That&#x27;s a pretty good bet. It works in cattle, and pigs (which are among the most closely related non-primates). And chickens. So maybe all vertebrates.<p>But I wonder whether there&#x27;s more to it than &quot;feed efficiency&quot;. Gut flora arguably changes nutrient mix before absorption. And some nutrients likely favor weight gain more than others. So perhaps one can recolonize with gut flora that favor overall health vs weight gain.