This study aims to investigate the effects of galacto-oligosaccharides (GOS) combined with human milk oligosaccharide 2’-fucosyllactose (2’-FL) on the absorption efficiency of amino acids, fatty acids, and minerals in infant formula. An in vitro simulated digestion of infant formula was carried out in a dynamic infant gastroduodenal digestion system. After 0, 30, 60, 120, and 180 min, the transport rates and apparent permeability coefficients (P_app) of nutrients in digestion products were evaluated using the Caco-2 cell model. The results showed that the transport rates of total free amino acids (28.08%–36.98% vs. 24.81%–33.67%), butyric acid (11.02%–16.80% vs. 9.66%–13.29%), caprylic acid (8.22%–14.49% vs. 7.41%–13.03%), capric acid (7.31%–12.66% vs 6.21%–11.53%), calcium (12.02%–23.80% vs. 9.66%–19.29%), and zinc (9.22%–18.49% vs. 7.41%–15.03%) and corresponding P_app were significantly higher in infant formula with added GOS and 2’-FL than in infant formula without added GOS or 2’-FL (P < 0.05), while the differences in the transport rates and P_app of iron and magnesium were not significant (P > 0.05). These data suggest that GOS and 2’-FL can significantly enhance the in vitro absorption efficiency of free amino acids, medium- and short-chain fatty acids, calcium, and zinc in infant formula digests by intestinal cells, independent of regulating the intestinal microbiota.

As consumers’ demand for healthy diets grows, the nutritional fortification of milk and dairy products, as important components of the human diet, has gradually become a hot topic in food science and nutrition research. However, some bioactive substances added to milk and dairy products exhibit poor stability and reduced bioavailability due to factors such as processing, storage and transportation conditions as well as gastrointestinal stresses, which limits their promotion and application. Therefore, in order to achieve nutritional fortification of target active components in milk and dairy products, it is essential to develop suitable encapsulation technologies that can effectively enhance the stability of bioactive substances and improve their bioavailability. This article systematically summarizes common bioactive substances in milk and dairy products including bioactive peptides, fatty acids, polyphenols, and probiotics, etc. A systematic review is presented of recent progress in the application of encapsulation technologies such as spray-drying, freeze-drying, emulsification, and complex coacervation in enhancing the processing stability, storage stability, delivery efficiency, and bioavailability of bioactive compounds in milk and dairy products. Moreover, the application of encapsulation technologies for bioactive substances in milk and dairy products is elucidated. The problems of insufficient bio-stability and bioavailability of milk and dairy products are summarized. Finally, future trends in the encapsulation of bioactive compounds in milk and dairy products by intelligent responsive delivery systems and green natural wall materials are envisaged.