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Alcohol and SIBO: Impact on Digestive Health

Updated: Jan 2

We're shedding light on the intriguing relationship between alcohol and SIBO (Small Intestinal Bacterial Overgrowth). Understanding how alcohol affects the gut can help you to make better decisions about you overall health and well-being.

The Intricacies of SIBO: Small Intestinal Bowel Overgrowth

SIBO, or Small Intestinal Bacterial Overgrowth, is a condition that arises when there's an abnormal increase in the population of bacteria in the small intestine. Normally, the small intestine has a relatively low bacterial count compared to the colon, which allows for efficient nutrient absorption and digestion.

However, when this delicate balance is disrupted, it can lead to a range of uncomfortable symptoms and health issues.

Common symptoms of SIBO include abdominal pain, gas, bloating, diarrhea, malabsorption, altered bowel habits and even weight loss in severe cases. Understanding the causes and triggers of SIBO is crucial in managing and preventing this condition.

Health gut health depends of healthy gut bacteria in the large bowel with minimal bacteria in the small bowel. When SIBO occurs, the overgrowth of bacteria in the small intestine can lead to various digestive symptoms and other health issues.

Alcohol and SIBO, Dr Deb Brunt, Otepoti Integrative Health

How Common is SIBO?

In people with irritable bowel syndrome (IBS), between 31-54% test positive for SIBO by breath test (Ford 2009). SIBO is especially common in people with IBS who are women, those with older age and those with diarrhoea symptoms of IBS (Chen 2018).

One study reported rates of SIBO as high as 80% among women with endometriosis (Matthias 1998).

What are the symptoms of SIBO?

SIBO symptoms can vary from person to person. They include:

  • Abdominal pain and discomfort: This can range from mild bloating to significant pain and cramps.

  • Gas and bloating: Due to the fermentation of undigested food in the small intestines by the excess bacteria.

  • Diarrhoea: Sometimes, the increased bacteria can disrupt normal digestion and cause diarrhea.

  • Malabsorption: The excessive bacteria can interfere with nutrient absorption, and also production of substances that have a negative effect on health.

What causes SIBO?

SIBO can be caused by a variety of factors (Rao 2019), including:

  • impaired intestinal motility or dysmotility (the movement of food through the digestive tract),

  • structural abnormalities in the small intestine,

  • previous abdominal surgery such as hysterectomy, gastrectomy, cholecystectomy or colectomy or

  • certain medical conditions that slow down digestion (parkinsons, diabetes, hypothyroidism).

It is also associated with inflammatory bowel disease, dyspepsia, rosecea and restless leg syndrome and small bowel diverticulae.

Some studies also show a connection with SIBO and proton-pump inhibitors (PPI) such as omeprazole or pantoprazole. Because they reduce acid in the stomach, it is thought they contribute to small bowel overgrowth due to reduced gastric acid. One study fround 25% of patients treated with PPI for 3 years had SIBO vs 6% of healthy controls (ie people without PPI use). (Lombardo 2010)

How is SIBO diagnosed?

Diagnosis of SIBO often involves methane and hydrogen breath testing that detect the presence of both hydrgen and methane, produced by the overgrowth of bacteria in the small bowel.

How is SIBO treated?

Treatment typically includes antibiotics to reduce the small bowel bacterial overgrowth, along with dietary modifications to help manage symptoms and prevent recurrence.

Some doctors prefer herbal anti-microbials as they often have the dual function of inhibiting growth of problematic bacteria wihle encouraging growth of beneficial bacteria.

The Link Between Alcohol and SIBO

There is a potential link between SIBO (Small Intestinal Bacterial Overgrowth) and alcohol consumption.

Some studies have identified moderate alcohol consumption to be associated with increased risk of SIBO.

A study of 210 patients who underwent breathtesting, found 58% of moderate alcohol consumers had SIBO compared with 38% of those how consumed no alcohol.

