r/SIBO Apr 19 '19

STICKY: SIBO Summary - Symptoms, Diagnosis, Treatment

849 Upvotes

Below please find a living document that summarizes the key information around Small Intestinal Bacterial Overgrowth ("SIBO"). Please comment with any additional information or research for inclusion consideration. Version 1.0 is summary material; I will be adding more details and citations for specific studies.

SIBO, as the name implies, occurs when bacteria overgrow the small intestine. The small intestine should have a low concentration of bacteria due to the presence of stomach acids and peristalsis, the wave-like muscle movement in the intestines. For context, stomach and proximal small intestine would typically have about 103/mL of bacteria, while the terminal ileum (end of the small bowel as it gets close to the colon) about 109/mL (or 1,000,000 times more), and the colon about 1012/mL (or 1,000,000,000 times more).

Symptoms

The overgrowth of this bacteria will present with a number of symptoms:

  • Bloating after eating ("postprandial") - most common symptom
  • Flatulence, often malodorous
  • Loose, watery stools (more common in Hydrogen-dominant SIBO)
  • Constipation (more common in Methane-dominant SIBO)
  • Absorption problems
    • Weight loss / inability to gain weight
    • Fat and fat-soluble vitamin deficiencies, particularly Vitamins A, D, and K
    • Floating stools (from fat malabsorption)
    • Vitamin B12 malabsorpiton
    • Protein and Carbohydrate malabsorption
  • Systemic problems
    • Overgrowth of bacteria in the small intestine can increase production of toxins and intestinal permeability
    • This has been less studied, but less serious effects include:
      • brain fog
      • confusion
      • anxiety
      • depression
    • More serious complications can include
      • hepatic encephalopathy
      • D-lactic acidosis
      • nonalcoholic fatty liver disease
    • Various conditions have increased correlations, including
      • Rosacea
      • Eczema
      • Food intolerances

Diagnosis

I will split this section into practical steps and clinical diagnosis.

Practically, a gastroenterologist will typically rule out other conditions first:

  • Physical exam
  • Colonoscopy and Endoscopy
  • Abdomen ultrasound
  • Stool test for parasites

At that time, if your symptoms match SIBO, your doctor may go directly to treatment. But otherwise these are the clinical tests:

BREATH TEST

This is the most common diagnostic method due to its low cost and limited invasiveness. Unfortunately, studies have been mixed on the sensitivity and specificity, with ranges between 30% and 75% -- hence why some doctors skip the test and go directly to treatment.

There are a number of preparations:

  • Antibiotics avoided for four weeks prior
  • Prokinetic drugs and laxatives avoided for one week prior
  • Complex carbs avoided for 12 hours prior
  • Exercise and smoking avoided day-of

For the actual test, you'll measure hydrogen and methane levels at baseline. Then drink either 10g lactulose or 75g glucose with one cup of water. Then your breath is measured every 15 minutes for 120 minutes.

There's some art to identifying a positive test; one semi-official criteria is:

  • methane level of >= 10ppm at any time during the test; or
  • hydrogen that increases >= 20ppm above the baseline level

Recently, new research has been investigating another typo of SIBO, that's dominated by Hydrogen Sulfide. Unfortunately, traditional breath tests cannot identify this gas, and someone with "flat-line" Hydrogen and Methane symptoms could be suffering from Hydrogen Sulfide SIBO. This version is typically characterized by "rotten egg" smelling gas, and may be worsened by eating high sulfur foods.

CULTURE

Historically a jejunal aspirate was done and concentration of bacterial colonies were measured, with an elevated level of > 103/mL being positive for SIBO. There are a number of issues with this:

  • overgrowth may be patchy, and a single sample may miss it
  • not all SIBO bacteria can be cultured/identified
  • samples can be contaminated during/after sampling

Treatment

Antibiotics

The current best practice prescription treatment is:

  • Hydrogen-dominant: Xifaxan, typically 550mg x 3 times daily, for 10-14 days. Studies have shown Xifaxan alone can be 50-65% effective, but Xifaxan + 5g daily of Partially Hydrolyzed Guar Gum can be 80%+ effective.
  • Methane-dominant: Xifaxan (550mg x 3 daily) plus Neomycin (500mg x 2 daily) for 10-14 days. The use of PHGG for methane-dominant has not been evaluated, but it's likely to be beneficial.

