# The Influence of Various Types of Functional Bread on Postprandial Glycemia in Healthy Adults
## 1 Introduction  
The rising prevalence of diet-related diseases combined with growing health awareness and self-care among the general population have prompted scientists and the food industry to seek ways to meet the consumer's needs. In this regard, functional foods designed to provide health benefits beyond primary nutritional effects were brought to the market [1; 2; 3; 4]. The aim of enhancing the nutritional profile with functional ingredients (such as vitamins, probiotics, minerals, n-3 fatty acids, dietary fiber, and antioxidants) was to support better health outcomes, reduce the risk of chronic diseases, and improve physical and mental well-being [1; 5]. Bread, a staple food in many cultures worldwide, can be a significant part of the carbohydrate products in the diet. At a global level, cereal grains are an essential source of energy (30-50% of daily intake) and carbohydrates (40-60% of daily intake), and whole grain products are also a good source of dietary fiber (40-60% of daily intake), bioactive compounds (phenolic acids, flavones, flavonoids, glutathione, and plant sterols), vitamins and minerals including thiamin, folate, phosphorus, potassium, zinc, and manganese. However, bakery products could also be a significant source of added sodium, contributing 33% of daily sodium intake, with about 17% from bread [6; 7]. By incorporating ingredientsthat boost its nutritional profile, bread can serve as a functional food with various health benefits [8]. Thus, functional bakery products are becoming increasingly popular. Various types of flour and ingredients are used in several combinations and proportions to increase their functionality. In Europe and North America, often-used cereals for bakery products include wheat, rye, corn, oats, rice, and grain-like seeds such as buckwheat, amaranth, and quinoa [9]. A key area of research focuses on the impact of innovative products based on whole-meal flour, with the addition of grains and seeds, on postprandial glycemia [10; 11] as it plays a significant role in maintaining cardiometabolic health. Postprandial glucose, along with related hyperinsulinemia and dyslipidemia, is associated with the risk of chronic metabolic diseases, including obesity, type 2 diabetes, and cardiovascular disease [12]. Remarkably, at the same HbA1c level, improving postprandial glycemia results in greater CVD benefits than improving fasting hyperglycemia in diabetic individuals [13]. Effective strategies for postprandial glycemia management involve delaying gastric emptying and slowing carbohydrate digestion and glucose absorption. Personalized approaches, including nutritional interventions such as reducing total carbohydrate intake, consuming low glycemic index foods, and adding fibers, can reduce the risk of postprandial hyperglycemia [14; 15]. The glycemic index (GI) concept is a simple classification of carbohydrate-containing food based on its impact on postprandial glycemic responses [16]. The glycemic index is determined using the ISO 26642:2010 method for labeling purposes [17]. Key steps in this ISO method include recruiting participants, preparing tested food samples, taking blood samples at specified time points within 2 h after consumption of a test sample, and data analysis. This procedure is precise enough to differentiate between low-GI and high-GI foods with a high accuracy rate ranging from 97% to 99% [18]. Starch is the primary carbohydrate present in plants (including grains). Its hydrolysis provides 40-80% of the total human energy intake. Starch is a polysaccharide comprising two main components: amylose and amylopectin--polymers of glucose with different structural arrangements. The ratio of amylose to amylopectin can vary significantly across different plant sources, influencing the starch's texture, gelatinization, and digestibility [19]. It has been shown that starch with a high amylose content can lead to a reduced glycemic response, causing a smoother rise in blood glucose levels [20].