Histamine Intolerance and SIBO

Michael Eisenwasser 2 min read

SIBO comes up a lot in conversations about histamine intolerance. It stands for small intestinal bacterial overgrowth.

I'm not a doctor, and most of what's written about SIBO goes deeper than I can vouch for. This is the basic version: what it is, why it comes up next to histamine intolerance, and when to ask a doctor about it.

What SIBO is

SIBO means there are too many bacteria in the small intestine. The symptoms people describe most often:

Bloating within an hour or two of eating, often out of proportion to the meal
Gas and a full, tight feeling
Diarrhea, constipation, or a mix of both
Symptoms that overlap with IBS, like bloating and pain
New food reactions that keep appearing over time

Why it comes up with histamine

A lot of the histamine you get from food is handled in the gut, so gut problems and histamine symptoms often show up together. Some gut bacteria can also produce histamine themselves, which may be one reason some probiotics make some people feel worse.

The connection isn't straightforward, and researchers are still working it out. But it's part of why careful eating alone sometimes isn't enough, and why it can be worth asking whether a gut problem is involved rather than only adjusting the diet.

When to ask a doctor about it

Bloating shows up quickly even with foods you normally tolerate
Symptoms don't settle after weeks of careful eating
Things started after food poisoning, a gut infection, or a course of antibiotics
New food reactions keep appearing instead of the list staying stable

None of this is proof. But if several of these sound familiar, ask your doctor whether SIBO could be involved. There are tests for it, and testing and treatment are things to work through with a doctor, not on your own. It's a good thing to raise when you're talking to your doctor about histamine intolerance.

What you can do in the meantime

Keep notes. A few weeks of meal and symptom notes gives your doctor much more to work with. Write down when the bloating starts and what you ate beforehand.

Keep food fresh. Freshness lowers your histamine load without cutting more foods out.

Be careful with probiotics. Some strains make some people feel worse, so it's worth pausing before adding new ones, and worth mentioning them to your doctor.

Don't keep a highly restricted diet going indefinitely. The elimination phase is meant to be temporary. If restriction isn't helping, that's a reason to talk to a doctor, not to cut more foods.