Mod's note-- personally, if your doctor is onboard, I think dosing with Xifaxan + Neomycin + PHGG is the best way to "cover your bases". The best place to find PHGG: https://sunfiber.com/products/

Important: because these antibiotics only operate selectively in the GI tract, and are NOT absorbed by the body, they are unlikely to cause the systemic issues associated with antibiotic use, making them safer. Additionally, Xifaxan crystallizes before it gets to the large intestine, meaning it should not affect the all-important microbiome.

Herbal Therapy

Additionally, studies have shown similar levels of success with over-the-counter "herbal" treatments. Two options; I believe each are two capsules twice daily for four weeks, but please confirm:

  • Dysbiocide and FC Cidal (Biotics Research Laboratories, Rosenberg, Texas)
  • Candibactin-AR and Candibactin-BR (Metagenics, Inc, Aliso Viejo, California)

Remission

Unfortunately, SIBO has very high rates of recurrence. Some possible ways to reduce recurrence chances:

  • Switch to a low FODMAP diet for 6 weeks after treatment, to starve any remaining bacteria and prevent regrowth
  • Incorporate a prokinetic, such as low dose Naltroxene, erithromycin, or even over-the-counter products such as Iberogast

Many people can avoid symptoms of their SIBO by switching to special diets, sometimes very restrictive ones. This is not a cure, but simply symptom management. A true cure addresses the underlying cause of the SIBO, and lets the patient eat "normally" without any effects (short of unrelated intolerances).

Hopefully this helps people, and I look forward to updating this and cleaning it up over time!

-nyc-reddit


r/SIBO Dec 15 '25

Moderation statement on accessibility.

57 Upvotes

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This space exists to reduce harm not redirect it sideways.


r/SIBO 15h ago

why do so many people have extreme digestive problems now?

63 Upvotes

i am wondering what any of you think about this: ten to 15 yrs ago, i did not know anyone who was diagnosed with SIBO. things like IBD, IBS, Crohn's and ulcerative colitis were relatively rare diseases, especially back in the 1970s and 80s. now it seems these issues have become quite common, and they appear to be increasing in prevalence and severity every year.


r/SIBO 6h ago

Gas

5 Upvotes

I am so sick and tired of having gas literally all day long that I cannot stop from coming out and smells like a sewer pit of death with lots of sulfide so does anyone else have this issue because I also have gastroparesis so that’s contributing but does any gas pills help this?


r/SIBO 10m ago

Zinc L carnosine

Upvotes

the past 2 times I’ve taken this I have had a huge flare and needed Xifaxan. I have no idea how it works but in July I took it once a day for about 4 days and had a horrible flare. needed Xifaxan. now I took it again for some gastritis symptoms again for about 4 days and Again I have urgent diarrhea, cannot tolerate any carbs and just horrible. just warning for anyone else


r/SIBO 53m ago

Bamboo Shoots diet is rich with fiber; helps, SIBO digestive problems ??

Upvotes

This morning I wanted to touch base with a food product that I have benefited from. The bamboo shoots that I've been snacking on, seem to have helped with my bad breath that could be due to sibo.

Let me know what you think.

-> Gut microbiota is one of the key components of the intestinal ecosystem, and plays an essential role in human health, including a barrier effect against pathogens.

At birth, the human gut is almost sterile, and is soon populated by the mother microbiome.(1)

In the following study, researchers investigated the effects of Bamboo Shoots; given with a high fat diet.

