# Microbiome-Based Interventions for Food Safety and Environmental Health
## 5 Challenges and Limitations Associated with MBT
### Technical and Logistical Challenges in Implementation  
One of the foremost technical challenges in the development of effective MBT is the isolation and cultivation of effective microbial strains, which is challenging due to the complexity of the human microbiome and the specific conditions required for their growth, as many beneficial microbes thrive only in the unique environment of the human body [127]. The human microbiome is incredibly diverse, with thousands of bacterial species coexisting in various body sites. Determining which specific strains have therapeutic potential involves extensive screening and validation, which is challenging because the effectiveness of probiotics varies by strain and is often specific to different body environments and diseases [128]. For example, _Bacteroides_ sp. colonizes the colon and ececum, _Lactobacillus_ sp. and _E. coli_ Nissle 1917 thrive in the small intestine, while _Lactobacillus lactis_ does not colonize the intestine, making disease biogeography crucial in determining the suitable probiotic for treatment [129].  
Identifying the mechanistic elements of host-microbe interactions and microbe-microbe interactions of potential probiotic strains has proven challenging, as they are usually influenced by many internal and external factors such as diet, antimicrobials, genotype, and environment [130]. For example, the critical role that vaginal delivery plays in transferring beneficial microbes from mother to newborn that colonize the baby's skin and gut highlights a technical and logistical challenge in implementing MBT in ensuring the appropriate seeding and maintenance of beneficial microbial communities in individuals, especially those born via cesarean section [130]. Cesarean births prevent this beneficial microbial transfer, leading to the acquisition of environmental microbes, which increases the risk of chronic diseases in adulthood, such as diabetes, obesity, asthma, and neurological disorders [131]. This can however be mitigated through methods such as vaginal microbial transfer (also known as \"vaginal seeding\"), where beneficial bacteria from the mother's vaginal canal are applied to the newborn's skin or mouth immediately after birth, helping to introduce beneficial microbes that are typically acquired during a vaginal delivery [132].  
There are practical challenges associated with the preparation of probiotics, especially for commercial purposes. Probiotics face destabilization during manufacturing and storage due to stressors such as heat, oxygen, mechanical force, osmotic shock, and changes in pH [127]. The commonly used process of spray-drying often induces thermal stress, with elevated temperatures potentially denaturing proteins and causing cell damage in probiotics, which presents significant challenges in the implementation of MBT, as maintaining the stability and viability of probiotics becomes difficult [133]. Osmotic shock can also result during the drying process because it raises intracellular osmolarity, which modifies the cellular membrane, thereby reducing the viability of microbiome therapies [133]. Similarly, the ability of probiotics to survive during production and storage is impacted by oxidative stress, as their proteins, lipids, and DNA can be harmed by reactive oxygen species, which are produced when oxygen is partially reduced to water [134]. Spray-dried cells may be more susceptible to oxidative stress because dehydration causes cellular damage [127].