EFSA indicates precisely: “non-digestible carbohydrates are resistant to hydrolysis and absorption in the small intestine and therefore do not contribute to postprandial glycaemia. In that opinion, the Authority noted that a claim on non-digestible carbohydrates and reduction of postprandial glycaemic responses had already been assessed by the Authority with a favorable outcome and it concluded that a cause and effect relationship had been established between the consumption of foods or beverages containing non-digestible carbohydrates, and a reduction of postprandial glycaemic responses and compared with foods or beverages containing glycaemic carbohydrates.”
Fibregum (Acacia gum) is a non-digestible carbohydrate that allows its classification as dietary fiber and therefore it can benefit of the health claims validated by Regulation (EU) 2016/854. In order to bear the health claim on blood glucose, Fibregum must replace at least 30% of the sugars contained in the food or drink of reference.
Full regulation here.