SIBO Treatment in Maine: How We Diagnose and Treat Bacterial Overgrowth

You eat something simple. A salad, a piece of bread, a handful of fruit. Within 30 minutes, your stomach looks six months pregnant. The bloating is so bad you have to unbutton your pants. Gas that won't stop. Cramping that doubles you over after meals. Maybe diarrhea, maybe constipation, sometimes both in the same week.

You've tried cutting gluten. Cutting dairy. Probiotics from the health food store. Peppermint tea. Your doctor ran a basic metabolic panel and told you it's IBS. Take some fiber. Manage your stress. Here's a referral for a colonoscopy that comes back clean.

None of it explains why eating has become something you dread.

If this sounds familiar, the problem might not be what you're eating. It might be what's growing where it shouldn't be. Small Intestinal Bacterial Overgrowth (SIBO) is one of the most underdiagnosed gut conditions we see at our clinic in South Portland, and it responds well to treatment once you actually identify it.

What SIBO Actually Is

Your large intestine is supposed to house most of your gut bacteria. Trillions of them. That's normal and healthy. Your small intestine, by contrast, should have relatively few bacteria. It's designed for nutrient absorption, not fermentation.

SIBO happens when bacteria migrate into the small intestine and colonize it. These bacteria ferment carbohydrates before your body can absorb them, producing hydrogen, methane, or hydrogen sulfide gas. The result is bloating, pain, altered bowel habits, and over time, nutrient malabsorption that affects everything from your energy to your hair.

Research estimates that SIBO may be present in up to 78% of patients diagnosed with IBS. That's not a fringe finding. It suggests that a significant number of people carrying an IBS diagnosis actually have a treatable bacterial overgrowth that nobody tested for.

SIBO Symptoms Beyond "Just Bloating"

Most patients come in describing the gut symptoms first. Bloating after meals. Excessive gas. Abdominal pain or pressure. Diarrhea, constipation, or an unpredictable alternation between the two.

But SIBO doesn't stay in the gut. The downstream effects show up across the body:

• Fatigue that doesn't improve with sleep, because nutrient absorption is compromised
• Iron deficiency or B12 deficiency anemia, even with adequate dietary intake
• Skin issues like rosacea, eczema, or acne that flare with certain foods
• Brain fog, difficulty concentrating, poor short-term memory
• Joint pain or body aches driven by systemic inflammation
• Unintentional weight changes, either gain or loss depending on the type of SIBO
• Mood changes, anxiety, or depression linked to disrupted gut-brain signaling

Patients who've been dealing with these symptoms for years often don't connect them to their gut. They're seeing a dermatologist for the skin, a psychiatrist for the mood, a rheumatologist for the joints. Nobody looks at the gut as the common thread.

Why Conventional Testing Misses SIBO

A standard primary care visit for digestive complaints usually involves a basic metabolic panel, maybe a CBC, sometimes a stool test for pathogens. If everything comes back "normal," you get an IBS label and a recommendation to eat more fiber.

The problem is that none of those tests look for bacterial overgrowth in the small intestine. They're checking for infection, inflammation markers, or organ function. SIBO doesn't show up on any of them.

Even gastroenterologists frequently miss it. A colonoscopy examines the large intestine. An endoscopy can see the upper GI tract but doesn't quantify bacterial populations. The standard workup for digestive complaints wasn't designed to detect SIBO.

How We Test for SIBO at Med Matrix

The primary diagnostic tool for SIBO is a lactulose breath test. You drink a sugar solution that humans can't digest but bacteria can. As bacteria in the small intestine ferment the lactulose, they produce gases that are absorbed into the bloodstream and exhaled through the lungs. We measure those gases at timed intervals over two to three hours.

The pattern of gas production tells us several things:

• Whether SIBO is present
• What type of SIBO you have (hydrogen-dominant, methane-dominant, or hydrogen sulfide)
• How severe the overgrowth is
• Where in the small intestine the bacteria are concentrated

This matters because the type determines the treatment. Methane-dominant SIBO tends to cause constipation and responds to different antimicrobials than hydrogen-dominant SIBO, which more commonly causes diarrhea. Treating them the same way is one reason so many patients fail their first round of treatment elsewhere.

We also run our 80+ biomarker panel to check for the downstream damage SIBO causes: iron, B12, folate, vitamin D, inflammatory markers, thyroid function, and a full metabolic workup. Many SIBO patients have nutrient deficiencies that need to be corrected alongside the overgrowth itself.

