Bloating: Which supplements can help?

*Note: The header image is AI-generated

In the morning, your jeans still fit loosely, by the afternoon the waistband is tight, and by evening your stomach feels like a little balloon. Maybe you've already stood in front of a shelf full of capsules and powders and wondered if any of it actually works. Peppermint oil, psyllium husks, probiotics, enzymes: The selection is large, and the promises on the packaging often are too. What has really proven convincing in studies, however, is much less well known. And not every remedy is right for every cause. In this article, you'll learn which supplement groups are well studied for bloating, what you should pay attention to when taking them, and when bloating should be medically investigated.

A bloating supplement can help, but not every one is equally effective and not for every cause. Peppermint oil and simeticon are the best studied, while psyllium husks are particularly convincing for constipation, and probiotics have so far only provided initial evidence.

Which supplement groups are considered truly proven for bloating?

Peppermint oil and simeticon are the best supported. Psyllium husks are clearly convincing for constipation, while the picture is mixed for bloating in the context of irritable bowel syndrome. Probiotics and digestive enzymes have so far provided initial evidence, but no more.

Briefly explained: A meta-analysis statistically summarizes several individual studies and is therefore more meaningful than any study on its own. Randomized-controlled (short RCT) means: The participants are randomly assigned to a group with the active ingredient and one with a placebo, so that expectations and chance do not distort the result.

Every classification applies only to the symptoms for which the remedy was actually tested. That is why this limitation is stated in parentheses right next to it.

It gets exciting when you look at who the remedies were tested on. The peppermint oil data comes almost entirely from people with irritable bowel syndrome (meaning: recurring abdominal pain with altered bowel habits, without an organic cause being found). The German S3 guideline for irritable bowel syndrome therefore explicitly lists peppermint oil as an option for pain and bloating. Simeticon, on the other hand, was investigated primarily for acute gas in the stomach, so for a completely different problem.

Fiber deserves a second look. In the older irritable bowel syndrome meta-analysis, only soluble fibers like psyllium husks benefited, while insoluble ones like bran did not. The effect was moderate: Mathematically, about one out of seven treated people had an additional benefit (2).

The newer evaluation sees no clear benefit at all in the overall picture. Honestly, that means: unclear.

With probiotics, it is often acted as if the matter is settled. It is not. Every strain behaves differently, and what worked in one study with a certain mixture cannot simply be transferred to another preparation.

Fiber and psyllium husks: When they work and what you should pay attention to

Psyllium husks are particularly worth considering when sluggish digestion is behind the bloating. In the constipation meta-analysis, more people responded to fiber supplements than to the comparison treatment. Psyllium husks performed the best. The authors themselves urge caution, because the included studies differ greatly.

Now comes the part that surprises many: Psyllium husks can cause bloating themselves at the beginning. The reason lies in the gut: The bacteria there ferment part of the fiber, producing gas in the process. The European Medicines Agency monograph therefore lists bloating at the beginning of intake as a known side effect, which generally subsides on its own over time (3).

Starting slowly with small amounts gives the gut time to adjust. At least as important is drinking: Psyllium husks bind water and swell. If the liquid is missing, the bloating can intensify, in the worst case there is even a risk of an obstruction of the esophagus or intestine (3).

Rule of thumb for drinking: Around 30 ml of water per gram of psyllium husks, plus a total of 1.5 to 2 liters of liquid throughout the day. For 5 g of psyllium husks, that would be about 150 ml directly for intake.

If you take medication regularly, the time interval is crucial. The gel-forming husks can delay how well other active ingredients are absorbed. The EMA monograph therefore calls for at least 30 to 60 minutes apart before or after other medications (3). This applies to thyroid hormones, anticoagulants, and heart glycosides, but also minerals like iron, zinc, calcium, and vitamin B12.

For thyroid hormones and diabetes medications, the monograph expressly recommends medical supervision, because the dose may need to be adjusted. A short conversation at the practice or pharmacy before starting clarifies this in a few minutes.

If you prefer to take psyllium husks as a capsule instead of powder in a glass: The CLAV Digestive Complex contains 2,200 mg of psyllium husks per daily serving, combined with fennel, caraway, and calcium. Click here for the product.

Probiotics, peppermint oil & co.: What each option does

Peppermint oil has the most convincing numbers. In the large meta-analysis, the chance of improvement in overall symptoms under peppermint oil was around 2.4 times higher than under placebo, almost 1.8 times higher for abdominal pain, and side effects did not occur more frequently (1). For a herbal remedy, that is really remarkable.

Stomach acid-resistant capsules were tested, which release the oil only in the intestine. Those prone to heartburn sometimes tolerate peppermint oil worse. Simeticon works completely differently, namely purely physically. It is an anti-foaming agent: Many small gas bubbles in the intestine flow together into larger ones, which the body gets rid of more easily. According to the product information, the active ingredient is not absorbed into the body, but rather excreted unchanged. Interactions with other medications are not known so far.

