Maintaining a Healthy Microbiome
Novel And Emerging Therapies For Microbiome Health
Fecal Microbiota Transplantation
One of the most exciting areas of microbiome research has been fecal microbiota transplantation, which involves the transfer of a fecal suspension, containing gut microbes, from a healthy subject to an unhealthy subject for therapeutic purposes. The procedure has generally been performed through enema or a tube that is introduced into the stomach or duodenum. However, in a 2017 study on patients with recurring Clostridium difficile infections, an oral capsule of freeze-dried fecal microbes was comparably effective to delivery via colonoscopy in preventing recurrences (Gallo 2016; Kao 2017).
Fecal microbiota transplantation has become an important treatment option in recurrent intractable C. difficile infections, for which its efficacy is close to 90% (Liubakka 2016; Cammarota 2017; Matijasic 2016). Clinical research, though in its early days, suggests it may also have value in treating a number of inflammatory and metabolic conditions associated with dysbiosis, such as inflammatory bowel disease (Matijasic 2016), irritable bowel syndrome (Distrutti 2016), obesity and type 2 diabetes (Marotz 2016), and autism spectrum disorders (Kang, Adams 2017). Furthermore, fecal microbiota transplantation so far appears to have an excellent safety profile (Cammarota 2017).
Bacteriophages, or phages, are viruses that infect specific bacteria but do not infect human cells (Doss 2017). Phages, believed to be the most abundant organisms on earth, are an integral part of the human microbiome, where they are thought to manage bacterial communities by limiting target species (Mirzaei 2017; Keen 2015). Phage therapy is being explored as an alternative to antibiotic therapy for certain conditions and, potentially, for eliminating harmful bacteria from the body's microbial communities (McCarville 2016; Lin, Koskella 2017).
An abundant and diverse community of phages inhabits the oral cavity, and specific phages or their enzymes have shown promise for treating periodontal disease and preventing dental plaque (Szafranski 2017). Phages that target infection-causing gastrointestinal bacteria such as Vibrio cholerae (the cause of cholera) (Yen 2017), Helicobacter pylori (Wan 2011), C. difficile (Nale 2016), Shigella dysenteriae (Mai 2015), and some harmful Escherichia coli strains (Dalmasso 2016) have been identified and hold therapeutic potential. Older reports of phage therapy being used successfully to prevent and treat various other types of bacterial infections, including those of the skin, urinary tract, and eyes, have emerged and provide a basis for future research (Chanishvili 2012).