A four-year research programme conducted by doctoral student Aira Serviento in partnership with Etienne Labussière and David Renaudeau of INRAE took a deep dive into the mechanisms of heat stress in swine (2022), which also shed light on the live yeast's modes of action.

A trial was conducted using metabolic chambers to evaluate the effect of live yeast supplementation and feeding frequency in male finishing pigs subjected to heat stress. It complemented previous studies by looking deeper into the metabolic pathways involved in heat stress adaptation.

Findings show increased resistance to heat stress was possibly attributable to improved insulin sensitivity of the pigs fed live yeast. Their insulin:glucose ratio was significantly lower around meals. This may contribute to higher energy efficiency during heat stress.

Improved sensitivity to insulin can be explained by two main mechanisms of action of the live yeast: improvement of intestinal integrity during stress and increased production of short chain fatty acids in the gut, thanks to microbiota modulation.

It is noteworthy that in humans — where the live yeast S. boulardii has been widely documented for 100 years — S. boulardii
supplementation has been reported to attenuate diabetic related complications such as hyperglycemia (due to impaired insulin activity or production) by microbiota modulation and improved immune responses.