What Causes SIBO in the First Place

Bacteria don't just wander into the small intestine for no reason. Something broke down in the body's natural defenses. Understanding what allowed the overgrowth is just as important as clearing it, because if you only kill the bacteria without fixing the underlying cause, SIBO comes back. And it often does. Recurrence rates are high when the root cause goes unaddressed.

The most common drivers we see in our patients:

Low stomach acid. Stomach acid is your first line of defense against bacteria entering the small intestine. Proton pump inhibitors (PPIs) like omeprazole suppress acid production. Long-term PPI use is strongly associated with SIBO development. Aging, chronic stress, and H. pylori infection also reduce stomach acid.

Impaired motility. Your small intestine has a built-in cleaning mechanism called the migrating motor complex (MMC). Between meals, it sweeps bacteria and debris downward into the large intestine. If the MMC is damaged or sluggish, bacteria accumulate. Food poisoning is one of the most common triggers. The toxins from certain bacteria (particularly Campylobacter and Salmonella) can damage the nerves that control the MMC, setting the stage for SIBO months or years later.

Structural issues. Abdominal adhesions from surgery, endometriosis, or diverticulosis can create pockets where bacteria get trapped and multiply.

Chronic stress and thyroid or adrenal dysfunction. Both slow gut motility. Hypothyroidism in particular is a well-documented risk factor for SIBO because it slows transit time throughout the entire digestive tract.

Immune suppression. Low secretory IgA, autoimmune conditions, or chronic illness can reduce the body's ability to keep bacterial populations in check.

Our Treatment Approach: More Than Just Antimicrobials

Clearing SIBO is a multi-phase process. Killing bacteria is step one. But if that's the only step, recurrence is almost guaranteed.

Phase 1: Reduce the overgrowth

We use herbal antimicrobials as our first-line treatment. Research published in Global Advances in Health and Medicine found that herbal protocols were as effective as rifaximin (the standard pharmaceutical antibiotic for SIBO) and had fewer side effects. The specific herbs depend on your SIBO type.

For hydrogen-dominant SIBO: berberine, oregano oil, and neem are common choices. For methane-dominant SIBO (sometimes called IMO, intestinal methanogen overgrowth): we add allicin from garlic, which specifically targets the methane-producing archaea that standard antibiotics often miss.

Treatment typically runs four to six weeks. We retest after to confirm the overgrowth has cleared before moving to the next phase.

Phase 2: Repair the gut lining

SIBO damages the intestinal lining. The bacteria produce endotoxins that increase intestinal permeability (sometimes called "leaky gut"). This allows partially digested food particles, bacterial byproducts, and toxins to cross into the bloodstream, triggering immune reactions and systemic inflammation.

We support gut repair with targeted nutrients: L-glutamine for intestinal cell regeneration, zinc carnosine for mucosal integrity, and anti-inflammatory botanicals. Peptide therapy with BPC-157 can also support gut tissue healing at the cellular level.

Phase 3: Restore healthy motility

This is the step most practitioners skip, and it's the main reason SIBO recurs. If the MMC isn't working properly, bacteria will recolonize the small intestine within months.

Prokinetic agents (natural or pharmaceutical) taken between meals stimulate the MMC. Ginger extract, 5-HTP, and low-dose erythromycin are common options. We also address the upstream causes: thyroid optimization, stress management, and meal spacing (the MMC only activates during fasting periods, which is why constant snacking is counterproductive for SIBO patients).

Phase 4: Rebuild the microbiome

After clearing the overgrowth and restoring motility, we reintroduce beneficial bacteria strategically. Not all probiotics are appropriate for SIBO patients. Some strains can actually worsen symptoms. We use specific soil-based organisms and spore-based probiotics that colonize the large intestine without feeding small intestinal overgrowth.

Prebiotic foods are reintroduced gradually as tolerance improves. The goal is a diverse, resilient gut microbiome that resists future overgrowth.

Diet During SIBO Treatment

Diet alone won't cure SIBO, but the wrong diet will make treatment harder. Bacteria in the small intestine feed on fermentable carbohydrates. Reducing their food supply while antimicrobials do their work makes treatment more effective.

