# Microbiome-Based Interventions for Food Safety and Environmental Health
## 4 Current Applications for Microbiome-Based Interventions
### Prebiotics in Food Safety  
Unlike probiotics, which introduce live foreign bacteria into the human GIT, prebiotics encourage the growth of certain beneficial species that are already present in the gut, particularly but not limited to lactobacilli and bifidobacteria [77]. Prebiotics are non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and activity of beneficial microorganisms in the gut [78]. Prebiotic oligosaccharides are full in a variety of fruits and vegetables, and therefore consuming them through diet may be a more natural way to obtain prebiotics [77]. The oligosaccharides found in human breast milk are thought to be the prototypical prebiotic because they encourage the colons of exclusively breastfed newborns to grow bifidobacteria and lactobacilli preferentially [77]. This phenomenon may be responsible for some of the immunological and other advantages that breastfed infants experience [79]. In food animals, certain natural microflora species (such as _Bifidobacteria_, _Butyriibrio_, and _Lactobacillus_) that are known to function antagonistically against pathogens benefit from a competitive advantage provided by some prebiotics [80]. Additionally, prebiotics may lower colonic inflammation and colitis [81], supply some limiting nutrients directly to the intestinal mucosa, and provide the substrates necessary for intestinal bacteria to ferment, thereby increasing the synthesis of B vitamins [80].  
Different studies have demonstrated the role of prebiotics in food safety, such as a reduction in the presence of foodborne pathogens by promoting the growth of beneficial bacteria, serving as a substrate for probiotic growth, enhancing gastrointestinal functions, the immune system, calcium and magnesium absorption, blood glucose levels, and plasma lipids [82]. For instance, ref. [83] examined the effects of probiotics and prebiotics on controlling _Salmonella_ spp. in chickens, revealing that _B. subtilis_ probiotic and Levoxyl prebiotic treatments significantly improved survival rates and reduced the growth of _Salmonella enteritidis_ and _Salmonella typhimurium_. While the _B. subtilis_ probiotic was found to have antimicrobial properties that inhibited the growth of these harmful bacteria, Levoxyl, a prebiotic, supported the growth of beneficial gut microbes that competed with _Salmonella_ for nutrients and space. Together, these treatments improved the survival rates of chickens by enhancing the balance of gut microbiota and reducing the prevalence of _Salmonella_ infections, indicating that the oral application of these treatments in infected broiler chickens could effectively enhance their resistance against nalidixic acid-resistant _Salmonella_ strains. Similarly, ref. [84] investigated the effect of _Salmonella_ Typhimurium infection on the gut microbiota in laying chickens and evaluated how an in-feed probiotic supplement can restore microbial balance and reduce _Salmonella_ load. They found that _Salmonella_ infection caused significant dysbiosis in the gut by reducing the abundance of beneficial microbial genera such as _Lactobacillus_, _Bacteroides_, and _Alistipes_ and increasing the presence of genera such as _Eisenbergiella_ and _Oscillihacter_, which favor _Salmonella_ growth. Probiotic supplementation helped restore gut microbiota balance by increasing the abundance of previously displaced beneficial genera and enhancing levels of propionate and butyrate, which were not significantly affected by _Salmonella_ challenge. Continuous probiotic use notably reduced the overall _Salmonella_ load in feces and internal organs, highlighting its effectiveness in controlling _Salmonella_ infections. Similarly, prebiotics may also have a beneficial effect on the proliferation of probiotic bacteria, as shown in a study by [85], where they found that the prebiotic effect of rice increased the number of _Bifidobacterium_ cells in zygurt mixed with rice as opposed to plain zygurt.