An apothecary-based practice study reported rapid improvement in gas-related symptoms. However, the study was initiated by the manufacturer, so it is an observation from practice and not independent evidence. Digestive enzymes should be assessed with similar caution. Alpha-galactosidase breaks down certain sugars from legumes before the intestinal bacteria can ferment them. There are only a few small studies on this.

For the combination of pancreatin and simeticon, most participants rated the effect as good or very good in an application observation. However, the observation had no comparison group and a close connection to the manufacturer.

The probiotics remain. Here, the situation is strain-specific and inconsistent: Some studies see less bloating, others no difference from placebo. Because almost every study tests a different mixture, the results can hardly be combined. Anyone who still wants to try it at least has a fair experiment ahead of them. If you are interested in a probiotic: FLORA | Bacterial Complex by CLAV is a vegan preparation with 23 multiplying bacterial strains from bifido- and lactic acid bacteria. It is not suitable for pregnant women, nursing mothers, adolescents, and children. Click here for the product.

If you want to know more about the topic, this article might be interesting for you: when probiotics are useful for the gut.

Do you even need a supplement, or is diet enough?

Often, diet is enough, and that is actually good news. The German Society for Nutrition recommends adults at least 30 g of fiber per day, many do not reach that. At the same time, everyday habits cause air in the stomach: Those who eat hastily swallow air, and also a lot of sparkling water, irregular meals, or large portions of legumes or cabbage at once can bloat the stomach.

Anyone who starts here, gradually increases the fiber with whole grains, vegetables, and fruit, and drinks enough, often solves the problem completely without a capsule. A supplement can complement, it cannot replace a balanced diet. If you want to know more about the topic, this article might be interesting for you: the most common causes of a bloated stomach.

When bloating should be medically investigated

Occasional bloating after a hearty meal is harmless. It is still completely understandable if at some point the question arises whether there is more behind it. Going to the family doctor's practice makes sense if the symptoms last for weeks or keep coming back, although you have already tinkered with your diet. This applies even more to severe or increasing abdominal pain, unintentional weight loss, blood in the stool, fever, or a permanently altered digestion without a recognizable reason.

There, you can specifically check what is going on, such as lactose or fructose intolerance, which can be detected with a simple breath test. This saves you months of trying out remedies that do not fit the cause at all. A supplement does not replace this investigation.

The honest assessment: Understand first, then choose

Which supplement is right for you, in the end, is decided by the cause, not a brand name. For sluggish digestion, psyllium husks are the obvious choice, for irritable bowel syndrome-typical symptoms, peppermint oil has the best study evidence, for acute gas in the stomach, simeticon. Probiotics and enzymes remain a try with an open outcome.

The most sensible next step costs nothing: Write down for one or two weeks what you eat, how much you drink, and when the stomach speaks up. Often, a pattern already shows itself, and then you know whether more fiber and water are enough, whether a certain supplement group is an option, or whether an appointment at the practice is the smarter way.

Sources

(1) Alammar N, Wang L, Saberi B, et al. (2019): The impact of peppermint oil on the irritable bowel syndrome: a meta-analysis of the pooled clinical data. BMC Complementary and Alternative Medicine. PMID: 30654773. 

(2) Moayyedi P, et al. (2014): The effect of fiber supplementation on irritable bowel syndrome: a systematic review and meta-analysis. American Journal of Gastroenterology. PMID: 25070051. 

(3) European Medicines Agency, Committee for herbal medicinal products (EMA/HMPC) (2013): Community herbal monograph on Plantago ovata Forssk., seminis tegumentum. As an official monograph, it is not an individual study, but summarizes the state of knowledge on the application and safety of psyllium husks. It lists bloating at the beginning of intake as a known side effect, emphasizes sufficient fluid intake, and recommends a distance of 30 to 60 minutes from other medications. The monograph is freely available on the website of the European Medicines Agency.

Frequently asked questions about supplements for bloating

How quickly does a supplement work against bloating?

There is no fixed time promise. In the studies, peppermint oil ran for at least two weeks, psyllium husks for constipation at least four weeks; simeticon works as an anti-foaming agent directly in the intestine, without any absorption into the body.

Is a vegan probiotic worse than a conventional one?

No. Vegan means that the capsule, carrier substances, and manufacturing do without animal components. Whether a probiotic does something depends on the strains contained, and the study evidence is equally inconsistent for all preparations.

Which foods and drinks are traditionally used for bloating?

Fennel, caraway, and cumin teas are the classics, plus ginger. At least as much helps to eat slowly, reduce sparkling water, and eat legumes in smaller portions, so that the intestine gets used to it.

Are fennel or cumin oil similarly well studied as peppermint oil?

No. Individually, both are significantly less studied. Cumin oil appears in studies mainly in combination with peppermint oil, so its own contribution can hardly be calculated.

What if the supplement does not help after a few weeks?

Then a stop and a new look at the cause makes sense. Maybe the group does not fit the actual problem, or there is an intolerance behind it that can be clarified medically.