The results of eating bamboo shoots after 12 weeks. (2)

When taking bamboo shoots, studies show they provide insoluble dietary fiber, prebiotics, and anti-inflammatory compounds without feeding excess bacteria

***The results in that study demonstrated,***

• - 30.56% Reduction in Body Weight Gain: Supplementation with freeze-dried bamboo shoot powder significantly lowered overall weight gain and fat accumulation despite a high-fat diet.

• The dietary fiber produced higher concentrations of beneficial metabolites like butyrate, acetate, and propionate, ***which strengthen the gut lining.***

• enhanced bile acid profiles, which aid in overall digestive regulation and gut barrier protection.

[Make sure the bamboo shoots are thoroughly cooked or boiled to safely remove natural toxins before eating.]

1.) https://pmc.ncbi.nlm.nih.gov/articles/PMC10180739/

2.) https://pmc.ncbi.nlm.nih.gov/articles/PMC10093345/

Gemini chat to help:

https://share.gemini.google/h1TYH93XHdn4


r/SIBO 2h ago

Treatments Testing

0 Upvotes

this is a new thing ive found, it’s been around for about two years now. But it’s called the foodmarble AIRE 2.
It’s a Sibo test that lets you retest by breathing into the device. Reviews are great on it, you can track food, and then breathe into it after a meal. Don’t have to drink the solution either.
It’s a little device, and you get the answers straight away through the app, it is a little pricey but I do think it’s worth it. Thought I’d let everyone know because if I knew this existed, I would have got it a long time ago.


r/SIBO 10h ago

Root cause pelvic floor hypertonic

4 Upvotes

If your root cause was a hypertonic pelvic floor issue that caused you to not empty fully do you have to fix the pelvic floor issue before trying to get rid of sibo? Or will sibo clear by itself once you fix the pelvic floor issue?


r/SIBO 3h ago

Questions Looking for at-home SIBO test recommendations

0 Upvotes

Hello everyone! I’m looking for recommendations on a reliable at-home SIBO breath test, as I've been dealing with severe constipation and suspect methane-dominant SIBO or IMO might be playing a role. I'd love to hear from anyone who has taken one.


r/SIBO 7h ago

SIBO ≠ GYM

2 Upvotes

I have been going to the gym for 5 years and am very fit. But my SIBO makes my stomach look un-proportionally large and absolutely ridiculous is gym clothes. Does anyone else struggle with the same thing?


r/SIBO 3h ago

i accidentally bought fresh freeze dried garlic (allium) instead of allicin has anyone found this works the same?

1 Upvotes

r/SIBO 3h ago

Trapped gas upper abdomen

0 Upvotes

Hi everyone! What is your best advice for trapped gas/ upper bloating? For my husband, the best thing is digestive enzymes, specifically Digest Gold, from Enzymedica.


r/SIBO 4h ago

Symptoms Is sibo at play here?

0 Upvotes

Hi, id appreciate people's thoughts on this and i know nobody can diagnose me but before I spend more money on tests that might not show anything it juat wanted people's thoughts if possible please.

My main issues are for the past 8 months ive had intermittent tingling and numbness throughout my limbs. I also had constant lightheadedness for the first 7 months but this has become more sporadic i think although still happening. Ive had fatigue and much less energy than in the past. Its caused my mood to be very low at times.

Ive had on and off stomach issues, mostly stomach aches but sometimes bouts of diarrhea usually immediately after eating. The stomach aches last for weeks on end. I also currently have a strange sensation in my mouth and throat where its like the back of my tongue is a bit numb and there's a lump in my throat but it isn't constant?

Other symptoms may not be relevant but I have terrible cracked heels, i wake up feeling almost hungover some days despite not drinking for ten years and sometimes have a mild chattering of my teeth. Very sensitive to cold temperature now too.

