Small Intestine Bacterial Overgrowth, often referred to as SIBO, is characterized by excessive growth of unhealthy gut bacteria. The bacteria produce a disruptive amount of gas leading to symptoms including bloating, abdominal pain, and diarrhea. The disruptive gases include methane and hydrogen.
While prescription antibiotics are a standard to kill off this bacteria, antimicrobial herbs are an alternative option.
A holistic approach to SIBO treatment involves removing some of the excessive bacteria and also supporting the gut health. Overgrowth is not the only concern since SIBO also causes gut damage.
Herbal Therapies in Comparison to Antibiotics
A clinical trial in 2014 by Johns Hopkins University found herbal therapy to be as effective as a pharmaceutical antibiotics for the treatment of SIBO. The antibiotic involved was Rifaximin. This study is the first of many to show the efficacy of herbal therapy for SIBO.
One hundred and four patients who recently tested positive for SIBO were offered either an herbal therapy or rifaximin for four weeks. The herbal therapies included four different commercial preparations. Each option included four to ten different herbs. These herbs included sage leaf, Chinese licorice root, Chinese skullcap root, berberine, oregano oil, and lemon balm. Two of the herbs, berberine and oregano oil, are further discussed below.
The researchers found the herbal therapies to be as effective as Rifaximin to treat SIBO. Notably, some of the patients who received Rifaximin did not see any improvements with their SIBO. Those who were unsuccessful with Rifaximin then selected a triple antibiotic therapy or an “herbal rescue therapy.” This herbal rescue option was additionally found to be as effective as the antibiotic route.
A Difference in Side Effects
The study found a notable difference in side effects between the two groups. In the Rifaximin group, 9% experienced Clostridium difficile and non-C. difficile associated diarrhea. In the herbal therapy group, only 1% experienced diarrhea.
Antibiotics tend to be more damaging to the gut microbiome in general. The researchers hypothesized that since the herbal therapies are less disruptive to the gut microbiome, they are more likely to protect the healthy gut bacteria. Healthy gut bacteria are essential for preventing harmful bacterial growth, such as C. difficle. On the contrary, taking antibiotics can lead to an increase in opportunistic infections such as C. difficult because antibiotics increases bacterial resistance. Increased bacterial resistance can cause an unbalanced gut with more unhealthy than healthy bacteria.
Why Not Antibiotics?
Antibiotics in controversial because it kills both harmful and beneficial bacteria in the gut. Just seven days of a common antibiotic, clindamycin, has been shown to reduce supportive gut bacteria and diversity for over a period of two years. Herbal antimicrobials are more protective against supportive bacteria, therefore does not negatively impact the gut long term.
Berberine (huang lian su) is a compound found in Oregon grape, barberry, and goldenseal. It acts as an antimicrobial for hydrogen-producing bacteria, by halting bacterial cell division. Hydrogen- producing bacteria is present in the gut when people experience diarrhea-heavy SIBO. Fortunately, berberine is often found in Chinese traditional formulas utilized to treat bacterial diarrhea.
In a review in 2011,researchers explained that berberine most significantly impacts growth of Staphylococcus, Streptococcus, Salmonella, Klebsiella, Clostridium, Pseudomonas, Proteus, Shigella, Vibrio, and Cryptococcus bacteria species. Streptococcus, Proteus mirabilis, Staphylococcus, Clostridium, and Klebsiella pneumoniae are a handful of the main bacteria responsible for hydrogen-based SIBO.
Berberine has many other functions. It can also support the growth of healthy bacteria in our guts! While studying berberine’s antimicrobial effect against E. coli, researchers in 2008 found berberine to have no negative effect on lactobacilli and bifidobacteria, two beneficial gut bacteria.
Oregano oil is another herbal antimicrobial. It is a well-documented ingredient that directly inhibits the growth of intestinal microbes.
In 2009, scientists tested oregano oil (Origanum vulgare Linn.) against 111 gram-positive bacteria from 23 different species. The oil successfully exhibited antibacterial activity. However when the oil was decocted, the bacteria became resistant.
Allicin (da suan) is another common antimicrobial. It is the active ingredient in garlic. Allicin helps to eliminate the hydrogen producing bacteria while also supporting the lining of the small intestine. It is found to help relieve the constipation-heavy symptoms of SIBO.
While allicin has demonstrated antimicrobial activity on its own, It has also been found to increase the efficacy of other therapies, including antimicrobial drugs. If an individual were to take an antibiotic, an addition of allicin might help support the drug’s action while protecting gut health.
Significant Potential for the Future
SIBO was only recently named in 2004. Therefore, the research behind herbs as a therapy for SIBO is just beginning.
Scientists in 2020 published a protocol for systematic review and meta-analysis on Chinese herbal medicine for SIBO. The herbs include garlic, black cumin, cloves, cinnamon, thyme, all-spice, bay leaves, mustard and rosemary. All of these herbs have demonstrated antimicrobial properties.
Research on the efficacy of Chinese herbal medicine for SIBO is currently limited, therefore more placebo controlled studies need to be performed in the future. As of now, this article will hopefully help provide high-quality evidence for health practitioners and their patients.
SIBO is a tricky disease that involves several steps to restore a healthy gut microbiome. Some of these steps may involve herbs, antibiotics, and diet alterations. There are a variety of herbs that can help treat SIBO, a few of which are mentioned above that are backed by scientific reaserch. Chinese medicine holds valuable tools to help resolve SIBO