Early life Lactobacillus rhamnosus GG colonisation inhibits intestinal tumour formation

Background Gut microbiota dysbiosis is closely related to the progression of colorectal cancer. Our previous study revealed that early life colonisation with Lactobacillus rhamnosus GG ( LGG ) had long-term positive effects on health. We sought to investigate whether early life LGG colonisation could inhibit intestinal tumour formation in offspring. Methods Adult C57BL/6 female mice were mated with Apc min/+ male mice. Pregnant mice with the same conception date received 10 8 cfu live or fixed LGG from day 18 of pregnancy until natural delivery. After genotyping, offspring mice received 10 7 cfu of live or fixed LGG for 0–5 days after birth. Results Early life LGG colonisation significantly promoted intestinal development, inhibited low-grade intestinal inflammation and altered the gut microbiota composition of offspring in the weaning period (3 week old). Notably, early life LGG colonisation reduced the multiplicity of intestinal tumours in adulthood (12 week old), possibly due to inhibition of Wnt signalling and promotion of tumour cell apoptosis. Importantly, at the genus level, Bifidobacterium and Anaeroplasma with potential anti-tumour effects were increased in adulthood, while Peptostreptococcus , which potentially contributes to tumour formation, was decreased. Conclusions Early life LGG colonisation inhibited the intestinal tumour formation of offspring in adulthood.