Gut exposure to chlamydia may reduce gut infection

Exposing the gut to chlamydia -- sexually transmitted infection that may not cause symptoms -- protects against subsequent infection in the genital tract and other tissues, a new research has suggested.

According to the researchers, chlamydia is the most sexually transmitted diseases and causes infertility, ectopic pregnancy and pelvic inflammatory disease if left untreated.
The findings of the study, published in the journal Infection and Immunity, indicates that exposing the gut first to chlamydia is a novel avenue to explore in preventing the genital infection.

However, when the genital tract is the site of initial chlamydia exposure, a different outcome may result.In this scenario, genital chlamydia spreads to the gut and induces responses that promote further disease in the genital tract.

"This research emphasises the pre-exposure of chlamydia to the gastrointestinal (GI) tract as a vaccine," said Guangming Zhong, Professor from University of Texas Health Science Center at San Antonio.

Human exposure to chlamydia is unpredictable, perhaps coming through genital or non-genital sexual contact with an infected partner and perhaps via contact with contaminated materials.

Researchers used a mouse model that is a controlled way to study chlamydia transmission.
The team found that if the gut is the first site to be colonized by chlamydia bacteria, then the mice are immunized against further disease. The gut infection is benign. 

But if the genital tract is the first to be infected, the resulting disease is harmful.
This results in a worse disease prognosis, including the possibility of infertility because the disease is advanced before symptoms are evident, the researcher said.

"If you are exposed to chlamydia in the GI tract first, it's a vaccine, but if you are exposed in the genital tract first, you may have enhanced disease," Zhong mentioned.
The researcher is also exploring the possibility that Chlamydia trachomatis, the bacterium that causes chlamydia, could be delivered orally as a vaccine.

"We take probiotics for our GI health. In the future, we may add chlamydia as a probiotic for the gut. Once the bacteria are established in the GI tract, they don't spread," Zhong mentioned.

Chlamydia is especially common among young people, and the CDC estimates 1 in 20 sexually active young women age 14-24 have the STD, the researchers noted.