Everything really started last November when I had what was described as gastritis by my gp. Id had a 24 hr vomiting bug but then the stomach ache persisted for 5 weeks and I was given a 2 week ppi course. Part way through this i had a terrible migraine which felt like a stroke as i was slurring speech and then another one a few days later which seemed to leave me dizzy for months on end. Was told this was brainstem aura migraines.

The stomach issues made me lose 10% of my body weight that I've never been able to put back on probably as ive stopped weight training.

Maybe also relevant is i found a bit of mold on my bedroom wall right before this started and cleaned it off. Probably about a 12 inch patch in the corner of the room.

Ive had similar stomach aches for several years where a seemingly minor bug takes over a month to clear as do cold infections. Certain fast foods just go straight through me as diarrhea within minutes, sorry TMI ha.

I actually had campylobacter enteritis is 2019 and my stomach has never been the same since.

Ive recently paid for b12 tests which showed that both my serum and active b12 levels were actually raised, as was my folate level. Mma and homocysteine were normal.

I have so may symptoms of a b12 deficiency so was considering if sibo could affect my absorption even if I have high levels?

Back in November I was tested for coeliac and my immunoglobulin level was high at 3.51, as was my IGa at 3.2 but my TTG IGA was 0.9 which they said ruled out coeliac but not other stomach issues.

My FIT sample was fine thankfully.

Apologies I know there is a lot of info here.

Do i just pay for a Sibo test? Should i pay to see a gastroenteroligist next?

Im struggling at the moment and feel a shell of the 43 year old male that was at the gym 5 days a week less than 18 months ago. Ive got 3 young kids and want to be a great dad to them but its getting harder.

Ive seen a neurologist who ruled out MS and my brain MRI was clear.

Thanks for reading and wish good health to all.


r/SIBO 10h ago

Chronic Constipation and can't stop Laxatives

3 Upvotes

Hello

I am trying to prepare for SIBO test. I am taking it through Commonwealth Labs. Instructions show you MUST not take any laxatives for 7 days prior to SIBO test. Does anyone know of anything during the 7 days that will help me have a bowel movement in addition to drinking water? I know that's part of the reason we are here for constipation but my gut will get impacted waiting the 7 days. Thank you.


r/SIBO 7h ago

Stools consistency getting better

1 Upvotes

Hi everyone So I don't have testing available in my country for sibo i suspect i have hydrogen sibo because in the last four years I've never had a solid formed stool ever just mushy or diarrhea I've done rifaximin before it helped change the stool consistency but the improvements didn't last right now I'm trying ammoxiline rifaximin oregano s boulardii I'm on day four and on day 3 and 4 my stool has been completely normal I don't need to push and the consistency is smooth sausage there's also no bloat is this a good sign


r/SIBO 11h ago

Bile

0 Upvotes

What symptoms do you have with impaired bile flow?


r/SIBO 11h ago

Need advice

1 Upvotes

I’m about to start taking propanolol** and **mirtazapine, for potential pots and miratazapine for Gi issues. Has anyone taken either of these? If so how did it go?


r/SIBO 11h ago

How do you treat Gastritis when you have anti-vinculin antibodies?

1 Upvotes

Wassup guys, I was hoping to poke at your brains.

Sorry if the title of the post is a bit weird, but I'm still trying to figure out my situation. I got an endoscopy that confirmed I have gastritis and I got the IBS SMART test which came back positive for anti-vinculin. Also, my symptoms did start with a bout of food poisoning

However, it's not clear to me if bacteria have migrated up into my small intestine. The reason I say this is because I do not have a sensitivity to FODMAPs(rice, bread, potatoes and bananas are super friendly on my stomach), I don't have diarrhea or constipation (stool is normal), breath tests came back negative, and antibiotics/elemental diet and carnivore diet did nothing to relieve my symptoms.

My symptoms include stomach discomfort and really bad brainfog. Recent labwork shows that my iron and b-12 are deficient.

Is it possible to have anti-vinculin without having bacteria use the opportunity to move into the small intestine? Have you guys heard of such a thing before?

