Effect of alimentary microbial inoculation on freeze tolerance in Helix pomatia L. snails

Exogenous bacterial species, which mainly populate the intestines of Helix pomatia snails, also affect various biological processes that are crucial to the survival of the host. However, the microbiota undergoes changes during overwintering, as feeding is suspended, leading to serious health consequences for the host. This study aims to investigate whether the food supplementation of snails with a microbiological inoculation containing bacterial strains isolated from the intestines of overwintering snails could improve their cold tolerance in summer. The experiment was conducted on two groups: a control group without supplementation; and an experimental group given the microbiological inoculation. The supercooling point (SCP) of their body fluids was measured to assess the effects of supplementation on the cold tolerance of wild snails in the summer. The results showed that the SCP for the snails in the experimental group was statistically significantly lower than for the snails in the control group, with a mean SCP value of −1.73°C compared to −0.97°C (p < 0.05). These findings confirm that the microbiota has a significant impact on cold tolerance in snails, and the microbiological inoculation had a positive impact on lowering the supercooling temperature of H . pomatia in the summer. This sheds new light on the mechanism of this species’ adaptation to cold, which still remains a mystery.