Study Finds Gluten-Removed Beers May Contain Other Gut Triggers

Celiac.com 03/04/2026 - This study examined whether beers made from barley that are marketed as “gluten-free” because they are processed to remove gluten are actually different from regular barley beers when it comes to two other gut-relevant components: fermentable short-chain carbohydrates (especially fructans) and amylase and trypsin inhibitor proteins. The researchers also validated practical laboratory methods for measuring these components in beer and tested how much the levels change between brands and between production batches over time. 

Why the Researchers Looked Beyond Gluten

Many people with celiac disease strictly avoid gluten, yet some continue to experience digestive symptoms. In addition, many people without celiac disease report symptoms after consuming wheat or barley products, and some of those symptoms may be related to fermentable carbohydrates or other proteins rather than gluten alone. Beer is a special case because some products are made from barley (a gluten-containing grain) but are processed so that gluten tests below legal thresholds. The researchers wanted to know whether these “gluten-removed” beers differ from regular beers in fructans and amylase and trypsin inhibitor proteins, since both have been suggested as potential symptom triggers in sensitive individuals.

How the Study Was Done

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The team analyzed sixty beer samples representing ten commercial Spanish macrobrewery brands, with three different production batches per brand collected across three years. Each brand included a “gluten-removed” version and a standard gluten-containing counterpart. The beers were also categorized by factors such as original extract category (a measure linked to the starting concentration of dissolved solids before fermentation), alcohol presence, and batch number.

Before comparing products, the researchers validated measurement methods for total fructans and for amylase and trypsin inhibitor activity in beer. For fructans, they used a spiking approach and found strong recovery and consistency. For amylase and trypsin inhibitor proteins, they used an inhibitory activity approach (how much the beer sample inhibited an enzyme) and validated it using barley-derived inhibitor extracts added at known levels. These steps were designed to confirm that the assays perform reliably in the beer matrix. 

Main Findings: “Gluten-Removed” Was Not Lower in These Other Components

The key outcome was straightforward: beers processed to remove gluten did not show meaningful reductions in total fructans or amylase and trypsin inhibitor proteins compared with their regular gluten-containing counterparts. In other words, the process that makes these beers meet gluten labeling rules did not necessarily change the levels of these other compounds that may contribute to symptoms in some people. 

This matters because some consumers choose these beers expecting them to be “gentler” on digestion. The findings suggest that, depending on the person’s sensitivity and how much is consumed, these beers could still contribute to symptoms related to fermentable carbohydrates or amylase and trypsin inhibitor proteins, even when gluten measurements fall below regulatory thresholds. 

How Much Did Fructans and Amylase and Trypsin Inhibitor Proteins Vary?

The study found that levels varied widely across products and, importantly, across production batches. The researchers reported that original extract category and batch differences explained a large share of the variability for both total fructans and amylase and trypsin inhibitor proteins. Alcohol content also mattered for some outcomes, with alcohol showing a significant effect on amylase and trypsin inhibitor levels in the statistical analysis, and non-alcoholic beers showing lower fructan levels in the comparisons discussed by the authors.

A practical interpretation is that two beers from the same brand family might not behave the same from a symptom standpoint if they come from different batches or if their brewing parameters differ in ways reflected by original extract category. The authors emphasize that batch-to-batch variability is meaningful enough that monitoring should not assume perfect consistency.

What This Could Mean for Digestive Symptoms

Fructans are a type of fermentable carbohydrate that can draw water into the intestine and can be rapidly fermented by gut bacteria, leading to gas and bloating in sensitive individuals. The study notes that beer has often been thought of as relatively low in these fermentable carbohydrates, but measurable fructan levels were present in the tested beers. The symptom relevance can depend heavily on how much beer is consumed at a sitting and whether multiple servings are consumed in social settings.

Amylase and trypsin inhibitor proteins are natural cereal proteins found in grains like barley and wheat. Some laboratory research suggests these proteins may contribute to inflammatory signaling in the gut for certain people. This study demonstrates that these proteins (measured through enzyme inhibition activity) are present in commercially available barley beers, and that “gluten-removed” versions are not necessarily lower in this regard.

Why the Authors Recommend New Quality Controls

Because the study found substantial variability driven by original extract category and batch, and because “gluten-removed” labeling did not predict lower fructan or amylase and trypsin inhibitor levels, the authors suggest that breweries consider implementing specific controls for these compounds, similar in spirit to how gluten content is currently controlled and regulated. The overarching message is that gluten alone may not explain why some people feel unwell after drinking certain beers.

Why This Study Could Be Meaningful for People With Celiac Disease

For people with celiac disease, strict gluten avoidance remains essential. However, real-world experiences vary: some people report symptoms even when they consume products labeled as gluten-free, including beers processed to remove gluten. This study helps explain one reason why symptoms might persist for some individuals: beers that meet gluten labeling rules may still contain other gut-active components such as fructans and amylase and trypsin inhibitor proteins at levels similar to regular beers.

This does not prove that these components will trigger symptoms in every person with celiac disease, and it does not replace medical guidance. But it does offer a clearer, more practical takeaway: if a person with celiac disease feels unwell after drinking “gluten-removed” barley beer, the cause may not be gluten alone. The findings support the idea that better labeling, better batch monitoring, and more comprehensive testing could eventually help consumers make choices that match their individual tolerance and symptom patterns.

Read more at: sciencedirect.com