Moderate alcohol consumption means no more than 1 unit of alcohol per day for women or 2 units of alcohol per day for men.

Gut Motility

One of the factors contributing to SIBO is impaired gut motility, which is the movement of food through the digestive tract. Alcohol has been known to slow down gut motility, which could create an environment where bacteria accumulate in the small intestine.

Changes in Intestinal pH

The pH levels in the digestive system play a significant role in maintaining a balanced microbial environment. Excessive alcohol intake may alter these pH levels, potentially favoring the growth of certain types of bacteria in the small intestine.

Immune System Impact

Chronic alcohol consumption can weaken the immune system, including the immune defenses in the gut. A compromised immune response in the gut might contribute to the development or persistence of SIBO.

Intestinal Barrier Function

The intestinal lining serves as a protective barrier, preventing unwanted substances and bacteria from entering the bloodstream. Alcohol might compromise the integrity of this barrier, making it easier for bacteria to migrate from the colon to the small intestine, contributing to SIBO.

Frequently Asked Questions about Alcohol and SIBO

If I have SIBO can I drink alcohol?

If you have been diagnosed with SIBO it is not advisable to drink alcohol while you are on a restorative gut programme.

Once you have eradicated SIBO, if alcohol use was a factor contributing to the development of SIBO you may want to limit alcohol intake to minimise the chance of SIBO recurrance.

What kind of alcohol can I drink with SIBO?

If you have been diagnosed with SIBO, it is best to avoid alcohol in any form. This includes: beer, wine, hard liquors and mixed drinks.

Is there an alcoholic drink that is better for SIBO?

No. All forms of alcohol can contribute to the development or recurrence of symptoms associated with SIBO. It is best to avoid alcohol altogether.

Is Kombucha safe for SIBO?

Kombucha is a fermented tea beverage and thus can contain some alcohol. While it is generally considered safe for most people, those with SIBO should avoid kombucha as the fermentation process may contribute to the growth of bacteria in the small intestine. It is best to consult withyour doctor or a registered dietitian for advice.

Does alcohol affect a SIBO test?

Yes. If you are scheduled to take a SIBO breath test, it is best to avoid alcohol for at least 24 hours before the test as it may interfere with the results.

Final Thoughts

  • SIBO can cause a variety of unpleasant symptoms and is a leading contriuter to irritable bowel syndrome.

  • It is important to be aware that alcohol consumption can impact on your gut health.

  • Seek medical advice if you think you may be experiencing symptoms of SIBO. Those who may benefit from SIBO breath testing include those with symptoms of irritable bowel syndrome, especially if you have ongoing symptoms despite standard treatment.

  • Through dietary changes, including alcohol cessation, and/or antibiotic or herbal antimicrobials, pre and probiotics it is possible to reduce the overgrowth of bacteria in the small intestine, restore balance in your gut, improving digestive health.

Hope you found this informaton helpful, we'd love to support you further.

Dr Deb Brunt @ Ōtepoti Integrative Health would love to support you with all aspects of your health and wellbeing including gut health.

Dr Deb Brunt is a specialist GP and menopause doctor in Dunedin, New Zealand and offers telehealth consults around New Zealand.


Lombardo L, Foti M, Ruggia O, et al. Increased incidence of small intestinal bacterial overgrowth during proton pump inhibitor therapy. Clin Gastroenterol Hepatol. 2010 Jun;8(6):504-8.

Rao SSC, Bhagatwala J. Small Intestinal Bacterial Overgrowth: Clinical Features and Therapeutic Management. Clin Transl Gastroenterol. 2019 Oct;10(10):e00078.

Ford AC, Spiegel BM, Talley NJ, et al. Small intestinal bacterial overgrowth in irritable bowel syndrome: systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2009 Dec;7(12):1279-86.

Mathias JR, Franklin R, Quast DC, et al. Relation of endometriosis and neuromuscular disease of the gastrointestinal tract: new insights. Fertil Steril. 1998 Jul;70(1):81-8.


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