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SIBO: How Long for Antibiotics to Start Working?


Senior Member
United Kingdom
(Don't feel you have to read this whole message - please feel free to just address the section in bold if you have any advice. The remainder is background in case anyone is interested).

I began a course of antibiotics last week for SIBO and, while it definitely had an effect, I'm not sure how positive it has been and I'm interested in people's input.

The changes they caused included significant flatulence and what I feel is a Herxheimer reaction to dead bacteria (achiness, fatigue, some depression).

I actually had to come off the antibiotics a couple of days ago as I started having an adverse reaction to one of them (Neomycin, was causing problems with my hearing and the doctor advised me to stop). Out of precaution I have stopped both until my ears are better.

Since then, the Herx symptoms have resided somewhat, and I am roughly back to the state I was in prior to starting the antibiotics, but no better. I know I only managed to do half the course but I was hoping it would have had some noticeable affect by now - I know from tests I have significant SIBO issues and I had hoped the Herx was proof I was killing a lot of bad stuff.

In people's experience how long would it take for a successful round of antibiotics to start having a positive effect on SIBO and related symptoms?

One other thing I should add is that my tolerance for the stomach acid drops has gone way up since beginning the antibiotics. Last week I was only able to have 6 drops before every meal; any more and I'd get this weird flushing sensation plus an autoimmune reaction.

...I did some research and apparently these can be caused by a weakened stomach lining not being able to withstand the extra acidic environment, however the fact that the antibiotics improved it so much makes me suspect that the actual cause was a damaged small intestinal lining.

Something else that might have been helping in this regard has been a supplement called "Perm Plus", which you take 20 minutes before a meal and is supposed to promote healing of the gut lining (it contains things like glutamine).

Whatever the reason, I am glad at least my tolerance of the Acid Drops has gone way up as it signifies to me that something has gone right. It's just a tad frustrating it's not really evident anywhere else thus far. Hopefully over time I will gradually start to notice an improvement even if I don't fully recover? I suspect I might need a few rounds of antibiotics given how bad my condition has been in the past.

Finally I should probably note that my diet hasn't been 100% perfect for SIBO eradication. Ideally throughout this I should really just have been eating meats and very low FODMAP veggies. But as I've mentioned elsewhere on this site I've also had methylation issues, and have to take supplements to that effect.

As a result, anything with large levels of folate or methionine (ie, vegetables and meat) really triggers my autoimmunity, and so my diet for the past few months has largely consisted of quinoa and small amounts of meat, the former seeming to be one of the foods that least triggers my autoimmunity.

I have read conflicting stuff about quinoa - some SIBO diets allow it because it is low FODMAP and passes through the system quickly due to its high fibre content. Others strictly ban it due to its starch content. For me, eating it doesn't cause any immediate negative side effects, like the flatulence or gastro symptoms I get from FODMAP foods, and it passes through my system very quickly and keeps my bowel movements very regular. I'm hoping that these are indicators that they're not feeding the SIBO? Again any input here is much appreciated.

Thanks in advance,