your gastroenterologist when needed, and I don't replace medical treatment your disease requires.
What working with me looks like
- A 20-minute welcome consult to talk through your situation and see whether my practice is a good fit.
- A 90-minute first visit. I review your history and prior testing and set out a testing plan.
- A written plan that maps out your next steps, with clear instructions and handouts on gut repair, diet and any antifungal protocol. You put it into practice one change at a time, at a pace your body can handle.
- 60-minute follow-up visits to review test results and adjust treatment based on your response.
Stool and urine tests are done at home, and blood work can be done at a local draw site in California.
Frequently asked questions
- Do you treat SIBO and gut problems for patients outside the Bay Area?
- Yes. I see patients with SIBO, SIFO, IBS, IBD, candida and other gut problems anywhere in California by video. I'm licensed in California, so patients need to be located in the state. If you live outside California, your own doctor can still get my guidance: clinicians can book a one-on-one case consult with me about your care, while they remain your treating physician.
- Which stool test do you use, and why?
- I prefer comprehensive stool testing that combines culture, microscopy, PCR and stool chemistry. It can detect live bacteria and yeast and identify parasites, and it measures digestion and inflammation. DNA-only microbiome tests give a snapshot of bacterial diversity but miss fungi and parasites, and their results can vary by lab technique.
- My SIBO keeps coming back. Why?
- SIBO has a high recurrence rate, because treatment often targets only the overgrowth itself. Lasting improvement depends on fully addressing the deeper root causes that allowed it to develop. Common ones are slow motility, low stomach acid, a stressed nervous system, and other drivers such as mold or mast cell activation. I treat the overgrowth and work on those root causes at the same time.
- Do I have to follow a strict candida diet forever?
- No. My anti-candida approach is phased. A strict elimination phase comes first, then a repair phase, then planned reintroduction, where you track how you respond to each food. The goal is a varied, gut-supportive diet you can sustain.
- Why do I feel worse when I start gut treatment?
- When yeast or bacteria die off, they release byproducts that can temporarily cause fatigue, headaches, brain fog or flu-like symptoms. Fiber and probiotics can also cause temporary bloating. These are signals to slow down, not push through. I build doses up gradually and support elimination so reactions stay manageable.
- Is gut health connected to mold and mast cell problems?
- Often, yes. Mold and yeast can colonize the gut and sinuses, creating exposure from inside the body. Gut inflammation can lower DAO, the enzyme that breaks down histamine from food. Many of my patients have gut, mold and mast cell problems at the same time, and I treat them together.
Next steps
Related: Mold and environmental illness · Mast cell activation · Complex chronic illness
- Book a 20-minute welcome consult to see whether we're a good fit.
- Not sure where to start? Take the 5-minute Protocol Audit to see which areas may be adding to your symptoms.
- Already on a gut protocol that isn't working? A Protocol Review looks at what you're doing and what might be holding you back.
Functional Medicine SF provides virtual care for patients located in California. This page is for education and is not individual medical advice.