full article to previous abstract: fecal transplant from male mice to female mice resulted in an increase in Testosterone production in the female mice revealing a link between the gut microbial population, diversity and Testosterone production.
The incidence of T1D in these mice is positively correlated with the “femaleness” of the microbiota
These results support the hypothesis that the host androgen level is influential in determining the composition of the microbiota, which in turn affects T1D initiation and progression
a high testosterone level enriches the microbiota for specific organisms such as segmented filamentous bacteria (SFB) and Escherichia coli or Shigella–like (SECS) strains.
A minimum level of testosterone and specific male-enriched microbes working together upregulate M2 macrophage and IFN-γ producing T cells in pancreatic lymph nodes. Microarray data show that both the IFN-γ and IL-1β pathways are also stimulated.
These microbes also upregulate host testosterone
In four independent experiments, the authors found no universal unique “male microbiome”
they did find that four distinct combinations of microbial groupings (with an interesting lack of overlap at the individual family level in the four experiments) were enhanced by androgen
one species consists of the segmented filamentous bacteria (SFB) and belongs to the Firmicutes, whereas the other is an Escherichia coli or Shigella–like (SECS) strain belonging to the Proteobacteria
colonization with protective microbiomes—e.g., SPF microbiota, SFB, and SECS—is positively correlated with high blood testosterone levels in male mice
A direct implication of this study is that probiotic administration or fecal transplantation is a theoretically possible approach to protection against T1D