Malt diastase is an enzyme derived from malted barley that primarily functions to break down starches into simpler sugars, aiding the digestive process. Its use for supporting or treating gas and bloating is grounded in biochemical rationale and limited clinical evidence. The enzyme's activity may help individuals who experience digestive discomfort due to incomplete carbohydrate digestion, a common cause of gas and bloating. By facilitating the breakdown of complex carbohydrates, malt diastase can potentially reduce the substrate available for fermentation by intestinal bacteria, thereby decreasing gas production.

Despite the plausible mechanism, robust clinical studies evaluating malt diastase specifically for gas and bloating are sparse. Most available evidence consists of small studies, case reports, or extrapolation from the established use of other digestive enzymes. Some combination digestive enzyme supplements that include malt diastase have shown modest benefits in reducing symptoms like bloating in patients with functional dyspepsia or pancreatic insufficiency, but these studies do not isolate the effect of malt diastase alone.

Overall, while the scientific basis is reasonable and there is minor clinical support, the evidence does not reach high levels of rigor or consensus. Therefore, malt diastase is sometimes included in digestive enzyme formulations for gas and bloating, but the strength of evidence supporting this specific use is limited.