"The intestinal microbiota of healthy individuals is known to confer a number of health benefits relating to, for example, pathogen protection, nutrition, host metabolism and immune modulation [O'Hara and Shanahan, 2006; Sekirov et al. 2010]. Historically, culture-based analysis has indicated that the gut of a healthy adult share bacterial species that are common among the majority of individuals."
"As the volume of data relating to the composition and functional potential of the gut microbiota increases, the number of diseases that have been linked with alterations in our gut microbial community has also expanded. Indeed, the many instances of such potential associations are too great to summarize in this review and thus here the focus is on associations that have been the focus of greatest attention, that is, the possibility of a link between the gut microbiota and chronic GI diseases, including irritable bowel syndrome (IBS) and IBD, systemic diseases such as type 2 diabetes (T2D) and obesity, as well as the onset of colorectal cancer (CRC)."
"As shown in the above, there is growing evidence that the gut microbiota plays a central role in human GI health and disease. It is therefore logical that modulating the gut microbiota should be considered as a therapeutic strategy to treat chronic disease. The approaches investigated include the use of prebiotics, supplementation with probiotics, reconstitution of bacterial populations by faecal transplantation or by employing antimicrobials to eliminate pathogens or manipulate the gut microbiota in a way that will benefit host health."
"Use of oral probiotic cultures to restore the gut microbiota has led to promising results in the treatment of intestinal disorders such as UC and obesity [Andreasen et al. 2010; Bibiloni et al. 2005; Kadooka et al. 2010]. While it can be argued, however, that oral probiotic doses do not provide sufficient microbial numbers to fully influence the populations of the colon, it may be that these microbes exert their influence through complex means, such as the production of an antimicrobial or a modulation of the immune system. Faecal microbial transplantation (FMT) is becoming a more commonly used approach to replenishing the GI microbiota (for reviews see Borody and Khoruts, and Floch) [Borody and Khoruts, 2011; Floch, 2012]. The aim of FMT is to reintroduce a stable community of GI microbes from a healthy donor to replace the disrupted populations in a diseased individual. In particular, FMT has been used in the treatment of recurrent Clostridium difficile infection when standard treatment has failed. FMT has been found to be successful in C. difficile treatment, with disease remission reported in up to 92% of cases [Gough et al. 2011]."
"Our gut microbiota evolves with us and plays a pivotal role in human health and disease. We now know that the resident microbiota influence host metabolism, physiology and immune system development while perturbation of the microbial community can result in chronic GI disease. While the revolution in molecular technologies has provided us with the tools necessary to more accurately study the gut microbiota, we now need to more accurately elucidate the relationships between the gut microbiota and several intestinal pathologies. Understanding the part that microbial populations play in GI disease is fundamental to the ultimate development of appropriate therapeutic approaches. The concept of altering our gut community by microbial intervention in an effort to improve GI health is currently a topic that is receiving considerable interest. The targeting of specific components of the gut microbiome will potentially allow the removal of the harmful organisms and enrich the beneficial microbes that contribute to our health."
In case you skipped over it, this study shows the effectiveness of the probiotic VSL#3: Bibiloni et al. 2005