Despite the article's headline about BJs, this summary of a study seems to be referring to vaginal sex, not oral. If so, then there may be no health benefit to gay men who swallow semen, although it may certainly make their PARTNERS feel better.
Perhaps the full study addresses this issue. But seminal fluid that enters the body through the mouth must pass through the digestive system, where the various components named may not survive intact to be absorbed into the body, but be broken down into other elements that lack anti-depressant qualities.
Whereas semen deposited in the vagina might be absorbed into the body without degradation. This also raises the question of unprotected anal sex. Would semen deposited there be more effectively absorbed into the body than through the digestive tract, preserving the claimed anti-depressant benefits?
This is setting aside the issue of the risks of unprotected anal sex. But among long-term monogamous lovers, who are regularly tested, could anal have beneficial health aspects? Leading in turn to a possible increase in couples who practice versatility, so that both partners benefit equally.
Anyone care to volunteer for a new round of studies?