IMPE Abstracts

We are in the midst of an obesity epidemic with one in three NZ preschool children overweight/obese. We have looked at whether microbiome treatment could ameliorate child obesity in those born by (i) Cesarean section (CS) and (ii) obese teenagers. (i) Association studies have shown a 30% increased risk of childhood obesity in those born by CS. A lack of exposure to maternal vaginal bacteria with CS disrupting the normal population of the early infant gut microbiome has been proposed to explain this association. This has led to the widespread practice of “vaginal seeding”. We conducted a pilot RCT to examine whether the transfer of maternal vaginal microbiome into the gut of newborn born by elective CS could establish a more normal infant gut microbiome. We did not show a difference in gut microbiome composition or functional potential in CS seeded vs placebo infants at 1 and 3 months of age challenging the practice of vaginal seeding to prevent child obesity. (ii) Gut microbiome dysbiosis is associated with obesity and type 2 diabetes. Gut (or fecal) microbiome transfer (FMT) from an obese human donor leads to obesity in the germ-free mouse. Conversely, gut microbiome transfer from a lean donor to an obese mouse leads to weight loss. Human trials are needed to understand the therapeutical potential of FMT. We conducted a double-blinded, placebo, RCT of FMT (encapsulated, orally administered) from “super donors” to 87 obese teenagers (14-18 years) with six months follow-up. Each recipient received the microbiome from four same sex donors, administered as a single treatment (32 capsules over 2 days). The treated group showed a change in gut microbiome vs baseline throughout the study demonstrating successful engraftment of the donor microbiome. FMT did not lead to weight loss during the study. However, FMT led to a reduction in abdominal fat (DXA) at 6, 12 and 26 weeks. In those with metabolic syndrome at the start of the study FMT led to resolution in 73% (treated) vs 17% (placebo). Interestingly interim analyses of follow-up 4-5 years after initial treatment show reduction in; BMI (0.35 SDS, approx. 20 kg), total body fat (7.2%) and waist circumference (14 cm) (all P<0.001). FMT for obesity particularly if combined with diet may have long term benefits that include weight loss and metabolic health. Further research is required to confirm our findings and identify which bacteria are key to the health benefits seen.