t is my hypothesis that testosterone is increasing within the population. I think this is the cause of the “Secular Trend,” the increase in size and earlier puberty in children. The changes in testosterone affect availability of dehydroepiandrosterone (DHEA). One of the consequences of increasing testosterone is reduced immune response as high testosterone may reduce the availability of DHEA and, therefore, its natural stimulus of the immune system.

I think this is why antibiotic-resistant organisms are increasing within the population. When DHEA is present in optimal amounts, the immune system mounts a sufficient response in individuals with optimal DHEA. As DHEA declines within the population, antibiotic-resistant organisms increase.

It is my hypothesis that cortisol (stress) evolved to counteract the positive effects of DHEA on neuronal function.  That is, cortisol reduces initial motivation produced by DHEA to continue during “fight or flight” circumstances. An increased cortisol to DHEA ratio also reduces the effects of DHEA in tissues other than the brain.

Cortisol in excess for prolonged times reduces the immune response.

Alpha-lactalbumin has been demonstrated to increase prolactin and decrease cortisol (Am J Clin Nutr. 2000 Jun;71(6):1536-44). Prolactin is a specific and direct stimulator of DHEA production. Therefore, alpha-lactalbumin increases DHEA and reduces cortisol.

I suggest the findings of Marks, et al., may be explained by increases in available DHEA and reduction in cortisol which increases the natural ability of the immune response to antibiotic-resistant organisms.