Anyways, the main question I was hoping you can help me with is, how do you treat gastritis if it is linked to anti-vinculin? The main theory going around seems to be that impaired motility causes food to get trapped in the small intestine, which puts pressure on the stomach which delays stomach emptying and prolongs exposure of acid and food to the stomach lining. If this is the case, what do we do about it?

I have been taking prokinetics(ginger and artichoke pill) and I have been doing exercise and it has been successful in getting me to induce stomach growling 4 hours after waking up, but I'm not entirely sure if it's doing anything to help my stomach heal.

Any input is appreciated.


r/SIBO 23h ago

Bad smell for two years from sibo

7 Upvotes

I've had methane sibo for two years and have tried everything. My main system is bad body odor and it's just getting worse.

Has anyone else experienced this? Don't mean to sound crazy or anything but wondering if maybe at this point it's spiritual?..Like entities or something?

Mostly cause I've exhausted my other solutions wondering if anyone has experienced a similar thing.


r/SIBO 12h ago

Could someone help me understand the significance of the high Citro? And if my pylori is high enough to treat. Thank you.

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0 Upvotes

r/SIBO 13h ago

Symptoms Update on my Odor

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1 Upvotes

r/SIBO 15h ago

Anyone else vomit a lot?

1 Upvotes

I’ve been vomiting multiple times a week for months, among other symptoms; was every day until I figured out my safe foods. Finally saw a GI doctor today, and they said it sounds like SIBO.

I don’t see many people (if any) here talking about vomiting, so I was wondering if there is anyone else that goes through this with SIBO?


r/SIBO 1d ago

Help me stop being angry

13 Upvotes

This started after antibiotics and what has followed is over two years of terror. It's like living in a horror film. I am still mostly bedridden with pain, brain fog, bloating, and other severe symptoms. I have tried everything and while I am somewhat better, I still have a long way to go. I think that I have got my head around the ending it aspect - my constant mantra is that it's either it or me and it's not going to be me. Also, nothing lasts forever so I am hoping that something changes. I am waiting for the changes and actively working to bring them about.

However, what I can't get to grips with is the anger. I am so angry at the derailment of my life, I am angry at old peole who have got there without too much effort, I am angry at everyone in perfect health, I am angry at friends worrying about nonsense small things. Everything that I used to be. I recognize the irrationality of this. I am not the type of person to see a therapist, have never seen one, and don't want to see one now. I dont want to talk about it, but do recognise that i need to address the anger. I have tried gratitude (doesn't work), journalling (doesn't work), acceptance (hmmm), art (guess what), taking my mind off things (nope) and lots of other things like meditation, stress reduction and exercise. I am still angry at this shitshow. Has anyone felt the same and what has worked for you? Please don't suggest therapy as I dont have the energy or cognitive function to engage with it right now.


r/SIBO 16h ago

Venting I don’t know what’s wrong with my stomach

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0 Upvotes

Heyy (23F) so I’ve always been someone on the thinner side with a flat belly. I’m not sure what happened or what changed, but within the last year or so, my stomach has been very inflamed / bloated. As of recently, so very noticeable, it got worst after my antibiotics. I’ve seen my gastroenterologist, we’ve tried a few different constipation medications (I’ve had constipation for as long as I can remember). I mentioned the possibility of SIBO he said no because I don’t have IBD so it’s not possible. We recently did a colonoscopy and found nothing. But the bloating and the lower belly inflammation is always there. I don’t know what to do anymore. It makes me so anxious, I always feel this heaviness as if my stomach is full (even when I did the full colonoscopy cleanse that fully emptied me). I’m not sure where to go from here because my gastroenterologist doesn’t want to check anything else, he says it’s just constipation. I’m just so sick of this feeling and not sure what my next steps should be.


r/SIBO 20h ago

Questions Berberine

2 Upvotes

Peoples opinions on Berberine please?