Faecal matter transplantation fast becoming an exact science

Faecal matter transplantation (FMT) science is maturing and becoming increasingly accepted by the medical community, says an expert.

While the original use of FMT was as a last-ditch effort at treating Clostridium difficile infection, the scientific community has begun to trial its use in a broader array of diseases, said Dr David Ong, visiting senior consultant gastroenterologist, National University Hospital, Singapore. Ong was speaking at the recent Annual Scientific Meeting of the Malaysian Society of Gastroenterology and Hepatology (GUT 2022) in Kuala Lumpur.

FMT is not as simple as taking a stool sample from a healthy individual and implanting it into the diseased person. Rather, it is a painstaking process that involves rigorous donor screening—testing donor blood and faecal matter for various infectious and deleterious agents. At the end of the process, very few donors make the cut, thus the high price tag of FMT, which stands at around RM$30,000 per dose, said Ong. However, the benefits may justify the cost of a FMT procedure.  

Ong noted that FMT is only the start of the journey towards precision microbiome-based therapies. It is likely in the years to come, there will be single molecule or single strain bacteria therapeutics being marketed for specific disease or conditions. Currently, analysis of gut microbiome reveals a wealth of data for patients. The advent of technology has contributed significantly towards the study and potential use of gut microbiome, said Ong. Technological advances like next generation sequencing, cloud computing and big data analytics all contribute towards improved insight into human health and in this case, the gut microbiome.

The first randomized controlled trial using FMT for the treatment of C. difficile was published in 2013. The study ended early due to the effectiveness of FMT—81 percent of patients achieved a cure after one single infusion while over 90 percent achieved a cure after a second infusion of FMT. More recently, there are studies pointing to FMT being effective in areas such as autism spectrum, Alzheimer’s disease, inflammatory bowel disease, irritable bowel syndrome and even improved response to cancer treatment. [Sci Rep 2019;9:5821, Transl Psychiatry 2019;9:189, Gut 2020;69(5):859–867]

Gut diversity likely fixed by 3 years of age
Ong said babies are born with a relatively sterile gut. Their first exposure comes from inoculation via vaginal birth, which is important. This is because the bacteria that colonise babies from vaginal microbiota are rich in Lactobacillus and Prevotella spp, which are natural bacteria colonising the gut. Whereas babies delivered via Caesarean are colonised predominantly by skin microbiota such as Staphylococcus, Corynebacterium and Propionibacterium spp. Baby feeding choices also influence baby’s gut colonisation with breastfed babies having increased aerobic organisms such as Bifidobacterium spp and decreased Clostridium and Bacteroides spp. Meanwhile, bottle-fed infants have increased anaerobes and facultative anaerobes in their guts, such as Clostridium and Bacteroides spp. Additional factors such as diet and environmental exposure contribute to a child’s microbiome. Once a child is exposed to solid food, the gut microbiome shifts towards an adult-like microbiota and remains remarkably constant for the rest of their lives. [Gastroenterology 2014;146(6):1564–1572] 

Low diversity of gut microbiome is associated with conditions such as obesity, inflammatory bowel disease and colorectal cancer. Conversely, a high microbiome diversity is associated with a healthy person or someone having good gut health.