**6. Future works and perspectives**

It has been shown that the development of gastrointestinal disease is due to an imbalance in the host response (physical, commensal microbiota, adaptive/innate immune systems) to bacterial infections. There has been an increasing accumulation of evidence (*in vitro*, *in silico*, and some *in vivo*) supporting the key role that the resident microbiota in the gut plays in mitigating bacterial infections as well as metabolic and physical diseases. There has been development of novel therapies all designed to replace/regenerate the lost beneficial commensal strains in a variety of diseases such as IBS, IBD, acute gastroenteritis, NEC, RCDI, etc. There has been tremendous success in the treatment of RCDI, IBS, and IBD using FMT therapy. However, it is still unclear from all the evidence that giving probiotics and/or prebiotics will mitigate all gastrointestinal diseases [13]. The beneficial effects of a probiotic(s)/prebiotic mixture is utterly dependent on many factors including: time of dosage in relation to disease, probiotic strains used, prebiotics given, dosage, time of treatment, pre, post, and the pre-existing health and/or the microbiota of the host. Additionally, the clinical trials should also be developed with statistical power to clearly answer the question at hand.
