Neomycin – Why Fix Your Gut Does Not Recommend Its Use for SIBO-C

Big pharma is always finding new ways to resurrect older medications to treat diseases. Since so many of our current antibiotics are becoming microbial resistant, older medications despite their side effects are being brought out to the forefront to tackle dysbiosis and even gut issues. Neomycin is one such drug that is being used to treat methane dominant archaea dysbiosis or known as SIBO with constipation. Many people reading this blog entry might have a tube of the topical antibiotic Neosporin in their medicine cabinet. Neosporin contains neomycin as its main antimicrobial agent. So, what is neomycin and why I do not recommend its usage in people suffering from SIBO-C?

Neomycin and Why Does Fix Your Gut Not Recommended It?

Neomycin is aminoglycoside antibiotic that is mainly applied topically. Aminoglycoside antibiotics are derived from compounds produced by bacteria from the genus Streptomyces and work well against Gram-negative aerobic bacterial infections. Neomycin has also been shown to be effective against archaeal dysbiosis which is why the antibiotic is recommended for people that are suffering from SIBO-C. Neomycin is rarely used orally and is not used as an intravenous antibiotic because of its extreme side effect profile. Minute doses of neomycin are used as a preservative for some vaccinations but is claimed to be safe because of the dosage.1 2 3 4

So what are the side effects associated with aminoglycosides?5

  • Ototoxicity
  • Nephrotoxicity
  • Vestibulotoxicity
  • Mitochondrial toxicity
  • Tinnitus
  • Hearing issues and loss
  • Balance issues
  • Vertigo
  • Ataxia
  • Skin rashes and hypersensitivity (mainly in topical preparations)
  • Gastrointestinal upset (diarrhea or constipation)
  • Prolongation of the effects of neuromuscular blockers and medications (succinylcholine, curare-like drugs)
  • Worsen symptoms of weakness in people suffering from myasthenia gravis

Many of the severe side effects of aminoglycoside antibiotics occur from its mechanism of action against the messenger RNA of bacteria which also seem to cause oxidative stress within our mitochondria as well (remember our mitochondria might have been bacteria once). Aminoglycosides are especially damaging to the mitochondria of the auditory system and the kidneys. Aminoglycosides are transported through the Gram-negative bacterial cell wall (lipopolysaccharide) where it interferes with messenger RNA translation, inhibiting protein synthesis and leading to premature bacterial death. In addition, the mitochondrial mutations 1555A>G and 1494C>T seem to increase the chances of aminoglycosides and mitochondrial toxicity. Finally, both endotoxins released from Gram-negative bacterial die off and the use of loop diuretic medications while taking neomycin (which I believe is caused from a reduction in electrolytes and fluid which can increase mitochondrial stress) increase the risk of mitochondrial toxicity.6

“Hirose et al. reports the combined administration of aminoglycosides with loop diuretics exacerbates ototoxic injury in mice when compared with controls and mice injected only with aminoglycosides. Cochlear uptake of aminoglycosides is also increased by endotoxemia-induced inflammation.”

“Once in hair cell cytosol AGs interact with mitochondrial 12S ribosomal subunit causing inaccurate translation of mitochondrial proteins. The downstream implication of faulty protein synthesis is eventual cell death either through caspase-mediated or non-caspase-mediated apoptosis. Additionally, AG interaction with iron species has been shown to produce reactive oxygen species (ROS), which also leads to cell death through apoptosis. Previous in vitro experiments have shown an alteration in antioxidant defense system in melanocytes induced by aminoglycosides, which may be an additional contributing factor in the onset of ototoxicity. Rizzi et al. has also shown a clear progression of hair cell death originating at the basal turn and moving toward apical turn of the cochlea. This progression moves in line with the onset of deafness, as high frequency loss is observed before the loss of lower frequencies.”\7

Neomycin is believed not to be absorbed orally, which is why it is recommended in people with SIBO-C. However, there are case reports that were done when it was used more frequently in the 1960’s and 1980’s that showed that even when taken orally it can cause ototoxicity. Many people from the SIBO Facebook group have also reported developing or worsening tinnitus and hearing issues when taking neomycin for SIBO-C. It is interesting that the report that was done in 1983 mentions that ototoxicity is more common in people with gastrointestinal inflammation (mainly people with SIBO suffer from this also known as “leaky gut.”

“Ototoxicity is viewed as an uncommon complication of oral neomycin most likely to occur in patients with renal failure or gastrointestinal inflammation.” 8

What to Do If You Need to Take an Aminoglycoside

The primary cause of aminoglycoside side effects appears to be mitochondrial toxicity. In addition, I would recommend talking with your doctor about avoiding taking an aminoglycoside if you are also taking a loop diuretic, or discuss briefly lowering the dosage or stop taking the diuretic because it can increase the risk of ototoxicity. There are studies that advocate the use of N-acetylcysteine (NAC) to produce glutathione to reduce mitochondrial oxidative stress and death. I do not recommend the use of NAC or glutathione in people that have mercury amalgams or are mercury burdened because of improper chelation. Finally, I would recommend asking your doctors about the medication Alinia and if needed Flagyl instead of Neomycin to treat SIBO-C.9 10 11 12 13

Theoretical Aminoglycoside Protection Protocol