Effects of Prebiotics and Human Milk–Derived Oligosaccharides on Ovalbumin- or Mite-Induced Experimental Allergic Asthma in Murine Models: A Systematic Review and Meta-Analysis

Allergic asthma is a chronic inflammatory disease characterized by bronchial hyperresponsiveness, eosinophilic inflammation, and increased production of Th2 cytokines, including IL-4, IL-5, and IL-13. Experimental models using rodents sensitized with ovalbumin or mite-derived allergens, particularly Dermatophagoides pteronyssinus, have been widely employed to investigate the pathophysiological mechanisms involved in the disease. In recent years, growing evidence has indicated that the intestinal microbiota plays an important role in modulating the immune system through the so-called gut–lung axis. In this context, prebiotics and oligosaccharides derived from human milk, known as Human Milk Oligosaccharides (HMOs), have been investigated due to their immunomodulatory potential. Among these compounds, the following stand out: fructooligosaccharides (FOS) galactooligosaccharides (GOS) mannanoligosaccharides (MOS) 2-fucosyllactose (2-FL) 2,3-sialyllactose (3-SL) 2,6-sialyllactose (6-SL) These oligosaccharides may modulate the intestinal microbiota, promote the expansion of beneficial bacteria, and influence systemic immune responses, including inflammatory processes in the airways. Although experimental studies suggest protective effects of these compounds against allergic pulmonary inflammation, the results remain heterogeneous regarding the immunological mechanisms involved and the magnitude of the observed effects. Therefore, a systematic review of the preclinical literature may provide a critical synthesis of the available evidence and help identify important gaps for future investigations.