We typically recommend a modified low-FODMAP or specific carbohydrate diet during the treatment phase. This means temporarily reducing:

• Certain fruits (apples, pears, watermelon, stone fruits)
• Garlic and onion (high in fructans)
• Legumes and lentils
• Wheat and rye
• Lactose-containing dairy
• Sugar alcohols (xylitol, sorbitol, found in many "sugar-free" products)

This is a treatment diet, not a life sentence. Staying on a restrictive diet indefinitely starves beneficial bacteria too. Once the overgrowth is cleared and the gut is healing, we systematically reintroduce foods and track which ones you tolerate. Most patients can return to a varied diet within a few months.

Our providers work with you on nutritional planning throughout this process so you're not guessing what to eat.

The SIBO and Hormone Connection

Gut health and hormone balance are deeply interconnected. SIBO disrupts both, and hormonal imbalances can perpetuate SIBO. We see this overlap constantly in our patients.

Hypothyroidism slows gut motility, creating conditions for bacterial overgrowth. Estrogen dominance (common in perimenopause) can impair bile flow, which normally helps control bacterial populations in the small intestine. Chronic gut inflammation from SIBO disrupts the gut-brain axis, affecting cortisol regulation, sleep quality, and mood.

This is why we don't treat SIBO in isolation. If your thyroid is underperforming or your hormones are out of range, addressing the gut alone won't produce lasting results. Our functional medicine approach looks at all of these systems together.

When to Consider SIBO Testing

You don't need a referral or a formal IBS diagnosis to get tested. If you're dealing with any combination of the following, SIBO should be on the list of things to rule out:

• Bloating that worsens throughout the day or after meals
• Chronic gas, cramping, or abdominal distension
• Alternating diarrhea and constipation
• Food intolerances that seem to multiply over time
• Nutrient deficiencies despite a decent diet
• Fatigue, brain fog, or skin issues that track with digestive flare-ups
• Previous food poisoning followed by ongoing digestive problems
• History of PPI use

If you've already been diagnosed with IBS and treatments aren't working, testing for SIBO is a logical next step that many gastroenterologists skip.

What to Expect Working With Our Team

We have 7 providers at Med Matrix in South Portland, Maine. Over 3,000 patients have come through our clinic, and gut issues are one of the most common reasons people walk through the door.

Your process starts with a 60-minute provider consultation where we review your full health history, symptoms, and any previous test results. We order the breath test and our 80+ biomarker panel so we can see the full picture. Once results are in, your provider sits down with you for another full hour to explain every finding and build your treatment plan.

Follow-up visits track your progress. We retest to confirm the overgrowth is clearing. We adjust the plan as your body responds. You have direct access to your care team between visits.

This isn't a 15-minute appointment where you leave with a prescription and a handshake. We stay with you through the entire process.

Frequently Asked Questions

How long does SIBO treatment take?

Most patients go through an initial antimicrobial phase of four to six weeks, followed by gut repair and motility support over the next two to three months. Total treatment time from first visit to stable resolution is typically three to six months. Some patients with severe or recurrent SIBO may need longer. We retest throughout to make sure treatment is working and adjust if it's not.

Can SIBO come back after treatment?

Yes, and recurrence is common when only the bacteria are treated without addressing the root cause. That's why our protocol includes motility restoration, addressing underlying conditions like thyroid dysfunction or low stomach acid, and rebuilding the microbiome. Patients who complete all four phases of treatment have significantly lower recurrence rates than those who stop after antimicrobials alone.

Is SIBO the same as IBS?

No. IBS is a symptom-based diagnosis. It describes what you're experiencing (bloating, altered bowels, pain) without explaining why. SIBO is a specific, testable condition that can cause IBS symptoms. Many patients diagnosed with IBS actually have SIBO as the underlying driver. Testing for SIBO doesn't replace an IBS diagnosis, but it can explain it and open the door to targeted treatment instead of symptom management.

Do I need to follow a special diet forever?

No. The dietary restrictions during SIBO treatment are temporary. They reduce the food supply for overgrown bacteria while antimicrobials clear the overgrowth. Once treatment is complete and the gut lining has healed, most patients can reintroduce the foods they were reacting to. We guide the reintroduction process so you know exactly which foods your body handles well and which ones to be cautious with.

Stop Managing Symptoms. Find the Cause.

If you've been told it's just IBS, just stress, just something you have to live with, and nothing has actually fixed the problem, it's worth looking deeper.

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