How Lactobacillus Bacteria May Improve Your Chances of Getting Pregnant

New research indicates women with high levels of these bacteria in their uterus have a better likelihood of conceiving

Lactobacillus | Bay Area Fertility Doctor | Couple happy with home pregnancy testIn recent times more and more attention has been given to the symbiotic role bacteria have on human health. Many doctors now recommend eating foods like yogurt that contain lactobacillus bacteria – or “helpful” bacteria ­­– as a way to improve digestion and overall health.

But lactobacillus bacteria are not just found in the things we eat. In fact, bacteria are always present in some parts of the body, including lactobacillus bacteria. Recent studies have been looking at the influence these bacteria that cohabit in the human body may have on overall health.

Until recently, doctors have conceptually divided the human body into different parts as being “sterile” (without bacteria present) or “nonsterile.” For example, it has long been known that bacteria inhabit the vagina, but the uterus was thought to be sterile. However, a new study by researchers from Spain with corroboration from Stanford University has shown that bacteria actually inhabit both the vagina and the uterus.

The type of bacteria present in the uterus may be influenced by the bacteria in the vagina. In addition, the researchers’ preliminary studies suggest that the bacterial flora in the endometrium, which is the lining of the uterus, may in fact influence a woman’s ability to get pregnant and have a baby.

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Why your uterus likes lactobacillus

The researchers in the study first looked at the presence of different bacteria in the vagina and the uterus and found that the two were similar. A normal healthy bacterial flora in the vagina is predominantly lactobacillus bacteria. Having an abundance of bacteria in the vagina which are not lactobacillus can cause conditions such as vaginosis.

They then studied the bacterial flora at different times in the menstrual cycle and found that in the uterine environment, the bacterial flora was generally not under influence of the hormonal changes in a menstrual cycle. This means the make-up of bacteria remained consistent before the uterine lining was receptive to pregnancy and during the period when pregnancy could occur.

The researchers also evaluated the percentage of lactobacillus bacteria present in the uterus of each of the study’s subjects. They categorized each sample from the study’s subjects as either having more than 90 percent lactobacillus bacteria or less than 90 percent.

When the researchers evaluated the bacterial profile of the uterine lining in women undergoing in vitro fertilization (IVF) who conceived, miscarried or had a live born baby, they found that the women who had predominantly lactobacillus in their microbiota (90 percent or more) had a higher chance of having a live born baby. This means, that in addition to keeping other parts of our bodies healthy, lactobacillus may also play a role in how receptive our bodies are to pregnancy.

Based on the results of their study, the researchers also postulated that the endometrial microbiota which is nonlactobacilli may trigger an inflammatory response in the endometrium that negatively affects the success of embryo implantation. In this context, inflammation is a broad term which means that the immune system is on heightened activity to ward off bacteria, viruses or disease states. Inflammation, in general, has a negative impact on fertility.

This is an exciting area of research which suggests that treatments directed toward establishing a healthy bacterial flora with a high percentage of lactobacillus in the uterus may help improve pregnancy rates in women with infertility. It holds promise of simple treatments to help establish a normal healthy bacterial flora in the uterus that can help treat infertility.