I recently posted Wheat Belly and Undoctored Blog posts about the probiotic species, Lactobacillus reuteri, that in experimental models (aged mice) generated some fascinating effects, including thicker hair, no weight gain (compared to obese controls), more muscle preservation, increased dermal (skin) thickness and increased testosterone. They observed that the L. reuteri-supplemented mice looked and acted more youthful. What made the findings even more surprising was the magnitude of these effects: the increase in dermal thickness, for instance, was an unprecedented 35%, the increase in skin thickness 100%, the increase in testosterone nearly 8-fold.
Another study from this same MIT group supplementing L. reuteri (strain ATCC PTA 6475) to aged mice makes some additional fascinating observations:
- Wound healing time was cut in half, essentially restoring youthful capacity for repair. Hair regrowth was more rapid.
- Collagen deposition was dramatically improved. (Recall that collagen loss/destruction in skin and other organs is part of the aging process.)
- Oxytocin blood levels in females more than doubled, likely explaining the acceleration of wound healing (as well as increased grooming behavior).
Consistent with their observation that L. reuteri supplementation yielded youthful effects, vigorous wound healing is a marker for health and youthfulness, as is collagen deposition in skin. Oxytocin levels also decline as we age and, beyond impairing wound healing, a lack of oxytocin can have other effects that include impaired insulin responses, higher blood sugar, and weight gain.
In other studies, oxytocin has been demonstrated to exert substantial weight-reducing effects when administered intranasally (24 units four times per day in human subjects and resulted in more than 18 pounds lost over 8 weeks with no change in diet). This oxytocin-raising method, i.e., L. reuteri supplementation, suggests another way to obtain the varied benefits of higher oxytocin levels. (I shall be discussing the importance of oxytocin in weight, emotion, and sexual interest management in future.) Oxytocin is known to be anorexigenic, i.e., it reduces or eliminates the desire to eat.
Once again, we have to bear in mind that these observations were made in mice and there was no parallel human study. We also need to be careful about the judging the effects of a single species of microorganism, as they do not exist in isolation but in a complex microbial community with multi-faceted interactions with each other and the host. Nonetheless, the effects were so dramatic that it is tempting to wonder if any of these effects translate to human benefits.
I shall soon be reporting on my personal high-dose L. reuteri experience, as some interesting things happened.